Objective: Short sleep duration induces hormonal perturbations contributing to hyperphagia, insulin resistance, and obesity. The majority of these studies are conducted in young adults. This analysis in a large (n= 769) sample of postmenopausal women (median age 63y) sought to 1) confirm that sleep duration and sleep quality are negatively correlated with circulating leptin concentrations and 2) to examine the relationship between self-reported sleep, dietary energy intake, and diet quality, as well as, investigate the role of leptin in these associations. Design and Methods: Sleep duration/ quality, insomnia, and dietary intake were determined via self-report. Blood samples were collected following an overnight fast to assess serum leptin concentration. All analyses were adjusted for total body fat mass. Results: Women reporting ≤6h sleep/night had lower serum leptin concentrations than those reporting ≥8h sleep (P= 0.04). Furthermore, those with ≤6h sleep/night reported higher dietary energy intake (p=0.01) and lower diet quality (P= 0.04) than the reference group (7h sleep/night). Women sleeping ≥8h also reported lower diet quality than the reference group (P= 0.02). Importantly, serum leptin did not confound these associations. Conclusions: These results provide evidence that sleep duration is inversely associated with serum leptin and dietary energy intake in postmenopausal women.
Genetic factors have an important role in body mass index (BMI) variation, and also likely have a role in the weight loss and body composition response to physical activity/exercise. With the recent identification of BMI-associated genetic variants, it is possible to investigate the interaction of these genetic factors with exercise on body composition outcomes.
Jiang, P., Missoum, S. and Chen, Z., “Fusion of clinical and stochastic finite element data for hip fracture risk prediction”, Journal of Biomechanics, Volume 48, Issue 15, 26 November 2015, Pages 4043. PMID: 26482733 http://www.ncbi.nlm.nih.gov/pubmed/26482733
Jiang, P., Missoum, S., and Chen, Z., Optimal SVM Parameter Selection for Non-separable and Unbalanced Datasets. Structural and Multidisciplinary Optimization, vol. 50, 2014, pp. 523-535.