Background. Obesity and short sleep duration are significant public health issues with evidence suggesting these conditions are associated with premature mortality, cardiovascular disease, metabolic syndrome, and inflammation. In the United States, 37.9% of adults are classified as obese, having a body mass index (BMI) of 30 kg/m2 or greater. Stratified by sex, 35.2% of men and 40.5% of women meet the BMI cut-point for obesity. Similarly, curtailed sleep duration is commonplace, with an estimated 35.3% of adults in the United States receiving less than the recommended 7 hours of sleep during a 24-hour period. In recent years, there has been an increased interest in the potential link between obesity and short sleep duration due to: (1) the apparent parallel increase in prevalence of both conditions over the past few decades; (2) their overlapping association with cardiometabolic outcomes; and (3) the potential causal connection between the two health issues. Research. The proposed investigation will seek to contribute to the development of a comprehensive adiposity-sleep model, while laying the groundwork for a future program of research seeking to prevent and treat adiposity and sleep-related cardiometabolic disease risk factors. The study proposed within this K-award is intended to investigate four topics pertinent to the adiposity-sleep hypothesis: (1) the relationship between adiposity and sleep duration; (2) sex-based differences in the relationship between adiposity and sleep duration; (3) influence of adiposity indices and sleep duration on cardiometabolic outcomes; and (4) the role of socioecological factors as effect modifiers in the relationship between adiposity indices, sleep, and cardiometabolic outcomes. To address these aims, the proposed study will employ a large-scale survey (n=1,000) to recruit 159 subjects (53 normal weight, 53 overweight, and 53 obese) to be assessed in two phases. Phase 1, an in-lab study, will be used to gather objective adiposity indices (air displacement plethysmography and anthropometrics) and cardiometabolic data (blood pressure, pulse wave velocity and pulse wave analysis, and blood-based biomarker). Phase 2, a one-week, home-based study, will be used to gather sleep-related data (home sleep testing/sleep apnea, actigraphy, sleep diaries). During Phase 2, detailed demographic and socioecological data will be collected to contextualize hypothesized adiposity and sleep-associated cardiometabolic disease risk factors. Collection and analyses of these data will provide necessary information to customize future observational and intervention research. Training. Pedagogically, the training plan for the K01 is comprised of the didactic training (coursework, seminars, symposia), mentoring (directed research, readings, tutorials), and dissemination deliverables (publications, presentations, and proposals) required to complete the proposed project and to initiate a pathway towards research independence. This career development plan builds upon the applicant?s previous obesity and sleep health research and couples these two independent health issues into an interconnected line of inquiry.
Obesity and short sleep duration are highly prevalent, interconnected risk factors for cardiometabolic disease in adults; however, a comprehensive adiposity-sleep model has remained elusive due to the complexity of the relationship between these two health-related states. The training and research proposed in this career development award will form the background of new lines of epidemiological and experimental inquiry seeking to unpack the relationship between adiposity, sleep, and cardiometabolic disease. This stream of research holds substantial promise for public health; objective, empirical data regarding the interaction between adiposity and sleep, contextualized within a socioeconomic framework, are important for understanding the pathogenesis of cardiometabolic disease and for developing public health interventions to prevent its conception and treat its consequences.
