Lipid assessment, metabolic syndrome and coronary heart disease risk

Although the total to high-density lipoprotein cholesterol ratio (TC/HDL-C) has been used for decades to identify individuals at risk for coronary heart disease (CHD), apolipoprotein-based (apolipoprotein B/apolipoprotein A-I [apoB/apoA-I]) and nuclear magnetic resonance spectroscopy (NMR)-based lipoprotein concentrations (low-density lipoprotein(NMR) /high-density lipoprotein(NMR) [LDL(NMR) /HDL(NMR)]) may also be useful for CHD risk stratification.

In a case-control study conducted within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk study population, 870 individuals who developed CHD during a 6-year follow-up were matched to 1659 controls on the basis of gender, age and enrollment time. LDL(NMR) and HDL(NMR) were measured by proton NMR spectroscopy.

After adjusting for traditional CHD risk factors, men in the top quintile of the various lipoprotein ratios proved to be at increased CHD risk (OR = 2·59 [95% IC, 1·76-3·83] for TC/HDL-C ratio, 2·59 [1·75-3·83] for apoB/apoA-I ratio and 2·78 [1·86-4·17] for LDL(NMR) /HDL(NMR) ratio) compared with men in the bottom quintile. Similar associations were observed in women (OR = 2·86 [1·71-4·80] for TC/HDL-C ratio, 2·94 [1·74-4·97] for apoB/apoA-I ratio and 2·03 [1·21-3·43] for LDL(NMR)/HDL(NMR) ratio). Compared with participants with only one component of the metabolic syndrome, those who had five had an increased TC/HDL-C ratio (73·0% and 80·4% in men and women respectively), apoB/apoA-I ratio (58·0% and 62·9% in men and women respectively) and for LDL(NMR)/HDL(NMR) ratio (52·6% and 54·1% in men and women respectively).

In this European study population, the TC/HDL-C, apoB/apoA-I and LDL(NMR) /HDL(NMR) ratios were similarly associated with components of the metabolic syndrome and CHD risk.