Effects of regular walking on cardiovascular risk factors and body composition in normoglycemic women and women with type 3 diabetes

OBJECTIVE - To examine the impact of a 12-week walking program on body comp osition and risk factors for cardiovascular disease in women with type 2 di abetes and in normoglycemic women with first-degree diabetic relatives. RESEARCH DESIGN AND METHODS - There were 11 postmenopausal women with type 2 diabetes and 20 normoglycemic women of similar age and BMI who were asked to walk 1 h per day on 5 days each week for 12 weeks. Fitness (estimated V O2max) was assessed with a 1.6-km walking test; body composition was measur ed by dual-energy X-ray absorptiometry; and sex hormone, metabolic, and lip id concentrations were measured in serum. RESULTS - After 12 weeks, estimated VO2max improved in both groups (P < 0.0 05). In the diabetic women, BMI and fat content of the upper body and andro id waist region decreased (P < 0.05). Concentrations of fasting blood gluco se (P < 0.05), HbA(1c) (P < 0.05), total cholesterol (P < 0.005), and LDL c holesterol (P < 0.05) decreased, while HDL cholesterol and sex hormones wer e unchanged. In contrast, normoglycemic women failed to lose body fat after 12 weeks of exercise in a walking program. However, their HbA(1c), total c holesterol, LDL cholesterol, sex hormone-binding globulin, and total testos terone concentrations decreased (P < 0.05). On pooling the data and includi ng diabetes as a categorical grouping variable, step-wise multiple regressi on analysis indicated that the change in centralized body fat, but not the change in VO2max was related to change in fasting blood glucose. CONCLUSIONS - Twelve weeks of walking increased the fitness of diabetic and normoglycemic women. Improvement of fasting blood glucose was related to t he loss of centralized body fat rather than to improved fitness.