Leisure-Time Physical Activity and Coronary Risk Factors in Women

BACKGROUND: Evidence that physical activity is cardioprotective in women is not as strong as that observed in men. Furthermore, the extent to which exercise protects against coronary heart disease via its influence on classical risk factors remains unclear. This study examines the relationship between reported physical activity, a range of coronary heart disease risk factors and a 10-year predicted coronary heart disease risk score. METHODS: A cross-sectional study of 14,077 female employees aged 30-64 years who were screened between 1988 and 1991 was employed. Measurements included systolic and diastolic blood pressure, body mass index, serum total cholesterol, high-density lipoprotein cholesterol, total cholesterol:high-density lipoprotein cholesterol ratio, low-density lipoprotein cholesterol, triglycerides, apolipoprotein A1, apolipoprotein B, lipoprotein a and fasting blood glucose. Participants were divided into three groups according to reported average frequency of vigorous leisure-time physical activity, that is zero, one to two, or three or more episodes per week. RESULTS: Increasing activity frequency was associated with lower systolic and diastolic blood pressure, total cholesterol, total cholesterol:high-density lipoprotein cholesterol ratio, triglycerides and body mass index (all P < 0.001), low-density lipoprotein cholesterol (P = 0.003), apolipoprotein B (P = 0.04) and blood glucose (P = 0.01) and higher high-density lipoprotein cholesterol (P < 0.001) and apolipoprotein A1 (P = 0.03). There was no association with lipoprotein a. After controlling for possible confounders, these relationships remained statistically significant except for apolipoprotein B and glucose. The odds ratios for being in the top quintile of predicted 10-year coronary heart disease risk for individuals in each category of activity were 1.0 (inactive), 0.70 (one to two episodes of activity per week) and 0.77 (three or more episodes of activity per week). CONCLUSION: Women engaging in vigorous, leisure-time physical activity have a less atherogenic coronary heart disease risk factor profile than those who do not, which translates into a potential reduction of approximately 30% in coronary heart disease risk.