Cross-Sectional and Prospective Associations of Rest-Activity Rhythms with Metabolic Markers and Type 2 Diabetes in Older Men
RESEARCH DESIGN AND METHODS Baseline rest-activity rhythms were derived from actigraphy using extended cosine model analysis. Fasting glucose, insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were measured from fasting blood at baseline and after ~3.5 years. T2D were defined using self-report, medication use and fasting glucose.
RESULTS In the cross-sectional analysis (n=2,450), lower 24-hour amplitude:mesor ratio (i.e., mean-activity-adjusted rhythm amplitude) and reduced overall rhythmicity, were associated with higher fasting insulin and HOMA-IR (all p-trend < 0.0001), indicating increased insulin resistance. The odds of baseline T2D were significantly higher among those in the lowest quintile of amplitude (OR Q1 vs Q4 (95% CI), 1.63 (1.14, 2.30)) and late acrophase group (OR late vs normal (95% CI), 1.46 (1.04, 2.04)). In the prospective analysis (n=861), multiple rest-activity characteristics predicted a 2-3 fold increase in T2D risk, including a lower amplitude (OR Q1 vs Q4 (95% CI), 3.81 (1.45, 10.00)) and amplitude:mesor ratio (2.79 (1.10, 7.07), reduced overall rhythmicity (3.49 (1.34, 9.10)), and a late acrophase (2.44 (1.09, 5.47)).
CONCLUSIONS Rest-activity
rhythm characteristics are associated with impaired glycemic metabolism and
homeostasis and higher risk of incident T2D.
