Identifying risk factors for development of nephrolithiasis in end-stage renal disease patients

Abstract

Introduction: We sought to assess the incidence and risk factors for stone development in patients with end-stage renal disease (ESRD) on hemodialysis (HD).
 Methods: Medical records of patients receiving HD between 2007 and 2017 were retrospectively reviewed. Patients who had been on HD for at least three months and had imaging studies (computed tomography [CT] scans or ultrasound [US]) pre- and post-initiation of HD were included. Exclusion criterion was presence of stones pre-HD. De novo stones were defined as renal stones found on followup imaging. Demographics, laboratory data, comorbidities, and dialysis characteristics were compared between non-stone-formers and stone-formers using propensity score matching.
 Results: A total of 133 patients met the inclusion criteria. Their median age was 68.5 years, median body mass index 28.7 kg/m2, and median dialysis duration 59.5 months. After HD, 14 (10.5%) patients developed de novo stones and their median dialysis-to-stone duration was 23.5 months. When compared with non-stone-formers, stone-formers had significantly lower incidence of hypertension (48.2% vs. 14.3%; p=0.03), lower serum ionized calcium (1.16 vs. 1.07 mmol/L; p=0.01) and magnesium (0.95 vs. 0.81 mmol/L; p=0.01), and significantly higher serum uric acid (281.5 vs. 319.0 mmol/L; p=0.03). Multivariate analysis demonstrated that lower serum ionized calcium (adjusted odds ratio [OR] 0.00001; 95% confidence interval [CI] 0–0.18) and magnesium (adjusted OR 0.0003; 95% CI 0–0.59) were significantly associated with stone formation.
 Conclusions: The incidence of de novo nephrolithiasis in ESRD patients on HD was 10.5%. Increased serum uric acid, decreased serum magnesium and ionized calcium, and absence of hypertension were associated with increased stone-formation in ESRD patients on HD.

Alpha-Blocker Prescribing Trends for Ureteral Stones: A Single-Centre Study

“…15 However, patients in this audit were predominantly diagnosed through the use of CT scans (93.8%), and exclusion of non-CT patients was not done to reduce selection bias. Selection bias does however remain due to the retrospective single-centre study design, and not all variables were captured, such as baseline comorbidities, 16 preadmission alpha-blocker usage or variations in clinician training. This single-centre study may also have limited generalisability to other health-care services, where clinician education and practice may vary.…”