Both restless legs syndrome (RLS) and periodic leg movements in sleep (PLMS) may be associated with incident cardiovascular disease (CVD). However, the individual contributions of these factors to adverse CVD outcomes are unknown. During the MrOS Sleep Study, 2823 men (mean age = 76.3 years) participated in a comprehensive sleep assessment from 2000 to 2002. RLS was identified by self-report of a physician diagnosis of RLS. A periodic limb movement of sleep index (PLMI) was derived from unattended in-home polysomnography. Incident cardiovascular events were centrally adjudicated during 8.7 ± 2.6 years of follow-up. The primary outcome was all-cause CVD; secondary outcomes included incident myocardial infarction (MI) and cerebrovascular disease. Cox proportional hazards regression models were adjusted for multiple covariates, including PLMI, to examine if there were independent associations of RLS and PLMI to the outcomes. Physician-diagnosed RLS was reported by 2.2% and a PLMI ≥ 15 was found in 59.6% of men. RLS was not associated with the composite CVD outcome. RLS was significantly associated with incident MI (Hazard ratio [HR] = 2.02, 95% CI, 1.04-3.91) even after adjustment for multiple covariates. Results were only modestly attenuated when PLMI was added to the model. PLMI also was found to predict incident MI (per SD increase in PLMI, HR = 1.14, 95% CI, 1.00-1.30, p = .05), and was materially unchanged after addition of RLS. The independent risk that RLS confers for MI suggests a role for non-PLMS factors such as sleep disturbance, shared genetic factors, or PLM-independent sympathetic hyperactivity.

Objective

This study examines associations between the risk of sleep apnea and abdominal obesity (assessed by waist-to-hip ratio (WHR)) and general obesity (assessed by body mass index (BMI)) in a sample of Chinese and Korean American immigrants.

Methods

The dataset included Chinese and Korean participants aged 50-75 who were recruited from primary care physicians' clinics from April 2018 to June 2020 in the Baltimore-Washington D.C. Metropolitan area (n = 394). Abdominal obesity was determined if WHR ≥ 0.9 in men and WHR ≥ 0.85 in women. General obesity was determined if BMI ≥ 30. The risk of sleep apnea was determined by using the Berlin questionnaire. Poisson regression models examined associations between sleep apnea risk and obesity. Models controlled for socio-demographic risk factors.

Results

Twelve percent of the study participants were classified as a high risk for sleep apnea, and 75% had abdominal obesity whereas 6.4% had general obesity. High risk of sleep apnea was positively associated with abdominal obesity (PR = 1.31, 95% CI: 1.17-1.47) and general obesity (PR = 2.19, 95% CI: 0.90-5.32), marginally significant at p < 0.1).

Conclusions

Chinese and Korean immigrants living in the USA who are at high risk of sleep apnea have higher abdominal obesity, even after accounting for sociodemographic characteristics. Abdominal obesity may be a better indicator than general obesity when examining the risk of sleep apnea among Asian Americans.

Information on clinical trial

Name: Screening To Prevent ColoRectal Cancer (STOP CRC) among At-Risk Asian American Primary Care Patients NCT Number: NCT03481296; Date of registration: March 29, 2018 URL: https://clinicaltrials.gov/ct2/show/NCT03481296?term=Sunmin+Lee&draw=2&rank=1.

OBJECTIVES: To determine the association between objectively measured sleep and subsequent placement in a nursing home or a personal care home. DESIGN: Prospective cohort. SETTING: Participants homes and sites of the Study of Osteoporotic Fractures. PARTICIPANTS: One thousand six hundred sixty-four community-dwelling women with a mean age of 83 ± 4. MEASUREMENTS: At baseline, participants completed an average of 4 nights of wrist actigraphy; they provided data on place of residence at baseline and at follow-up, 5 years later. RESULTS: At baseline, participants had a mean total sleep time of 408 ± 72 minutes, mean wake after sleep onset of 71 ± 43 minutes, and mean sleep efficiency of 79 ± 11%. At follow-up, 71 (4%) were residing in a nursing home, and 127 (8%) were in a personal care home. Women with the most wake after sleep onset (by quartile) had more than twice the odds as those with the least of placement in a nursing home (adjusted odds ratio (AOR) = 2.94, 95% confidence interval (CI) = 1.34-6.44) or a personal care home (AOR = 2.33, 95% CI = 1.26-4.30). Similarly, women with the lowest sleep efficiency had more than three times the odds as those with the highest of nursing home placement (AOR = 3.25, 95% CI = 1.35, 7.82) and more than twice the odds of placement in a personal care home (AOR = 2.38, 95% CI = 1.33, 4.24). There was no association between sleep duration and placement. CONCLUSION: In very old community-dwelling women, greater wake after sleep onset and lower sleep efficiency are risk factors for placement in a nursing home or personal care home. Sleep duration alone does not appear to increase the risk of placement in these long-term care settings.

Human cognitive performance is a key function whose biological foundations have been partially revealed by genetic and brain imaging studies. The sleep electroencephalogram (EEG) is tightly linked to structural and functional features of the central nervous system and serves as another promising biomarker. We used data from MrOS, a large cohort of older men and cross-validated regularized regression to link sleep EEG features to cognitive performance in cross-sectional analyses. In independent validation samples 2.5-10% of variance in cognitive performance can be accounted for by sleep EEG features, depending on the covariates used. Demographic characteristics account for more covariance between sleep EEG and cognition than health variables, and consequently reduce this association by a greater degree, but even with the strictest covariate sets a statistically significant association is present. Sigma power in NREM and beta power in REM sleep were associated with better cognitive performance, while theta power in REM sleep was associated with worse performance, with no substantial effect of coherence and other sleep EEG metrics. Our findings show that cognitive performance is associated with the sleep EEG (r = 0.283), with the strongest effect ascribed to spindle-frequency activity. This association becomes weaker after adjusting for demographic (r = 0.186) and health variables (r = 0.155), but its resilience to covariate inclusion suggest that it also partially reflects trait-like differences in cognitive ability.

Introduction

Little is known about the longitudinal association between napping and cognitive impairment in older adults.

Methods

We used wrist actigraphy to measure naps in 2751 community-dwelling older men. Cognition was assessed repeatedly over 12 years, and clinically significant cognitive impairment was determined by physician diagnosis, Alzheimer's medication use or a significant cognitive decline.

Results

After adjustment for all covariates, men with longer napping duration had greater cognitive decline and higher risk of cognitive impairment. Men who napped for ≥120 min/day (vs. <30 min/day) were 66% more likely to develop cognitive impairment (odds ratio = 1.66, 95% CI: 1.09-2.54) in 12 years. Further adjustment for nighttime sleep quality did not appreciably alter the results. The association between napping and cognitive impairment was more pronounced among those with higher sleep efficiency and average sleep duration.

Discussion

Napping might be useful as an early marker of cognitive impairment in the elderly, and its cognitive effects may differ by nighttime sleep.

Study objectives

To examine the association between periodic limb movements in sleep (PLMS) and change in selected aspects of cognition in community-dwelling older men.

Methods

We studied 2,636 older men without dementia who underwent in-home polysomnography with measurement of the periodic limb movement index (PLMI) and periodic limb movement arousal index (PLMAI) using piezoelectric sensors. Random-effects models and logistic regression were used to examine the association between PLMI, PLMAI, and 3- to 4-y change in cognition.

Results

After multivariable adjustment, men with a high PLMI had greater decline on the Trail Making Test - Part B (P trend = 0.02); those with a PLMI ≥ 30 were 48% more likely (odds ratio = 1.48, 95% confidence interval = 1.05-2.07) to experience the development of significant cognitive impairment (≥ 1 SD above mean change). Further adjustment for sleep efficiency, nocturnal hypoxemia, or dopaminergic medication use and analysis among men without Parkinson disease (n = 2,607) showed similar findings. No significant association was found for PLMAI or for Modified Mini-Mental State Examination scores.

Conclusions

Among older men without dementia, higher PLMS frequency was associated with greater decline in cognition, particularly in executive function.

Study objectives

To evaluate the association between obstructive airway disease (OAD) and sleep apnea in older men.

Methods

A community-based cross-sectional study of 853 community-dwelling older men (mean age 80.7 ± 4.1 years [range 73 to 90]) across 6 centers in the United States from the Outcomes of Sleep Disorders in Older Men Study. Sleep was objectively measured using full in-home polysomnography and lung function was objectively measured using spirometry. The association of OAD (pre-bronchodilator FEV1/FVC ratio < 0.7 and FEV1 < 80% predicted) and sleep apnea (apnea-hypopnea index [AHI] ≥ 15 events/hour) was assessed using logistic regression.

Results

OAD and sleep apnea were identified in 111 (13.0%) and 247 (29.0%) men, respectively. In univariate analysis, participants with OAD had a lower AHI (mean ± SD; 8.7 ± 11.7 vs. 12.7 ± 13.8, P = 0.0009) and a lower prevalence of sleep apnea (14.4 vs. 31.1%, P = 0.0003) compared to participants without OAD. OAD remained independently associated with a lower odds of sleep apnea (odds ratio 0.30, 95% CI 0.16 to 0.55, P = 0.0001) after adjustment for demographics, body composition, smoking, and potential mediators (arousal index, time spent in rapid eye movement sleep). Individuals with OAD and sleep apnea (n = 16) had an increased arousal index and lower oxygen saturation level as compared to individuals with OAD alone (P values < 0.05).

Conclusions

Obstructive airway disease was associated with a lower prevalence of sleep apnea in a cohort of community-dwelling elderly men, and unexplained by differences in adiposity or sleep architecture. Although uncommon in this cohort, coexisting sleep apnea and OAD was associated with increased sleep fragmentation and nocturnal oxygen desaturation compared to OAD alone.

Study objectives

While sleep apnea has been associated with cardiovascular disease (CVD) risk factors in white individuals in the U.S., these associations in Chinese and Korean Americans are less well-understood, particularly how these associations vary by age, gender, Asian origin, obesity, chronic conditions, and daytime sleepiness.

Methods

We used a sample of Chinese and Korean Americans ages 50-75 (n = 394) from the Baltimore-Washington DC Metropolitan Area to examine the associations of high risk (HR) sleep apnea with diagnoseable hypercholesterolemia and diabetes, as well as the following biomarkers: total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol/HDL-C ratio, triglycerides, and glucose (non-fasting). Poisson models included demographic factors, socioeconomic status, and body mass index (BMI). We tested for potential effect modifiers.

Results

HR-sleep apnea was associated with higher LDL-C level (β = 14.56, p < 0.05) and higher total cholesterol/HDL ratio (β = 0.64, p < 0.01). Younger respondents had higher levels of triglycerides associated with HR-sleep apnea than older respondents. For men, HR-sleep apnea was associated with higher total cholesterol, total cholesterol/HDL-C ratio, and triglycerides. Obese and overweight respondents had positive associations between HR-sleep apnea and total cholesterol, total cholesterol/HDL ratio, and triglycerides, while underweight/normal weight individuals did not. The interactions between snoring and daytime sleepiness were associated with hypercholesterolemia and diabetes.

Conclusions

This study demonstrates associations between sleep apnea risk and dyslipidemia among Chinese and Korean Americans. Associations were particularly pronounced among younger, male, overweight/obese, and sicker individuals. Future research should examine how to improve sleep health in Asian American populations to improve CVD risk.

Objectives

To determine the association between objectively measured sleep and subsequent placement in a nursing home or a personal care home.

Design

Prospective cohort.

Setting

Participants' homes and sites of the Study of Osteoporotic Fractures.

Participants

One thousand six hundred sixty-four community-dwelling women with a mean age of 83 ± 4.

Measurements

At baseline, participants completed an average of 4 nights of wrist actigraphy; they provided data on place of residence at baseline and at follow-up, 5 years later.

Results

At baseline, participants had a mean total sleep time of 408 ± 72 minutes, mean wake after sleep onset of 71 ± 43 minutes, and mean sleep efficiency of 79 ± 11%. At follow-up, 71 (4%) were residing in a nursing home, and 127 (8%) were in a personal care home. Women with the most wake after sleep onset (by quartile) had more than twice the odds as those with the least of placement in a nursing home (adjusted odds ratio (AOR) = 2.94, 95% confidence interval (CI) = 1.34-6.44) or a personal care home (AOR = 2.33, 95% CI = 1.26-4.30). Similarly, women with the lowest sleep efficiency had more than three times the odds as those with the highest of nursing home placement (AOR = 3.25, 95% CI = 1.35, 7.82) and more than twice the odds of placement in a personal care home (AOR = 2.38, 95% CI = 1.33, 4.24). There was no association between sleep duration and placement.

Conclusion

In very old community-dwelling women, greater wake after sleep onset and lower sleep efficiency are risk factors for placement in a nursing home or personal care home. Sleep duration alone does not appear to increase the risk of placement in these long-term care settings.