Among females, the APLN T-1860C polymorphism (OR = 4.39, 95% CI = 1.25–15.28) and apelin concentration (OR = 0.45, 95% CI = 0.23–0.92) were significantly associated with obesity (P < 0.05). This evidence concerns the gene APLN and obesity due to melanocortin 4 receptor deficiency.