Blood Pressure and Fasting Plasma Glucose rather than Metabolic Syndrome Predict Coronary Artery Calcium Progression: The Rancho Bernardo Study

Abstract

Objective: To examine the association of the metabolic syndrome (MetS), defined by WHO and ATP-III criteria, and its components with coronary artery calcium (CAC) progression.

Research Design and Methods: Participants were 338 older community-dwelling men and women without known heart disease who had measurements of heart disease risk factors and coronary artery calcium (CAC) at 2 clinic visits with an average interval of 4.5 years. Progression was defined as an increase in total CAC volume score ≥2.5 mm³.

Results: At baseline mean age was 67.6 years; MetS was present in 15.1% by WHO criteria and 11.8% by ATP-III criteria; 5.3% met both criteria. Participants with WHO-defined MetS had a greater change in total CAC volume score than those without (P = 0.001). There was no significant difference in CAC volume change by ATP-III-defined MetS status (P = 0.69). Overall 46.4% of participants were CAC progressors. In logistic regression analyses adjusted for age, sex, smoking status, and low density lipoprotein cholesterol, neither WHO nor ATP-III defined MetS predicted CAC progression. Among MetS components, only hypertension was independently associated with CAC progression (OR 2.11 95% CI 1.33-3.3x, P = 0.002). Fasting blood glucose (>100 mg/dL) was an independent predictor of CAC progression, but only for the 118 participants younger than age 65 (OR 2.3 95% CI 1.01-5.5, P = 0.04).

Conclusions: In older adults without known heart disease, blood pressure levels and fasting plasma glucose were better independent determinants of CAC progression than MetS itself.