At the same time, the effect of GG vs. AA COMT rs6269 polymorphisms was significant for the patients with diabetes, β = −0.24, Post SD = 0.11, 95% CI [−0.46, −0.03], p < 0.001, but not for those without diabetes, β = 0.07, Post SD = 0.05, 95% CI [−0.02, 0.17], p = 0.140. The gene discussed is COMT; the disease is diabetes mellitus.