Serum leptin has no effect on coronary collateral development in patients with non-ST- elevation acute coronary syndromes: an observational study

Objective: We attempted to investigate the potential association between leptin and coronary collateral vessel development in patients with non-ST elevation acute coronary syndromes (NSTE-ACS). Methods: One hundred and nineteen consecutive patients with NSTE-ACS with high-grade coronary stenosis or occlusion in at least one epicardial coronary artery were prospectively enrolled in a cross-sectional observational study. Serum leptin levels measured in all patients. Collateral circulation was graded according to the Rentrop classification. Firstly, we divided patients into two groups as good and poor collateral group. Patients with Rentrop 2.3 were regarded as good collateral group. Patients in Rentrop grades 0, 1 classified as poor collateral group. Secondly, patients were divided into collateral (+) group and collateral (-) group. Collateral (+) group included the patients with grade 1, 2, 3 collateral development. Collateral (-) group was composed of the patients with Rentrop 0. Statistical analysis was performed using Student t-test, Mann-Whitney U test, Chi-square test, Kruskal -Wallis test and Spearman's correlation. Results: We did not find statistically significant difference between good and poor collateral groups with regard to leptin levels [4.2 (1.8-8.6) ng/mL and 6.4 (2.4-12.6) ng/mL, p=0.22, respectively]. There was no statistically significant difference in leptin levels between collateral (+) group and collateral (-) groups [4.7 (1.7-10.5) ng/mL and 6.8 (2.7-12.1) ng/mL, p=0.33, respectively]. We observed that there was lower leptin level at higher Rentrop grades [Rentrop 0; 6.8 (2.5-12.5) ng/mL, Rentrop 1; 5.9 (1.7-14.1) ng/mL, Rentrop 2; 4.3 (1.7-8.7) ng/mL, Rentrop 3; 3.9 (2.1-9.7) ng/mL]. However, this difference did not reach statistically significant level (p=0.54). In addition, we did not find statistically significant correlation between Rentrop grades and leptin levels (p=0.246, r=-0.107). Conclusion: The present study reveals no association between serum leptin level and coronary collateral development.