Joint associations of body mass index and waist-to-height ratio with sleep duration among Saudi adolescents

Background: Numerous studies have shown significant associations between short sleep duration and overall or abdominal obesity. However, no study has reported on the joint association of body mass index (BMI) and waist-to-height ratio (WHtR) with sleep duration in adolescents. Aim: To examine the joint associations of BMI and WHtR with sleep duration among Saudi adolescents. Subjects and methods: A school-based cross-sectional study was conducted involving 2852 secondary-school students (51.7% females) aged 15-19 years, randomly selected using a multistage stratified cluster sampling. Self-reported sleep duration was assessed and BMI was classified into high and low categories according to the IOTF classification, whereas WHtR categories were based on above and below 0.5. Results: The low BMI-low WHtR category had the longest mean sleep duration (7.27 hours/day), whereas the high BMI-high WHtR group had the shortest sleep duration (7.02 hours/day; p=0.003) (aOR=0.832, 95% CI=0.698-0.992, p=0.040). In addition, high BMI-low WHtR or low BMI-high WHtR groups didn't significantly associate with reduced sleep duration among adolescents. Conclusion: The joint association of high BMI-high WHtR increases adolescent's risk of having reduced sleep duration. Future research should seek to confirm such findings and provide an explanation for this association.