COMT and diabetes mellitus: Men (B = −0.318, SE = 0.139, p = 0.022) and older individuals (B = 0.041, SE = 0.007, p = 0.001) were more likely to drop out, after accounting for pulse pressure (PP; p = 0.375), cardiovascular diseases (CVDs; hypertension, stroke, and diabetes; p = 0.409), years of education (p = 0.275), and COMT allelic variation (p = 0.061).