Changes in Physical Fitness Predict Improvements in Modifiable Cardiovascular Risk Factors Independently of Body Weight Loss in Subjects With Type 2 Diabetes Participating in the Italian Diabetes and Exercise Study (IDES)

Abstract

OBJECTIVE Physical fitness is inversely related to mortality in the general population and in subjects with type 2 diabetes. Here, we present data concerning the relationship between changes in physical fitness and modifiable cardiovascular risk factors in subjects with type 2 diabetes from the Italian Diabetes and Exercise Study. RESEARCH DESIGN AND METHODS Sedentary patients with type 2 diabetes (n = 606) were enrolled in 22 outpatient diabetes clinics and randomized to twice-a-week supervised aerobic and resistance training plus exercise counseling versus counseling alone for 12 months. Baseline to end-of-study changes in cardiorespiratory fitness, strength, and flexibility, as assessed by Vo2max estimation, a 5–8 maximal repetition test, and a hip/trunk flexibility test, respectively, were calculated in the whole cohort, and multiple regression analyses were applied to assess the relationship with cardiovascular risk factors. RESULTS Changes in Vo2max, upper and lower body strength, and flexibility were significantly associated with the variation in the volume of physical activity, HbA1c, BMI, waist circumference, high-sensitivity C-reactive protein (hs-CRP), coronary heart disease (CHD) risk score, and inversely, HDL cholesterol. Changes in fitness predicted improvements in HbA1c, waist circumference, HDL cholesterol, hs-CRP, and CHD risk score, independent of study arm, BMI, and in case of strength, also waist circumference. CONCLUSIONS Physical activity/exercise-induced increases in fitness, particularly muscular, predict improvements in cardiovascular risk factors in subjects with type 2 diabetes independently of weight loss, thus indicating the need for targeting fitness in these individuals, particularly in subjects who struggle to lose weight.