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

TLDR

Total cholesterol/HDL‑C and LDL‑C/HDL‑C ratios are used to predict ischemic heart disease risk, but no consensus exists on which index is superior. The study aimed to show that LDL‑C/HDL‑C may underestimate ischemic heart disease risk in overweight hyperinsulinemic men with high triglyceride–low HDL‑C dyslipidemia. The authors examined 2,103 middle‑aged men from Quebec, measuring fasting metabolic profiles and classifying them into triglyceride tertiles to compare LDL‑C/HDL‑C and TC/HDL‑C ratios. They found that, for a given LDL‑C/HDL‑C ratio, the TC/HDL‑C ratio was markedly higher in men with the highest triglycerides, and that TC/HDL‑C variation correlated more strongly with insulin‑resistance markers than LDL‑C/HDL‑C, indicating TC/HDL‑C is a better risk indicator.

Abstract

<h3>Background</h3> 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. <h3>Methods</h3> 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. <h3>Results</h3> 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 (&gt;168 mg/dL [&gt;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 (<i>P</i>&lt;.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. <h3>Conclusion</h3> 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.