Leisure-time physical activity and risk of microvascular complications in individuals with type 2 diabetes: A UK Biobank study
We aimed to determine dose-response associations, including the minimal effective level, between leisure-time physical activity and risk of incident neuropathy, nephropathy, and retinopathy.
RESEARCH DESIGN AND METHODS
This cohort study included 18,092 individuals with type 2 diabetes from the UK Biobank. Self-reported leisure-time physical activity was converted into metabolic equivalent of task-hours/week (MET-hrs). Participants were categorised into no physical activity (0 MET-hrs/week), below recommendations (>0-7.49 MET-hrs/week), at recommendations (7.5-14.9 MET-hrs/week), and above recommendations (≥15 MET-hrs/week). Microvascular complications were identified from hospital inpatient records using diagnosis codes. We used Cox regression analysis to calculate adjusted hazard ratios (aHR) and restricted cubic splines to identify the minimal effective level of physical activity.
During a median follow-up of 12.1 years, 672 individuals (3.7%) were diagnosed with neuropathy, 1,839 (10.2%) with nephropathy, and 2,099 (11.7%) with retinopathy. Any level of physical activity was associated with a lower risk of neuropathy and nephropathy, but not retinopathy. Compared with those reporting no physical activity, the aHR of neuropathy was 0.71 (0.53-0.90) below recommendations, 0.73 (0.56- 0.96) at recommendations, and 0.67 (0.52-0.87) above recommendations. Corresponding aHRs for nephropathy were 0.79 (0.68-0.92), 0.80 (0.67-0.95), and 0.80 (0.68-0.95). The association with retinopathy was weaker: 0.91 (0.78-1.06), 0.91 (0.77-1.08), and 0.98 (0.84-1.15).
Any level of leisure-time physical activity was associated with a lower risk of neuropathy and nephropathy but not retinopathy in individuals with type 2 diabetes. For both neuropathy and nephropathy, the minimal effective physical activity level may correspond to less than 1.5 hours of walking/week.