The effects of one year of voluntary physical activity and structured exercise on patients with type 2 diabetes and the metabolic syndrome : the Italian diabetes and exercise study

Abstract

The IDES study was a large prospective multicentre Randomized Controlled Trial aimed to evaluate the efficacy of twelve months of intensive lifestyle intervention on modifiable cardiovascular disease risk factors in a large cohort of people (606 subjects) with type2 diabetes and the metabolic syndrome. Primary outcome was HbA1c reduction, secondary outcomes were traditional and non traditional cardiovascular risk factors. This thesis was a sub-projects of the IDES study aimed to evaluate the effects of a structured exercise program on a series of selected metabolic (HbA1c; systolic and diastolic blood pressure; BMI; waist circumference) and physical fitness parameters (maximal oxygen consumption, upper body and lower body strength, flexibility) and the difference between high and low exercise intensities. Study Design: 606 Subjects were randomized into a control group receiving a standard treatment (exercise counselling aimed to increase voluntary physical activity; plus diet, plus drugs) and an exercise group receiving the same standard treatment plus a combined aerobic and resistance exercise program (two sessions a week). Voluntary physical activity was recorded by means of a validated questionnaire (Minnesota Leisure Time Physical Activity), exercise was recorded by means of a dedicated software. Both physical activity and exercise data were transformed into metabolic equivalents (METs.h-1.w-1 ). The exercise group was further randomized into an high intensity group (70% of maximal oxygen consumption and 80% of one repetition maximum) and a low intensity group (55% of maximal oxygen consumption and 60% of one repetition maximum) to see the effects of different exercise intensities on the selected metabolic and physical fitness parameters. Results: both exercise and control group statistically increased their voluntary physical activity. The exercise groups showed a statistical significant improvement in all the metabolic and physical fitness parameters; control group significantly improved only in maximal oxygen consumption and systolic and diastolic blood pressure. When the control group was divided into quintiles of accumulated non supervised physical activity, the more active subjects showed improvements in all the evaluated parameters. When the exercise group was divided into high and low intensity groups and further analyzed, no differences were evaluated between the two exercise group. Conclusion: This study showed that a structured exercise program plus a standard treatment is better than a standard treatment alone in the improvement of the selected metabolic and physical fitness parameters. Only the more active subjects in the control group showed significant improvements in all the evaluated parameters. Moreover, in this class of subjects training at different exercise intensity did not produced significant differences. [Resumen Teseo]