Metabolic evaluation of high-risk stone formers: a retrospective study

Background The purpose of this study was to assess the metabolic abnormalities in high-risk stone formers. Methods This was a retrospective observational study done at Tribhuvan University Teaching Hospital, Nepal, over 1-year period. High-risk stone formers were identified and were evaluated with serum chemistries and 24-h urinary chemical evaluation. Stone analysis was also included whenever available. Common metabolic abnormalities and stone analysis results were reported and compared with different studies. Continuous variables were expressed as mean ± SD. Categorical variables were expressed as percentage and proportions. Results During 1 year of period, sixty-five patients had undergone extensive metabolic evaluation, but complete data were available for only forty-six patients. Of the total patients ( n = 46), 63% were male ( n = 29) and rest (36.9%) were female. Mean age of patients was 34.4 ± 15.1 years. Common reasons for metabolic evaluation were multiple stones (40%), bilateral stones (27%), recurrent stones (17%) and others (16%). Most common stone type was mixed stone with predominant composition being calcium oxalate mono- and dihydrate (62.9%). Twenty-four-hour urinary metabolic evaluation showed hyperoxaluria (32.6%) as most common abnormalities followed by hypocitraturia (21.7%) and hypocalciuria (21.7%). Conclusion Hyperoxaluria and hypocitraturia are common metabolic abnormalities in our patients. These findings help in counselling dietary measures to patients.