Age‐Specific Associations of Moderate‐to‐Vigorous Physical Activity With Relative and Absolute Risk of Type 2 Diabetes in UK Biobank Participants

Aims We assessed the age‐specific associations between moderate‐to‐vigorous physical activity (MVPA) and incident type 2 diabetes. Materials and Methods We included UK Biobank participants with valid accelerometry data without diabetes mellitus at baseline ( N = 87 975; 62.7 years [IQR, 55.6–67.9]; 57% women). We examined whether age, sex and baseline metabolic disease status modified the associations of MVPA volume (lower versus higher) and, in exploratory analyses, MVPA timing (later‐day versus earlier‐day) with incident type 2 diabetes. Age‐specific relative and absolute associations were assessed across 5‐year age bins using hazard ratios (HRs) and incidence rate differences (IRDs), and additionally stratified by sex and baseline metabolic disease status. Results Associations of MVPA volume with type 2 diabetes were most consistently modified by age, baseline prediabetes (all p ‐values for interaction < 0.05), with stronger associations observed among participants younger than the median population age (< 62.7 years, HR = 2.44 [95% CI: 2.05–2.90] versus HR = 1.65 [95% CI: 1.47–1.86]) and participants without prediabetes. Across 5‐year age groups, HRs declined with age, whereas IRDs increased in the overall population. No clear effect modification was observed for the association between MVPA timing and type 2 diabetes risk. Conclusions The relative association between higher MVPA volume and lower type 2 diabetes risk attenuated with age and was weaker among individuals with prediabetes, whereas absolute risk reductions were larger among older and metabolically higher‐risk individuals. These findings support considering both relative and absolute measures when targeting MVPA interventions for type 2 diabetes prevention.