Body mass index and the initial manifestation of coronary heart disease in women aged 40-59 years.

Abstract

A population-based case-control study was conducted to evaluate body mass as a coronary heart disease (CHD) risk factor among women 40-59 years of age. Cases were women aged 40-59 whose first manifestation of CHD was angina (No. = 133), nonfatal myocardial infarction (No. = 90), and sudden unexpected death (No. = 18) during 1960-1982. Two randomly selected controls were matched on age and time of the initial disease manifestation of the case. The adjusted relative risk for weight and body mass index respectively demonstrated a moderate association with all CHD as well as with angina, but no association with definite CHD (myocardial infarction or sudden unexpected death). To determine if the observed association between body mass index and angina was possibly attributable to differential misclassification bias (i.e. obese women were, in contrast to non-obese women, preferentially labelled as having coronary artery disease) data for angina were stratified by confirmed versus unconfirmed cardiac origin. In the unconfirmed angina analysis, the 75th percentile for weight contrasted with the 25th percentile was associated with a 50% increase in the risk of being labelled as having angina (adjusted odds ratio (OR) = 1.59, 95% confidence interval (CI): 1.11-2.28), while a similar contrast for Quetelet Index was also associated with a nearly 2-fold increase in the risk of being labelled as having angina (adjusted OR = 1.74, 95% CI: 1.18-2.57).(ABSTRACT TRUNCATED AT 250 WORDS)