Ratio of Total to LDL Cholesterol Is Best Predictor Of Coronary Heart Disease

Current guidelines for lipid management may misclassify subjects with both high and low levels of high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C).

Using the ratio of total cholesterol to HDL-C as the initial screening tool can avoid this, say specialists at hospitals in Taipei, Taiwan, China.

To evaluate the adequacy of current total and LDL-C-based approaches in lipid management, the specialists assessed the efficacy of various lipid and lipoprotein measurements at baseline for predicting the risk of coronary heart disease.

They also determined the associated risk of coronary heart disease in subgroups stratified by different lipid and lipoprotein screening strategies.

The specialists analysed data from a Chinese population-based prospective cohort study started in 1990.

During eight years of follow-up, 213 of 3,159 participants (6.7 percent) without coronary heart disease aged 35 years or older developed coronary heart disease. The total cholesterol/ HDL-C ratio was the most powerful lipoprotein predictor of future coronary heart disease, with a hazard ratio 1.21 for a 1.0 increment in ratio.

Patients with high-risk LDL cholesterol levels (more than 160 mg/dl, 4.2 mmol/l) and low total cholesterol/HDL cholesterol ratios (5.0 or less) had an incidence of coronary heart disease of 4.9 percent. This was similar to those with low levels of both LDL-C (130 mg/dl or less) and total cholesterol/HDL cholesterol ratios (4.6 percent).

By contrast, subjects with low-risk LDL-C levels (130 mg/dl, 3.4 mmol/l or less) and high total cholesterol/HDL-C ratios (more than 5.0) had a 2.5-fold higher incidence of coronary heart disease than those with similar LDL-C levels but low total cholesterol/HDL-C ratios.

Using a total cholesterol/HDL-C cholesterol ratio of 5.0 as the cut-off point was associated with significantly better specificity and accuracy and similar (though lower) sensitivity than an LDL-C level of 130 mg/dl (3.4 mmol/l).

Specificity was 73 percent with the total cholesterol/HDL-C ratio and 59 percent with the LDL-C measure. Accuracy was 72 percent with the total cholesterol/HDL-C ratio and 58 percent with the LDL-C measure. Sensitivity was 50 percent with the total cholesterol-HDL-C ratio and 53 percent with the LDL-C measure.

American Journal of Cardiology 2001; 88(7):737-743