Advertisement

Perceived stress, recent stressors, and distress in relation to sleep disturbance and duration among middle-aged and older Asian immigrants

Open AccessPublished:December 24, 2022DOI:https://doi.org/10.1016/j.sleh.2022.11.005

      Abstract

      Objective

      This study aimed to examine the associations of perceived stress, stressors, and distress with sleep disturbance and duration among Asian immigrants.

      Design/setting/participants

      The sample included 400 Asian immigrants aged 50-75 years old recruited from primary care physicians’ clinics.

      Methods

      We fit multivariable regression models to examine the associations of perceived stress, stressors, and distress with self-reported sleep disturbance and duration. We tested effect modifications by language proficiency, years in the United States, acculturative stress, and social support.

      Results

      A total of 73 (18.3%) participants reported any sleep disturbance, and the average time in bed was 7.25 hours (SD = 1.17). Higher perceived stress (PR = 1.15, 95% CI = 1.06, 1.26), stressors (PR = 1.32, 95% CI = 1.13, 1.59), and distress (PR = 1.36, 95% CI = 1.21, 1.57) were associated with a higher prevalence of any sleep disturbance. These associations were not modified by language proficiency, years in the United States, acculturative stress, and social support. On the other hand, the associations of perceived stress and distress with time in bed were modified by years in the United States. Specifically, higher levels of distress were associated with shorter times in bed only among adults who have resided in the United States for less than 10 years.

      Conclusion

      Perceived stress, stressors, and distress were associated with a higher prevalence of sleep disturbance. Moreover, perceived stress and distress had stronger associations with times in bed among recent immigrants. Future sleep health research in Asian Americans should consider the important role of stress and distress, especially among recent immigrants.

      Keywords

      Introduction

      Sleep deficiency and sleep disturbance are highly prevalent among middle-aged and older adults and are associated with increased risk of morbidity and mortality.
      • Buxton OM
      • Marcelli E.
      Short and long sleep are positively associated with obesity, diabetes, hypertension, and cardiovascular disease among adults in the United States.
      It is estimated that about 40%-70% older adults report chronic sleep problems.
      • Miner B
      • Kryger MH.
      Sleep in the aging population.
      Several age-related factors may have contributed to a high prevalence of sleep problems among middle-aged and older adults, including age-related physiologic changes (eg, menopause for women), chronic conditions (eg, obesity, heart disease), decreased physical activity, and major life changes (eg, retirement, bereavement).
      • Neikrug AB
      • Ancoli-Israel S.
      Sleep disorders in the older adult—a mini-review.
      However, poor sleep health is not an integral part of the aging process, and sleep problems do not equally affect all adults. Existing research has documented higher rates of sleep disorder and shorter sleep duration among minority adults, especially African American adults, than among White adults.
      • Chen X
      • Wang R
      • Zee P
      • et al.
      Racial/ethnic differences in sleep disturbances: the Multi-Ethnic Study of Atherosclerosis (MESA).
      ,
      • George KM
      • Peterson RL
      • Gilsanz P
      • et al.
      Racial/ethnic differences in sleep quality among older adults: Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study.
      Increasing research has suggested poorer sleep outcomes among Asian Americans relative to other racial and ethnic groups.
      • Chen X
      • Wang R
      • Zee P
      • et al.
      Racial/ethnic differences in sleep disturbances: the Multi-Ethnic Study of Atherosclerosis (MESA).
      ,
      • George KM
      • Peterson RL
      • Gilsanz P
      • et al.
      Racial/ethnic differences in sleep quality among older adults: Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study.
      For example, in a study of 2230 adults aged 54-93 years and older from The Multi-Ethnic Study of Atherosclerosis Sleep Cohort, Chinese Americans had a higher prevalence of severe sleep-disordered breathing than White, Black, or Hispanic adults.
      • Chen X
      • Wang R
      • Zee P
      • et al.
      Racial/ethnic differences in sleep disturbances: the Multi-Ethnic Study of Atherosclerosis (MESA).
      In another study of 1664 community-dwelling adults aged 65 years and older, Black and Asian older adults had shorter sleep duration than Latino older adults.
      • George KM
      • Peterson RL
      • Gilsanz P
      • et al.
      Racial/ethnic differences in sleep quality among older adults: Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study.
      Identifying factors contributing to sleep problems among Asian American adults will inform effective strategies to reduce sleep disparities and improve sleep health for all.
      Research has identified stressors—that is, social or environmental demands, losses, or perceived threats that cause stress—and stress, referring to an individual's response to stressors, as important to sleep health.
      • Hill TD
      • Dowd-Arrow B
      • Ellison CG
      • Hale L
      • McFarland M
      • Burdette AM.
      Gun ownership, community stress, and sleep disturbance in America.
      ,
      • Han KS
      • Kim L
      • Shim I.
      Stress and sleep disorder.
      Distress is a distinct but closely related construct, referring to a negative emotional response to severe or prolonged stress, that is also relevant to sleep. Stress (and distress) could activate the dysfunction of the hypothalamic-pituitary-adrenal axis and elevate cortisol levels, which can disrupt sleep cycles and lead to a sleep disorder.
      • Vgontzas AN
      • Chrousos GP.
      Sleep, the hypothalamic–pituitary–adrenal axis, and cytokines: multiple interactions and disturbances in sleep disorders.
      Stress may also lead to increased heart rate reactivity and reduced vagal tones, which have been associated with poor sleep health.
      • Charles LE
      • Slaven JE
      • Mnatsakanova A
      • et al.
      Association of perceived stress with sleep duration and sleep quality in police officers.
      Furthermore, stress may be related to unhealthy coping behaviors such as poor eating habits and drug or alcohol abuse, both of which are linked to sleep problems.
      • Martyn-Nemeth P
      • Penckofer S
      • Gulanick M
      • Velsor-Friedrich B
      • Bryant FB.
      The relationships among self-esteem, stress, coping, eating behavior, and depressive mood in adolescents.
      ,
      • Tavolacci MP
      • Ladner J
      • Grigioni S
      • Richard L
      • Villet H
      • Dechelotte P.
      Prevalence and association of perceived stress, substance use and behavioral addictions: a cross-sectional study among university students in France, 2009–2011.
      Stressors, stress, and distress have been operationalized in various ways. Some sleep health studies have included reports of recent stressors or stressful events,
      • Li Y
      • Gu S
      • Wang Z
      • et al.
      Relationship between stressful life events and sleep quality: rumination as a mediator and resilience as a moderator.
      often assessing stress by counting the number of stressful events. Other research has characterized stress as a 2-way process where individuals interact with the environment.
      • Cohen S
      • Kamarck T
      • Mermelstein R.
      A global measure of perceived stress.
      This type of studies typically use a general measure of perceived stress to ask individuals whether an individual perceives a given situation as stressful.
      • Cohen S
      • Kamarck T
      • Mermelstein R.
      A global measure of perceived stress.
      Distress, on the other hand, is often conceptualized as the psychosocial response to severe and prolonged stressors. Measures of stressors, perceived stress, and distress correlate, but their associated factors and health outcomes may be different. For example, previous research shows that psychosocial variables (eg, social support) were associated with both perceived stress and stressful life events, whereas demographic factors (eg, education, income) were associated with stressful life events only, suggesting that perceived stress and stressful life events may capture different aspects of stress.
      • Kingston D
      • Heaman M
      • Fell D
      • Dzakpasu S
      • Chalmers B.
      Factors associated with perceived stress and stressful life events in pregnant women: findings from the Canadian Maternity Experiences Survey.
      These different measures of stress have also been shown to be differentially associated with health outcomes. For example, in a study of 5313 middle-aged and older adults, stressful life events were associated with higher odds of diabetes and hypertension, but these associations were not observed for perceived stress.
      • Gallo LC
      • Roesch SC
      • Fortmann AL
      • et al.
      Associations of chronic stress burden, perceived stress, and traumatic stress with cardiovascular disease prevalence and risk factors in the HCHS/SOL Sociocultural Ancillary Study.
      On the other hand, in this same study, perceived stress, but not stressful life events, was associated with greater odds of currently smoking. Taking together, these findings indicate that there is a value in examining different stress-related variables in a single study to achieve a comprehensive understanding of the stress-sleep relationship.
      Mapping our understanding of various factors onto the Asian immigrants requires acknowledging that this group is heterogeneous in various aspects, including their length of stay in the United States, language proficiency, and the degree of acculturative stress experienced. The acculturative stress theory postulates that adapting to a new society may lead to adjustment strain among immigrants, increasing their vulnerabilities to maladaptive behaviors.
      • Berry JW.
      Acculturation and adaptation in a new society.
      Guided by the acculturative stress theory, one may hypothesize that immigrants with lower acculturation levels, or with high acculturative stress, may have more difficulty in coping with stress; thus, their stress (or distress)-sleep associations may be stronger than those with higher acculturation levels or with lower acculturative stress. Alternatively, the healthy immigrant effect theory suggests that immigrants are healthier than native-born residents, but their health advantages decrease with longer residency.
      • Abraido-Lanza AF
      • Dohrenwend BP
      • Ng-Mak DS
      • Turner JB.
      The Latino mortality paradox: a test of the" salmon bias" and healthy migrant hypotheses.
      Following the healthy immigrant effect theory, one may hypothesize that immigrants who are more acculturated are more likely to adopt unhealthy behaviors, increasing their risk of stress and health problems. Despite the competing theories, limited empirical research has tested these 2 theories in relation to sleep problems among Asian immigrants.
      Social support may also modify the associations of perceived stress, stressors, and distress with sleep duration and disturbance among Asian immigrants. According to the stress-buffering hypothesis, social resources may act as a buffer against the harmful effects of stress on health outcomes.
      • Cohen S
      • McKay G.
      Social support, stress and the buffering hypothesis: a theoretical analysis.
      The trust, emotional support, advice, and information people receive from their support network may provide valuable resources for coping with stress, thereby weakening the stress-sleep associations. On the other hand, a lack of social support may exacerbate feelings of social isolation and loneliness among immigrants, increasing their vulnerability when facing stress and exacerbating their sleep problems. Social support has been identified as an important psychosocial resource among Asian immigrants for buffering against the impacts of stress on various health outcomes, but its modifying roles on the stress-sleep relationship are relatively understudied.
      • Xu L
      • Chi I
      Acculturative stress and depressive symptoms among Asian immigrants in the United States: the roles of social support and negative interaction.
      This study aimed to assess whether perceived stress, stressors, and distress are associated with sleep disturbance and duration and whether levels of acculturation, acculturative stress, and social support moderate these associations among middle-aged and older Asian immigrants. We hypothesized that (1) higher levels of perceived stress, stressors, and distress would be associated with a higher prevalence of sleep disturbance; (2) higher levels of perceived stress, stressors, and distress would be associated with a shorter time in bed as a proxy for sleep duration, and (3) acculturation levels, acculturative stress, and social support would modify the associations, with more pronounced associations among immigrants who were less acculturated, who had a higher level of acculturative stress, and those with weaker social support.

      Methods

      Data

      Data were collected as part of a colorectal cancer screening randomized controlled trial. From August 2018 to June 2020, 400 community-dwelling Asian Americans (200 Chinese and 200 Korean) aged 50-75 years old were recruited from primary care physicians’ clinics in the Washington, D.C. Metropolitan Area. Inclusion criteria were: (1) self-identified Chinese or Korean; (2) age between 50 and 75 years; (3) not completed stool blood test within the past year; and (4) not completed a colonoscopy within the past 10 years. We excluded adults who had a family history of colorectal cancer, a history of removing polyps, inflammatory bowel disease, or a history of colorectal cancer.
      Ninety-two percent of data collection was completed in-person via a self-administered questionnaire, whereas the remaining 8% was collected by a research assistant-led phone survey due to the restriction on in-person research activities with the COVID-19 outbreak. The questionnaire was translated into Chinese and Korean, and the surveys were conducted in participants’ preferred languages (Mandarin (49.5%), Korean (50%), or English (0.5%)). All participants gave written informed consent before participating. This study was approved by the Institutional Review Boards of the University of Maryland and the University of California, Irvine.

      Measures

      Perceived stress

      Perceived stress was assessed using the Perceived Stress Scale,
      • Cohen S
      • Kamarck T
      • Mermelstein R.
      Perceived stress scale.
      which consists of 10 questions querying the frequency of feelings and thoughts related to events and situations during the past month. Sample items include “In the last month, how often have you been upset because of something that happened unexpectedly” and “In the last month, how often have you felt that you were unable to control the important things in your life?” The responses range from 0 (never) to 5 (very often). The Perceived Stress Scale has been well-validated among Chinese and Koreans.
      • Lee J
      • Shin C
      • Ko YH
      • et al.
      The reliability and validity studies of the Korean version of the Perceived Stress Scale.
      ,
      • Tang L-l
      • Zhang Y-n
      • Pang Y
      • Zhang H-w
      • Song L-l
      Validation and reliability of distress thermometer in Chinese cancer patients.
      In our study, the internal consistency was satisfactory with alpha = 0.71.

      Recent stressors

      Questions related to recent stressors and distress were derived from the National Comprehensive Cancer Network Distress Thermometer and Problem List (DTPL).

      National Comprehensive Cancer Network. (2018). NCCN Distress Thermometer and Problem List for Patients. Retrieved from https://www.nccn.org/patients/resources/life_with_cancer/pdf/nccn_distress_thermometer.pdf

      The DTPL includes an overall distress scale and a list of problems that assess various domains of stressors. Specifically, participants were asked to indicate whether they have encountered problems in the past week pertaining to: (1) child or grandchild care (eg, babysitting), (2) housing, (3) insurance/finance, (4) transportation, (5) work, (6) conflicts with children, (7) conflicts with partners, and (8) family health issues. All questions were rated by a yes or no response,

      National Comprehensive Cancer Network. (2018). NCCN Distress Thermometer and Problem List for Patients. Retrieved from https://www.nccn.org/patients/resources/life_with_cancer/pdf/nccn_distress_thermometer.pdf

      and we summed the number of yes responses to obtain a count of recent stressors (range: 0-8; mean, 1.24; standard deviation (SD), 1.61). The DTPL has been validated in Chinese and Korean populations.
      • Tang L-l
      • Zhang Y-n
      • Pang Y
      • Zhang H-w
      • Song L-l
      Validation and reliability of distress thermometer in Chinese cancer patients.
      ,
      • Shim EJ
      • Shin YW
      • Jeon HJ
      • Hahm BJ.
      Distress and its correlates in Korean cancer patients: pilot use of the distress thermometer and the problem list.

      Perceived distress

      We measured distress by the distress thermometer from DTPL, a 0-10 visual analogue scale vertically oriented in the form of a thermometer.
      • Donovan KA
      • Grassi L
      • McGinty HL
      • Jacobsen PB.
      Validation of the distress thermometer worldwide: state of the science.
      Participants were asked to rate how much distress they have been experiencing in the past week. This scale has been widely used in psycho-oncology research across different cultures.
      • Donovan KA
      • Grassi L
      • McGinty HL
      • Jacobsen PB.
      Validation of the distress thermometer worldwide: state of the science.
      The range of the scale in this sample was 0-10 (mean, 3.65; SD, 2.42).

      Sleep disturbance

      Sleep disturbance was assessed using the 8-item Patient-Reported Outcomes Measurement Information System Sleep Disturbance questionnaire, which assesses perception of sleep quality, depth, and restoration over the past 7 days.
      • Cella D
      • Riley W
      • Stone A
      • et al.
      The Patient-Reported Outcomes Measurement Information System (PROMIS) developed and tested its first wave of adult self-reported health outcome item banks: 2005–2008.
      All items were scored on a 5-point Likert scale ranging from not at all or never (1) to very much or always (5). We summed the scores across the items to obtain a total raw score and then converted the sum score to a standardized T-score using a conversion table.
      • Yu L
      • Buysse DJ
      • Germain A
      • et al.
      Development of short forms from the PROMISTM sleep disturbance and sleep-related impairment item banks.
      We classified the T-scores into 4 categories: none to slight, mild, moderate, and severe. Given that 81.2% of participants were in the “none to slight” category, we further categorized sleep disturbance into a binary variable (0 = none to slight, 1 = any sleep disturbance).

      Time in bed

      We used time in bed as a proxy for sleep duration. We assessed self-reported time-in-bed by asking participants their usual sleep and wake time in hours and minutes. Specifically, participants were asked, “What's your usual sleep and wake time?” We calculated the total time in bed by subtracting sleep time from wake time.

      Acculturation levels

      We assessed acculturation levels through years in the United States and language proficiency. Years in the United States were measured by asking participants the number of years that they had been in the United States and were categorized as: (1) 0-10 years and (2) more than 10 years. A cut-off of 10 years was used because prior research has suggested 10 years as a marker for assimilation and has shown threshold effects on health outcomes including obesity and depressive symptoms.
      • Lincoln KD
      • Chatters LM
      • Taylor RJ
      • Jackson JS.
      Profiles of depressive symptoms among African Americans and Caribbean Blacks.
      ,
      • Goel MS
      • McCarthy EP
      • Phillips RS
      • Wee CC.
      Obesity among US immigrant subgroups by duration of residence.
      Language proficiency was assessed by asking participants how well they spoke English. Responses range from (1) fluent like a native speaker to (5) not at all. Because of small sample sizes in some groups, we recategorized language fluency as (1) good (fluent like a native speaker, well) and (2) poor/so-so/not at all.

      Acculturative stress

      We assessed acculturative stress using a 9-item scale with a dichotomized response to each item. Sample items include whether feeling guilty for leaving the family in a home country and whether having difficulty in interactions with others because of English proficiency. We summed up the scores of the 9 items to create a composite score. The scale has been widely used to assess acculturative stress among Asian immigrants.
      • Lueck K
      • Wilson M.
      Acculturative stress in Asian immigrants: the impact of social and linguistic factors.

      Perceived social support

      Perceived social support was measured by the DUKE-UNC Functional Social Support Questionnaire,
      • Broadhead WE
      • Gehlbach SH
      • De Gruy FV
      • Kaplan BH.
      The Duke-UNC Functional Social Support Questionnaire: measurement of social support in family medicine patients.
      which includes 8 Likert-scale items related to perceived functional support (eg, get love and affection, get chances to talk to someone about problems). Responses range from much less than I would like (1) to as much as I would like (5). A composite score was created by taking the mean of the 8 questions, with a higher score indicating greater social support.

      Covariates

      Sociodemographic factors including income, education, employment status, and marital status have been linked to sleep problems.
      • Grandner MA
      • Patel NP
      • Gehrman PR
      • et al.
      Who gets the best sleep? Ethnic and socioeconomic factors related to sleep complaints.
      Likewise, lower socioeconomic status, being unmarried, or being unemployed have also been shown to be associated with a greater level of stress.
      • Almojali AI
      • Almalki SA
      • Alothman AS
      • Masuadi EM
      • Alaqeel MK.
      The prevalence and association of stress with sleep quality among medical students.
      Informed by prior research, we included covariates for age (years), sex (female vs. male), Asian subgroup (Chinese vs. Korean), income (<$10K; $10K-$39,999; $40K-$69,999,>=$70K), education (less than high school; high school; some college; college or more), employment status (full-time, part-time, not employed), marital status (married/living as married vs. currently not married), and body mass index (BMI; kg/m2).

      Statistical analyses

      We first conducted descriptive analyses for the overall sample and stratified by sleep disturbance status (none to light vs. mild/moderate/severe) and time in bed (7-9 hours vs. <7 hours or >9 hours). Second, we ran logistic regression models to determine the associations between stress and sleep disturbance. Prevalence ratios and 95% confidence intervals were estimated using the logistic models as implemented by the “prLogisticBootMarg” function in R package “prLogistic.”

      Ospina R, Amorim LD. prLogistic: estimation of prevalence ratios using logistic models. 2013. Accessed November 15, 2021. http://cran.uni-muenster.de/web/packages/prLogistic/index.html

      Third, we fit linear regression models to estimate differences in time in bed (hours) per unit difference in stress (or distress). The main analyses involved 3 sets of models: age-adjusted (model 1); model 1 plus sex and Asian subgroup (model 2); and model 2 plus sociodemographic and socioeconomic variables and BMI (model 3). To determine whether the associations of stress, stressors, and distress with sleep problems were separately modified by level of acculturation, acculturative stress, and social support, we fitted additional models by adding the main effect of years in the United States, language proficiency, acculturative stress, and social support and a multiplicative interaction term between each variable and stress. Notably, as only 8 out of the 47 participants who lived in the United States for less than 10 years had any sleep disturbance, we did not examine effect modification by years in the United States for sleep disturbance due to a lack of statistical power. We performed stratified analyses when significant interactions were observed. All analyses were performed in R.

      Sensitivity analyses

      In a sensitivity analysis, we treated time in bed as a categorical variable (<7 hours, 7-9 hours (reference), and >9 hours) to understand which category has the strongest association with stress.

      Results

      The sample includes 400 Asian American immigrants (mean age: 58 years (SD = 6)). A total of 199 were born in China, 200 were born in Korea, and one was born in Indonesia. Of the participants, 52.8% were female, 31.4% had an annual income lower than $40,000, 33.6% had a high school or lower degree, 21.2% were not employed, and 85.2% were married or were living as married (Table 1). A total of 73 (18.3%) participants (26 Chinese and 43 Koreans) reported any sleep disturbance. The average time in bed was 7.25 hours (SD = 1.17), and it was similar between Chinese (mean = 7.41, SD = 1.14) and Korean immigrants (mean = 7.09, SD = 1.18).
      Table 1Sample characteristics in the sample overall and by sleep disturbance and time in bed among Asian immigrants (N = 400)
      Sleep disturbanceSleep duration (time in bed)
      None to light

      (N = 327)
      Any sleep disturbance

      (N = 73)
      7-9 hours in bed

      (N = 269)
      <7 hours or >9 hours in bed

      (N = 131)
      Total

      (N = 400)
      Age
       Mean (SD)58.4 (6.50)58.5 (5.74)58.3 (6.57)58.6 (5.93)58.4 (6.36)
      Sex
       Male164 (50.2%)25 (34.2%)131 (48.7%)58 (44.3%)189 (47.2%)
       Female163 (49.8%)48 (65.8%)138 (51.3%)73 (55.7%)211 (52.8%)
      Asian subgroup
       Chinese173 (52.9)27 (37.0%)147 (54.6%)53 (40.5%)200 (50.0%)
       Korean154 (47.1)46 (63.0%)122 (45.4%)78 (59.5%)200 (50.0%)
      Income
       <$10K17 (5.2%)8 (11.0%)15 (5.6%)10 (7.6%)25 (6.2%)
       $10K-$39,99983 (25.4%)18 (24.7%)76 (28.3%)25 (19.1%)101 (25.2%)
       $40K-$69,999124 (37.9%)30 (41.1%)91 (33.8%)63 (48.1%)154 (38.5%)
       >=$70K103 (31.5%)17 (23.3%)87 (32.3%)33 (25.2%)120 (30.0%)
      Education
       Less than high school35 (10.7%)8 (11.0%)29 (10.8%)14 (10.7%)43 (10.8%)
       High school73 (22.3%)18 (24.7%)63 (23.4%)28 (21.4%)91 (22.8%)
       Some college59 (18.0%)9 (12.3%)37 (13.8%)31 (23.7%)68 (17.0%)
       College or more160 (48.9%)38 (52.1%)140 (52.0%)58 (44.3%)198 (49.5%)
      Employment status
       Full-time190 (58.1%)41 (56.2%)151 (56.1%)80 (61.1%)231 (57.8%)
       Part-time66 (20.2%)18 (24.7%)62 (23.0%)22 (16.8%)84 (21.0%)
       Not employed71 (21.7%)14 (19.2%)56 (20.8%)29 (22.1%)85 (21.2%)
      Marital status
       Married/living as married286 (87.5%)55 (75.3%)233 (86.6%)108 (82.4%)341 (85.2%)
       Not currently married41 (12.5%)18 (24.7%)36 (13.4%)23 (17.6%)59 (14.8%)
      BMI24.6 (3.48)24.7 (3.70)24.6 (3.41)24.8 (3.74)24.6 (3.51)
      Years in the United States
       ≤10 years39 (11.9%)8 (11.0%)34 (12.6%)13 (9.9%)47 (11.8%)
       >10 years288 (88.1%)65 (89.0%)235 (87.4%)118 (90.1%)353 (88.3%)
      Language proficiency
       Good76 (23.2%)15 (20.5)63 (23.4%)28 (21.4%)91 (22.8%)
       Poor/So so/Not at all251 (76.8%)58 (79.5%)206 (76.6%)103 (78.6%)309 (77.3%)
      Acculturative stress1.5 (1.5)2.2 (1.8)1.50 (1.49)1.91 (1.63)1.6 (1.6)
      Social support3.8 (0.8)3.3 (1.0)3.84 (0.84)3.54 (0.94)3.7 (0.9)
      SD, standard deviation. BMI, body mass index.
      Compared with participants who reported no or slight sleep disturbance, those who reported mild/moderate/severe sleep disturbance were more likely to be female, with lower income, with a high school degree or lower, be working on a part-time job, currently unmarried, have more acculturative stress, or have fewer social support. Compared with those who spent 7-9 hours in bed, those who spent <7 hours or >9 hours were more likely to be female, with lower education, with lower income, currently being unmarried, report more acculturative stress, or have fewer social support. The stress measures were moderately correlated, with a correlation of r = 0.25 (p < .001) for recent stressors and perceived stress, r = 0.37 (p < .001) for perceived stress and distress, and r = 0.41 (p < .001) for recent stressors and distress.
      After adjusting for age in model 1, each one-unit increase in perceived stress was associated with 1.15 times the prevalence of any sleep disturbance (PR = 1.15, 95% CI = 1.08, 1.24) (Table 2). The associations remained similar after adjusting for Asian subgroup, sex, and socioeconomic covariates, and BMI. Similarly, after adjusting for age, each additional stressor was associated with 1.32 times the prevalence of sleep disturbance (PR = 1.32, 95% CI = 1.14, 1.53). The associations were slightly attenuated after adjusting for all covariates. Regarding distress, after adjusting for age, each one-unit increase in distress was associated with 1.33 times the prevalence of sleep disturbance (PR = 1.33, 95% CI = 1.18, 1.52). The associations were slightly increased after adjusting for sex and Asian subgroup and then slightly decreased after further adjusting for socioeconomic covariates and BMI.
      Table 2Associations of perceived stress, stressors, and distress with sleep disturbance among Asian immigrants (N = 400)
      Model 1Model 2Model 3
      PR (95% CI)PR (95% CI)PR (95% CI)
      Perceived stress (range: 2-26)1.15 (1.08,1.24)1.14 (1.06,1.23)1.15 (1.06,1.26)
      Stressors (range: 0-8)1.32 (1.14,1.53)1.28 (1.13,1.48)1.32 (1.13, 1.59)
      Distress (range: 0-10)1.33 (1.18,1.52)1.34 (1.21,1.55)1.36 (1.21,1.57)
      PR, prevalence ratio; CI, confidence interval.
      Model 1 was adjusted for age; model 2 was adjusted age, sex, and Asian subgroup; model 3 was adjusted age, sex, Asian subgroup, income, education, marital status, employment status, and body mass index.
      We found little evidence that perceived stress and distress were associated with time-in-bed (Table 3). For recent stressors, in the model adjusted for age, sex, and Asian subgroup, each additional stressor was associated with a decrease in time in bed of 4.8 minutes (β = -4.8, 95% CI = (-9, -0.6)); however, the association become null after further controlling for socioeconomic covariates and BMI.
      Table 3Associations of perceived stress, stressors, and distress with time in bed (in minutes) among Asian immigrants (N = 400)
      Model 1Model 2Model 3
      β (95% CI)β (95% CI)β (95% CI)
      Perceived stress (range: 2-26)0.6 (-1.2,1.8)0.6 (-0.6,2.4)0.6 (-1.2,1.8)
      Stressors (range: 0-8)-5.4 (-9.6, -1.2)-4.8 (-9.0, -0.6)-3.6 (-7.8,0.6)
      Distress (range: 0-10)-0.6 (-3.6,2.4)-0.6 (-3.0,2.4)0.6 (-2.4,3.0)
      CI, confidence interval.
      Model 1 was adjusted for age; model 2 was adjusted age, sex, and Asian subgroup; model 3 was adjusted age, sex, Asian subgroup, income, education, marital status, employment status, and body mass index.
      We did not find evidence that the association of perceived stress, stressors, or distress with sleep disturbance were moderated by any of the acculturation variables or social support. For time in bed, we did not find evidence that the associations of perceived stress, stressors, or distress with time in bed were modified by language proficiency, acculturative stress, or social support. However, the associations of perceived stress (βperceived stress*sleep = 0.10, 95% CI = 0.02, 0.19) and distress (βdistress*sleep= 0.20, 95% CI = 0.06, 0.35) with time in bed were modified by years in the United States (Fig. 1a-c). Particularly, the associations between distress and time in bed were only evident among those who have resided in the United States for fewer than 10 years (Supplementary Table S2).
      Fig 1
      Fig. 1Associations of perceived stress, stressors, distress with time in bed by years in the United States among 400 Chinese and Korean immigrants. Note. All models were adjusted for age, sex, Asian subgroup, education, income, marital status, employment status, and body mass index.

      Sensitivity analysis

      We examined the stress and distress variables in relation to time in bed as a categorical outcome. After adjusting for all covariates, associations of perceived stress, stressors, and distress with categorical time in bed were not observed (Supplementary Table S1).

      Discussion

      This study examined the associations of perceived stress, stressors, and distress with sleep disturbance and duration among 400 Chinese and Korean immigrants. Higher perceived stress, stressors, and distress were associated with a greater prevalence of sleep disturbance. Additionally, the associations between distress and time in bed were only evident among adults who have resided in the United States for fewer than 10 years.
      Our findings regarding the positive associations of perceived stress, stressors, and distress with sleep disturbance are consistent with the broader literature. For example, a study of 306 medical students found a strong association between high psychological distress and poor sleep quality.
      • Almojali AI
      • Almalki SA
      • Alothman AS
      • Masuadi EM
      • Alaqeel MK.
      The prevalence and association of stress with sleep quality among medical students.
      In a recent large study of 4201 adults aged 65 years and older, higher perceived stress was independently associated with poorer sleep quality.
      • Zaidel C
      • Musich S
      • Karl J
      • Kraemer S
      • Yeh CS.
      Psychosocial factors associated with sleep quality and duration among older adults with chronic pain.
      Our study advances the literature by considering perceived stress, stressors, and distress simultaneously and focusing on Asian immigrants, a fast-growing population understudied in sleep health research. Our findings indicate that stress and distress are important to consider when studying and possibly treating sleep disturbance in Asian Americans.
      Our findings that perceived stress, stressors, and distress were not associated with shorter time in bed in the overall population add complexity to the unclear pattern of results on stress and sleep duration within the literature. Existing research on stress and sleep duration has yielded inconclusive findings, with some research showing that stress is associated with shorter duration, while other research fails to find evidence for a relation between stress and sleep duration.
      • Choi DW
      • Chun SY
      • Lee SA
      • Han KT
      • Park EC.
      Association between sleep duration and perceived stress: salaried worker in circumstances of high workload.
      Our consideration of years in the United States as an effect modifier suggests that the null findings might have been driven by immigrants who have lived in the United States for more than 10 years. For immigrants who had been in the United States for less than 10 years, higher distress was strongly associated with shorter sleep duration. These findings contradict the healthy immigrant effect, which suggests that the health advantages of immigrants diminish over time. Our findings that language proficiency and acculturative stress did not modify the stress-sleep association suggest that we should consider factors beyond language or cultural barriers that may influence the stress and sleep problems among recent immigrants. Compared with immigrants who have been in the United States for a longer period, recent immigrants may be more likely to take low-skilled jobs with long working hours, non-standard schedules, and poor working conditions. As such, they might be more likely to be exposed to high stress and have shorter sleep duration. Although we accounted for employment status, we did not have information about occupation type or work hours. Future research should examine if occupational characteristics (eg, schedule, demands and controls, etc.) influence the stress-sleep relationship among Asian Americans. Notably, since only 4 Korean participants had been in the United States for less than 10 years, we did not have sufficient power to evaluate whether the effect modifications by years in the United States differ between Korean and Chinese adults. Future research with larger sample sizes should replicate our analyses to assess the modifying role of acculturation factors on the associations between stress and sleep problems among Asian immigrants.
      Our findings that the associations of perceived stress, stressors, and distress with sleep duration and disturbance did not differ depending on levels of social support are unexpected and are inconsistent with prior research which showed social support mitigates stress-sleep relationships.
      • Van Schalkwijk FJ
      • Blessinga AN
      • Willemen AM
      • Van Der Werf YD
      • Schuengel C.
      Social support moderates the effects of stress on sleep in adolescents.
      ,
      • Pow J
      • King DB
      • Stephenson E
      • DeLongis A.
      Does social support buffer the effects of occupational stress on sleep quality among paramedics? A daily diary study.
      Some research suggests that visible support may have unexpected negative consequences, including lowering one's self-esteem.
      • Bozo Ö
      • Toksabay NE
      • Kürüm O.
      Activities of daily living, depression, and social support among elderly Turkish people.
      This might be especially true among older immigrants, as too much support received may induce feelings of “being a burden” to their family or relatives, and therefore the support they receive may not function as a buffer to protect them against sleep problems.
      Our findings should be interpreted with limitations. First, given the cross-sectional design, reverse causation is possible as the presence of sleep problems may change the perception of stress and levels of distress. Sleep problems may disrupt family functioning and lead to a higher prevalence of stressful life events such as conflicts within families. Future longitudinal research should examine whether there are reciprocal relationships between stress and sleep problems among Asian Americans. Second, we used data from a non-probability sample of patients from primary care physicians’ clinics, which included only Chinese and Korean immigrants whose life experiences may be different from other Asian immigrant subgroups. As such, our sample is not representative of the general Asian immigrant population and our findings have limited external validity. However, given the limited evidence available in the literature, our study represents an important first step to understanding stress and sleep health among Asian immigrants. Third, we relied on self-reported sleep measures, which might have been subject to reporting bias. Due to the self-report nature of the sleep measures, we were also unable to assess sleep onset latency and comprehensively capture sleep duration. Future studies should include objective sleep assessments to validate the findings of the present study. Last, although our stress measures have been widely used in the literature, they are not comprehensive and may be subject to measurement errors. For example, we did not have information about perceived discrimination, a type of stressors that have been associated with sleep problems.
      • Slopen N
      • Lewis TT
      • Williams DR.
      Discrimination and sleep: a systematic review.
      However, our measures of perceived stress and distress might allow us to capture the negative effects of the stressful events that were omitted in the recent stressor measure used in the present study.
      In sum, perceived stress, stressors, and distress were associated with a higher prevalence of sleep disturbance among Asian immigrants and the associations were not modified by levels of acculturation, acculturative stress, and social support. Further, distress was associated with shorter times in bed only among those who resided in the United States for less than 10 years. The consistent associations of stress, stressors, and distress with sleep disturbance point to the importance of considering these constructs within sleep disturbance interventions among Asian immigrants. The different patterns of findings regarding the associations between stress (distress) and time in bed by years in the United States require further investigations. Specifically, research with larger sample sizes should replicate our study and move beyond acculturative stress and social support to explore other factors that contribute to the stress (distress) and sleep duration associations among recent immigrants.

      Declaration of conflict of interest

      The authors have declared no conflicts of interest.

      Appendix. Supplementary materials

      References

        • Buxton OM
        • Marcelli E.
        Short and long sleep are positively associated with obesity, diabetes, hypertension, and cardiovascular disease among adults in the United States.
        Soc Sci Med. 2010; 71: 1027-1036
        • Miner B
        • Kryger MH.
        Sleep in the aging population.
        Sleep Med Clin. 2020; 15: 311-318
        • Neikrug AB
        • Ancoli-Israel S.
        Sleep disorders in the older adult—a mini-review.
        Gerontology. 2010; 56: 181-189
        • Chen X
        • Wang R
        • Zee P
        • et al.
        Racial/ethnic differences in sleep disturbances: the Multi-Ethnic Study of Atherosclerosis (MESA).
        Sleep. 2015; 38: 877-888
        • George KM
        • Peterson RL
        • Gilsanz P
        • et al.
        Racial/ethnic differences in sleep quality among older adults: Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study.
        Ethn Dis. 2020; 30: 469
        • Hill TD
        • Dowd-Arrow B
        • Ellison CG
        • Hale L
        • McFarland M
        • Burdette AM.
        Gun ownership, community stress, and sleep disturbance in America.
        Sleep Health. 2022; 8: 161-166
        • Han KS
        • Kim L
        • Shim I.
        Stress and sleep disorder.
        Exp Neurobiol. 2012; 21: 141
        • Vgontzas AN
        • Chrousos GP.
        Sleep, the hypothalamic–pituitary–adrenal axis, and cytokines: multiple interactions and disturbances in sleep disorders.
        Endocrinol Metab Clin. 2002; 31: 15-36
        • Charles LE
        • Slaven JE
        • Mnatsakanova A
        • et al.
        Association of perceived stress with sleep duration and sleep quality in police officers.
        Int J Emerg Ment Health. 2011; 13: 229
        • Martyn-Nemeth P
        • Penckofer S
        • Gulanick M
        • Velsor-Friedrich B
        • Bryant FB.
        The relationships among self-esteem, stress, coping, eating behavior, and depressive mood in adolescents.
        Res Nurs Health. 2009; 32: 96-109
        • Tavolacci MP
        • Ladner J
        • Grigioni S
        • Richard L
        • Villet H
        • Dechelotte P.
        Prevalence and association of perceived stress, substance use and behavioral addictions: a cross-sectional study among university students in France, 2009–2011.
        BMC Public Health. 2013; 13: 1-8
        • Li Y
        • Gu S
        • Wang Z
        • et al.
        Relationship between stressful life events and sleep quality: rumination as a mediator and resilience as a moderator.
        Front Psychiatry. 2019; 10: 348
        • Cohen S
        • Kamarck T
        • Mermelstein R.
        A global measure of perceived stress.
        J Health Soc Behav. 1983; 24: 385-396
        • Kingston D
        • Heaman M
        • Fell D
        • Dzakpasu S
        • Chalmers B.
        Factors associated with perceived stress and stressful life events in pregnant women: findings from the Canadian Maternity Experiences Survey.
        Matern Child Health J. 2012; 16: 158-168
        • Gallo LC
        • Roesch SC
        • Fortmann AL
        • et al.
        Associations of chronic stress burden, perceived stress, and traumatic stress with cardiovascular disease prevalence and risk factors in the HCHS/SOL Sociocultural Ancillary Study.
        Psychosom Med. 2014; 76: 468
        • Berry JW.
        Acculturation and adaptation in a new society.
        Int Migr. 1992; 30: 69
        • Abraido-Lanza AF
        • Dohrenwend BP
        • Ng-Mak DS
        • Turner JB.
        The Latino mortality paradox: a test of the" salmon bias" and healthy migrant hypotheses.
        Am J Public Health. 1999; 89: 1543-1548
        • Cohen S
        • McKay G.
        Social support, stress and the buffering hypothesis: a theoretical analysis.
        Handbook of Psychology and Health (Volume IV). Routledge, 2020: 253-267
        • Xu L
        • Chi I
        Acculturative stress and depressive symptoms among Asian immigrants in the United States: the roles of social support and negative interaction.
        Asian Am J Psychol. 2013; 4: 217
        • Cohen S
        • Kamarck T
        • Mermelstein R.
        Perceived stress scale.
        Meas Stress Guide Health Soc Sci. 1994; 10: 1-2
        • Lee J
        • Shin C
        • Ko YH
        • et al.
        The reliability and validity studies of the Korean version of the Perceived Stress Scale.
        Korean J Psychosom Med. 2012; 20: 127-134
        • Tang L-l
        • Zhang Y-n
        • Pang Y
        • Zhang H-w
        • Song L-l
        Validation and reliability of distress thermometer in Chinese cancer patients.
        Chin J Cancer Res. 2011; 23: 54-58
      1. National Comprehensive Cancer Network. (2018). NCCN Distress Thermometer and Problem List for Patients. Retrieved from https://www.nccn.org/patients/resources/life_with_cancer/pdf/nccn_distress_thermometer.pdf

        • Shim EJ
        • Shin YW
        • Jeon HJ
        • Hahm BJ.
        Distress and its correlates in Korean cancer patients: pilot use of the distress thermometer and the problem list.
        Psycho-Oncology J Psychol Soc Behav Dimens Cancer. 2008; 17: 548-555
        • Donovan KA
        • Grassi L
        • McGinty HL
        • Jacobsen PB.
        Validation of the distress thermometer worldwide: state of the science.
        Psycho-oncology. 2014; 23: 241-250
        • Cella D
        • Riley W
        • Stone A
        • et al.
        The Patient-Reported Outcomes Measurement Information System (PROMIS) developed and tested its first wave of adult self-reported health outcome item banks: 2005–2008.
        J Clin Epidemiol. 2010; 63: 1179-1194
        • Yu L
        • Buysse DJ
        • Germain A
        • et al.
        Development of short forms from the PROMISTM sleep disturbance and sleep-related impairment item banks.
        Behav Sleep Med. 2012; 10: 6-24
        • Lincoln KD
        • Chatters LM
        • Taylor RJ
        • Jackson JS.
        Profiles of depressive symptoms among African Americans and Caribbean Blacks.
        Soc Sci Med. 2007; 65: 200-213
        • Goel MS
        • McCarthy EP
        • Phillips RS
        • Wee CC.
        Obesity among US immigrant subgroups by duration of residence.
        JAMA. 2004; 292: 2860-2867
        • Lueck K
        • Wilson M.
        Acculturative stress in Asian immigrants: the impact of social and linguistic factors.
        Int J Intercult Relat. 2010; 34: 47-57
        • Broadhead WE
        • Gehlbach SH
        • De Gruy FV
        • Kaplan BH.
        The Duke-UNC Functional Social Support Questionnaire: measurement of social support in family medicine patients.
        Med Care. 1988; 26: 709-723
        • Grandner MA
        • Patel NP
        • Gehrman PR
        • et al.
        Who gets the best sleep? Ethnic and socioeconomic factors related to sleep complaints.
        Sleep Med. 2010; 11: 470-478
      2. Ospina R, Amorim LD. prLogistic: estimation of prevalence ratios using logistic models. 2013. Accessed November 15, 2021. http://cran.uni-muenster.de/web/packages/prLogistic/index.html

        • Almojali AI
        • Almalki SA
        • Alothman AS
        • Masuadi EM
        • Alaqeel MK.
        The prevalence and association of stress with sleep quality among medical students.
        J Epidemiol Glob Health. 2017; 7: 169-174
        • Zaidel C
        • Musich S
        • Karl J
        • Kraemer S
        • Yeh CS.
        Psychosocial factors associated with sleep quality and duration among older adults with chronic pain.
        Popul Health Manag. 2021; 24: 101-109
        • Choi DW
        • Chun SY
        • Lee SA
        • Han KT
        • Park EC.
        Association between sleep duration and perceived stress: salaried worker in circumstances of high workload.
        Int J Environ Res Public Health. 2018; 15: 796
        • Van Schalkwijk FJ
        • Blessinga AN
        • Willemen AM
        • Van Der Werf YD
        • Schuengel C.
        Social support moderates the effects of stress on sleep in adolescents.
        J Sleep Res. 2015; 24: 407-413
        • Pow J
        • King DB
        • Stephenson E
        • DeLongis A.
        Does social support buffer the effects of occupational stress on sleep quality among paramedics? A daily diary study.
        J Occup Health Psychol. 2017; 22: 71
        • Bozo Ö
        • Toksabay NE
        • Kürüm O.
        Activities of daily living, depression, and social support among elderly Turkish people.
        J Psychol. 2009; 143: 193-206
        • Slopen N
        • Lewis TT
        • Williams DR.
        Discrimination and sleep: a systematic review.
        Sleep Med. 2016; 18: 88-95