Renal function assessment in adults with recurrent calcium kidney stone disease

The prevalence of nephrolihiasis and chronic kidney disease has risen over the past three decades, we sought to determine if person with a history of kidney stones have lower renal function relative to non stone formers. Methods: We conducted a case-control study utilizing 138 recurrent calcium kidney stone formers and 127 age and gender matched controls with no history of renal disease, all subjects were aged 30-55 years old, with no history of hypertension, diabetes mellitus, congestive heart failure and liver disease and also no urinary tract obstruction and medications can affect Glomerular Filtration Rate (GFR). We estimated GFR by Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EP I) equations and categorized using cut points suggested by Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines. Results: Mean GFR in case group and control group was: 80.17(18.45) ml/min/1.73m2 and 83.80(15.75) ml/ min/1.73m2 respectively (P value: 0.09). Distribution of subjects among stone formers in stage I, II, III was 59(42.8%), 71(51.4%) and 8(5.8%) and in control group was 67(52.8%), 59(46.4%) and 1(0.8%) respectively, (p: 0.03). There was an inverse correlation between GFR and number of passed stone but there was no significant correlation between history of extracorporeal shock wave lithotripsy (ESWL) or percutaneous nephrolithotomy (PCNL) and estimated GFR. Conclusion: Recurrent calcium stone disease may be associated with nephron damage and an increased risk of chronic kidney disease