Co-occurrence of metabolic factors and the risk of coronary heart disease: a prospective cohort study in the Netherlands.

BACKGROUND: Prevalence of metabolic factors such as diabetes, hypertension, obesity, HDL and total cholesterol that are associated with an increased risk of coronary heart disease (CHD) is increasing worldwide. However, less is known about combinations of these factors that are associated with the highest CHD risk. Therefore, the associations between combinations of these metabolic factors and the incidence of CHD, acute myocardial infarction (AMI), and unstable angina pectoris (UAP) were studied in the Cardiovascular Registry Maastricht (CAREMA) cohort study. METHODS: The CAREMA study consists of 21,148 participants, born in 1927-1977 and randomly sampled from Maastricht and surrounding communities in 1987-1997. At baseline, all participants completed a self-administered questionnaire. Height, weight, blood pressure, total and HDL cholesterol levels were measured during a physical examination. After follow-up of maximally 16.9 years, 780 CHD, 437 AMI, and 286 UAP cases of first occurrence were registered. Incidence rate ratios (RRs) were estimated using Cox proportional hazards models adjusted for age, sex, smoking, and alcohol consumption. RESULTS: Compared with subjects without any of the metabolic factors, the RRs of CHD were 2.37, 4.34, and 7.36 for subjects with 1, 2, or ≥ 3 metabolic factors, respectively. These RRs were higher for AMI but lower for UAP. Especially combinations of metabolic factors that included diabetes or both a low HDL (≤ 0.9 mmol/L in men; ≤ 1.0 mmol/L in women) and high total cholesterol (≥ 6.21 mmol/L) were associated with increased risks. CONCLUSION: The risk of total CHD, AMI, and UAP varies considerably between different combinations of metabolic factors.