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/m^2) and 36 matched female controls (age 33.6 ± 6.1 years, BMI 27.3 ± 4.7 kg/m^2) 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 $$\left( {\dot VO_{2\max } } \right)$$ 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 $$\dot VO_{2\max } $$ 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).