Does a population-based multifactorial lifestyle intervention increase social inequality in physical activity? The Inter99 study.

AIM: To examine the effect of a multifactorial lifestyle intervention on 5-year change in physical activity (PA) and to explore whether length of education had an impact on the effect of the intervention. METHODS: Two random samples (high intervention group A, n=11 708; low intervention group B, n=1308) were invited for a health examination, assessment of absolute risk of ischemic heart disease and individual lifestyle counselling. The participation rate was 52.5%. High-risk individuals in group A were also offered group-based counselling on diet and PA and/or smoking cessation. High-risk individuals in group B were referred to usual care. All high-risk individuals were reinvited for examination and counselling after 1 and 3 years, and all participants were reexamined after 5 years. The control group (group C, n=5264, response rate 61.1%) answered a mailed questionnaire. Change in self-reported PA from baseline to 5-year follow-up was the main outcome. Level of education was classified as no vocational training, ≤4 years and >4 years. Data were analysed using longitudinal linear regression models with random intercepts. RESULTS: In men, the high-intensity intervention had a beneficial effect on PA level after 5 years. The age- or time-related decrease in PA was approximately 30 min/week less compared to men in the control group (p<0.0001). Level of education had no significant impact on the effect of the intervention neither in men (p=0.39) nor in women (p=0.32). CONCLUSION: A population-based multifactorial lifestyle intervention did not influence social inequality in PA.

Five-year change in physical activity is associated with changes in cardiovascular disease risk factors: the Inter99 study.

OBJECTIVE: To evaluate whether five-year changes in self-reported physical activity level were associated with changes in waist circumference, weight, serum lipids and blood pressure. METHODS: In the Inter99 study (1999-2006) in Copenhagen, Denmark, 4039 men and women (30-60 years) answered questions on lifestyle and provided blood samples and anthropometric measures at baseline and after five years. Multiple regression analyses were performed with five-year value of each cardiovascular biomarker as outcome and change in physical activity level as explanatory variable. RESULTS: Approximately 50% of the study population were men (n=2023). Change in physical activity level was inversely associated with change in weight (p<0.0001), waist (p<0.0001), diastolic blood pressure (p=0.04), total cholesterol (p=0.006), LDL (p=0.007), triglycerides (p=0.02) and with a composite risk score "the Copenhagen risk score" (p<0.0001), and positively associated with HDL in men (p=0.01). CONCLUSION: Five-year changes in physical activity level were significantly associated with relevant changes in weight, waist circumference, diastolic BP and serum lipids in a population-based cohort of adult men and women. Change in physical activity level induced a significant change in HDL concentration in men only. Women's use of hormone replacement therapy may partly explain this gender difference.