Association of Habitual Daily Physical Activity With Glucose Tolerance and β-Cell Function in Adults With Impaired Glucose Tolerance or Recently Diagnosed Type 2 Diabetes From the Restoring Insulin Secretion (RISE) Study.
Level 4 - case-series / case-control
Cross-sectional observational analysis of baseline cohort/trial data
PubMed 31177181 · doi:10.2337/dc19-0538
What was done
Researchers analyzed baseline cross-sectional data from 230 adults (mean age 54.5 ± 8.5 years; mean BMI 35 ± 5.5 kg/m²; 42.6% women) with impaired glucose tolerance or drug-naive, recently diagnosed type 2 diabetes participating in the Restoring Insulin Secretion (RISE) Study. Habitual physical activity was measured using wrist accelerometers worn for 7 consecutive days to determine total physical activity counts (TAC). Participants underwent a 3-hour oral glucose tolerance test (OGTT) and a hyperglycemic clamp to assess glucose tolerance (fasting glucose, 2-hour glucose, glucose incremental area under the curve [G-iAUC]), insulin sensitivity (clamp-derived M/I ratio), and β-cell responses (acute C-peptide response, steady-state C-peptide, maximal β-cell response, and OGTT C-peptide index).
What was found
The daily mean TAC was 233,460 counts. After adjustment for confounders, higher TAC was associated with higher clamp-derived insulin sensitivity (M/I). However, TAC showed no association with fasting plasma glucose, 2-hour glucose, or G-iAUC. After adjusting for insulin sensitivity (M/I), higher TAC was not associated with any measures of β-cell response. Numerical effect estimates, confidence intervals, and p-values were not provided in the abstract.
Why it matters
These findings indicate that habitual physical activity in early dysglycemia is linked to metabolic health primarily via improved peripheral insulin sensitivity rather than direct enhancements in β-cell secretory capacity.
Limits
The study is cross-sectional, preventing causal inference. The abstract reports no numerical effect sizes or confidence intervals for the observed associations. Results apply specifically to adults with prediabetes or drug-naive, recently diagnosed type 2 diabetes and may not generalize to treated or advanced populations.
Cited by
- supports Physical activity enhances muscle insulin sensitivity, leading to lower insulin secretion in response to a given quantity of carbohydrate.