A critical evaluation of high density lipoprotein cholesterol as an index of coronary artery disease risk in Malaysians

Fasting serum specimens from (a) 217 male and 46 female patients with coronary artery disease (CAD), aged 35-75 years, who had undergone angioplasty (PTCA) / coronary artery bypass graft (CABG), and (b) 160 apparently healthy controls (106 males, 54 females, aged 30-75 years), were assessed for serum lipid profile. Both sex and ethnicity significantly influenced the levels of serum high density lipoprotein cholesterol (HDLC); in the controls, females had higher HDLC levels than males (46.7 mg/dl vs 38.5 mg/dl, p<0.00l), while the Indian males possessed significantly lower HDLC values than the male Malay or Chinese. HDLC, triglycerides (TG) and the atherogenic index- LDLC/HDLC ratio were significantly different between the CAD patients and the healthy controls, while total cholesterol (TC) and LDLC did not seem to be of diagnostic value. Serum HDLC was lower in the CAD patients compared to the healthy controls in both sexes (p<0.001), either expressed as HDLC per se or as % HDLC. This observation combined with the odds ratio (OR) values of 0.24 and 0.28 for HDLC and % HDLC respectively in males, firmly establishes HDL as a protective factor of CAD in Malaysians. Significance testing for the X2 values associated with the OR values for the various lipid indices, together with the findings on the receiver-operating characteristices (ROC) curves, i.e. plots of sensitivity vs 1-specificity, indicated that HDLC, % HDLC and TQ were equally efficient as a means of risk assessment to CAD in Malaysians.