CONTEXT: Understanding intersubject variability in glycemic control following exercise training will help individualize treatment.
OBJECTIVE: Our aim was to determine whether this variability is related to training-induced changes in insulin sensitivity or pancreatic β-cell function.
DESIGN, SETTING, AND PARTICIPANTS: We conducted an observational clinical study of 105 subjects with impaired glucose tolerance or type 2 diabetes.
INTERVENTIONS AND MAIN OUTCOME MEASURES: Individual subject changes in fitness (VO2max), glycemia (glycosylated hemoglobin, fasting glucose, oral glucose tolerance test), insulin sensitivity (hyperinsulinemic-euglycemic clamp), oral glucose-stimulated insulin secretion (GSIS), and disposition index (DI) were measured following 12 to 16 weeks of aerobic exercise training. Regression analyses were used to identify relationships between variables.
RESULTS: After training, 86% of subjects increased VO2max and lost weight. Glycosylated hemoglobin, fasting glucose, and 2-hour oral glucose tolerance test were reduced in 69%, 62%, and 68% of subjects, respectively, while insulin sensitivity improved in 90% of the participants. Changes in glycemic control were congruent with changes in GSIS such that 66% of subjects had a reduction in first-phase GSIS, and 46% had reduced second-phase GSIS. Training increased first- and second-phase DI in 83% and 74% of subjects. Training-induced changes in glycemic control were related to changes in GSIS (P < .05), but not insulin sensitivity or DI, and training-induced improvements in glycemic control were largest in subjects with greater pretraining GSIS.
CONCLUSIONS: Intersubject variability in restoring glycemic control following exercise is explained primarily by changes in insulin secretion. Thus, baseline and training-induced changes in β-cell function may be a key determinant of training-induced improvements in glycemic control.
|Number of pages||11|
|Journal||The Journal of clinical endocrinology and metabolism|
|Publication status||Published - Oct 2013|
- Blood Glucose
- Body Mass Index
- Diabetes Mellitus, Type 2
- Exercise Therapy
- Glucose Intolerance
- Glucose Tolerance Test
- Insulin Resistance
- Insulin-Secreting Cells
- Treatment Outcome
- Weight Loss