Relationship of Physical Activity Behavior with Insulin Sensitivity over Five Years after Diagnosis of Type 2 Diabetes

Regular physical activity is a key element of lifestyle recommendations for patients with type 2 diabetes (T2D), yet adherence to physical activity (PA) and its association with insulin sensitivity in newly diagnosed T2D is less known.

This study assessed PA behavior during the first year after diagnosis and 5 years later by the validated Baecke questionnaire, which comprises sports-, leisure- and work-related activities, in recent-onset T2D (n=215) and healthy individuals (CON; n=84), adjusted for age, sex and body mass index. Insulin sensitivity was assessed from hyperinsulinemic-euglycemic clamps and maximal oxygen consumption (VO2max) from spiroergometry at baseline and after 5 years.

Patients with T2D had a lower total Baecke (8.1±1.4) and sports index (2.7±0.8) than CON (8.8±1.4; 3.2±0.8; all p<0.05; mean±standard deviation). Compared to CON, VO2max was 28% lower in T2D (p<0.05). Whole-body insulin sensitivity was 41% lower in T2D than in CON (p<0.01). At baseline, sports index correlated positively with insulin sensitivity (T2D r=0.17; CON r=0.32, both p<0.05) and VO2max (T2D r=0.38; CON r=0.32, both p<0.01). Of note, higher PA participation at 5 years after diagnosis associated with decreased body weight (r=-0.30; p<0.01) and improved physical performance (r=0.32; p<0.05) in T2D. Although at 5 years changes in PA did not impact hemoglobin A1c as a parameter for glycemic control, higher PA participation associated positively with changes in whole-body insulin sensitivity in T2D (r=0.26; p<0.05).

In conclusion, lower PA participation contributes to worsening of body weight, physical fitness and insulin resistance in T2D, even during the initial course of disease.