Exercise training has greater effects on insulin sensitivity in daughters of patients with type 2 diabetes than in women with no family history of diabetes

Abstract

Aims/hypothesis: Sedentary offspring of patients with type 2 diabetes are often more insulin-resistant than persons with no family history of diabetes, but when active or fit offspring of type 2 diabetic patients are compared with non-diabetic persons, differences in insulin resistance are less evident. This study aimed to determine the effects of an exercise training intervention on insulin sensitivity in both groups. Methods: Women offspring (n=34) of type 2 diabetic patients (offspring age 35.6±7.0 years, BMI 28.1±5.1 kg/m2) and 36 matched female controls (age 33.6±6.1 years, BMI 27.3±4.7 kg/m2) participated. Body composition, fitness and metabolic measurements were made at baseline and after a controlled 7 week exercise intervention. Results: At baseline, insulin sensitivity index (ISI) was 22% lower in offspring than controls (p<0.05), despite similar body fat and maximal oxygen uptake (V̇O2max) values in the two groups. ISI increased by 23% (p<0.05) in offspring following the exercise intervention, compared with 7% (NS) in the controls. Increases in V̇O2max were similar in both groups (controls 12%, offspring 15%, p<0.05 for both). Plasma leptin concentrations decreased significantly in the offspring (-24%, p<0.01) but not in controls (0%, NS). Change in ISI correlated significantly with baseline ISI (r=-0.47, p<0.0005) and change in leptin (r=-0.43, p<0.0005). The latter relationship was not attenuated by adjustment for changes in body fat. Conclusions/interpretation: Offspring, but not controls, significantly increased ISI in response to an exercise intervention, indicating that insulin sensitivity is more highly modulated by physical activity in daughters of patients with type 2 diabetes than in women with no family history of the disease. Trial registration: NCT00268541. Funding: British Heart Foundation (PG/03/145). © 2008 The Author(s).