(A) Prevalence of metabolic syndrome in different age subgroups. Age subgroups 1 to 6 referred to the followings: age ≤ 25 years, 25 years < age ≤ 35 years, 35 years < age ≤ 45 years, 45 years < age ≤ 55 years, 55 years < age ≤ 65 years, age > 65 years. *Significant difference between genders with P < 0.01. (B) Prevalence of metabolic syndrome in different total bilirubin (TBIL) subgroups. TBIL subgroups 1 to 4 in male referred to the followings: TBIL ≤ 9.90 μmol/L, 9.90 μmol/L < TBIL ≤ 12.90 μmol/L, 12.90 μmol/L < TBIL ≤ 16.80 μmol/L, TBIL > 16.80 μmol/L. TBIL subgroups 1 to 4 in female referred to the followings: TBIL ≤ 8.00 μmol/L, 8.00 μmol/L < TBIL ≤ 10.30 μmol/L, 10.30 μmol/L < TBIL ≤ 13.40 μmol/L, TBIL > 13.40 μmol/L. *significant difference between genders with P < 0.01. (C) Prevalence of metabolic syndrome in different gamma glutamyltransferase (GGT) subgroups. GGT subgroups 1 to 4 in male referred to the followings: GGT ≤ 20.00U/L, 20.00U/L < GGT ≤ 30.00U/L, 30.00U/L < GGT ≤ 48.00U/L, GGT > 48.00U/L. GGT subgroups 1 to 4 in female referred to the followings: GGT ≤ 11.00U/L, 11.00U/L < GGT ≤ 15.00U/L, 15.00U/L < GGT ≤ 21.00U/L, GGT > 21.00U/L. *significant difference between genders with P < 0.01. (D) Prevalence of metabolic syndrome in different alanine aminotransferase (ALT) subgroups. ALT subgroups 1 to 4 in male referred to the followings: ALT ≤ 17.00U/L, 17.00U/L < ALT ≤ 24.00U/L, 24.00U/L < ALT ≤ 34.00U/L, ALT > 34.00U/L. ALT subgroups 1 to 4 in female referred to the followings: ALT ≤ 13.00U/L, 13.00U/L < ALT ≤ 16.00U/L, 16.00U/L < ALT ≤ 22.00U/L, ALT > 22.00U/L. *significant difference between genders with P < 0.01.