Serum high-density lipoprotein-cholesterol levels modify the association between plasma levels of oxidatively modified low-density lipoprotein and coronary artery disease in men
Zhang, B.; Bai, H.; Liu, R.; Kumagai, K.; Itabe, H.; Takano, T.; Saku, K.
Metabolism, Clinical and Experimental 53(4): 423-429
We investigated the association among plasma levels of oxidatively modified low-density lipoprotein (Ox-LDL), high-density lipoprotein-cholesterol (HDL-C), and the prevalence of coronary artery disease (CAD) in a case-control study. Cases (n=183; male, M/female, F:138/45, age: 64.9+or-10.6 years) were defined as patients with angiographically proven coronary atherosclerosis (>=50% stenosis) and controls were subjects with normal coronary arteries (n=74, M/F:36/38, age: 57.6+or-14.4 years). The patients were diagnosed at the Fukuoka University Hospital in Japan from 1994 to 1996. Plasma Ox-LDL levels were measured by a sensitive detection method using the monoclonal antibody DLH3. In women, both Ox-LDL and lipid variables were similar between cases and controls. In men, cases had significantly lower (P<0.05) levels of HDL-C (39.1+or-10.3 v 42.8+or-10.9 mg/dl) and apolipoprotein (apo) A-I than controls, while the difference in Ox-LDL between cases and controls was not significant (1.05+or-0.79 and 0.83+or-0.65 ng/10 micro g LDL protein, respectively). However, HDL-C levels interacted with the association between Ox-LDL levels and CAD in males: increased Ox-LDL levels were significantly associated with CAD after controlling for age when HDL-C levels were high, but were not associated with CAD when HDL-C levels were low, as assessed by a multiple logistic regression analysis. In addition, the combination of HDL-C and Ox-LDL levels was a better indicator for CAD in males than HDL-C levels alone (-2 log likelihood, 24.1 v 19.4) after controlling for age and conventional risk factors of CAD, while Ox-LDL levels were not significantly associated with CAD. HDL-C levels interact with the association between plasma Ox-LDL levels and CAD in men, and increased Ox-LDL levels are an indicator of CAD in male subjects with high HDL-C levels.