Association between baseline risk factors, cigarette smoking, and CHD mortality after 10.5 years. MRFIT Research Group

Abstract

Methods: The association between baseline risk factors and death from coronary heart disease (CHD) after 10.5 years was investigated for cigarette smokers and nonsmokers who entered the Multiple Risk Factor Intervention Trial (MRFIT).

Results: Rates per thousand person-years of CHD mortality were higher for smokers than for nonsmokers at every level of baseline risk factors examined. There were significant associations between CHD mortality and plasma low-density lipoprotein and high-density lipoprotein cholesterol for smokers and nonsmokers. The inverse association between CHD mortality and high-density lipoprotein cholesterol was significantly stronger among nonsmokers compared with that among smokers and was attributable to a very strong association for former smokers. An inverse relationship between CHD and body mass index was evident for smokers and nonsmokers. Rates of CHD death rose sharply when levels of fasting glucose exceeded 140 mg/dl, and there was a significant association between CHD mortality and blood sugar levels for nonsmokers but not for smokers. For both smokers and nonsmokers, an inverse univariate association between alcohol consumption and CHD mortality was evident. This association, however, did not persist after adjustment for plasma high-density lipoprotein cholesterol.

Conclusion: Intervention on blood pressure and blood lipids is particularly important among cigarette smokers because of their increased risk of CHD death. The different associations between high-density lipoprotein cholesterol, fasting serum glucose, and CHD mortality for smokers and nonsmokers requires further investigation.