Self-reported sleep duration and napping, cardiac risk factors and markers of subclinical vascular disease: cross-sectional study in older men

Associations between sleep duration, sleep disturbance and cardiovascular disease biomarkers among adults in the United States

BACKGROUND

Sleep problems are associated with abnormal cardiovascular biomarkers and an increased risk of cardiovascular diseases (CVDs). However, studies investigating associations between sleep problems and CVD biomarkers have reported conflicting findings. This study examined the associations between sleep problems and CVD biomarkers in the United States.

METHODS

Data were from the National Health and Nutrition Examination Survey (NHANES) (2007-2018) and analyses were restricted to adults ≥ 20 years (n = 23,749). CVD biomarkers [C-reactive Protein (CRP), low-density lipoproteins, high-density lipoproteins (HDL), triglycerides, insulin, glycosylated hemoglobin (HbA1c), and fasting blood glucose] were categorized as abnormal or normal using standardized cut-off points. Sleep problems were assessed by sleep duration (short [≤ 6 h], long [≥ 9 h], and recommended [> 6 to < 9 h) and self-reported sleep disturbance (yes, no). Multivariable logistic regression models explored the associations between sleep duration, sleep disturbance, and CVD biomarkers adjusting for sociodemographic characteristics and lifestyle behaviors.

RESULTS

The mean sleep duration was 7.1 ± 1.5 h and 25.1% of participants reported sleep disturbances. Compared to participants with the recommended sleep duration, those with short sleep duration had higher odds of abnormal levels of HDL (adjusted odds ratio [aOR] = 1.20, 95% confidence interval [CI] = 1.05-1.39), CRP (aOR = 3.08, 95% CI = 1.18-8.05), HbA1c (aOR = 1.25, 95% CI = 1.05-1.49), and insulin (aOR = 1.24, 95% CI = 1.03-1.51). Long sleep duration was associated with increased odds of abnormal CRP (aOR = 6.12, 95% CI = 2.19-17.15), HbA1c (aOR = 1.54, 95% CI = 1.09-2.17), and blood glucose levels (aOR = 1.45, 95% CI = 1.07-1.95). Sleep disturbance predicted abnormal triglyceride (aOR = 1.18, 95% CI = 1.01-1.37) and blood glucose levels (aOR = 1.24, 95% CI = 1.04-1.49).

CONCLUSION

Short and long sleep durations were positively associated with abnormal CRP, HDL, HbA1c, blood glucose, and insulin levels, while sleep disturbance was associated with abnormal triglyceride and blood glucose levels. Since sleep is a modifiable factor, adopting healthy sleeping habits may create a balanced metabolism and reduce the risk of developing a CVD. Our study may provide insights into the relationship between sleep duration, sleep disturbance, and CVD risk.

Association between napping and type 2 diabetes mellitus

As the incidence of type 2 diabetes mellitus (T2DM) is increasing rapidly and its consequences are severe, effective intervention and prevention, including sleep-related interventions, are urgently needed. As a component of sleep architecture, naps, alone or in combination with nocturnal sleep, may influence the onset and progression of T2DM. Overall, napping is associated with an increased risk of T2DM in women, especially in postmenopausal White women. Our study showed that napping >30 minutes (min) increased the risk of T2DM by 8-21%. In addition, non-optimal nighttime sleep increases T2DM risk, and this effect combines with the effect of napping. For nondiabetic patients, napping >30 min could increase the risks of high HbA1c levels and impaired fasting glucose (IFG), which would increase the risk of developing T2DM later on. For diabetic patients, prolonged napping may further impair glycemic control and increase the risk of developing diabetic complications (e.g., diabetic nephropathy) in the distant future. The following three mechanisms are suggested as interpretations for the association between napping and T2DM. First, napping >30 min increases the levels of important inflammatory factors, including interleukin 6 and C-reactive protein, elevating the risks of inflammation, associated adiposity and T2DM. Second, the interaction between postmenopausal hormonal changes and napping further increases insulin resistance. Third, prolonged napping may also affect melatonin secretion by interfering with nighttime sleep, leading to circadian rhythm disruption and further increasing the risk of T2DM. This review summarizes the existing evidence on the effect of napping on T2DM and provides detailed information for future T2DM intervention and prevention strategies that address napping.

Excessive daytime sleepiness, morning tiredness, and prognostic biomarkers in patients with chronic coronary syndrome

BACKGROUND

Sleep-related breathing disorders (SRBD) are related to cardiovascular outcomes in patients with chronic coronary syndrome (CCS). Whether SRBD-related symptoms are associated with prognostic biomarkers in patients with CCS is not established.

METHODS

Associations between frequency (never/rarely, sometimes, often, always) of self-reported SRBD-related symptoms (excessive daytime sleepiness [EDS]; morning tiredness [MT]; loud snoring; multiple awakenings/night; gasping, choking, or apnea when asleep) and levels of biomarkers related to cardiovascular prognosis (high-sensitivity C-reactive protein [hs-CRP], interleukin 6 [IL-6], high-sensitivity cardiac troponin T [hs-cTnT], N-terminal pro B-type natriuretic peptide [NT-proBNP], cystatin C, growth differentiation factor 15 [GDF-15] and lipoprotein-associated phospholipase A2 activity) were assessed at baseline in 15,640 patients with CCS on optimal secondary preventive therapy in the STABILITY trial. Cross-sectional associations were assessed by adjusted linear regression models testing for trends with the never/rarely category serving as reference.

RESULTS

EDS was associated (geometric mean ratio, 95% confidence interval) with increased levels of IL-6 (often 1.07 [1.03-1.10], always 1.15 [1.10-1.21]), GDF-15 (often 1.03 [1.01-1.06], always 1.07 [1.03-1.11]), NT-proBNP (always 1.22 [1.12-1.33]), and hs-cTnT (always 1.07 [1.01-1.12]). MT was associated with increased levels of IL-6 (often 1.05 [1.01-1.09], always 1.09 [1.04-1.15]), and GDF-15 (always 1.06 [1.03-1.10]). All symptoms were to some degree associated with higher levels of hs-CRP and loud snoring was also associated with decreased levels of NT-proBNP and hs-cTnT.

CONCLUSIONS

In patients with CCS, stepwise increased frequency of SRBD-related symptoms, such as EDS and MT, were associated with gradually higher levels of IL-6 and GDF-15, each reflecting distinct pathophysiological pathways.

Association of night-time sleep duration and daytime napping with all-cause and cause-specific mortality in older British men: Findings from the British Regional HeartStudy

Short and long night-time sleep and daytime napping in young and middle-aged populations were associated with increased mortality, but it is unclear in very older people. The aim of this prospective study was to assess the associations in people aged >70 years. We examined the data of British Regional Heart Study, which included 1722 men aged 71-92 years and had night-time sleep duration and daytime napping measured at baseline and were followed up for nine years. There were 597 deaths. Compared to night-time sleep at 7-<8 h, age-adjusted hazard ratio of all-cause mortality in participants sleeping <6 h was 1.04 (95% CI 0.80-1.35), 1.07 (0.85-1.34) in 6-<7 h, 1.04 (0.83-1.30) in 8-<9 h and 0.93 (0.65-1.33) in ≥9 h. Further adjustments for other co-variables still showed no association, and neither the association with cardiovascular mortality nor non-cardiovascular mortality. Daytime napping, however, was associated with mortality. After adjustment for age, smoking, physical activity, obesity, cardiovascular diseases, diabetes, frailty, general health, anti-hypertensive medication and C-reactive protein level, hazard ratio of all-cause mortality in participants with daytime napping >1-h versus no napping was 1.62 (1.18-2.22) and hazard ratio of non-cardiovascular mortality was 1.77 (1.22-2.57). The fully adjusted hazard ratio of cardiovascular mortality was not significantly increased 1.26 (0.69-2.28), although age-adjusted hazard ratio was significant 1.94 (1.20-3.16). In the elderly men, daytime napping was independently associated with increased all-cause and non-cardiovascular mortality, while its association with cardiovascular mortality could be explained by cardiovascular risk factors and co-morbidities. Night-time sleep duration was not associated with mortality risk.

The relationship between sleep duration and arterial stiffness: A meta-analysis

Chronically short (<7 h) and long (>9 h) sleep duration may increase cardiovascular disease (CVD) risk relative to the recommended sleep duration (7-9 h). The objective of this study was to evaluate the effects of short and long sleep duration on arterial stiffness, a marker of CVD risk, in adults. Eleven cross-sectional studies were reviewed with a total sample size of 100,050 participants (64.5% male). Weighted mean differences (WMD) and 95% confidence intervals (95% CI) were calculated and pooled using random effects models, and standardized mean differences (SMD) were calculated to determine effect size magnitude. Compared to the recommended sleep duration, both short (WMD = 20.6 cm/s, 95% confidence intervals (CI): 13.8-27.4 cm/s, SMD = 0.02) and long sleep duration (WMD = 33.6 cm/s, 95% CI: 20.0-47.2 cm/s, SMD = 0.79) were associated with higher (detrimental) pulse wave velocity (PWV). The associations between short sleep and higher PWV in adults with cardiometabolic disease, and long sleep and higher PWV in older adults, were also significant in sub-group analysis. These findings indicate short and long sleep duration may contribute to subclinical CVD.

Causal relationships of excessive daytime napping with atherosclerosis and cardiovascular diseases: a Mendelian randomization study

STUDY OBJECTIVES

Previous observational studies have found conflicting evidence on the relationship between daytime napping and incident cardiovascular diseases (CVDs), but it remains unclear whether these associations present causality. This study aims to verify whether and why there is a causal relationship between these parameters, and whether there is an etiological basis.

METHODS

A two-sample Mendelian randomization analysis was performed using 79 single nucleotide polymorphisms associated with daytime napping. Summary-level data for coronary atherosclerosis, peripheral atherosclerosis, total CVD, and five CVD outcomes were obtained from the FinnGen study. Meta-analyses were aimed at investigating the relationships of excessive daytime napping with total CVD, coronary heart disease, myocardial infarction (MI), and stroke incidence. Subgroup, network meta-analysis (NMA) and trial sequential analysis (TSA) were also performed in this study.

RESULTS

The inverse-variance weighted method demonstrated that a genetic predisposition to more frequent daytime napping was significantly associated with higher odds of coronary atherosclerosis (odds ratio [OR] = 1.55, 95% confidence interval [CI]: 1.11 to 2.17), MI (OR = 1.63, 95% CI: 1.06 to 2.50), and heart failure (OR = 1.80, 95%CI: 1.28 to 2.52). In NMA, an increased risk of developing CVD in people who napped for more than 60 min a day than those who did not nap was demonstrated and then supported by TSA results (summary relative risk = 1.98, 95% CI: 1.39 to 2.82).

CONCLUSION

Habitual daytime napping is causally associated with an increased risk of incident CVD primarily via the development of coronary atherosclerosis. An average napping duration of more than 60 min is associated with an elevated risk of CVD in all participants.

Association of daytime napping frequency and schizophrenia: a bidirectional two-sample Mendelian randomization study

BACKGROUND

The bidirectional causal association between daytime napping frequency and schizophrenia is unclear.

METHODS

A bidirectional two-sample Mendelian randomization (MR) analysis was conducted with summary statistics of top genetic variants associated with daytime napping frequency and schizophrenia from genome-wide association studies (GWAS). The single nucleotide polymorphisms (SNPs) data of daytime napping frequency GWAS came from the UK Biobank (n = 452,633) and 23andMe study cohort (n = 541,333), while the schizophrenia GWAS came from the Psychiatric Genomics Consortium (PGC, 36,989 cases and 113,075 controls). The inverse variance weighted (IVW) analysis was the primary method, with the weighted median, MR-Robust Adjusted Profile Score (RAPS), Radial MR and MR-Pleiotropy Residual Sum Outlier (PRESSO) as sensitivity analysis.

RESULTS

The MR analysis showed a bidirectional causal relationship between more frequent daytime napping and the occurrence of schizophrenia, with the odds ratio (OR) for one-unit increase in napping category (never, sometimes, usually) on schizophrenia was 3.38 (95% confidence interval [CI]: 2.02-5.65, P = 3.58 × 10^-6), and the beta for the occurrence of schizophrenia on daytime napping frequency was 0.0112 (95%CI: 0.0060-0.0163, P = 2.04 × 10^-5). The sensitivity analysis obtained the same conclusions.

CONCLUSION

Our findings support the bidirectional causal association between more daytime napping frequency and schizophrenia, implying that daytime napping frequency is a potential intervention for the progression and treatment of schizophrenia.

Association between sleep duration and sleep quality with arterial stiffness: A systematic review and meta-analysis

BACKGROUND

Altered sleep parameters, such as duration and quality, play an important role in the pathogenesis and progression of cardiovascular diseases, as well as in all-cause morbidity and mortality. It has been suggested that the specific mechanisms underlying this association could be through the influence of sleep parameters on vascular markers, such as arterial stiffness (AS), although this remains unclear. Thus, in this meta-analysis, we aimed to assess the association between sleep duration and sleep quality with AS in adults.

METHODS

PubMed, Scopus, Web of Science and Cochrane Library databases were searched from inception to July 30, 2021. The DerSimonian and Laird method was used to compute pooled effect size estimates and their respective 95% confidence intervals (95% CIs) of the association of sleep duration and sleep quality with AS. The Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies from the United States National Institute of Health National Heart, Lung, and Blood Institute was used to assess the risk of bias.

RESULTS

Finally, 14 studies (8 cross-sectional studies and baseline data from 6 prospective longitudinal studies) involving 97,837 individuals between 18 and 92 years of age were included. Our results showed that increased sleep duration, as continuous values, does not influence AS (effect size [ES]: 0.00; 95% CIs: -0.15, 0.15) in the general population. However, when sleep duration was longer than 8 hours (ES: 0.21; 95% CIs: 0.06, 0.36), according to sleep categories, a significant increase in pulse wave velocity was shown. Poor sleep quality was associated with increased AS (ES: 0.13; 95% CIs: 0.04, 0.21) in the general population. The overall risk of bias for studies examining sleep duration was fair in 77.8% of the included studies and the overall risk of bias for studies examining sleep quality was fair in 55.6%.

CONCLUSIONS

Our findings showed that both long sleep duration and poor sleep quality were associated with AS in adults. These findings underscore the influence of sleep on vascular health markers, specifically AS, as a possible pathway to explain the increased cardiovascular morbidity and mortality associated with sleep disorders.

Evaluating the role of rare genetic variation in sleep duration

OBJECTIVES

To explore the roles of rare and high-impact variants in sleep duration.

DESIGN

Based on the recently released UK Biobank 200k exome dataset, an exome-wide association study was conducted to detect rare variants (minor allele frequency <0.01) contributing to sleep duration. Variant annotations were performed by the software tool ANNOVAR. Gene-based burden tests of sleep duration were conducted by the SKAT R-package. After quality control, 137,047 subjects were included in this study. CAUSALdb database was used to explore the related mental traits of identified genes.

RESULTS

We detected 730,572 variants with MAF < 1%, including 3873 frameshift variants, 3977 nonframeshift variants, 449,632 nonsynonymous variants, 1293 startloss variants, 10,254 stopgain variants, 413 stoploss variants, 261,130 synonymous variants, and 3102 variants are annotated as unknown. The burden test of exonic variants detected two exome-wide significant associations for sleep duration including TMIE at 3p21.31 (P_{Bonferroni adjusted} = 0.015) and ZIC2 at 13q32.3 (P_{Bonferroni adjusted} = 0.047). There are only nonsynonymous contained in TMIE; as for ZIC2, we detected 2 annotations of variants: nonsynonymous (P_{Bonferroni adjusted} =2.04 × 10^-4) and nonframeshift (P_{Bonferroni adjusted} =0.85). TMIE and ZIC2 were reported to be associated with several mental traits, such as chronotype, depression, and brain natriuretic peptide in published study.

CONCLUSION

This study reported 2 novel candidate genes for a sleep duration, supporting the roles of rare genetic variants in the regulation of sleep duration.

Sleep duration, vegetable consumption and all-cause mortality among older adults in China: a 6-year prospective study

BACKGROUND

Sleep duration and vegetable consumption are associated with mortality at old age (termed as sleep-mortality linkage and vegetable-mortality linkage, respectively). Yet, little is known about the interplay of sleep duration and vegetable consumption on mortality.

METHODS

A dataset of nationwide longitudinal survey with 13,441 participants aged 65 years or older recruited in 2008 and followed up till 2014 was used. Sleep duration was classified into five groups (≤5, 6, 7-8, 9, and ≥ 10 h/day). Vegetable consumption was classified as either high frequency (eating vegetables almost daily) or low frequency. We used parametric Weibull hazard regression models to estimate associations of sleep duration and frequency of vegetable consumption with mortality, adjusting for demographics, socioeconomic factors, family/social support, health practice, and health conditions.

RESULTS

Over the six-year study period, when only demographics were present, participants sleeping ≤5, 6, 9, and ≥ 10 h/day had relative hazard (RH) of mortality 1.18 (p < 0.001), 1.14(p < 0.01), 1.06 (p > 0.1), and 1.30 (p < 0.001), respectively, compared to those sleeping 7-8 h/day. The HRs were attenuated to 1.08 (p < 0.05), 1.08 (p < 0.05), 1.09 (p < 0.1), 1.18(p < 0.001), respectively, when all other covariates were additionally adjusted for. High frequency of eating vegetables was associated with 22% lower risk of mortality (RH= 0.78, p < 0.001) compared to low frequency in the demographic model, and with 9% lower risk (RH = 0.91, p < 0.05) in the full model. Subpopulation and interaction analyses show that the sleeping-mortality linkage was stronger in female, urban, oldest-old (aged ≥80), and illiterate participants compared to their respective male, rural, young-old, and literate counterparts. High frequency of vegetable intakes could offset the higher mortality risk in participants with short-sleeping duration, but low frequency of eating vegetables could exacerbate mortality risk for participants with either short or long sleep duration; and except for few cases, these findings held in subpopulations.

CONCLUSIONS

Too short and too long sleep durations were associated with higher mortality risk, and infrequent vegetable consumption could exacerbate the risk, although frequent vegetable intake could offset the risk for short sleep duration. The relationship between these two lifestyles and mortality was complex and varied among subpopulations.

Effects of sleep deprivation on endothelial function in adult humans: a systematic review

Sleep deprivation is highly prevalent and is associated with increased cardiovascular disease (CVD) morbidity and mortality. Age-related alterations in sleep and chronobiology may exaggerate CVD susceptibility in older individuals. The mechanisms responsible for the association between sleep deprivation and CVD are not fully understood, but endothelial dysfunction may play a central role. Our objective was to conduct a systematic literature review to evaluate the evidence on the effects of sleep deprivation on endothelial function (EF). This review adhered to the PRISMA guidelines and was pre-registered with PROSPERO (#CRD42020192485, 07/24/2020). We searched PubMed, Web of Science, Embase, and Cochrane Library for articles published through May 1, 2020. Eligibility criteria included publication in English and use of well-established EF methodologies in adult humans. Two investigators independently performed the literature search, study selection, data extraction, risk-of-bias assessment, and qualitative data synthesis. Out of 3571 articles identified, 24 articles were included in the systematic review. Main findings include the following: (1) shorter sleep duration is associated with lower macrovascular EF; (2) not sleeping 7-9 h/night is linked with impaired microvascular EF; (3) sleep restriction impairs micro- and macrovascular EF; (4) acute total sleep deprivation impairs micro- and macrovascular EF but data on macrovascular EF are less consistent; and (5) shift work impairs macrovascular EF. In conclusion, sleep deprivation impairs EF, which may explain the link between insufficient sleep and CVD. Future investigations should fully elucidate the underlying mechanisms and develop strategies to combat the adverse endothelial effects of sleep deprivation across the lifespan.

On the Association Between Sleep Quality and Arterial Stiffness: A Population Study in Community-Dwelling Older Adults Living in Rural Ecuador (The Atahualpa Project)

STUDY OBJECTIVES

Evidence of an association between atherosclerosis and sleep quality is limited and has not been studied in remote rural settings, where living conditions are different than in urban centers. We aimed to assess the relationship between the aortic pulse wave velocity (PWV) and sleep quality in older adults living in rural Ecuador.

METHODS

Atahualpa residents aged 60 years or older identified during door-to-door surveys, who consented to participate, underwent face-to-face interviews with the Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality. Aortic PWV determinations were performed for arterial stiffness estimation (as a surrogate of atherosclerosis).

RESULTS

A total of 303 individuals were included (mean age: 70.3 ± 7.8 years; 59% women). Univariate logistic regression showed a significant association between the aortic PWV and poor sleep quality (odds ratio [OR] 1.22; 95% confidence interval [CI] 1.07-1.39; P = .003). A multivariate logistic regression model, adjusted for demographics, cardiovascular risk factors, oily fish intake and psychological distress showed a significant association between increased PWV and poor sleep quality (OR 1.59; 95% CI 1.12-2.25; P = .009). Similar significance was noted when the model was adjusted for neuroimaging signatures of cerebral small-vessel disease and stroke (OR 1.47; 95% CI 1.07-2.03; P = .019).

CONCLUSIONS

This study shows a significant independent association between the aortic PWV and poor sleep quality in older adults living in rural Ecuador. Results provide more insights into the relevance of the impact of sleep disorders on cardiovascular diseases.

CLINICAL TRIAL REGISTRATION

The Atahualpa Project has been registered at ClinicalTrials.gov. The identifier number is NCT01627600, and the date was: 10/02/2012.

CITATION

Del Brutto OH, Mera RM, Peñaherrera E, Costa AF, Peñaherrera R, Castillo PR. On the association between sleep quality and arterial stiffness: a population study in community-dwelling older adults living in rural ecuador (the atahualpa project). J Clin Sleep Med. 2019;15(8):1101-1106.

Sleeping Difficulty and Subjective Short Sleep Duration are Associated with Serum N-terminal Pro-brain Natriuretic Peptide Levels in the Elderly Population

Objective It is well known that poor sleep increases the risk of heart failure (HF). However, the underlying mechanisms remain unclear. In this study, we investigated the association of poor sleep with hemodynamic stress on the left ventricle, which was a key factor for the development of HF in elderly individuals. Methods A total of 2,301 participants (≥65 years old) without cardiac disease were enrolled in this cross-sectional analysis. We evaluated the subjective sleep quality, sleeping difficulty, subjective sleep duration, use of sleeping pills, and daytime dysfunction using the Pittsburgh Sleep Quality Index, a 19-item self-reported questionnaire. We assessed serum N-terminal pro-brain natriuretic peptide (NT-proBNP) as a marker of hemodynamic stress on the left ventricle, and we defined high NT-proBNP as a serum NT-proBNP level ≥ 125 pg/mL. Results Sleeping difficulty was significantly associated with high NT-proBNP levels [odds ratio (OR), 1.46; 95% confidence interval (CI), 1.16-1.85; p<0.005]. A subjective short sleep duration was also significantly associated with high NT-proBNP levels (OR, 1.69; 95% CI, 1.03-2.75; p<0.05). A subjective poor sleep quality, the use of sleeping pills, and daytime dysfunction were not associated with serum NT-proBNP levels. All data were adjusted for the age, sex, body mass index, serum hemoglobin concentration, serum creatinine level, systolic blood pressure, diastolic blood pressure, and use of antihypertensive medications. Conclusion Poor sleep was associated with high hemodynamic stress to the left ventricle in elderly population.

Napping in Older Adults: A Review of Current Literature

Purpose of Review

Daytime napping-frequently reported among older populations-has attracted increasing attention in geriatric research due to its association with multiple health conditions. This review aims to integrate the latest knowledge about napping in older adults to provide implications for future research.

Recent Findings

The prevalence of napping in older adults ranges from 20% to 60% in different studies, but has been consistently reported to be higher than in other age groups. Age-related changes in circadian rhythm and sleep patterns, cultural beliefs, chronic conditions, medications, and lifestyle changes contribute to the high prevalence of napping in older adults. Daytime napping has been associated with multiple health conditions in older adults. Naps of short duration (e.g., 30 minutes) are reported in adults with better health; naps with longer durations (e.g., >90 minutes) have been linked to adverse cardiovascular and diabetes outcomes, declining cognitive function, and increased mortality. Current evidence in the literature, however, is not enough for us to determine the exact role of napping in the health of older adults.

Summary

Longitudinal and interventional studies are needed to investigate the influence of napping and the critical parameters such as duration, timing, and frequency on health in older adults and the underlying mechanisms. A combination of objective and self-reported measurements of napping are recommended instead of self-reported data only.

Sleep Duration and Cardiovascular Health in a Representative Community Population (from NHANES, 2005 to 2016)

The 2016 American Heart Association Scientific Statement on sleep duration and cardiovascular risk suggested that optimal sleep duration is critical for cardiovascular health, with both long and short sleep duration associated with adverse health outcomes. We examined the relation between sleep duration and cardiovascular health among the general population in the United States from 2005 to 2016. We sought to investigate associations between sleep duration and the prevalence of coronary artery disease, heart failure (HF), stroke, hypertension, diabetes mellitus (DM), and hyperlipidemia. Using the National Health and Nutrition Examination Survey, we identified all patients with HF, coronary artery disease, hypertension, hyperlipidemia, DM, and stroke from 2005 to 2016. Multivariable logistic regression analyses were performed to adjust for age, sex, body mass index (BMI), marital status, educational level, physical activity, sedentary activity, depression, blood pressure, lipid profiles, and hemoglobin. In total, 32,152 National Health and Nutrition Examination Survey participants responded to the sleep survey. Both short sleepers (<7 hours, n = 12,027) and long sleepers (>9 hours, n = 1,058) were older and more likely to have a higher BMI than optimal sleepers (7 to 9 hours, n = 19,067; all p values <0.05). After adjusting for confounding variables and in comparison to those with optimal sleep duration, short sleep duration was associated with a higher prevalence of previous stroke (odds ratio [OR] 1.45; 95% confidence intervals [CI] 1.23 to 1.70), HF (OR 1.65; 95% CI 1.40 to 1.95), DM (OR 1.35; 95% CI 1.23 to 1.49), and hyperlipidemia (OR 1.12; 95% CI 1.04 to 1.22), whereas long sleep duration was associated with a higher prevalence of previous stroke (OR 1.81; 95% CI 1.37 to 2.34) and HF (OR 1.47; 95% CI 1.08 to 1.97). In conclusion, both long and short sleep durations were associated with poor cardiovascular health in this cross-sectional study.

Chronic kidney disease, cardiovascular risk markers and total mortality in older men: cystatin C versus creatinine

Background

It remains uncertain whether cystatin C is a superior marker of renal function than creatinine in older adults. We have investigated the association between estimated glomerular filtration rate (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations based on creatinine (CKD-EPIcr) and cystatin C (CKD-EPIcys), and cardiovascular risk markers and mortality in older adults.

Methods

This is a cross-sectional and prospective study of 1639 British men aged 71–92 years followed up for an average of 5 years for mortality. Cox survival model and receiving operating characteristic analysis were used to assess the associations.

Results

The prevalence of chronic kidney disease (CKD) was similar using the two CKD-EPI equations, although cystatin C reclassified 43.9% of those with stage 3a CKD (eGFR 45–59 mL/min/1.732, moderate damage) to no CKD. However, CKD stages assessed using both CKD-EPIcr and CKD-EPIcys were significantly associated with vascular risk markers and with all-cause and cardiovascular disease mortality. In all men with CKD (eGFR <60 mL/min/1.732), the HRs (95% CI) for all-cause mortality after adjustment for cardiovascular risk factors compared with those with no CKD were 1.53 (1.20 to 1.96) and 1.74 (1.35 to 2.23) using CKD-EPIcr and CKD-EPIcys, respectively. Comparisons of the two CKD equations showed no significant difference in their predictive ability for mortality (difference in area under the curve p=0.46).

Conclusion

Despite reclassification of CKD stages, assessment of CKD using CKD-EPIcys did not improve prediction of mortality in older British men >70 years. Our data do not support the routine use of CKD-EPIcys for identifying CKD in the elderly British male population.

The association between physical and mental chronic conditions and napping

The objectives of this study were to assess the associations among various physical and mental chronic conditions and napping. A cross-sectional epidemiological survey was proposed within the NutriNet-Santé population-based e-cohort launched in France in 2009. Participants were 43,060 French volunteers aged 18 y and over with Internet access. A self-report questionnaire assessing sleep characteristics was administered in 2014. The main outcome (dependent) variable was weekday or weekend napping (yes/no). The main exposure (independent) variables were overweight/obesity, hypertension, diabetes, anxiety and depressive disorders, incident major cardiovascular diseases (myocardial infarction, stroke, unstable angina), and incident cancer (breast and prostate). The associations of interest were investigated with multivariable logistic regression analysis. No significant associations were found between major cardiovascular diseases or breast or prostate cancer and napping. Instead, we found that napping was more common among males (46.1%) than among females 36.9% (p < 0.0001). Individuals who were overweight or obese or had hypertension, diabetes, depression or anxiety disorders had an increased likelihood of napping compared with their healthy peers. The adjusted ORs ranged from 1.14 to 1.28″. In conclusion, most chronic conditions were independently associated with napping. Future longitudinal analyses are needed to elucidate causality.

Actigraphy-based sleep characteristics and aortic stiffness: the Multi-Ethnic Study of Atherosclerosis

The study aimed to examine the association between objective estimates of sleep duration and quality and aortic stiffness while accounting for the potential confounding effect of sleep-disordered breathing. Participants were part of the Multi-Ethnic Study of Atherosclerosis Sleep study. Sleep duration and quality were assessed by 7-day wrist actigraphy, sleep-disordered breathing by home polysomnography, and aortic stiffness by magnetic resonance imaging-based aortic pulse wave velocity (aPWV), ascending and descending aorta distensibility. Aortic stiffness of participants with "normal" sleep duration (6-8 hours) were compared with those of "short" (<6 hours) and "long" sleep duration (>8 hours) adjusting for common cardiovascular risk factors and apnea-hypopnea index. The sample consisted of 908 participants (mean age 68.4 ± 9.1 years, 55.3% female). There was a significant linear trend of increased aPWV across short (n = 252), normal (n = 552), and long sleep durations (n = 104) (P for trend = .008). Multivariable analysis showed that people with short sleep duration had 0.94 m/s lower aPWV (95% CI: -1.54, -0.35), compared with those with normal sleep duration. In this ethnically diverse community cohort, habitual short sleep duration as estimated by actigraphy was associated with lower aortic stiffness.

Sleep duration and subclinical atherosclerosis: The Aragon Workers' Health Study

BACKGROUND AND AIMS

Few studies have evaluated the association of sleep duration with subclinical atherosclerosis, and with heterogeneous findings. We evaluated the association of sleep duration with the presence of coronary, carotid, and femoral subclinical atherosclerosis in healthy middle-age men with low prevalence of clinical comorbidities.

METHODS

We performed a cross-sectional analysis of 1968 men, 40-60 years of age, participating in the Aragon Workers' Health Study (AWHS). Duration of sleep during a typical work week was assessed by questionnaire. Coronary artery calcium scores (CACS) was assessed by computed tomography and the presence of carotid plaque and femoral plaque by ultrasound.

RESULTS

In fully adjusted models, the odds ratios (95% CI) for CACS >0 comparing sleep durations of ≤5, 6, and ≥8 h with 7 h were 1.34 (0.98-1.85), 1.35 (1.08-1.69) and 1.21 (0.90-1.62), respectively (p = 0.04). A similar U-shaped association was observed for CACS ≥100 and for CACS. The corresponding odds ratios for the presence of at least one carotid plaque were ≤5, 6, and ≥8 h with 7 h were 1.23 (0.88-1.72), 1.09 (0.86-1.38), and 0.86 (0.63-1.17), respectively (p = 0.31), and for the presence of at least one femoral plaque were 1.25 (0.87-1.80), 1.19 (0.93-1.51) and 1.17 (0.86-1.61), respectively (p = 0.39).

CONCLUSIONS

Middle-aged men reporting 7 h of sleep duration had the lowest prevalence of subclinical coronary atherosclerosis as assessed by CACs. Our results support that men with very short or very long sleep durations are at increased risk of atherosclerosis.