Pancreatic β-cell function increases in a linear dose-response manner following exercise training in adults with prediabetes

Am J Physiol Endocrinol Metab. 2013 Nov 15;305(10):E1248-54. doi: 10.1152/ajpendo.00260.2013. Epub 2013 Sep 17.


Although some studies suggest that a linear dose-response relationship exists between exercise and insulin sensitivity, the exercise dose required to enhance pancreatic β-cell function is unknown. Thirty-five older obese adults with prediabetes underwent a progressive 12-wk supervised exercise intervention (5 days/wk for 60 min at ~85% HRmax). Insulin and C-peptide responses to an OGTT were used to define the first- and second-phase disposition index (DI; β-cell function = glucose-stimulated insulin secretion × clamp-derived insulin sensitivity). Maximum oxygen consumption (Vo2max) and body composition (dual-energy X-ray absorptiometry and computed tomography) were also measured before and after the intervention. Exercise dose was computed using Vo2/heart-rate derived linear regression equations. Subjects expended 474.5 ± 8.8 kcal/session (2,372.5 ± 44.1 kcal/wk) during the intervention and lost ~8% body weight. Exercise increased first- and second-phase DI (P < 0.05), and these changes in DI were linearly related to exercise dose (DIfirst phase: r = 0.54, P < 0.001; DIsecond phase: r = 0.56, P = 0.0005). Enhanced DI was also associated with increased Vo2max (DIfirst phase: r = 0.36, P = 0.04; DIsecond phase: r = 0.41, P < 0.02) but not lower body fat (DIfirst phase: r = -0.21, P = 0.25; DIsecond phase: r = -0.30, P = 0.10) after training. Low baseline DI predicted an increase in DI after the intervention (DIfirst phase: r = -0.37; DIsecond phase: r = -0.41, each P < 0.04). Thus, exercise training plus weight loss increased pancreatic β-cell function in a linear dose-response manner in adults with prediabetes. Our data suggest that higher exercise doses (i.e., >2,000 kcal/wk) are necessary to enhance β-cell function in adults with poor insulin secretion capacity.

Keywords: aging; glucose intolerance; insulin resistance; obesity; type 2 diabetes.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Exercise / physiology*
  • Female
  • Humans
  • Insulin-Secreting Cells / physiology*
  • Linear Models
  • Male
  • Middle Aged
  • Oxygen Consumption / physiology
  • Physical Education and Training / methods
  • Prediabetic State / physiopathology*
  • Prediabetic State / therapy
  • Time Factors
  • Weight Loss / physiology