Objectives Adiponectin is an adipose-secreted protein that shows atheroprotective property and inverse relation with coronary artery disease (CAD). HMW adiponectin has been reported as an active form of adiponectin, however, whether HMW or HMW-total adiponectin ratio is more important for cardioprotectin and a better marker for CAD remain controversial in different populations. Therefore, the present study aimed to investigate the association between HMW adiponectin and HMW-total adiponectin ratio with the severity of coronary atherosclerosis, and to compare their predictive values for the presence of CAD in a Chinese Han population.

Methods Serum levels of total and HMW adiponectin were measured in 382 early-onset CAD (EOCAD) patients and 305 matched controls undergoing coronary angiography by enzyme-linked immunosorbent assay (ELISA). EOCAD is particularly genetically determined that will be better for elucidating the pathogenesis of CAD, defined as CAD patients at or before the age of 55 years in men or 65 years in women. Gensini score was used to evaluate the severity of coronary atherosclerosis in coronary angiography.

Results Early-onset CAD patients were likely to have significantly higher levels of established cardiovascular risk factors such as triglycerides (1.96 ± 1.60 vs. 1.21 ± 0.60 mmol/L), LDL-cholesterol (2.87 ± 0.82 vs. 2.23 ± 0.50 mmol/L ) and hsCRP (0.51(0.16-1.90) vs. 1.81(0.15-20.00) mg/L, all P < 0.001) than those of controls, while HDL-cholesterol, total adiponectin and HMW adiponectin were extremely lower (1.15 ± 0.26 vs. 1.46 ± 0.39 mmol/L, 1.21(0.37-2.83) vs. 1.73(0.61-4.36) μg/ml, 0.46(0.14-1.49) vs. 0.91(0.39-3.26) μg/ml, respectively; all P < 0.001).

We also found that age was positively related with HMW adiponectin levels (r = 0.383, P < 0.001), and HMW-total adiponectin ratio (r = 0.429, P < 0.001), which implied that age might be a protective factor for coronary atherosclerosis in early-onset CAD patients. Total adiponectin, HMW adiponectin and HMW-total adiponectin ratio were all inversely correlate with Gensini score (r =-0.417, r =-0.637, r =-0.578, respectively; P < 0.001). In a multivariable linear regression model, HMW-total adiponectin ratio was significantly associated with the severity of coronary atherosclerosis (P < 0.05). Predictive value of HMW-total adiponectin ratio for the presence of CAD was significantly better than total adiponectin (AU ROC 0.806 vs. 0.674, P = 0.020), while was as effective as HMW adiponectin (0.806 vs. 0.797, P = 0.783).

Conclusions Decreased HMW-total adiponectin ratio and HMW adiponectin were associated with the severity of coronary atherosclerosis. HMW-total adiponectin ratio might serve as a novel marker for predicting the presence of CAD as effective as HMW adiponectin.