Associations between overall physical activity level and cardiovascular risk factors in an adult population

It is well established that physical activity level is inversely associated with cardiovascular morbidity and mortality, and with all-cause mortality. However, the dose-response relationship between physical activity and other cardiovascular disease risk factors is not fully understood. The aim of the present study was to explore the dose-response relationship between daily physical activity, as measured by a metabolic equivalent score, and BMI, waist circumference, waist hip ratio, total cholesterol, HDL, LDL, triglycerides, systolic and diastolic blood pressure.

A total of 1693 men and women, 33-64 years of age, from the 3 year follow-up of a population-based intervention study, were included in this cross-sectional study. Information on physical activity and other lifestyle factors was obtained by self-report questionnaire. Associations between activity level and biological variables were explored by general linear regression.

Data from 835 (51%) men and 805 (49%) women were included. Mean age was 50.8 years (33-64). A significant inverse association between average 24-hour physical activity level < or =45 METs and waist circumference (men p = 0.012, women p = 0.011), BMI (p = 0.0004), waist-hip-ratio (p = 0.002) and triglycerides (p = 0.0001) was found as well as a positive association with HDL (p = <0.0001). In those with an activity level above 45 METs there were no associations. No association was found with total cholesterol, LDL, systolic or diastolic blood pressure.

This study suggests a linear dose-response relationship between activity level and certain biological cardiovascular risk factors up to a threshold of a daily 24 h MET-score of 45, which corresponds to a moderate physical activity level.