Hypertriglyceridemia-waist phenotype marks high coronary risk
MedWire News: The hypertriglyceridemia-waist phenotype is a simple and robust marker for increased coronary risk, shows an analysis of the EPIC-Norfolk cohort.
"This was the case even among participants without traditional risk factors for coronary artery disease," note Jean-Pierre Després (Institut universitaire de cardiologie et de pneumologie de Québec, Canada) and colleagues in the Canadian Medical Association Journal.
The Norfolk cohort of the EPIC (European Prospective Investigation into Cancer and Nutrition) study comprises 21,787 people aged 45-79 years. At the time of the current analysis, they had been followed-up for 9.8 years, during which time 2109 developed coronary artery disease (CAD).
At baseline, 558 men and 292 women had the hypertriglyceridemia-waist phenotype, defined as a waist circumference of at least 90 cm in men and 85 cm in women combined with triglyceride levels of at least 2.0 and 1.5 mmol/l, respectively.
The researchers say that the original proponents of the hypertriglyceridemia-waist phenotype suggested that it could be a marker for hyperinsulinemia, hyperapolipoprotein B, and small, dense low-density lipoprotein (LDL) particles.
In the current study, this was borne out in a subanalysis of 2840 people who had complete anthropometric and metabolic data available. This found increased levels of apolipoprotein (apo) B and smaller LDL particles in participants with the hypertriglyceridemia-waist phenotype relative to those without, along with raised blood pressure and C-reactive protein and reduced levels of high-density lipoprotein cholesterol.
For instance, LDL peak particle size was 256.9 Å in men with the phenotype, compared with 261.0 Å in those without, while apo B levels were 1.44 versus 1.19 g/l.
CAD was 2.40-fold more likely to appear in men and 3.84-fold more likely to appear in women with the hypertriglyceridemia-waist phenotype than in their counterparts with normal waist circumferences and triglyceride levels.
After accounting for confounders, including age, lipid variables, blood pressure, and smoking habit, the risk increases were attenuated to 1.28- and 1.67-fold in men and women, respectively. But these remained statistically significant.
When classified into tertiles of coronary risk according to their Framingham risk scores, men and women with the hypertriglyceridemia-waist phenotype were at higher coronary risk than those in the same tertile who did not have the phenotype.
Després et al stress that the hypertriglyceridemia-waist phenotype should not replace current criteria for diagnosing the metabolic syndrome.
But they suggest that it might add value to coronary risk assessment tools such as the Framingham risk score.
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By Eleanor McDermid