Are sleep and depression independent or overlapping risk factors for cardiometabolic disease?

Association between sleep duration and the mini-mental score: the Northern Manhattan study

BACKGROUND

Short and long sleep duration are associated with increased mortality and worse global cognitive function, but is unclear if these relations persist after accounting for the risk of sleep disordered breathing (SDB). The aim of our study is determine the association between short and long sleep duration with worse global cognitive function in a racially/ethnically diverse elderly cohort.

METHODS

We examined sleep hours and global cognitive function cross-sectionally within the population-based Northern Manhattan Study cohort. We conducted nonparametric and logistic regression to examine associations between continuous, short (< 6 h) and long (≥ 9 h) sleep hours with performance on the Mini Mental State Examination (MMSE).

RESULTS

There were 927 stroke-free participants with data on self-reported sleep hours and MMSE scores (mean age 75 ± 9 years, 61% women, 68% Hispanics). The median (interquartile range) MMSE was 28 (10-30). Sleep hours (centered at 7 h) was associated with worse MMSE (β = -0.01; SE [0.004], p = 0.0113) adjusting for demographics, vascular risk factors, medications, and risk for SDB. Reporting long sleep (≥ 9 h) compared to 6 to 8 h of sleep (reference) was significantly and inversely associated with MMSE (adjusted β = -0.06; SE [0.03], p = 0.012), while reporting short sleep was not significantly associated with MMSE performance. Long sleep duration was also associated with low MMSE score when dichotomized (adjusted OR: 2.4, 95% CI: 1.1-5.0).

CONCLUSION

In this cross-sectional analysis among an elderly community cohort, long sleep duration was associated with worse MMSE performance.

Insomnia and the risk of incident heart failure: a population study

AIMS

Insomnia is highly prevalent among heart failure patients, but only a few small studies have investigated insomnia symptoms and risk of heart failure. We aimed to assess the prospective association between self-reported insomnia symptoms and the risk of incident heart failure in a large Norwegian cohort.

METHODS AND RESULTS

Baseline data on insomnia symptoms, including difficulty initiating sleep, difficulty maintaining sleep and having non-restorative sleep, socio-demographic variables, and health status, including established cardiovascular risk factors, were collected from 54 279 men and women 20-89 years of age who participated in the Nord-Trøndelag Health study (HUNT) between 1995 and 1997 and were free from known heart failure at baseline. The cohort was followed for incident heart failure from baseline through 2008. We used Cox proportional hazard models to assess the association of baseline insomnia symptoms with the risk of heart failure. A total of 1412 cases of heart failure occurred during a mean follow-up of 11.3 years (SD = 2.9 years), either identified at hospitals or by the National Cause of Death Registry. There was a dose-dependent association between the number of insomnia symptoms and risk of heart failure. The multi-adjusted hazard ratios were 0.96 (0.57-1.61), 1.35 (0.72-2.50), and 4.53 (1.99-10.31) for people with one, two, and three insomnia symptoms, compared with people with none of the symptoms (P for trend 0.021).

CONCLUSIONS

Insomnia is associated with an increased risk of incident heart failure. If our results are confirmed by others and causation is proved, evaluation of insomnia symptoms might have consequences for cardiovascular prevention.

Association between perceived insufficient sleep, frequent mental distress, obesity and chronic diseases among US adults, 2009 behavioral risk factor surveillance system

Background

Although evidence suggests that poor sleep is associated with chronic disease, little research has been conducted to assess the relationships between insufficient sleep, frequent mental distress (FMD ≥14 days during the past 30 days), obesity, and chronic disease including diabetes mellitus, coronary heart disease, stroke, high blood pressure, asthma, and arthritis.

Methods

Data from 375,653 US adults aged ≥ 18 years in the 2009 Behavioral Risk Factor Surveillance System were used to assess the relationships between insufficient sleep and chronic disease. The relationships were further examined using a multivariate logistic regression model after controlling for age, sex, race/ethnicity, education, and potential mediators (FMD and obesity).

Results

The overall prevalence of insufficient sleep during the past 30 days was 10.4% for all 30 days, 17.0% for 14–29 days, 42.0% for 1–13 days, and 30.6% for zero day. The positive relationships between insufficient sleep and each of the six chronic disease were significant (p < 0.0001) after adjustment for covariates and were modestly attenuated but not fully explained by FMD. The relationships between insufficient sleep and both diabetes and high blood pressure were also modestly attenuated but not fully explained by obesity.

Conclusions

Assessment of sleep quantity and quality and additional efforts to encourage optimal sleep and sleep health should be considered in routine medical examinations. Ongoing research designed to test treatments for obesity, mental distress, or various chronic diseases should also consider assessing the impact of these treatments on sleep health.

Do reports of sleep disturbance relate to coronary and aortic calcification in healthy middle-aged women?: Study of women's health across the nation

BACKGROUND

Poor sleep may be associated with the cardiovascular disease (CVD) morbidity and mortality. It is less clear if poor sleep is associated with subclinical CVD. We evaluated cross-sectional associations between self-reported sleep disturbance and duration and calcification in the coronary arteries (CAC) and aorta (AC) in healthy mid-life women.

METHODS

512 black and white women enrolled in the SWAN Heart Study, underwent a computed tomography protocol for measurement of CAC and AC and completed questionnaires about their sleep. Linear and partial proportional logit regression analyses adjusted for site, race, age, body mass index, and the Framingham risk score (model 1). Additional covariates of education, perceived health, hypnotic medication and alcohol use were evaluated (model 2), plus depressive symptoms (model 3).

RESULTS

AC was related to higher levels of trouble falling asleep, waking earlier than planned, overall poor sleep quality, and cough/snoring and shorter sleep duration in linear regression analyses (model 1). Adjustments for additional covariates showed that poor sleep quality and waking earlier than planned remained associated with higher AC (models 2 and 3). CAC was unrelated to sleep characteristics.

CONCLUSIONS

Poor sleep quality is related to AC in middle-aged women. Sleep quality should routinely be assessed in mid-life women.

Sleep quality as a potential mediator between psychological distress and diabetes quality of life in veterans with type 2 diabetes

OBJECTIVE

The goal of this study was to explore sleep quality as a potential mediator between depression symptoms and diabetes quality of life (DQOL), and anxiety symptoms and DQOL.

METHOD

Participants were 83 male and 3 female veterans with type 2 diabetes (Mage = 62.4). Self-report measures were completed during the baseline assessment of a larger intervention study conducted at the VA Boston Healthcare System.

RESULTS

Depression symptoms, anxiety symptoms, and sleep quality were all associated with DQOL. Additionally, sleep quality had a partial indirect effect on the relationships between depression symptoms and DQOL, and between anxiety symptoms and DQOL.

CONCLUSIONS

These findings suggest that sleep quality may have an important role in the way that psychological distress affects diabetes quality of life.

Association between depressive symptoms and metabolic syndrome in police officers: results from two cross-sectional studies

Policing is one of the most dangerous and stressful occupations and such stress can have deleterious effects on health. The purpose of this study was to examine the association between depressive symptoms and metabolic syndrome (MetSyn) in male and female police officers from two study populations, Buffalo, NY and Spokane, WA. Depressive symptoms were measured using the Center for Epidemiologic Studies-Depression (CES-D) scale. MetSyn was defined using the 2005 AHA/NHBLI guidelines. Analysis of covariance was used to describe differences in number of MetSyn components across depressive symptom categories. The number of MetSyn components increased significantly across categories of CES-D for Spokane men only (p-trend = 0.003). For each 5-unit increase in CES-D score, odds increased by 47.6% for having hypertriglyceridemia, by 51.8% for having hypertension, and by 56.7% for having glucose intolerance. Exploring this association is important since both are predictors of future chronic health problems and the results could be helpful in developing future gender-specific prevention and intervention efforts among police officers.

Sleep loss due to worry and future risk of cardiovascular disease and all-cause mortality: the Scottish Health Survey

BACKGROUND

The association between specific sleeping disorders and risk of cardiovascular disease (CVD) is unclear. We assessed the association between sleep loss due to worry and future risk of CVD and death in a representative sample of community dwelling adults.

METHODS

A cohort of 11,905 adults (aged 53.4 ± 12.2 years, 42.2% male) without known history of CVD were drawn from the Scottish Health Surveys. Self-reported sleep disturbance was measured using a single item from the General Health Questionnaire. Incident CVD events (comprising CVD death, nonfatal myocardial infarction, coronary surgical procedures, stroke, and heart failure) over 8-year follow up were ascertained by a linkage to national registers; a total of 1448 CVD events and 1249 all-cause deaths were recorded.

RESULTS

15.6% of the sample reported 'rather more' or 'much more than usual' sleep loss due to worry over the prior 4 weeks. Sleep loss due to worry (much more than usual) was associated with elevated risk of CVD [age- and sex-adjusted hazard ratio (HR) 1.74, 95% confidence interval (CI) 1.35-2.25] and all-cause mortality (age- and sex-adjusted HR 2.02, 95% CI 1.57-2.61). Adjustment for a range of psychosocial, behavioural, and clinical risk factors partly attenuated the association, and in particular health behaviours (smoking, alcohol, physical inactivity) accounted for approximately 40% of the sleep-CVD relation.

CONCLUSION

Sleep loss due to worry was associated with a greater risk of CVD and all-cause mortality, but the association can be largely explained by intermediate risk factors such as health behaviours.

Poor sleep is associated with exaggerated cortisol response to the combined dexamethasone/CRH test in a non-clinical population

Although sleep disturbance has been shown to be associated with psychological distress and the hypothalamic-pituitary-adrenal (HPA) axis function, the simultaneous relationship between sleep, distress and HPA axis function is less clear. Here we examined the relationship between sleep quality as assessed with the Pittsburgh Sleep Quality Index, psychological distress as assessed with the Hopkins Symptom Checklist, and cortisol responses to the dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test in 139 non-clinical volunteers. Poor sleep was significantly correlated with greater cortisol response to the combined DEX/CRH challenge, but not with the cortisol level just before CRH challenge. When subjects were divided into three groups based on the suppression pattern of cortisol (i.e., incomplete-, moderate-, and enhanced-suppressors), poor sleep was significantly associated with the incomplete suppression in women while no significant association was found between sleep and the enhanced suppression. The association between poor sleep and exaggerated cortisol response to the CRH challenge became more clear in the regression analysis where the confounding effect of psychological distress was taken into consideration. These results indicate that poor sleep would be associated with exaggerated cortisol reactivity. The observed association of poor sleep with reactive cortisol indices to the CRH challenge, but not with the cortisol level after DEX administration alone, might add to the well-established evidence demonstrating the role of CRH in the regulation of sleep. Our findings further suggest that the mediation model would work better than the bivariate approach in investigating the relationship between sleep, distress and HPA axis reactivity.

Associations of Framingham risk score profile and coronary artery calcification with sleep characteristics in middle-aged men and women: Pittsburgh SleepSCORE study

BACKGROUND

Short and less efficient sleep may be risk factors for atherosclerosis. Few studies have investigated the associations between sleep characteristics and early cardiovascular disease (CVD) risk.

OBJECTIVE

Evaluate the associations between coronary artery calcification (CAC) and Framingham risk score profile with sleep characteristics in middle-aged men and women with no history of diagnosed myocardial infarction, interventional cardiology procedures, stroke, diabetes, or sleep disorders.

METHOD

224 participants enrolled in an epidemiological study of disparities in CVD risk were recruited for a 9-night assessment of sleep, with 2 nights of polysomnography (PSG) and 9 nights of actigraphy and sleep diaries. Of the 224 participants, 110 had high/moderate Framingham risk scores and 114 had low scores; 195 had computed tomography measures of CAC.

RESULTS

Individuals who had any CAC or higher Framingham risk scores had elevated apnea/hypopnea index (AHI) values, independent of age, race, and gender. The AHI association with CAC was nonsignificant in analyses adjusting for body mass index (BMI). Those with higher Framingham risk score profiles had shorter PSG sleep duration and less percent stage 3-4 and delta power sleep. High blood pressure and left ventricular hypertrophy were related to AHI and sleep duration, independent of BMI. Neither sleep duration nor efficiency was associated with CAC.

CONCLUSIONS

CAC was not associated with AHI, independent of BMI in a community-based sample of middle-aged men and women. Framingham risk score profiles were related to poor sleep. Sleep duration may not be related to early plaque burden in relatively healthy individuals.

Change in sleep duration and cognitive function: findings from the Whitehall II Study

STUDY OBJECTIVES

Evidence from cross-sectional studies shows that sleep is associated with cognitive function. This study examines change in sleep duration as a determinant of cognitive function.

DESIGN

Prospective cohort.

SETTING

The Whitehall II study.

PARTICIPANTS

1459 women and 3972 men aged 45-69 at baseline.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Sleep duration (≤ 5, 6, 7, 8, ≥ 9 h on an average week night) was assessed once between 1997-1999, baseline for the present study, and once between 2002-2004, average follow-up 5.4 years. Cognitive function was measured (2002-2004) using 6 tests: verbal memory, inductive reasoning (Alice Heim 4-I), verbal meaning (Mill Hill), phonemic and semantic fluency, and the Mini Mental State Examination (MMSE). In analyses adjusted for age, sex, and education, and corrected for multiple testing, adverse changes in sleep between baseline and follow-up (decrease from 6, 7, or 8 h, increase from 7 or 8 h) were associated with lower scores on most cognitive function tests. Exceptions were memory, and, for a decrease from 6-8 h only, phonemic fluency. Further adjustment for occupational position attenuated the associations slightly. However, firm evidence remained for an association between an increase from 7 or 8 h sleep and lower cognitive function for all tests, except memory, and between a decrease from 6-8 h sleep and poorer reasoning, vocabulary, and the MMSE. The magnitude of these effects was equivalent to a 4-7 year increase in age.

CONCLUSIONS

These results suggest that adverse changes in sleep duration are associated with poorer cognitive function in the middle-aged.