Protective effect of N-acetylcysteine on progression to end-stage renal disease: Necessity for prospective clinical trial.

BACKGROUND: We aimed to evaluate the potential benefits of N-acetylcysteine (NAC) on the risk of chronic kidney disease (CKD) progression to dialysis-requiring end-stage renal disease (ESRDd). METHODS: In a population-based cohort study of 145,062 individuals, 123,608 CKD patients who were followed up for 10years were included, and CKD patients treated with NAC (ICD-9-CM) were compared with those who were not treated. Using propensity score matching, we analyzed the predictors of CKD progression to ESRDd by Cox proportional hazards regression with adjustments for sex, age, and comorbidities, and evaluated the effect of NAC using cumulative defined daily dose (cDDD). RESULTS: NAC use was associated with a reduced risk for progression to ESRDd [hazard ratio (HR), 0.819; 95% confidence interval (CI), 0.781-0.965; P=0.017]. Risk reduction was proportional to cDDD in NAC users compared with that in NAC non users (HR, 0.835, 0.811, and 0.799 for cDDD 91-180, 181-360, and >360, respectively; P for trend=0.018). Risk reduction was apparent in women (P=0.001) and in younger-aged patients of 18-29years (P=0.021) and 30-39years (P=0.033), in the presence of hypertension (P=0.003), and in the absence of diabetes mellitus (P=0.042) and congestive heart failure (P=0.036). CONCLUSION: NAC use was associated with a reduced risk for progression to ESRDd. These results, obtained from retrospective data, indicate that a prospective study is warranted.