EXPECTED GAINS IN LIFE EXPECTANCY FROM VARIOUS CORONARY HEART-DISEASE RISK FACTOR MODIFICATIONS

Background. Despite much evidence that modifying risk factors for coronary heart disease can decrease morbidity and mortality, little is known about the impact of risk-factor modification on life expectancy. Methods and Results. We used the Coronary Heart Disease Policy Model, a state-transition computer simulation of the US population, to forecast potential gains in life expectancy from risk-factor modification for the cohort of Americans turning age 35 in 1990. Among 35-year-old men, we projected that the population-wide increase in life expectancy would be about 1.1 years from strict blood pressure control, 0.8 years from smoking cessation, 0.7 years from reduction of serum cholesterol to 200 mg/dl, and about 0.6 years from weight loss to ideal body weight. For women, reducing cholesterol to 200 mg/dl would have the greatest estimated impact-a gain of 0.8 years-whereas smoking cessation, blood pressure control, or weight loss would yield population-wide gains of 0.7, 0.4, and 0.4 years, respectively. Gains for 35-year-old individuals having a given risk factor are greater. We estimate that, on average, male smokers would gain 2.3 years from quitting smoking; males with hypertension would gain 1.1-5.3 years from reducing their diastolic blood pressure to 88 mm Hg; men with serum cholesterol levels exceeding 200 mg/dl would gain 0.5-4.2 years from lowering their serum cholesterol level to 200 mg/dl; and overweight men would gain an average of 0.7-1.7 years from achieving ideal body weight. Corresponding projected gains for at-risk women are 2.8 years from quitting smoking, 0.9-5.7 years from lowering blood pressure, 0.4-6.3 years from decreasing serum cholesterol, and 0.5-1.1 years from losing weight. Eliminating coronary heart disease mortality is estimated to extend the average life expectancy of a 35-year-old man by 3.1 years and a 35-year-old woman by 3.3 years. Conclusions. Population-wide gains in life expectancy from single risk-factor modifications are modest, but gains to individuals at risk can be more substantial.