The dose-response association between wearables-quantified incidental physical activity and type 2 diabetes: a prospective cohort study.

AIM: This prospective cohort study aimed to quantify dose-response associations between intensity-specific incidental physical activity (IPA) and the incidence of type 2 diabetes (T2D) in a large cohort of UK adults. A secondary aim was to estimate the T2D-specific equivalence of 1 minute of vigorous-intensity IPA relative to moderate- and light-intensity IPA. METHODS: Participants were adults from the UK Biobank accelerometry sub-study who self-reported as nonexercisers. Individuals were excluded if they had T2D at baseline, were using insulin therapy, or received a T2D diagnosis within 12 months of follow-up. T2D status was primarily derived from primary care records. Device-measured IPA was categorized into light (LIPA; 1.5 to <3 METs), moderate (MIPA; 3 to <6 METs), and vigorous (VIPA; ≥6 METs) intensities. Additional analyses examined the T2D-specific equivalence of 1 minute of VIPA to MIPA and LIPA. The reference group comprised participants accumulating neither MIPA nor VIPA. RESULTS: The primary analysis included 22 857 nonexercisers (mean age 62.1 ± 7.7 years, 42.8% male). Over a 7.8-year follow-up period, 721 (3.2%) participants developed T2D. MIPA and VIPA, but not LIPA, exhibited near-linear inverse associations with T2D risk. Median VIPA (4.75 minutes/day) was associated with a hazard ratio (HR) 0.62 [95% confidence interval (CI) 0.53-0.73], and median MIPA (23.70 minutes/day) showed a HR of 0.67 (95% CI: 0.52-0.86). One minute of VIPA/day was associated with an equivalent T2D risk reduction of 5.9 minutes MIPA/day and 46.6 minutes LIPA/day. CONCLUSION: MIPA and VIPA were associated with lower T2D risk in a dose-dependent manner. Although median LIPA was linked to reduced risk, it did not demonstrate a consistent dose-response relationship.