Leptin, leptin soluble receptor and coronary atherosclerosis

Objective: The adipose tissue-related hormone leptin plays an important role in the regulation of body weight. The role of leptin and leptin soluble receptor (sOb-R) in the development of coronary artery disease (CAD) is not clear.

Methods: We measured leptin and sOb-R in 543 consecutive patients (379 men, 164 women) referred for coronary angiography for the evaluation of established or suspected CAD. Coronary artery stenoses with lumen narrowing ≥50% were considered significant.

Results: Serum leptin correlated significantly with body mass index (BMI; r=0.443), with insulin resistance (HOMA-IR, r=0.339), with serum triglycerides (r=0.181), and with systolic as well as diastolic blood pressure (r=0.170 and r=0.133, respectively) and, inversely, with sOb-R (r=-0.346; p<0.01 for all correlations). Coronary angiography revealed significant coronary artery stenoses in 331 (61.0%) of our patients. Serum concentrations of leptin were significantly lower in patients with significant coronary artery stenoses than in patients without significant coronary artery stenoses (8.5±7.8 vs. 13.2±12.2 ng/ml; p<0.001). Multivariate logistic regression analysis adjusting for age, gender, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, BMI, diabetes, hypertension and smoking proved serum leptin inversely and independently associated with the presence of significant coronary artery stenoses, with a standardized adjusted odds ratio (OR) of 0.746, 95% confidence interval (CI) 0.566–0.983, p=0.038. In contrast to serum concentrations of leptin, serum concentrations of sOb-R did not significantly differ between patients with significant stenoses and those without such lesions (22.4±8.3 vs. 23.1±12.1 ng/ml; p=0.655).

Conclusions: Serum leptin but not sOb-R is significantly lower in patients with angiographically determined CAD.