Total cholesterol/HDL cholesterol ratio vs LDL cholesterol/HDL cholesterolratio as indices of ischemic heart disease risk in men - The Quebec Cardiovascular Study

Background: Total cholesterol (TC)/high-density lipoprotein cholesterol (HD L-C) and low-density lipoprotein cholesterol (LDL-C)/HDL-C ratios are used to predict ischemic heart disease risk. There is, however, no consensus on which of these 2 indices is superior. The objective of the present study wa s to present evidence that the LDL-C/HDL-C ratio may underestimate ischemic heart disease risk in overweight hyperinsulinemic patients with high trigl yceride (TG)-low HDL-C dyslipidemia. Methods: A total of 2103 middle-aged men in whom measurements of the metabo lic profile were performed in the fasting state were recruited from 7 subur bs of the Quebec metropolitan area. Results: The relationship of LDL-C/HDL-C to TC/HDL-C ratios was examined am ong men in the Quebec Cardiovascular Study classified into tertiles of fast ing TG levels. For any given LDL-C/HDL-C ratio, the TC/HDL-C ratio was high er among men in the top TG tertile (> 168 mg/dL [>1.9 mmol/L]) than in men in the first and second TG tertiles. Adjustment of the TC/HDL-C ratio for L DL-C/HDL-C by covariance analysis generated significant differences in aver age TC/HDL-C ratios among TG tertiles (P < .001). Greater differences in fe atures of the insulin resistance syndrome (insulinemia, apolipoprotein B, a nd LDL size) were noted across tertiles of the TC/HDL-C ratio than tertiles of the LDL-C/HDL-C ratio. Conclusion: Variation in the TC/HDL-C ratio may be associated with more sub stantial alterations in metabolic indices predictive of ischemic heart dise ase risk and related to the insulin resistance syndrome than variation in t he LDL-C/HDL-C ratio.