Table 4.

Threshold effect analysis of serum uric acid on creatine phosphokinase using two-piecewise linear regression

Creatine phosphokinase (IU/L)	Adjusted ß (95% CI), p value
Female
Serum uric acid < 428.3 μmol/L	0.10 (0.00, 0.10), 0.001
Serum uric acid > 428.3 μmol/L	-0.10 (-0.20, 0.00), 0.198
p interaction	0.039

Age, sex, race/ethnicity, education level, income poverty ratio, BMI, waist circumference, physical activity, smoking behavior, alcohol behavior, alanine aminotransferase, aspartate aminotransferase, high-density lipoprotein cholesterol, total cholesterol, triglycerides, low-density lipoprotein cholesterol, total protein, hypertension, diabetes, and weak/failing kidneys were adjusted. In the subgroup analysis for females and other races/ethnicities, the model was not adjusted for gender or race/ethnicity, respectively