Self-reported sleep duration and napping, cardiac risk factors and markers of subclinical vascular disease: cross-sectional study in older men.
ABSTRACT: STUDYOBJECTIVES:Daytime sleep has been associated with increased risk of cardiovascular disease and heart failure (HF), but the mechanisms remain unclear. We have investigated the association between daytime and night-time sleep patterns and cardiovascular risk markers in older adults including cardiac markers and subclinical markers of atherosclerosis (arterial stiffness and carotid intima-media thickness (CIMT)). METHODS:Cross-sectional study of 1722 surviving men aged 71-92 examined in 2010-2012 across 24 British towns from a prospective study initiated in 1978-1980. Participants completed a questionnaire and were invited for a physical examination. Men with a history of heart attack or HF (n=251) were excluded from the analysis. RESULTS:Self-reported daytime sleep duration was associated with higher fasting glucose and insulin levels (p=0.02?and p=0.01, respectively) even after adjustment for age, body mass index, physical activity and social class. Compared with those with no daytime sleep, men with daytime sleep >1?hour, defined as excessive daytime sleepiness (EDS), had a higher risk of raised N-terminal pro-brain natriuretic peptide of ?400?pg/mL, the diagnostic threshold for HF (OR (95%?CI)=1.88 (1.15 to 3.1)), higher mean troponin, reduced lung function (forced expiratory volume in 1 s) and elevated von Willebrand factor, a marker of endothelial dysfunction. However, EDS was unrelated to CIMT and arterial stiffness. By contrast, night-time sleep was only associated with HbA1c (short or long sleep) and arterial stiffness (short sleep). CONCLUSIONS:Daytime sleep duration of >1?hour may be an early indicator of HF.
Project description:Heart rate variability (HRV) is a reliable technique to evaluate autonomic activity and shows marked changes across a night of sleep. Previous nighttime sleep findings report changes in HRV during non-rapid eye movement sleep (NREM), which have been associated with cardiovascular health benefits. Daytime sleep, however, has been linked with both positive and negative cardiovascular outcomes. Yet, no studies have directly compared HRV profiles during an ecologically-valid daytime nap in healthy, well-rested adults to that of nighttime sleep. Using a within-subjects design, 32 people took a daytime nap and slept overnight in the lab at least one week apart; both sleep sessions had polysomnography, including electrocardiography (ECG), recorded. We measured inter-beat intervals (RR), total power (TP), low frequency power (LF; .04-.15?Hz), and high frequency power (HF; .15-.40?Hz) components of HRV during NREM and rapid eye movement (REM) sleep. Compared to the nap, we found longer RR intervals and decreased heart rate during the night for both Stage 2 and SWS and increased TP, LF and HF power during nighttime Stage 2 sleep only; however, no differences in the LFHF ratio or normalized HF power were found between the nap and the night. Also, no differences in REM sleep between the nap and night were detected. Similar relationships emerged when comparing the nap to one cycle of nighttime sleep. These findings suggest that longer daytime naps, with both SWS and REM, may provide similar cardiovascular benefits as nocturnal sleep. In light of the on-going debate surrounding the health benefits and/or risks associated with napping, these results suggest that longer daytime naps in young, healthy adults may support cardiac down-regulation similar to nighttime sleep. In addition, napping paradigms may serve as tools to explore sleep-related changes in autonomic activity in both healthy and at-risk populations.
Project description:Reduced sleep duration has been increasingly reported to predict obesity. However, timing and regularity of sleep may also be important. In this study, the cross-sectional association between objectively measured sleep patterns and obesity was assessed in two large cohorts of older individuals.Wrist actigraphy was performed in 3053 men (mean age: 76.4 years) participating in the Osteoporotic Fractures in Men Study and 2985 women (mean age: 83.5 years) participating in the Study of Osteoporotic Fractures. Timing and regularity of sleep patterns were assessed across nights, as well as daytime napping.Greater night-to-night variability in sleep duration and daytime napping were associated with obesity independent of mean nocturnal sleep duration in both men and women. Each 1?h increase in the standard deviation of nocturnal sleep duration increased the odds of obesity 1.63-fold (95% confidence interval: 1.31-2.02) among men and 1.22-fold (95% confidence interval: 1.01-1.47) among women. Each 1?h increase in napping increased the odds of obesity 1.23-fold (95% confidence interval: 1.12-1.37) in men and 1.29-fold (95% confidence interval: 1.17-1.41) in women. In contrast, associations between later sleep timing and night-to-night variability in sleep timing with obesity were less consistent.In both older men and women, variability in nightly sleep duration and daytime napping were associated with obesity, independent of mean sleep duration. These findings suggest that characteristics of sleep beyond mean sleep duration may have a role in weight homeostasis, highlighting the complex relationship between sleep and metabolism.
Project description:Our aim was to investigate how circadian adaptation to night shift work affects psychomotor performance, sleep, subjective alertness and mood, melatonin levels, and heart rate variability (HRV). Fifteen healthy police officers on patrol working rotating shifts participated to a bright light intervention study with 2 participants studied under two conditions. The participants entered the laboratory for 48 h before and after a series of 7 consecutive night shifts in the field. The nighttime and daytime sleep periods were scheduled during the first and second laboratory visit, respectively. The subjects were considered "adapted" to night shifts if their peak salivary melatonin occurred during their daytime sleep period during the second visit. The sleep duration and quality were comparable between laboratory visits in the adapted group, whereas they were reduced during visit 2 in the non-adapted group. Reaction speed was higher at the end of the waking period during the second laboratory visit in the adapted compared to the non-adapted group. Sleep onset latency (SOL) and subjective mood levels were significantly reduced and the LF?HF ratio during daytime sleep was significantly increased in the non-adapted group compared to the adapted group. Circadian adaptation to night shift work led to better performance, alertness and mood levels, longer daytime sleep, and lower sympathetic dominance during daytime sleep. These results suggest that the degree of circadian adaptation to night shift work is associated to different health indices. Longitudinal studies are required to investigate long-term clinical implications of circadian misalignment to atypical work schedules.
Project description:BACKGROUND:Pain and sleep disturbance are common among patients with heart failure (HF) and are associated with symptom burden, disability, and poor quality of life. Little is known about the associations between specific sleep characteristics and pain in people with HF. OBJECTIVE:The aim of this study was to describe the relationships between nocturnal sleep characteristics, use of sleep medication, and daytime sleep characteristics and pain among people with HF. METHODS:We conducted a cross-sectional study of stable participants with HF. We administered the SF36 Bodily Pain Scale, Pittsburgh Sleep Quality Index, and Sleep Habits Questionnaire and obtained 3 days of wrist actigraphy and 1 night of home unattended polysomnography. We conducted bivariate analyses and generalized linear models. RESULTS:The sample included 173 participants (mean [SD] age, 60 [16.1] years; 65.3% [n = 113] male). Insomnia symptoms (P = .0010), sleep duration (P = .0010), poor sleep quality (P = .0153), use of sleep medications (P = .0170), napping (P = .0029), and daytime sleepiness (P = .0094) were associated with increased pain. Patients with the longest sleep duration, who also had insomnia, had more pain (P = .0004), fatigue (P = .0028), daytime sleepiness (P = .0136), and poorer sleep quality (P < .0001) and took more sleep medications (P = .0029) than did those without insomnia. CONCLUSIONS:Pain is associated with self-reported poor sleep quality, napping, daytime sleepiness, and use of sleep medication. The relationship between pain and sleep characteristics differs based on the presence of insomnia and sleep duration. Studies are needed to evaluate the causal relationships between sleep and pain and test interventions for these cooccurring symptoms.
Project description:Background Night eating has been associated with an elevated risk of obesity, dyslipidemia, and cardiovascular disease. However, there is no longitudinal study on whether habitual night eating, regardless of diet quality and energy intake, is associated with arterial stiffness, a major etiological factor in the development of cardiovascular disease. Methods and Results The study included 7771 adult participants without cardiovascular disease, cancer, or diabetes mellitus prior to dietary assessment by a validated food frequency questionnaire in 2014 through 2015. Participants were categorized into 3 groups based on self-reported night-eating habits: never or rarely, some days (1-5 times per week), or most days (6+ times per week). Arterial stiffness was assessed by brachial-ankle pulse wave velocity at baseline and repeatedly during follow-ups. Mean differences and 95% CIs in the yearly change rate of brachial-ankle pulse wave velocity across the 3 groups were calculated, adjusting for age, sex, socioeconomic status, total energy intake, diet quality, sleep quality, and other cardiovascular disease risk factors. At baseline, 6625 (85.2%), 610 (7.8%), and 536 (6.9%) participants reported night eating as never or rarely, some days, or most days, respectively. During a mean 3.19 years, we observed a positive association between night-eating frequency and progression of arterial stiffness (<i>P</i> trend=0.01). The adjusted difference in brachial-ankle pulse wave velocity change rate between the group that ate at night most days and the group that never or rarely ate at night was 14.1 (95% CI, 0.6-27.5) cm/s per year. This association was only significant in women, but not in men (<i>P</i> interaction=0.03). Conclusions In an adult population free of major chronic diseases, habitual night eating was positively associated with the progression of arterial stiffness, a hallmark of arteriosclerosis and biological aging. Registration URL: https://www.chictr.org.cn; Unique identifier: ChiCTR-TNRC-11001489.
Project description:Excessive daytime sleepiness is a frequent complaint in Parkinson's disease (PD); however the frequency and risk factors for objective sleepiness remain mostly unknown. We investigated both the frequency and determinants of self-reported and objective daytime sleepiness in patients with Parkinson's disease (PD) using a wide range of potential predictors.One hundred and thirty four consecutive patients with PD, without selection bias for sleep complaint, underwent a semi-structured clinical interview and a one night polysomnography followed by a multiple sleep latency test (MSLT). Demographic characteristics, medical history, PD course and severity, daytime sleepiness, depressive and insomnia symptoms, treatment intake, pain, restless legs syndrome, REM sleep behaviour disorder, and nighttime sleep measures were collected. Self-reported daytime sleepiness was defined by an Epworth Sleepiness Scale (ESS) score above 10. A mean sleep latency on MSLT below 8 minutes defined objective daytime sleepiness.Of 134 patients with PD, 46.3% had subjective and only 13.4% had objective sleepiness with a weak negative correlation between ESS and MSLT latency. A high body mass index (BMI) was associated with both ESS and MSLT, a pain complaint with ESS, and a higher apnea/hypopnea index with MSLT. However, no associations were found between both objective and subjective sleepiness, and measures of motor disability, disease onset, medication (type and dose), depression, insomnia, restless legs syndrome, REM sleep behaviour disorder and nighttime sleep evaluation.We found a high frequency of self-reported EDS in PD, a finding which is however not confirmed by the gold standard neurophysiological evaluation. Current treatment options for EDS in PD are very limited; it thus remains to be determined whether decreasing pain and BMI in association with the treatment of sleep apnea syndrome would decrease significantly daytime sleepiness in PD.
Project description:Excessive daytime sleepiness (EDS) is highly prevalent among medical students and can have serious negative outcomes for both students and their patients. Little is known about the magnitude and predictors of EDS among medical college students. A meta-regression analysis was conducted to achieve these two targets. A systematic search was performed for English-language studies that reported the prevalence of EDS among medical students using the Epworth sleepiness scale (ESS), age, sex, sleep duration and sleep quality as predictive variables. A total of nine observational studies (K = 9, N = 2587) were included in the analyses. Meta-regression analyses were performed using mean age (years), sex (proportion of male subjects), sleep duration (hours/night) and sleep quality index score (continuous scale) as moderators for EDS-with the prevalence of EDS as an outcome variable. An interaction term of sleep duration X sleep quality was created to assess if these two variables simultaneously influenced the outcome variable. Utilizing the ESS, the pooled prevalence of EDS among medical students was 34.6% (95% Confidence Interval (CI) 18.3-50.9%). Meta-regression models of age, sex, sleep duration and sleep quality alone revealed poor predictive capabilities. Meta-regression models of sleep duration-sleep quality interaction revealed results with high statistical significance. The findings from this review contribute supporting evidence for the relationship between sleep duration and sleep quality scores (i.e., sleep duration X sleep quality score) in predicting EDS in medical students.
Project description:Excessive daytime sleepiness (EDS) is highly prevalent in the general population and is associated with occupational and public safety hazards. However, no study has examined the clinical and polysomnographic (PSG) predictors of the natural history of EDS.Representative longitudinal study.Sleep laboratory.From a random, general population sample of 1,741 individuals of the Penn State Adult Cohort, 1,395 were followed up after 7.5 years.Full medical evaluation and 1-night PSG at baseline and standardized telephone interview at follow-up. The incidence of EDS was 8.2%, while its persistence and remission were 38% and 62%, respectively. Obesity and weight gain were associated with the incidence and persistence of EDS, while weight loss was associated with its remission. Significant interactions between depression and PSG parameters on incident EDS showed that, in depressed individuals, incident EDS was associated with sleep disturbances, while in non-depressed individuals, incident EDS was associated with increased physiologic sleep propensity. Diabetes, allergy/ asthma, anemia, and sleep complaints also predicted the natural history of EDS.Obesity, a disorder of epidemic proportions, is a major risk factor for the incidence and chronicity of EDS, while weight loss is associated with its remission. Interestingly, objective sleep disturbances predict incident EDS in depressed individuals, whereas physiologic sleep propensity predicts incident EDS in those without depression. Weight management and treatment of depression and sleep disorders should be part of our public health policies.
Project description:The "first-night effect" of polysomnography (PSG) has been previously studied; however, the ability to quantify the sleep disruption level has been confounded with the use of PSG on all nights. We used actigraphy to quantify disruption level and examined characteristics associated with disruption.Totally, 778 older men (76.2 ± 5.4 years) from a population-based study at six US centers underwent one night of in-home PSG. Actigraphy was performed on the PSG night and three subsequent nights. Actigraphically measured total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), and sleep onset latency (SOL) from the PSG night and subsequent nights were compared. Linear regression models were used to examine the association of characteristics and sleep disruption.On average, sleep on the PSG night was worse than the following night (p < 0.05, TST 21 ± 85 min less, SE 2.3 ± 11.3% less, WASO 4.9 ± 51.8 min more, SOL 6.6 ± 56.2 min more). Sleep on the PSG night was significantly worse than that two and three nights later. Characteristics associated with greater sleep disruption on the PSG night included older age, higher apnea-hypopnea index, worse neuromuscular function, and more depressive symptoms. Minorities and men with excessive daytime sleepiness slept somewhat better on the PSG night.Among older men, there was sleep disruption on the PSG night, which may lead to sleep time underestimation. The increase of sleep on the night after the PSG suggests that data from the second monitoring may overestimate sleep.
Project description:Blood pressure variability (BPV) was proved as a cardiovascular risk factor. One of its mechanisms is related to arterial stiffness and ventriculo-arterial coupling; however its impact on subclinical cardiovascular dysfunction has not been evaluated yet.To assess the relationship between BPV on 24 hours, and subclinical left ventricle (LV), renal, and vascular dysfunction in diabetic and hypertensive patients.We studied 56 patients (57±9 years, 29 men) with mild-to-moderate hypertension and type 2 diabetes, no cardiovascular disease, normal ejection fraction and normal renal function. 24 hours ambulatory blood pressure monitoring (ABPM) was used to assess BPV, daytime (d) and night time (n), by: 1. mean (M); 2. standard deviation of mean (SD); 3. variance (Vr); 4. coefficient of variation (CV); 5. day/night variation: reverse dippers, non-dippers, dippers and extreme dippers; conventional and 2D speckle tracking echo to assess LV function; myocardial deformation was measured as global longitudinal strain (GLS). Endothelial (flow mediated dilation, FMD) and arterial function (intima media-thickness, IMT; pulse wave velocity, PWV), microalbuminuria were tested.Daytime BPV correlates inversely with subclinical myocardial function evaluated through GLS. Daytime systolic BPV correlates positively with IMT (all rho > 0.30, all p < 0.05). Also, there is a significantly inverse correlation between mean BP and GLS. We found a direct correlation between mean BP, but not BPV, and microalbuminuria (all rho > - 0.30 and all p < 0.05). We found no correlation between BPV and FMD, PWV. There were no differences for GLS, microalbuminuria and FMD between dipper groups.In diabetic patients with mild-to-moderate hypertension, increased daytime blood pressure variability correlates with subclinical left ventricular dysfunction and arterial function (IMT), while microalbuminuria correlates with elevated blood pressure, but not with blood pressure variability.