Temporal coordination of light exposure, physical activity and eating rhythms in relation to prevalent diabetes and glycaemic traits: a cross-sectional NHANES study.

AIMS: To examine associations of temporal coordination among 24-h light exposure, physical activity and eating patterns with prevalent diabetes and glycaemic traits. METHODS: We analysed 7133 adults (1397 with diabetes) from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Phasor analysis generated magnitude and phase for Light-Activity, Light-Energy and Activity-Energy pairs. Survey-weighted models assessed associations with prevalent diabetes and glycaemic traits. RESULTS: In primary Model 3, higher Light-Activity and Activity-Energy magnitudes were associated with lower odds of prevalent diabetes (odds ratio [OR] per 0.01-unit increase 0.964, 95% confidence interval [CI] 0.937-0.993; and 0.889, 0.816-0.968, respectively), whereas the Light-Energy 95% CI included 1.0 (OR 0.910, 95% CI 0.822-1.007). Larger Light-Activity phase was associated with higher odds (OR per 1 h 1.065, 95% CI 1.001-1.133). In Model 4, all three magnitude estimates moved towards 1.0 and their 95% CIs included 1.0. Among participants without diabetes, all three magnitudes were inversely associated with fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and 2-h oral glucose tolerance test (OGTT) glucose, but not fasting glucose. CONCLUSIONS: Prospective studies should evaluate temporality, reproducibility and clinical relevance.