LEP and type 2 diabetes mellitus: While serum 25(OH)D concentrations were significantly associated with TC (R2 = 0.168, B = − 0.329, P = 0.040), log leptin (R2 = 0.544, B = − 0.007, P = 0.021), and adiponectin (R2 = 0.144, B = 0.111, P = 0.033), but slightly associated with LDL-c (R2 = 0.133, B = − 0.278, P = 0.064) in only AA without T2D.