Non-HDL Cholesterol Contributes to the “Hypertriglyceridemic Waist” as a Cardiovascular Risk Factor
The Hoorn Study
The Hoorn Study
Lemieux et al. (1) described the “hypertriglyceridemic waist” as a marker of the atherogenic metabolic triad (hyperinsulinemia, hyperapolipoprotein B, and small, dense LDL) in men. In 287 men, those with a waist circumference ≥90 cm and with triglyceride levels ≥2 mmol/l had an odds ratio of 3.6 (95% CI 1.17–10.93) for having angiographically diagnosed coronary artery disease compared with those with smaller waists and lower triglyceride concentrations. We recently reported (2) the predictive value of non-HDL cholesterol and triglyceride concentrations for 10-year cardiovascular disease incidence in the Hoorn Study, a population-based cohort study of glucose tolerance. In people with abnormal glucose metabolism, high triglyceride concentration was associated with the risk of cardiovascular disease, particularly in people with high non-HDL cholesterol, but not in those with normal glucose metabolism (3).
We used the Hoorn Study data to prospectively investigate whether the risk associated with the hypertriglyceridemic waist differs between subjects with normal and abnormal glucose metabolism. Additionally, we studied whether non-HDL cholesterol adds to the predictive power of the hypertriglyceridemic waist in predicting cardiovascular disease. The Hoorn Study is a cohort study among 2,484 subjects in the Netherlands that started in 1989. Cardiovascular disease was defined as first new cardiovascular fatal or nonfatal event (3). Because the cutoff points for waist girth in men used by Lemieux et al. (1) are not applicable for women, we used waist ≥94 cm in men and ≥80 cm in women, according to the European Group of Insulin Resistance definition (4). The results show that in particular the combination of a large waist and a high triglyceride level (≥2 mmol/l) was associated with cardiovascular disease in subjects with both normal and abnormal glucose metabolism (hazard ratio 1.82 [95% CI 1.27–2.62] and 2.68 [1.89–3.81], respectively). These findings concur with those of Lemieux et al. (1). In addition, we observed that after stratification for non-HDL cholesterol, defined as the difference between total cholesterol and HDL cholesterol concentration, the risk associated with the hypertriglyceridemic waist was further increased by 50% in the presence of high non-HDL cholesterol concentrations (above the median, i.e., 5.2 mmol/l for men and 5.3 mmol/l for women) (Fig. 1). The hazard ratio for subjects with a combination of large waist, high triglycerides, and high non-HDL cholesterol concentrations was 2.94 (2.06–4.19).
Non-HDL cholesterol is closely linked to visceral obesity (5). Non-HDL cholesterol includes all cholesterol in potentially atherogenic triglyceride-rich lipoproteins and may be a better predictor for the “bad” triglycerides, which are associated with increased risk of cardiovascular disease (6).
In conclusion, in the Hoorn Study, non-HDL cholesterol contributes considerably to the risk associated with the hypertriglyceridemic waist. Further studies are clearly required to evaluate the clinical relevance of monitoring these particular variables for the assessment of cardiovascular risk.
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