The need to promote sleep health in public health agendas across the globe.

Healthy sleep is essential for physical and mental health, and social wellbeing; however, across the globe, and particularly in developing countries, national public health agendas rarely consider sleep health. Sleep should be promoted as an essential pillar of health, equivalent to nutrition and physical activity. To improve sleep health across the globe, a focus on education and awareness, research, and targeted public health policies are needed. We recommend developing sleep health educational programmes and awareness campaigns; increasing, standardising, and centralising data on sleep quantity and quality in every country across the globe; and developing and implementing sleep health policies across sectors of society. Efforts are needed to ensure equity and inclusivity for all people, particularly those who are most socially and economically vulnerable, and historically excluded.

Detecting Unique Analyte-Specific Radio Frequency Spectral Responses in Liquid Solutions-Implications for Non-Invasive Physiologic Monitoring.

With rising healthcare costs and the rapid increase in remote physiologic monitoring and care delivery, there is an increasing need for economical, accurate, and non-invasive continuous measures of blood analytes. Based on radio frequency identification (RFID), a novel electromagnetic technology (the Bio-RFID sensor) was developed to non-invasively penetrate inanimate surfaces, capture data from individual radio frequencies, and convert those data into physiologically meaningful information and insights. Here, we describe groundbreaking proof-of-principle studies using Bio-RFID to accurately measure various concentrations of analytes in deionized water. In particular, we tested the hypothesis that the Bio-RFID sensor is able to precisely and non-invasively measure and identify a variety of analytes in vitro. For this assessment, varying solutions of (1) water in isopropyl alcohol; (2) salt in water, and (3) commercial bleach in water were tested, using a randomized double-blind trial design, as proxies for biochemical solutions in general. The Bio-RFID technology was able to detect concentrations of 2000 parts per million (ppm), with evidence suggesting the ability to detect considerably smaller concentration differences.

Positive Airway Pressure Therapy Adherence and Health Care Resource Use in Patients With Obstructive Sleep Apnea and Heart Failure With Preserved Ejection Fraction.

Background Obstructive sleep apnea (OSA) is common in heart failure with preserved ejection fraction (HFpEF). However, current evidence is equivocal regarding the potential benefits of treating OSA with positive airway pressure (PAP) therapy in HFpEF. This study assessed the association between adherence to PAP therapy and health care resource use in patients with OSA and HFpEF. Methods and Results Administrative insurance claims data linked with objective PAP therapy usage data from patients with OSA and HFpEF were used to determine associations between PAP adherence and a composite outcome including hospitalizations and emergency room visits. One-year PAP adherence was based on an adapted US Medicare definition. Propensity score methods were used to create groups with similar characteristics across PAP adherence levels. The study cohort included 4237 patients (54.0% female, mean age 64.1 years); 40% were considered adherent to PAP therapy (30% intermediate adherent, 30% nonadherent). In the matched cohort, PAP-adherent patients had fewer health care resource use visits than nonadherent patients, a 57% decrease in hospitalizations, and a 36% decrease in emergency room visits versus the year before PAP initiation. Total health care costs were lower in adherent patients than nonadherent patients ($12 732 versus $15 610, P<0.001). Outcomes for intermediately adherent patients were most similar to those for nonadherent patients. Conclusions Treating OSA with PAP therapy in patients with HFpEF was associated with a reduction in health care resource use. These data highlight the importance of managing concomitant OSA in patients with HFpEF, and the need for strategies to enhance PAP adherence in this population.

Positive Airway Pressure Adherence and Health Care Resource Utilization in Patients With Obstructive Sleep Apnea and Heart Failure With Reduced Ejection Fraction.

Background Obstructive sleep apnea (OSA) is a common comorbidity in patients with heart failure, although current evidence is equivocal regarding the potential benefits of treating OSA with positive airway pressure (PAP) therapy in patients with heart failure. This study assessed the impact of adherence to PAP therapy on health care resource utilization in patients with OSA and heart failure with reduced ejection fraction. Methods and Results Administrative insurance claims data linked with objective PAP therapy use data from patients with OSA and heart failure with reduced ejection fraction were used to determine associations between PAP adherence and a composite outcome of hospitalizations and emergency room visits. One-year PAP adherence was based on an adapted US Medicare definition. Propensity score methods were used to create groups with similar characteristics across PAP adherence levels. The study cohort included 3182 patients (69.9% male, mean age 59.7 years); 39% were considered adherent to PAP therapy (29% intermediate adherent, 31% nonadherent). One year after PAP initiation, adherent patients had fewer composite visits than matched nonadherent patients, driven by a 24% reduction in emergency room visits for adherent patients. Composite visit costs were lower in adherent versus nonadherent patients ($3500 versus $5879, P=0.031), although total health care costs were not statistically different ($13 028 versus $14 729, P=0.889). Conclusions PAP therapy adherence in patients with OSA with heart failure with reduced ejection fraction was associated with a reduction in health care resource utilization. This suggests that greater emphasis should be placed on diagnosing and effectively treating OSA with PAP in patients with heart failure with reduced ejection fraction.

Impact of Cardiac Implantable Electronic Devices on Cost and Length of Stay in Patients With Surgical Aortic Valve Replacement and Transcutaneous Aortic Valve Implantation.

Surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI) in aortic stenosis are associated with arrhythmic complications that can require cardiac implantable electronic device (CIED) implantation, but impact on healthcare-associated cost (HAC) and length of stay (LOS) are unknown. This study aimed to assess differences among SAVR/TAVI patients with CIED implantation on HAC and LOS. Patients hospitalized for SAVR or TAVI between 2011 and 2017 on the National Inpatient Sample database were identified and stratified according to presence/type of CIED implantation. During this period, 95,262 patients were identified; 6,435 (6.8%) patients received CIED (median [interquartile range] age: 74.0 [66.0 to 82.0] years). The median adjusted HAC was $44,271 and LOS was 6 days. CIED implantation was associated with longer LOS and higher adjusted HAC in patients with SAVR and TAVI (p <0.0001). Patients with in-hospital death and complications because of SAVR or TAVI had longer preceding in-hospital days of admission. Male patients admitted to small hospitals and the West region had the highest HAC. In conclusion, CIED implantation for arrhythmias results in higher HAC and longer LOS in patients with aortic stenosis for both SAVR and TAVI.

Undiagnosed obstructive sleep apnea increases risk of hospitalization among a racially diverse group of older adults with comorbid cardiovascular disease.

STUDY OBJECTIVES: Undiagnosed obstructive sleep apnea (OSA) is associated with increased risk for subsequent cardiovascular events, hospitalizations, and mortality. The primary objective of this study was to determine the association between undiagnosed OSA and subsequent hospitalizations among older adults with preexisting cardiovascular disease (CVD). A secondary objective was to determine the risk of 30-day hospital readmission associated with undiagnosed OSA among older adults with CVD. METHODS: This was a retrospective cohort study of a 5% sample of Medicare administrative claims data for years 2006-2013. Beneficiaries aged 65 years and older diagnosed with CVD were included. Undiagnosed OSA was defined as the 12-month period prior to OSA diagnosis. A similar 12-month period among beneficiaries not diagnosed with OSA was used for the comparison group (no OSA). Our primary outcome was the first all-cause hospital admission. Among beneficiaries with a hospital admission, 30-day readmission was assessed for the first hospital admission only. RESULTS: Among 142,893 beneficiaries diagnosed with CVD, 19,390 had undiagnosed OSA. Among beneficiaries with undiagnosed OSA, 9,047 (46.7%) experienced at least 1 hospitalization whereas 27,027 (21.9%) of those without OSA experienced at least 1 hospitalization. Following adjustment, undiagnosed OSA was associated with increased risk of hospitalization (odds ratio 1.82; 95% confidence interval 1.77, 1.87) relative to no OSA. Among beneficiaries with ≥ 1 hospitalization, undiagnosed OSA was associated with a smaller but significant effect in weighted models (odds ratio 1.18; 95% confidence interval 1.09, 1.27). CONCLUSIONS: Undiagnosed OSA was associated with significantly increased risk of hospitalization and 30-day readmissions among older adults with preexisting CVD. CITATION: Kirk J, Wickwire EM, Somers VK, Johnson DA, Albrecht JS. Undiagnosed obstructive sleep apnea increases risk of hospitalization among a racially diverse group of older adults with comorbid cardiovascular disease. J Clin Sleep Med. 2023;19(7):1175-1181.

Adherence to continuous positive airway pressure reduces the risk of 30-day hospital readmission among older adults with comorbid obstructive sleep apnea and cardiovascular disease.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is underdiagnosed and undertreated among patients hospitalized with comorbid cardiovascular disease (CVD). Treatment of OSA may reduce health care utilization, but benefits of continuous positive airway pressure (CPAP) therapy are related to adherence. Benefits of CPAP among hospitalized individuals with OSA and CVD have not been well studied. We evaluated the effect of CPAP adherence on 30-day hospital readmission among Medicare beneficiaries hospitalized with OSA and CVD. METHODS: We conducted a retrospective cohort study of Medicare beneficiaries aged ≥ 65 years with pre-existing CVD who were newly diagnosed with OSA between 2009 and 2013, initiated CPAP, and were hospitalized. CPAP adherence was defined as nonadherent, partially adherent, or highly adherent based on the number of machine charges (< 4, 4-12, and > 12, respectively) over 25 months of follow-up. The primary outcome was 30-day hospital readmission. RESULTS: Among 1,301 beneficiaries meeting study criteria, the 30-day readmission rate was 10.2%. In adjusted models and compared to patients with low CPAP adherence, those with high adherence had lower odds of 30-day readmission (odds ratio 0.41; 95% confidence interval 0.24-0.70). The protective effect of high CPAP adherence on 30-day readmission was significant among beneficiaries with heart failure (odds ratio 0.50; 95% confidence interval 0.16, 0.79), but not among those with other CVD. CONCLUSIONS: In this nationally representative sample of older adults with CVD and comorbid OSA, high CPAP adherence was associated with lower odds of 30-day readmission. These results highlight the importance of screening for and treating OSA among individuals with CVD. CITATION: Bailey MD, Wickwire EM, Somers VK, Albrecht JS. Adherence to continuous positive airway pressure reduces the risk of 30-day hospital readmission among older adults with comorbid obstructive sleep apnea and cardiovascular disease. J Clin Sleep Med. 2022;18(12):2739-2744.

Continuous Positive Airway Pressure Adherence and Treatment Cost in Patients With Obstructive Sleep Apnea and Cardiovascular Disease.

Objective: To determine whether continuous positive airway pressure (CPAP) adherence reduces health care-related costs or use in patients with obstructive sleep apnea (OSA) and comorbid cardiovascular disease (CVD). Patients: A total of 23 million patients with CVD were identified in the Medicare fee-for-service database. Of the 65,198 who completed a sleep study between January 2016 and September 2018, 55,125 were diagnosed as having OSA and 1758 were identified in the 5% Medicare durable medical equipment (DME) database. Methods: Patients with DME claims were categorized as adherent (AD, treatment evidenced ≥91 days after CPAP initiation; n=614) or nonadherent (nAD, n=242) to CPAP therapy. In addition, 9881 individuals with CVD who were not diagnosed as having OSA after sleep testing and without CPAP initiation were included as control patients. Propensity score matching balanced the groups for age, sex, and comorbidities (eg, diabetes mellitus), resulting in 241 participants per cohort. Dependent variables included total episode-of-care, inpatient, outpatient, skilled nursing, home health, and DME costs across 12 months. Results: Total episode-of-care costs of AD participants ($6825) were lower than those of nAD ($11,312; P<.05) and control ($8102) participants. This difference (Δ) was attributable to fewer outpatient expenses (Δ$2290; P<.05) relative to the nAD group and fewer inpatient expenses (Δ$745) relative to the control group because skilled nursing costs were comparable between groups (P=.73). Conclusion: Adherence to CPAP treatment reduces annual health care-related expenses by 40% in Medicare patients with CVD and OSA.

Effects of Experimental Sleep Restriction on Energy Intake, Energy Expenditure, and Visceral Obesity.

BACKGROUND: Although the consequences of sleep deficiency for obesity risk are increasingly apparent, experimental evidence is limited and there are no studies on body fat distribution. OBJECTIVES: The purpose of this study was to investigate the effects of experimentally-induced sleep curtailment in the setting of free access to food on energy intake, energy expenditure, and regional body composition. METHODS: Twelve healthy, nonobese individuals (9 males, age range 19 to 39 years) completed a randomized, controlled, crossover, 21-day inpatient study comprising 4 days of acclimation, 14 days of experimental sleep restriction (4 hour sleep opportunity) or control sleep (9 hour sleep opportunity), and a 3-day recovery segment. Repeated measures of energy intake, energy expenditure, body weight, body composition, fat distribution and circulating biomarkers were acquired. RESULTS: With sleep restriction vs control, participants consumed more calories (P = 0.015), increasing protein (P = 0.050) and fat intake (P = 0.046). Energy expenditure was unchanged (all P > 0.16). Participants gained significantly more weight when exposed to experimental sleep restriction than during control sleep (P = 0.008). While changes in total body fat did not differ between conditions (P = 0.710), total abdominal fat increased only during sleep restriction (P = 0.011), with significant increases evident in both subcutaneous and visceral abdominal fat depots (P = 0.047 and P = 0.042, respectively). CONCLUSIONS: Sleep restriction combined with ad libitum food promotes excess energy intake without varying energy expenditure. Weight gain and particularly central accumulation of fat indicate that sleep loss predisposes to abdominal visceral obesity. (Sleep Restriction and Obesity; NCT01580761).

Impact of Atrial Fibrillation on Outcomes of Aortic Valve Implantation.

New or preexisting atrial fibrillation (AF) is frequent in patients undergoing aortic valve replacement. We evaluated whether the presence of AF during transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (SAVR) impacts the length of stay, healthcare adjusted costs, and inpatient mortality. The median length of stay in the patients with AF increased by 33.3% as compared with those without AF undergoing TAVI and SAVR (5 [3 to 8] days vs 3 [2 to 6] days, p <0.0001 and 8 [6 to 12] days vs 6 [5 to 10] days, p <0.0001, respectively). AF increased the median value of adjusted healthcare associated costs of both TAVI ($46,754 [36,613 to 59,442] vs $49,960 [38,932 to 64,201], p <0.0001) and SAVR ($40,948 [31,762 to 55,854] vs $45,683 [35,154 to 63,026], p <0.0001). The presence of AF did not independently increase the in-hospital mortality. In conclusion, in patients undergoing SAVR or TAVI, AF significantly increased the length of stay and adjusted healthcare adjusted costs but did not independently increase the in-hospital mortality.

CPAP adherence is associated with reduced inpatient utilization among older adult Medicare beneficiaries with pre-existing cardiovascular disease.

STUDY OBJECTIVES: To examine the impact of adherence to continuous positive airway pressure (CPAP) therapy on health care utilization among a nationally representative and sample of older adults with multiple morbidities and pre-existing cardiovascular disease and subsequently diagnosed with obstructive sleep apnea in the United States. METHODS: Our data source was a random 5% sample of Medicare administrative claims data. All participants (n = 1,921) were of age ≥ 65 years, diagnosed with cardiovascular disease and obstructive sleep apnea, and subsequently began treatment with CPAP between 2009-2013. Based on the number of CPAP machine charges, individuals were categorized as low, partial, or high adherers (ie, < 4, 4-12, and > 12 CPAP charges, respectively). The impact of CPAP adherence status on health care utilization was assessed across multiple points of service, including outpatient encounters, inpatient stays, emergency department visits, and prescription fills over 24 months following CPAP initiation. RESULTS: Significant differences in demographic and comorbid disease characteristics were observed between low adherers (n = 377), partial adherers (n = 236), and high adherers (n = 1,308). After adjusting for covariates and relative to low adherers, high adherers demonstrated reduced inpatient visits (hazard ratio 0.75; 95% confidence interval 0.57, 0.97). CONCLUSIONS: In this nationally representative sample of older Medicare beneficiaries with multiple morbidities and relative to low adherers, high adherers demonstrated reduced inpatient utilization. CITATION: Wickwire EM, Bailey MD, Somers VK, et al. CPAP adherence is associated with reduced inpatient utilization among older adult Medicare beneficiaries with pre-existing cardiovascular disease. J Clin Sleep Med. 2022;18(1):39-45.

Research Priorities in the Secondary Prevention of Atrial Fibrillation: A National Heart, Lung, and Blood Institute Virtual Workshop Report.

There has been sustained focus on the secondary prevention of coronary heart disease and heart failure; yet, apart from stroke prevention, the evidence base for the secondary prevention of atrial fibrillation (AF) recurrence, AF progression, and AF-related complications is modest. Although there are multiple observational studies, there are few large, robust, randomized trials providing definitive effective approaches for the secondary prevention of AF. Given the increasing incidence and prevalence of AF nationally and internationally, the AF field needs transformative research and a commitment to evidenced-based secondary prevention strategies. We report on a National Heart, Lung, and Blood Institute virtual workshop directed at identifying knowledge gaps and research opportunities in the secondary prevention of AF. Once AF has been detected, lifestyle changes and novel models of care delivery may contribute to the prevention of AF recurrence, AF progression, and AF-related complications. Although benefits seen in small subgroups, cohort studies, and selected randomized trials are impressive, the widespread effectiveness of AF secondary prevention strategies remains unknown, calling for development of scalable interventions suitable for diverse populations and for identification of subpopulations who may particularly benefit from intensive management. We identified critical research questions for 6 topics relevant to the secondary prevention of AF: (1) weight loss; (2) alcohol intake, smoking cessation, and diet; (3) cardiac rehabilitation; (4) approaches to sleep disorders; (5) integrated, team-based care; and (6) nonanticoagulant pharmacotherapy. Our goal is to stimulate innovative research that will accelerate the generation of the evidence to effectively pursue the secondary prevention of AF.

CPAP adherence is associated with reduced risk for stroke among older adult Medicare beneficiaries with obstructive sleep apnea.

STUDY OBJECTIVES: To examine the impact of adherence to continuous positive airway pressure (CPAP) therapy on risk of stroke among a nationally representative sample of older adults with obstructive sleep apnea. METHODS: We performed a retrospective cohort study among Medicare beneficiaries aged ≥ 65 years who were newly diagnosed with obstructive sleep apnea and had initiated CPAP (2009-2013). Monthly indicators of CPAP adherence included charges for machines, masks, or supplies and were summed over a 25-month follow-up to create a CPAP adherence variable. Stroke was modeled as a function of CPAP adherence using generalized estimating equations. RESULTS: We found that 5,757 beneficiaries met the inclusion criteria and were included in the final sample. Of these, 407 (7%) experienced stroke. After adjusting for demographic and clinical characteristics, CPAP adherence was associated with a reduced risk of stroke (hazard ratio, 0.98; 95% confidence interval, 0.96-0.99) over 25 months, indicating a 2% reduction in risk of stroke for each month of CPAP adherence. When sensitivity analyses were performed to stratify results by time since the first CPAP charge, the protective effect remained significant for the 12- and 6-month but not the 3-month outcome models. CONCLUSIONS: In this national analysis of older adult Medicare beneficiaries with obstructive sleep apnea, CPAP adherence was associated with significantly reduced risk of stroke.

CPAP adherence reduces cardiovascular risk among older adults with obstructive sleep apnea.

STUDY OBJECTIVES: To examine (1) the impact of adherence to continuous positive airway pressure (CPAP) therapy on risk for cardiovascular (CVD) events among a nationally representative sample of older adults with obstructive sleep apnea (OSA), and (2) the heterogeneity of this effect across subgroups defined by race, sex, and socioeconomic status. METHODS: We conducted a retrospective cohort study among Medicare beneficiaries aged ≥ 65 years with OSA (2009-2013). Monthly indicators of CPAP adherence (charges for machines, masks, or supplies) were summed over 25 months to create a CPAP adherence variable. New CVD events (ischemic heart disease, cardiac and peripheral procedures) were modeled as a function of CPAP adherence using generalized estimating equations. Heterogeneity of the effect of CPAP on new CVD events was evaluated based on race, sex, and socioeconomic status. RESULTS: Among 5024 beneficiaries diagnosed with OSA who initiated CPAP, 1678 (33%) demonstrated new CVD events. Following adjustment for demographic and clinical characteristics, CPAP adherence was associated with reduced risk of new CVD events (hazard ratio 0.95; 95% confidence interval 0.94, 0.96) over 25 months. When analyses were stratified by time since the first CPAP charge, the protective effect remained significant for the 12- and 6-month, but not 3-month, outcome models. No significant differences were observed in the protective effect of CPAP based on race, sex, or socioeconomic status. CONCLUSIONS: In this national study of older adult Medicare beneficiaries with OSA, CPAP adherence was associated with greatly reduced risk for CVD events. This risk reduction was consistent across race, sex, and socioeconomic subgroups.

Disparities in Hypertension Among African-Americans: Implications of Insufficient Sleep.

PURPOSE OF REVIEW: Sleep deficiency has been proposed as a potential contributor to racial disparities in cardiovascular health. We present contemporary evidence on the unequal burden of insufficient sleep in Blacks/African-Americans and the repercussions for disparate risk of hypertension. RECENT FINDINGS: The prevalence of insufficient sleep is high and rising and has been recognized as an important cardiovascular risk factor. Presumably due to a constellation of environmental, psychosocial, and individual determinants, these risks appear exacerbated in Blacks/African-Americans, who are more likely to experience short sleep than other ethnic/racial groups. Population-based data suggest that the risk of hypertension associated with sleep deficiency is greater in those of African ancestry. However, there is a paucity of experimental evidence linking short sleep duration to blood pressure levels in African-Americans. Blacks/African-Americans may be more vulnerable to sleep deficiency and to its hypertensive effects. Future research is needed to unequivocally establish causality and determine the mechanism underlying the postulated racial inequalities in sleep adequacy and consequent cardiovascular risk.

Differences of energy expenditure while sitting versus standing: A systematic review and meta-analysis.

Background Replacing sitting with standing is one of several recommendations to decrease sedentary time and increase the daily energy expenditure, but the difference in energy expenditure between standing versus sitting has been controversial. This systematic review and meta-analysis aimed to determine this difference. Designs and methods We searched Ovid MEDLINE, Ovid Embase Scopus, Web of Science and Google Scholar for observational and experimental studies that compared the energy expenditure of standing versus sitting. We calculated mean differences and 95% confidence intervals using a random effects model. We conducted different predefined subgroup analyses based on characteristics of participants and study design. Results We identified 658 studies and included 46 studies with 1184 participants for the final analysis. The mean difference in energy expenditure between sitting and standing was 0.15 kcal/min (95% confidence interval (CI) 0.12-0.17). The difference among women was 0.1 kcal/min (95% CI 0.0-0.21), and was 0.19 kcal/min (95% CI 0.05-0.33) in men. Observational studies had a lower difference in energy expenditure (0.11 kcal/min, 95% CI 0.08-0.14) compared to randomised trials (0.2 kcal/min, 95% CI 0.12-0.28). By substituting sitting with standing for 6 hours/day, a 65 kg person will expend an additional 54 kcal/day. Assuming no increase in energy intake, this difference in energy expenditure would be translated into the energy content of about 2.5 kg of body fat mass in 1 year. Conclusions The substitution of sitting with standing could be a potential solution for a sedentary lifestyle to prevent weight gain in the long term. Future studies should aim to assess the effectiveness and feasibility of this strategy.

Combining body mass index with measures of central obesity in the assessment of mortality in subjects with coronary disease: role of "normal weight central obesity".

OBJECTIVES: This study sought to assess the mortality risk of patients with coronary artery disease (CAD) based ona combination of body mass index (BMI) with measures of central obesity. BACKGROUND: In CAD patients, mortality has been reported to vary inversely with BMI ("obesity paradox"). In contrast,central obesity is directly associated with mortality. Because of this bidirectionality, we hypothesized that CAD patients with normal BMI but central obesity would have worse survival compared to individuals with other combinations of BMI and central adiposity. METHODS: We included 15,547 participants with CAD who were part of 5 studies from 3 continents. Multivariate stratifiedCox-proportional hazard models adjusted for potential confounders were used to assess mortality risk according to different patterns of adiposity that combined BMI with measures of central obesity. RESULTS: Mean age was 66 years, 60% were men. There were 5,507 deaths over a median follow-up of 2.4 years (IQR: 0.5 to 7.4 years). Individuals with normal weight central obesity had the worst long-term survival: a person with BMI of 22 kg/m2 and waist circumference (WC) of 101 cm had higher mortality than a person with similar BMI but WC of 85 cm (HR: 1.10[95% CI: 1.05 to 1.17]), than a person with BMI of 26 kg/m2 and WC of 85 cm (HR: 1.20 [95% CI: 1.09 to 1.31]), than a person with BMI of 30 kg/m2 and WC of 85 cm (HR: 1.61 [95% CI: 1.39 to 1.86]) and than a person with BMI of 30kg/m2 and WC of 101 cm (HR: 1.27 [95% CI: 1.18 to 1.39), p < 0.0001 for all). CONCLUSIONS: In patients with CAD, normal weight with central obesity is associated with the highest risk of mortality [corrected].

Effects of experimental sleep restriction on caloric intake and activity energy expenditure.

BACKGROUND: Epidemiologic studies link short sleep duration to obesity and weight gain. Insufficient sleep appears to alter circulating levels of the hormones leptin and ghrelin, which may promote appetite, although the effects of sleep restriction on caloric intake and energy expenditure are unclear. We sought to determine the effect of 8 days/8 nights of sleep restriction on caloric intake, activity energy expenditure, and circulating levels of leptin and ghrelin. METHODS: We conducted a randomized study of usual sleep vs a sleep restriction of two-thirds of normal sleep time for 8 days/8 nights in a hospital-based clinical research unit. The main outcomes were caloric intake, activity energy expenditure, and circulating levels of leptin and ghrelin. RESULTS: Caloric intake in the sleep-restricted group increased by +559 kcal/d (SD, 706 kcal/d, P=.006) and decreased in the control group by -118 kcal/d (SD, 386 kcal/d, P=.51) for a net change of +677 kcal/d (95% CI, 148-1,206 kcal/d; P=.014). Sleep restriction was not associated with changes in activity energy expenditure (P=.62). No change was seen in levels of leptin (P=.27) or ghrelin (P=.21). CONCLUSIONS: Sleep restriction was associated with an increase in caloric consumption with no change in activity energy expenditure or leptin and ghrelin concentrations. Increased caloric intake without any accompanying increase in energy expenditure may contribute to obesity in people who are exposed to long-term sleep restriction. TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT01334788; URL: www.clinicaltrials.gov.