Total Cholesterol/HDL Cholesterol Ratio vs LDL Cholesterol/HDL Cholesterol Ratio as Indices of Ischemic Heart Disease Risk in Men

The Quebec Cardiovascular Study
Isabelle Lemieux, MSc; Benoît Lamarche, PhD; Charles Couillard, PhD; Agnès Pascot, MSc; Bernard Cantin, MD, PhD; Jean Bergeron, MD, MSc; Gilles R. Dagenais, MD; Jean-Pierre Després, PhD
Arch Intern Med. 2001;161:2685-2692.
Background Total cholesterol (TC)/high-density lipoprotein cholesterol (HDL-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 was to present evidence that the LDL-C/HDL-C ratio may underestimate ischemic heart disease risk in overweight hyperinsulinemic patients with high triglyceride (TG)–low HDL-C dyslipidemia.
Methods A total of 2103 middle-aged men in whom measurements of the metabolic profile were performed in the fasting state were recruited from 7 suburbs of the Quebec metropolitan area.
Results The relationship of LDL-C/HDL-C to TC/HDL-C ratios was examined among men in the Quebec Cardiovascular Study classified into tertiles of fasting TG levels. For any given LDL-C/HDL-C ratio, the TC/HDL-C ratio was higher 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 LDL-C/HDL-C by covariance analysis generated significant differences in average TC/HDL-C ratios among TG tertiles (P<.001). Greater differences in features of the insulin resistance syndrome (insulinemia, apolipoprotein B, and 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 substantial alterations in metabolic indices predictive of ischemic heart disease risk and related to the insulin resistance syndrome than variation in the LDL-C/HDL-C ratio.
From the Quebec Heart Institute, Laval Hospital Research Center Mss Lemieux and Pascot and Drs Couillard, Cantin, Dagenais, Després), and the Lipid Research Center, CHUL Research Center (CHUQ) (Drs Lamarche, Couillard, Cantin, Bergeron, and Després and Mss Lemieux and Pascot), Sainte-Foy, Quebec.