ASSOCIATION OF HABITUAL SLEEP VARIABLITY WITH ABDOMINAL OBESITY IN ADOLESCENTS
Open Access
- Author:
- Liao, Lucia H
- Area of Honors:
- Biobehavioral Health
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Duanping Liao, Thesis Supervisor
David John Vandenbergh, Thesis Honors Advisor
Dr. Lori Anne Francis, Faculty Reader - Keywords:
- sleep variability
abdominal obesity
DEXA - Abstract:
- Poor sleep habits have often been considered a risk factor for obesity. The present study investigates the association between habitual sleep variability (HSV) and abdominal obesity in a population-based sample of adolescents. The study further examines the potential mediating role of physical activity and nutritional intake in the relationship between HSV and abdominal obesity. The study population consists of 304 adolescents who participated in the Penn State Child Cohort follow-up examination. HSV was calculated using actigraph-measured sleep duration on 7 consecutive nights. Dual-energy x-ray absorptiometry (DEXA) was used to determine abdominal obesity measurements, including android/gynoid ratio (AGR waist/hip ratio), android/whole body proportion (AWP), gynoid/whole body proportion (GWP), subcutaneous fat (SAT), visceral fat (VAT), and total fat (TAT) areas. Actigraph recordings over the course of one week were used to measure physical activity. The study used the Youth/Adolescent Food Frequency Questionnaire to obtain nutritional profiles. After adjusting for major confounders and habitual sleep duration, linear regression models showed a highly significant association between HSV and multiple abdominal obesity measures. With a 1-hour increase in HSV, TAT and VAT increased by 32.5 (12.1) cm2 and 6.85 (2.82) cm2 respectively. Mediation models showed that nutritional intake is a weak mediator between HSV and abdominal obesity association, whereas physical activity is not a mediator. In conclusion, this study achieves a better understanding of childhood obesity, a leading risk factor in early death and heart disease, by providing insight into the mechanism between sleep variability and obesity in adolescents. The results suggest that the mechanism between HSV and abdominal obesity can be partially explained by higher food intake but not by lower physical activity.