In the age <65 years group, after adjusting for gender, BMI, hypertension, diabetes, hyperlipidemia, FBG, HbA1c, TG, T-CHO, LDL-C, HDL-C, ALT, AST, GGT, TBIL, ALB, SCr, and SUA, CAP was positively correlated with FT3/FT4 before the inflection point at CAP = 277 dB/m (β = 0.000, p = 0.0011) but was negatively correlated with FT3/FT4 after the inflection point (β = −0.000, p = 0.0003). This evidence concerns the gene ALB and diabetes mellitus.