Pre-dialysis serum creatinine as an independent predictor of responsiveness to zinc supplementation among patients on hemodialysis.

ABSTRACT

BACKGROUND: To investigate whether pre-dialysis level of serum creatinine (SCre) could indicate the responsiveness to zinc supplementation of patients on maintenance hemodialysis (MHD). METHODS: We retrospectively reviewed the results of our previous randomized study of 91 patients who had been on MHD and received zinc supplementation with either zinc acetate hydrate (ZAH; zinc, 50 mg/day) or polaprezinc (PPZ; zinc, 34 mg/day). A late response to zinc supplementation was defined as a serum zinc level of < 80 µg/dL three months after the study began. Patients were divided into two groups late response (serum zinc level < 80 µg/dL) and early response (serum zinc level ≥ 80 µg/dL). Factors independently associated with a late response to zinc supplementation were determined using inverse probability of treatment weighting (IPTW) multivariate logistic analysis. RESULTS: Of 91 patients, 86 continued to receive zinc supplementation after three months. The mean pre-dialysis SCre level was 10.0 mg/dL. The number of patients with a late response and response to zinc supplementation was 32 and 54, respectively. There was a significant negative correlation between the pre-dialysis SCre and the Δserum zinc change for 3 months. (r = - 0.284, P = 0.008). IPTW multivariate analysis showed that a pre-dialysis SCre level ≥ 10.0 mg/dL (odds ratio, 3.71; 95% confidence interval; 1.24-11.1, P = 0.022) was an independent factor associated with a late response to zinc supplementation. CONCLUSIONS: Pre-dialysis SCre level was independently associated with responsiveness to zinc supplementation after three months in patients on MHD.