AHSG and nephrolithiasis: Both serum and urine fetuin-A levels were lower in the kidney stone group (676.3 ± 160.14 ng/mL; 166.6 ± 128.13 ng/mL, respectively) than in the control group (1455.6 ± 420.52 ng/mL; 2267.5 ± 1536.78 ng/mL, respectively) (p < 0.00001).