When adjusted for all factors significant in the univariate analysis (race, liver function, obesity, hypertension, dyslipidemia, smoking, physical activity, vigorous recreational activity, 2-hour glucose, HbA1C, high-density lipoprotein, triglyceride, vitamin D, and CRP) low total triiodothyronine (TT3) and low free T3 (FT3) were significantly associated with decreased HOMA-IR (adjusted coefficient = −0.486, 95% confidence interval [CI]: −0.936, −0.036; adjusted coefficient = −1.151, 95% CI: −1.952, −0.350, respectively). This evidence concerns the gene CRP and metabolic syndrome.