WCE 2018: The Relationship Between Ethnicity and Stone Composition in a Large Multi-Ethnic London NHS Trust

Paris, France (UroToday.com) The prevalence of urolithiasis in different ethnic groups has been described in the literature, but not much is known specifically about the relationship between stone composition and ethnicity. Vaggers et al. attempt to elucidate this relationship by conducting a retrospective laboratory stone analysis in patients within a highly diverse area of the UK. Repeat stone analysis was also conducted by looking at all previous stones within the last 10 years per patient to see if there was consistency with previous stone composition.

In total, 312 patients were identified and had laboratory stone analysis – 91 were white British, 63 were white other (16 eastern Europe, 6 western countries, 2 middle east, 39 unspecified), 94 were Asian, 19 were Black, and 45 were others. No significant differences were seen between stone composition and ethnicity (p=.095). However, the “white-other” group seemed to have a higher prevalence of uric acid stones than the other groups - 17% compared to 10% white British, 6% Asian, 0% Black and 6% other/ unknown. On repeat stone analysis, of the patients who had previous episodes of urolithiasis, 100% of the patients with calcium oxalate, uric acid, and cystine stones formed the same stone in the past. However, calcium phosphate stone formers had previous episodes of calcium oxalate and struvite stones, and struvite stone formers had a previous episodes of calcium phosphate stones.

While there were no significant differences based on ethnicity and stone composition revealed in this study, the presenter believes that further analysis of the “white other” group with regard to uric acid stones might reveal some subgroup differences. Additionally, there may be a link between calcium phosphate and struvite stone formation, which may lead some patients to form both types, during different episodes of urolithiasis.

Presented By: Sophie Vaggers, Bm BCh, Ba Medical Sciences

Authors: Ross Warner, Luke Forster, MSc MRCS, Zubeir Ali, Pallavi Pal, Stuart Graham

Written By: Max Towe for UroToday at the 36th World Congress of Endourology (WCE) and SWL - September 20-23, 2018 Paris, France