Researcher(s)
- Natalie Lewis, Nursing, University of Delaware
Faculty Mentor(s)
- Xiaopeng Ji, School of Nursing, University of Delaware
Abstract
Background: Approximately 40% of emerging adults (18–25 years) have at least one metabolic syndrome (MetS) risk factor, increasing future cardiometabolic risk. Poor sleep and insufficient physical activity (PA) are independently associated with MetS; however, their interactive effects remain unclear. This study examined whether PA moderates associations between sleep and MetS risk.
Methods: This secondary cross-sectional analysis included 60 emerging adults. Metabolic health was categorized as no versus ≥1 MetS risk factor (elevated waist circumference, blood pressure, fasting glucose, triglycerides, low HDL cholesterol). Sleep and PA were measured over 7 days using ActiGraph GT9X Link. Sleep variables included total sleep time (TST), sleep efficiency (SE), midsleep variability, and social jetlag. PA was assessed by daily steps and dichotomized at the median. Logistic regression models adjusted for age and sex tested main and interaction effects.
Results: 63% of participants (n = 38) had ≥1 MetS factor. Mean TST was 343 minutes. Longer TST was associated with lower odds of having ≥1 MetS factor (OR = 0.97, 95% CI: 0.94–0.99, p = .007), and PA moderated this (OR = 1.03, 95% CI: 1.01–1.06, p = .028), with a stronger protective association among less active participants. PA also moderated the association between SE and MetS (p=0.04), with higher SE associated with lower MetS risk only among more active participants (OR = 1.00, 95% CI: -0.11–-0.02, p = .01). Midsleep variability and social jetlag showed no association with MetS, nor did they interact with PA.
Conclusions: Longer sleep duration was associated with lower MetS risk, particularly among less active participants, while higher SE was associated with lower MetS risk only among more active participants. These findings suggest sleep and PA jointly influence metabolic health. Randomized clinical trials are needed to determine whether interventions targeting both sleep and PA improve cardiometabolic health.