Leisure-Time Physical Activity and the Metabolic Syndrome in the Finnish Diabetes Prevention Study

OBJECTIVE

To assess the effects of leisure-time physical activity (LTPA) and resistance training on metabolic syndrome (MetS) and its components in a post hoc analysis of the Finnish Diabetes Prevention Study, a randomized controlled lifestyle counseling trial.

RESEARCH DESIGN AND METHODS

A cohort of 486 middle-aged overweight men and women with impaired glucose tolerance were followed for an average of 4.1 years. The intervention and control groups were combined in the analyses. LTPA was assessed by questionnaires, dietary intake by food records, and features of the MetS by anthropometric and biochemical measures annually. Resistance training sessions were documented for 137 participants.

RESULTS

Increased moderate-to-vigorous LTPA, even after adjustments for changes in dietary intakes of total and saturated fat, fiber, and energy, and change in BMI was associated with a greater likelihood for resolution (29.7 vs. 19.1%; P = 0.004 in the upper versus lower third of change) and a lesser likelihood for development (23.5 vs. 44.7%; P = 0.041) of the MetS. Of the components of the MetS, the increase in moderate-to-vigorous LTPA was associated most strongly with improvement of glycemia. Among the 137 participants who participated in resistance training, MetS components were favorable in individuals who were in the upper third of participation rate (median 51 times/year) compared with individuals in the lowest third (median 8.5 times/year).

CONCLUSIONS

Increased moderate-to-vigorous LTPA was associated with a decreased likelihood of developing the MetS and an increased likelihood of its resolution in individuals at high risk for type 2 diabetes.The metabolic syndrome (MetS) is a constellation of interrelated metabolic risk factors, including abdominal obesity, insulin resistance, hyperglycemia, dyslipidemia, and elevated blood pressure, often accompanied by a prothrombotic and proinflammatory state (1,2). The underlying pathophysiology of the MetS is unclear, but both insulin resistance and abdominal obesity are considered main components (1,2). The MetS increases the risk of both type 2 diabetes (3) and cardiovascular disease (4,5).Recent recommendations for the prevention and treatment of the MetS and its components promote increased physical activity (including aerobic and resistance exercise), a healthy diet, and weight loss (2,6–8). In lifestyle interventions trials, the incidence of type 2 diabetes has been reduced by more than half in individuals with impaired glucose tolerance, and the prevalence of the MetS has also been decreased (9,10). In the Finnish Diabetes Prevention Study (DPS), increased moderate-to-vigorous leisure-time physical activity (LTPA) was strongly associated with a lower risk of type 2 diabetes, independently of dietary changes and weight loss (11).Some prospective epidemiological studies and uncontrolled trials have suggested that increased moderate-to-vigorous exercise decreases the incidence or prevalence of the MetS (8,12,13). However, data on the role of changes in LTPA in the prevention and treatment of the MetS in long-term studies are limited. Therefore, we conducted a post hoc analysis of the Finnish DPS. Our hypothesis was that the change in LTPA and participation in resistance training would be associated with the change in the MetS and its components.