Zhao Chen
Publications
Chen Z. Historical Relationships between Biological Anthropology and Body Composition. ACTA Anthropologica Sinica, August 2013, 32(3).
The study of circulating biomarkers and their association with disease outcomes has become progressively complex due to advances in the measurement of these biomarkers through multiplex technologies. The Least Absolute Shrinkage and Selection Operator (LASSO) is a data analysis method that may be utilized for biomarker selection in these high dimensional data. However, it is unclear which LASSO-type method is preferable when considering data scenarios that may be present in serum biomarker research, such as high correlation between biomarkers, weak associations with the outcome, and sparse number of true signals. The goal of this study was to compare the LASSO to five LASSO-type methods given these scenarios.
Clinical outcomes of the Women's Health Initiative (WHI) calcium plus vitamin D supplementation trial have been reported during 7.0 years of active intervention. We now report outcomes 4.9 years after the intervention stopped and cumulative findings.
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.