Effects of Chronotype on Sleep Duration and Body Composition Variables
Body composition changes with age. These changes include decreases in fat-free mass and increases in fat mass and central fat accumulation. Improving body composition will augment efforts to lower obesity rates and cardio-metabolic diseases (e.g. type 2 diabetes). Sleep may be a determinant of body composition, whereby shortened sleep duration predicts weight gain. However, evidence is inconsistent. Differences in chronotype (the extent to which an individual is a morning or an evening person) may explain these inconsistent findings. This study will examine the extent to which chronotype modifies the association between sleep duration, fat mass, and fat-free mass in adults.
We will examine the hypothesis that chronotype modifies the effect between sleep duration and obesity. Obesity will be regressed on the indicator for whether or not someone is a morning person or an evening person and sleep duration to determine this relationship. Then to determine potential causal pathways through which sleep duration impacts body composition, chronotype-specific differences in eating habits, physical activity, and body composition will be quantified using structural equation modeling. This approach will allow us to quantify the relationship of other potentially influential variables such as person, demographic, and environmental factors.
Malone, SK, Patterson F, Lu Y, Lozano A and Hanlon A (2015) Ethnic differences in sleep duration and morning-evening type in a population sample, Chronobiology International 33:2016 Issue 1, 10-21 http://dx.doi.org/10.3109/07420528.2015.1107729 http://www.tandfonline.com/doi/citedby/10.3109/07420528.2015.1107729?scroll=top&needAccess=true
Patterson, F., Malone, S.K., Lozano, A. et al. (2016) Smoking, Screen-Based Sedentary Behavior, and Diet Associated with Habitual Sleep Duration and Chronotype: Data from the UK Biobank, Ann. behav. med. (2016) 50: 715. doi:10.1007/s12160-016-9797-5 https://link.springer.com/article/10.1007/s12160-016-9797-5
Patterson F, Malone SK, Grandner MA, Lozano A, Perkett M and Hanlon A (2017) Interactive effects of sleep duration and morning/evening preference on cardiovascular risk factors. Eur J Public Health 2017 ckx029. doi: 10.1093/eurpub/ckx029 https://academic.oup.com/eurpub/article-lookup/doi/10.1093/eurpub/ckx029
|Lead investigator:||Dr. Alexandra Hanlon|
|Lead institution:||University of Pennsylvania|