Device-measured physical activity and its association with physical function in adults with type 2 diabetes mellitus

To quantify how differences in metrics characterizing physical activity and sedentary behaviour in type 2 diabetes are associated with physical function.

This analysis included participants' data from the Chronotype of Patients with Type 2 Diabetes and Effect on Glycaemic Control (CODEC) cross-sectional study. Data were stratified into two groups according to their short physical performance battery (SPPB) score (impaired physical function = SPPB < 10 and normal physical function = SPPB ≥ 10). Hand-grip strength, sit-to-stand 60 (STS-60) and the Duke Activity Status Index (DASI) score were used to assess functional capacity, while physical activity metrics were measured with a wrist-worn accelerometer. The associations between physical activity metrics and measures of functional capacity were analysed using generalized linear modelling.

Some 635 adults (median age 66 years, 34% female) were included in this analysis. Overall, 29% of the cohort scored < 10 in the SPPB test indicating impaired physical function. This group spent more time in prolonged sedentary behaviour (600.7 vs. 572.5 min) and undertook less-intense physical activity. Each sd increase in physical activity volume and intensity gradients for those with impaired physical function was associated with 17% more repetitions for STS-60 with similar associations seen for DASI score. Each sd in sedentary time was associated with 15% fewer repetitions in STS-60 and 16% lower DASI score in those with impaired physical function, whereas in normal physical function group it was 2% and 1%, respectively.

The strength of the associations for physical activity measures and functional capacity were modified by physical function status, with the strongest association seen in those with impaired physical function.