Improvement in β-cell function after diet-induced weight loss is associated with decrease in pancreatic polypeptide in subjects with type 2 diabetes
Journal of Diabetes and its Complications, 06/07/2012
Kahleova H et al. – After diet–induced weight loss, β–cell function improved in T2D subjects and remained unchanged after the addition of exercise. The authors demonstrate for the first time that these changes are associated with a decrease in pancreatic polypeptide (PP) secretion.
Methods- Subjects with T2D (n=74) received 24weeks of intervention: 12weeks of slimming diet (-500kcal/day) and the subsequent 12weeks of diet were combined with aerobic exercise.
- All subjects were examined at weeks 0, 12 and 24.
- β-cell function was assessed during standard meal tests.
- Insulin secretory rate (ISR) was calculated by C-peptide deconvolution, and β-cell function was quantified with a mathematical model.
- Plasma concentrations of gastrointestinal peptides were measured in a fasting state and during hyperinsulinemia induced by hyperinsulinemic isoglycemic clamp.
- Mean weight loss was 5.03±4.38kg (p<0.001) in weeks 0–12.
- Weight did not change significantly in weeks 12–24.
- Both insulin secretion at the reference level and glucose sensitivity increased in weeks 0–12 (by 33%±54% and by 26%±53%, respectively, p<0.001) and remained unchanged in weeks 12–24.
- Both fasting and hyperinsulinemic plasma concentrations of pancreatic polypeptide (PP) decreased in weeks 0–12 (p<0.05 for both) and did not change significantly in weeks 12–24.
- Changes in insulin secretion at the reference level correlated negatively with plasma concentrations of PP during hyperinsulinemia (r=-0.36; p<0.001).
- Changes in glucose sensitivity correlated negatively with changes in plasma concentrations of PP, both in fasting and during hyperinsulinemia (r=-0.2; p=0.01 for both).
- The correlations remained significant after adjustment for changes in body-mass-index.
