Family history influences clinical course of idiopathic calcium nephrolithiasis: case-control study of a large cohort of Italian patients.

AIM: To evaluate the contribution of family history of stones (FHS), up to second-degree relatives, on clinical course (age of first renal colic, bilateral disease, retained calculi, recurrences, urological procedures) of idiopathic calcium nephrolithiasis (ICN) and urinary parameters of lithogenic risk, a case-control study was carried out. METHOD: Clinical records of 2080 patients with ICN were evaluated and categorized according to FHS. Data about clinical course of disease and urinary parameters of lithogenic risk were collected. Student's t, Chi square tests and binary logistic regression were applied to discriminate groups with vs. without FHS. RESULTS: FHS was associated with an earlier onset of stone disease (age at first episode 32 ± 13 vs. 37 ± 15 years, p <0.001), particularly in females. After adjustment for multiple covariates, FHS was significantly associated to a higher risk of recurrence [odds ratio (OR) 1.2, 95 % confidence interval (1.1-1.4), p = 0.04], retained stones [OR 1.3, CI (1.1-1.5), p = 0.004], bilateral stones [OR 1.2, 95 % CI (1.1-1.5), p = 0.022] and urological procedures [OR 1.2, 95 % CI (1.1-1.5), p = 0.034]. FHS did not influence urinary parameters of lithogenic risk, except for calcium excretion in females. CONCLUSION: A positive family history influences the clinical course of ICN with some significant gender-related differences, substantially irrespective of urinary parameters of lithogenic risk.