Urine S-Adenosylmethionine are Related to Degree of Renal Insufficiency in Patients with Chronic Kidney Disease.

OBJECTIVE: To determine whether urine S-adenosylmethionine (SAM) might be an indicator of chronic kidney disease (CKD). METHODS: We investigated urine levels of SAM and related metabolites (S-adenosylhomocysteine and homocysteine cysteine) in 62 patients (average age, 65.9 years) with CKD (stages II-V). RESULTS: Patients with stages III-V CKD stages have significantly decreased urine levels and SAM/S-adenosylhomocysteine ratio and also cysteine/homocysteine ratio in blood plasma (P <.05), compared with patients with stage II CKD. Urine SAM levels allowed us to distinguish patients with mildly decreased kidney function from those with moderate to severe renal impairment (AUC, 0.791; sensitivity, 85%; specificity, 78.6%). CONCLUSIONS: Our study results demonstrate that urine SAM is a potent biomarker for monitoring renal function decline at early CKD stages. Urine SAM testing confers an additional advantage to healthcare professionals in that it is noninvasive.

Low S-adenosylmethionine/ S-adenosylhomocysteine Ratio in Urine is Associated with Chronic Kidney Disease.

OBJECTIVE: To evaluate the association of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) in urine with chronic kidney disease (CKD). METHODS: Case-control study including 50 patients with CKD and 20 healthy volunteers. RESULTS: SAM level and SAM/SAH ratio in urine were significantly lower in patients than in control individuals (P <.001 and P = .01, respectively). The estimated glomerular filtration rate was associated with the SAM level (P = .04) and the SAM/SAH ratio in urine (P = .01). CONCLUSION: CKD is associated not only with the decline in the SAM level but also with the decrease in the SAM/SAH ratio in urine. Thus, use of the urinary SAM/SAH ratio as a noninvasive diagnostic indicator of renal function seems promising.