Abstract
AIMS: To explore the amount-response associations between the duration of physical activity (PA) at different intensities and the risks of microvascular diseases (MVDs), with a particular focus on identifying the optimal amount of vigorous-intensity PA (VPA).
METHODS: In this prospective cohort study, PA of different intensities were measured using wrist-worn accelerometers. MVDs, including nephropathy, neuropathy, and retinopathy, were identified from hospital inpatient records. Cox models and restricted cubic splines were used to evaluate the associations.
RESULTS: This prospective study included 92,275 participants (40,256 males and 52,019 females) with a mean (SD) age of 61.7 (7.8) years. During a median follow-up of 7.9 years, a total of 5,201 individuals were diagnosed with MVDs, including 2,385 with nephropathy, 512 with neuropathy, and 2,666 with retinopathy. An L-shaped amount-response association for VPA and overall MVDs was observed (P value for non-linearity < 0.001), with the optimal amount of 38 (95 % CI: 34, 44) minutes/week, corresponding to an HR of 0.71 (95 % CI: 0.64, 0.77).
CONCLUSION: VPA of 34-44 min/week were associated with 23 %-36 % lower risks of overall MVDs, with a less pronounced decline in risk thereafter. These findings may have implications for the future revision of physical activity recommendations to better improve microvascular health.