Differences in Urinary Calculi Characteristics among the Three Main Racial Groups in KwaZulu-Natal, South Africa
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Keywords
characteristics, racial disparity, South Africa, Urinary calculi, Urolithiasis
Abstract
Racial differences in the characteristics of urinary calculi are poorly described in the South African context, limiting our local understanding of urolithiasis pathology and thwarting our efforts in designing appropriate preventative interventions. We sought to investigate differences in urinary calculi characteristics among the main racial groups in KwaZulu-Natal, South Africa. We conducted a retrospective chart review of patients with urinary calculi at a quaternary hospital in KwaZulu-Natal, South Africa, during 2018–2019. We collected data on the patient’s age, sex, race (Caucasian, Asian, Black African), residence, and pre-stenting. Five study outcomes were investigated across racial groups: number of calculi, location of the calculi, size of the calculi, density of the calculi (Hounsfield Unit measurement >600), and the number of operative interventions performed. Data were analyzed with descriptive statistics, the chi-squared test, and unadjusted/adjusted logistic regression. Our study sample consisted of 147 patients (10.9% Caucasian, 55.8% Asian, and 33.3% Black African). Most patients (86.4%) were from urban areas. A higher proportion of Black Africans had urinary calculi with Hounsfield Unit measurements >600 (P = 0.002). In the logistic regression models, Black Africans had a higher probability of having urinary calculi with Hounsfield Unit measurements >600 (Unadjusted Odds Ratio: 7.17, 95% Confidence Interval: 2.00–27.80; Adjusted Odds Ratio: 18.75, 95% Confidence Interval: 3.37–157.57). Our analysis suggests that Black Africans are at higher risk of having harder urinary calculi than other race groups. This has implications for urolithiasis management and highlights the importance of primary prevention in this group. We recommend additional research to confirm our findings.
References
2. Scales CD, Jr., Smith AC, Hanley JM, Saigal CS. Prevalence of kidney stones in the United States. Eur Urol. 2012 Jul;62(1): 160–5. 10.1016/j.eururo.2012.03.052
3. Alatab S, Pourmand G, El Howairis Mel F, Buchholz N, Najafi I, Pourmand MR, et al. National profiles of urinary calculi: a comparison between developing and developed worlds. Iran J Kidney Dis. 2016 Mar;10(2):51–61.
4. Lotan Y. Economics and cost of care of stone disease. Adv Chronic Kidney Dis. 2009 Jan;16(1):5–10. 10.1053/j.ackd.2008.10.002
5. Pearle MS, Calhoun EA, Curhan GC. Urologic diseases in America project: urolithiasis. J Urol. 2005 Mar;173(3):848–57. 10.1097/01.ju.0000152082.14384.d7
6. Hyams ES, Matlaga BR. Economic impact of urinary stones. Transl Androl Urol. 2014 Sep;3(3):278–83.
7. Fontenelle LF, Sarti TD. Kidney stones: treatment and prevention. Am Fam Physician. 2019 Apr;99(8):490–6.
8. Abi Tayeh G, Safa A, Sarkis J, Alkassis M, Khalil N, Nemr E, et al. Determinants of pyelonephritis onset in patients with obstructive urolithiasis. Urologia. 2022;89(1):100–3. 10.1177/03915603211035244
9. Rule AD, Krambeck AE, Lieske JC. Chronic kidney disease in kidney stone formers. Clin J Am Soc Nephrol. 2011 Aug;6(8):2069–75. 10.2215/CJN.10651110
10. Crivelli JJ, Maalouf NM, Paiste HJ, Wood KD, Hughes AE, Oates GR, et al. Disparities in kidney stone disease: a scoping review. J Urol. 2021 Sep;206(3):517–25. 10.1097/JU.0000000000001846
11. Gray D, Laing M, Nel F, Naudé JH. Composition of urinary calculi collected in the Durban area. S Afr Med J. 1982 Jan;61(4):121–5.
12. Lewandowski S, Rodgers A, Schloss I. The influence of a high-oxalate/low-calcium diet on calcium oxalate renal stone risk factors in non-stone-forming black and white South African subjects. BJU Int. 2001 Mar;87(4):307–11. 10.1046/j.1464-410x.2001.00064.x
13. Jardine T, Davids MR. Global dialysis perspective: South Africa. Kidney360. 2020;1(12):1432–6. 10.34067/KID.0005152020
14. Pillay-van Wyk V, Msemburi W, Laubscher R, Dorrington RE, Groenewald P, Glass T, et al. Mortality trends and differentials in South Africa from 1997 to 2012: second National Burden of Disease Study. Lancet Glob Health. 2016 Sep;4(9):e642–53. 10.1016/S2214-109X(16)30113-9
15. Takazawa R, Kitayama S, Tsujii T. Appropriate kidney stone size for ureteroscopic lithotripsy: When to switch to a percutaneous approach. World J Nephrol. 2015 Feb;4(1):111–17. 10.5527/wjn.v4.i1.111
16. Brisbane W, Bailey MR, Sorensen MD. An overview of kidney stone imaging techniques. Nat Rev Urol. 2016 Nov;13(11):654–62. 10.1038/nrurol.2016.154
17. Magwira CA, Kullin B, Lewandowski S, Rodgers A, Reid SJ, Abratt VR. Diversity of faecal oxalate-degrading bacteria in black and white South African study groups: insights into understanding the rarity of urolithiasis in the black group. J Appl Microbiol. 2012 Aug;113(2):418–28. 10.1111/j.1365-2672.2012.05346.x
18. Rodgers A. The riddle of kidney stone disease: lessons from Africa. Urol Res. 2006 Apr;34(2):92–5. 10.1007/s00240-005-0017-1
19. Kaufman DW, Kelly JP, Curhan GC, Anderson TE, Dretler SP, Preminger GM, et al. Oxalobacter formigenes may reduce the risk of calcium oxalate kidney stones. J Am Soc Nephrol. 2008 Jun;19(6):1197–203. 10.1681/ASN.2007101058
20. Hold GL. Western lifestyle: a “master” manipulator of the intestinal microbiota? Gut. 2014 Jan;63(1):5–6. 10.1136/gutjnl-2013-304969
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