Urinary stone composition: Gender and age variations, and evolution in the last 7 years.

  • Pedro Valente Serviço de Urologia do Centro Hospitalar do Tâmega e Sousa, Penafiel, Portugal
  • Hélder Castro Serviço de Urologia do Centro Hospitalar do Tâmega e Sousa, Penafiel, Portugal
  • Inês Pereira Unidade de Saúde Familiar Terras de Souza, Paredes, Portugal
  • Fernando Vila Serviço de Urologia do Centro Hospitalar do Tâmega e Sousa, Penafiel, Portugal
  • Paulo Araújo Serviço de Urologia do Centro Hospitalar do Tâmega e Sousa, Penafiel, Portugal
  • Cristina Vivas Serviço de Urologia do Centro Hospitalar do Tâmega e Sousa, Penafiel, Portugal
  • Ana Silva Unidade de Saúde Familiar Terras de Souza, Paredes, Portugal
  • Ana Oliveira Unidade de Saúde Familiar Terras de Souza, Paredes, Portugal
  • Joaquim Lindoro Serviço de Urologia do Centro Hospitalar do Tâmega e Sousa, Penafiel, Portugal
Keywords: Age Factors, Sex Factors, Spectrophotometry, Infrared, Urinary Calculi/chemistry, Urolithiasis


Objectives: To evaluate urinary stone composition in our institution, its gender and age, including variations and the evolution in the last 7 years.

Material and Methods: The authors reviewed all urinary stone analysis performed since January 2009 to September 2015 in our hospital – Centro Hospitalar do Tâmega e Sousa, Penafiel, Portugal. Patients were stratified by gender, age and stone composition analyzing the evolution of stone composition in different years. The stone analysis method was infrared spectroscopy.

Results: From 302 valid stone analysis reports, 55,3% were female and 44,7% were male patients. Mean patient age was 51±14 years old. A total of 7 different mineral components were identified. 51,6% (n=156) of all the stones had Calcium Oxalate, 41% (n=124) had Calcium Phosphate (33% of Apatite form), 37,7% (n=114) had Uric Acid, 22,1% (n=67) had Ammonium Urate, 9,6% (n=29) had Magnesium Ammonium Phosphate, 6,3% (n=19) had Sodium Urate, and 1,3% (n=4) had Cystine in its composition. Only 30,4% of stones had a single chemical compound. Of these 56% were pure stones of Calcium Oxalate, and 31% were pure stone of Uric Acid. The most frequent mixed stone was Calcium Oxalate + Calcium Phosphate (Apatite) followed by Uric Acid + Ammonium Urate comprehending 45% and 27% of all mixed stones respectively.

Related to the ethology we divided stones into 3 groups, pure non-infection, pure infection, and mixed with component of infection, and the prevalence was 37,7%, 4,3% and 57,9% respectively.

The distribution between genders was similar and the highest difference was in the Ammonium Urate compound with 28% prevalence in male and 17% in women. (p=0,379)
Patients after 50 years old had more prevalence of Uric Acid component accounting for 49% of their stones.(p<0,001) .

Along the 7 years of study we identified a significant reduction in the prevalence of mixed stones with component of infection, gradually decreasing from 89,6% in 2009 to 27% in 2015.

Conclusions: Calcium Oxalate calculus were the most prevalent, but this difference was not as important as in other studies worldwide. This study highlights the importance of the development of National and European database to report all regional stone composition variations.


Download data is not yet available.


1. Romero V, Akpinar H, Assimos DG. Kidney stones: a global picture of prevalence, incidence, and associated risk factors. Rev Urol. 2010;12:e86-e96.
2. Amato M, Lusini ML, Nelli F. Epidemiology of nefrolithiasis today. Urol Int. 2004;72 (Suppl 1):1-5.
3. Domingos F, Serra A. Nephrolithiasis is associated with an increased prevalence of cardiovascular disease. Nephrol Dial Transplant. 2011;26:864–8.
4. Daudon M, Traxer O, Lechevallier E, Saussine C. Épidémiologie des lithiases urinaires. Prog Urol. 2008;18:802-14.
5. Turk C, Knoll T, Petrik A, Sarica K, Skolarikos A, Straub M, et al. Guidelines on diagnosis and conservative management of urolithiasis. Eur Urol. 2016;69:468-74.
6. Daudon M, Donsimoni R, Hennequin C, Fellahi S, Le Moel G, Paris M, et al. Sex- and age-related composition of 10,617 calculi analyzed by infrared spectroscopy. Urol Res. 1995;23:319-26.
7. Daudon M, Bounxouei B, Santa Cruz F, Leite da Silva S, Diuf B, Angwafoo III FF, et al. Composition des calculs observés aujourd’hui dans les pays non industrialisés. Prog Urol. 2004;14:1151-61.
8. Ribeiro da Silva SV, Cordeiro de Matos D, Leite da Silva S, De Francesco Daher E, Campos HH, Bruno da Silva CA. Chemical and morphological analysis of kidney stones. A double-bind comparative study. Acta Cir Bras. 2010;25:444-8.
9. Costa-Bauzá A, Ramis M, Montesinos V, Conde A, Pizá P, Pieras E, et al. Type of renal calculi: variation with age and sex. World J Urol. 2007;25:415-21.
10. Alaya A, Nouri A, Belgith M, Saad H, Hell I, Hellara W, et al. Changes in kidney stones type according to sex and age in Tunisian patients. Actas Urol Esp. 2012; 36:171-7.
11. Nunes A, Pereira S, Sandul A, Garcia R, Ramos R, Silva R, et al. Urinary stone composition analysis – five-year experience of a major Portuguese urological center. Eur Urol Suppl. 2013; 12: 83.
12. Baltazar PM, Meirinha A, Patena-Forte JP, Severo LA, Campos-Pinheiro L. Urinary stone composition analysis in a representative sample of Portuguese population. Eur Urol Suppl. 2015; 14: 50
13. Daudon M, Doré JC, Jungers P, Lacour B. Changes in stone composition according to age and gender of patients: a multivariate epidemiological approach. Urol Res. 2004;32:241-7.
14. Bouatia M, Benramdane L, Idrissi M, Draoui M. An epidemiological study on the composition of urinary stones in Morocco in relation to age and sex. Afr J Urol. 2015;21:194-7.
15. Karabacak O, Dilli A, Saltas H, Yalçinkaya F, Yorukoglu A, Sertçelik M. Stone compositions in Turkey: An analysis according to Gender an Region. Urology. 2013; 82:532-8.
16. Hesse A, Brandleb E, Wilberte D, Kohrmannd KU, Alken P. Study on the prevalence and incidence of urolithiasis in Germany. Comparing the years 1979 vs. 2000. Eur Urol. 2003;44:709-13.
17. Sun X, Shen L, Cong X, Zhu H, He L, Lu J. Infrared spectroscopic analysis of 5,248 urinary stones from Chinese patients presenting with first stone episode. Urol Res. 2011; 39: 339-43.
18. Fiuza M, Cortez-Dias N, Martins S, Belo A. Síndrome metabólica em Portugal: prevalência e implicações no risco cardiovascular - resultados do estudo VALSIM. Rev Port Cardiol. 2008;27:1495-529.
19. Siener R, Ebert D, Nicolay C, Hesse A. Dietary risk factos for hyperoxaluria in calcium oxalate stone formers. Kidney Int. 2003;63:1037-43.
20. Kamel KS, Cheema-Dhadli S, Halperin ML. Studies on pathophysiology of the low urine pH in patients with uric acid stones. Kidney Int. 2002;61:988-94.
21. Knoll T, Schubert AB, Fahlenkamp D, Leusmann DB, Wendt-Nordahl G, Schubert G. Urolithiasis through the ages: data on more than 200,000 urinary stone analyses. J Urol. 2011;185:1304-11.