Healthy lifestyle in the primordial prevention of cardiovascular disease among young women

Abstract

Background: Overall mortality rates from coronary heart disease (CHD) in the United States have declined in recent decades, but the rate has plateaued among younger women. The potential for further reductions in mortality rates among young women through changes in lifestyle is unknown.

Objectives: The aim of this study was to estimate the proportion of CHD cases and clinical cardiovascular disease (CVD) risk factors among young women that might be attributable to poor adherence to a healthy lifestyle.

Methods: A prospective analysis was conducted among 88,940 women ages 27 to 44 years at baseline in the Nurses' Health Study II who were followed from 1991 to 2011. Lifestyle factors were updated repeatedly by questionnaire. A healthy lifestyle was defined as not smoking, a normal body mass index, physical activity ≥ 2.5 h/week, television viewing ≤ 7 h/week, diet in the top 40% of the Alternative Healthy Eating Index-2010, and 0.1 to 14.9 g/day of alcohol. To estimate the proportion of CHD and clinical CVD risk factors (diabetes, hypertension, and hypercholesterolemia) that could be attributed to poor adherence to a healthy lifestyle, we calculated the population-attributable risk percent.

Results: During 20 years of follow-up, we documented 456 incident CHD cases. In multivariable-adjusted models, nonsmoking, a healthy body mass index, exercise, and a healthy diet were independently and significantly associated with lower CHD risk. Compared with women with no healthy lifestyle factors, the hazard ratio for CHD for women with 6 lifestyle factors was 0.08 (95% confidence interval: 0.03 to 0.22). Approximately 73% (95% confidence interval: 39% to 89%) of CHD cases were attributable to poor adherence to a healthy lifestyle. Similarly, 46% (95% confidence interval: 43% to 49%) of clinical CVD risk factor cases were attributable to a poor lifestyle.

Conclusions: Primordial prevention through maintenance of a healthy lifestyle among young women may substantially lower the burden of CVD.

Keywords: coronary disease; diabetes; epidemiology; hypercholesterolemia; hypertension; risk factors.

Figure. Hazard ratios for coronary heart disease according to number of optimal lifestyle factors among women who have no CVD risk factors and one or more risk factors

The models were stratified by age and period and included parental history of MI, aspirin use, menopausal status, postmenopausal hormone use, parity, and oral contraceptive use. A ‘*’ indicates values significant at p = 0.05. P for interaction = 0.48.

Central Illustration. Hazard Ratios (95% CI) for Coronary Heart Disease or Diagnosis With a Clinical CVD Risk Factor (Diabetes, Hypertension, or Hypercholesterolemia) for Optimal Levels of Lifestyle Factors

The models were stratified by age (in months) and time period and included parental history of MI before 60 years of age, aspirin use, menopausal status, postmenopausal hormone use, parity, and oral contraceptive use. For CHD, the model also included history of hypertension or hypercholesterolemia at baseline. All healthy lifestyle factors were included simultaneously in the same model. CHD = coronary heart disease; MI = myocardial infarction.