IL6 and obstructive sleep apnea syndrome: EPC and CEC were not significantly different when comparing OSA vs. no OSA (Figure 3), while leptin and IL-6 were (leptin: 70.5 ± 54 vs. 40.3 ± 45.5 ng/mL, p = 0.015; IL-6 4.4 ± 2.7 vs. 2.5 ± 2.7 ng/mL, p = 0.006; Figure 4).