MC4R and type 2 diabetes mellitus: Moreover, rs17782313 in MC4R was related to a higher risk of T2DM among nonsmokers under the allelic (OR = 1.43, 95% CI = 1.00–1.95, p = 0.036), codominant (OR = 1.72, 95% CI = 1.12–2.64, p = 0.014), dominant (OR = 1.66, 95% CI = 1.11–2.50, p = 0.014) and additive (OR = 1.44, 95% CI = 1.03–2.01, p = 0.034) models.