Effectiveness of a lifestyle intervention on metabolic syndrome. A randomized controlled trial

Abstract

BACKGROUND: Intensive lifestyle intervention significantly reduces the progression to diabetes in high-risk individuals. OBJECTIVE: It is not known whether a program of moderate intervention might effectively reduce metabolic abnormalities in the general population. DESIGN: Two-arm randomized controlled 1-year trial. PATIENTS: Three hundred and thirty-five patients participated from a dysmetabolic population-based cohort of 375 adults aged 45-64 years in northwestern Italy. MEASUREMENTS: We compared the effectiveness of a general recommendation-based program of lifestyle intervention carried out by trained professionals versus standard unstructured information given by family physicians at reducing the prevalence of multiple metabolic and inflammatory abnormalities. RESULTS: At baseline, clinical/anthropometric/laboratory and lifestyle characteristics of the intervention (n=169) and control (n=166) groups were not significantly different. The former significantly reduced total/saturated fat intake and increased polyunsaturated fat/fiber intake and exercise level compared to the controls. Weight, waist circumference, high-sensitivity C-reactive protein, and most of the metabolic syndrome components decreased in the intervention group and increased in the controls after 12 months. Lifestyle intervention significantly reduced metabolic syndrome (odds ratio [OR]=0.28; 95% CI 0.18-0.44), with a 31% (21-41) absolute risk reduction, corresponding to 3.2 (2-5) patients needing to be treated to prevent 1 case after 12 months. The intervention significantly reduced the prevalence of central obesity (OR=0.33; 0.20-0.56), and hypertriglyceridemia (OR=0.48; 0.31-0.75) and the incidence of diabetes (OR=0.23; 0.06-0.85). CONCLUSION: A lifestyle intervention based on general recommendations was effective in reducing multiple metabolic/inflammatory abnormalities. The usual care by family physicians was ineffective at modifying progressive metabolic deterioration in high-risk individuals. © 2007 Society of General Internal Medicine.