Influence of socioeconomic disparities, temperature and humidity in kidney stone composition

Abstract

Introduction: Large variations in demographic, economic and environmental factors might influence the worldwide distribution of urolithiasis, but scarce data are available concerning their associations with stone composition. We aimed to evaluate the frequency and composition of kidney stones and their associations with temperature, humidity, and human development index (HDI). Materials and Methods: A total of 1,158 stones from distinct patients (47±14 years old, male/female 2:1) were included. The mean annual temperature and relative humidity of each town were considered separately. Results: Calcium oxalate monohydrate (COM) was disclosed in 38.8% of patients, calcium oxalate dihydrate (COD) in 22.1%, mixed COD/apatite in 9.4%, pure apatite in 1.9%, brushite in 1.8%, struvite in 8.3%, pure uric acid in 11.1%, mixed uric acid/COM in 5.6%, and cystine/rare types in 0.8%. Mean HDI of all pooled cities was 0.780±0.03. However, people living in HDI<0.800 regions had twice the odds of having a struvite stone versus those living in HDI>0.800 (OR=2.14, 95% CI 1.11-4.11). Furthermore, a progressive increase in the struvite stones frequency from 4.5 to 22.8% was detected from HDI>0.800 through HDI<0.700. No significant difference for other stone types was disclosed. Separate logistic regression models assessed the association of each stone composition with gender, temperature, humidity and HDI as covariates. Conclusion: Patients living in low HDI areas are more prone to develop struvite stones, possibly due to lower access to healthcare. Temperature and humidity did not represent a specific risk factor for any stone type in the present sample.

The epidemiology of kidney stones in Belgium based on Daudon’s morpho-constitutional classification: a retrospective, single-center study

“…In all analyzed stones and fragments the overall frequency of struvite accounted for 2.3%, similar to the frequency reported in Canada (2%), China (2.7% to 3%), Argentina (3%), Iraq (3%), Poland (3%) Italy (3.5%), but lower than the frequency reported in France (7.2%), or in Brazil (8.3%) [65,[79][80][81]. The discrepancy between our data findings and data from Pakistan (18%) or India (23%) or data from paediatric patients from Morocco (18%) could be attributed to the differences in epidemiological characteristics of the populations studied, especially a low human development index and related low access to healthcare (late diagnosis and/or delay in accurate treatment of UTI) rather than temperature and humidity [81]. It was recently reported that neurological bladder and CAKUT contributed to 38% of infectious stones in pediatric populations [25].…”

Prevalence and trends of urolithiasis among adults

“…Table 1 summarizes the findings of the studies that met our inclusion criteria. Twenty-three studies were identified reporting on urolithiasis epidemiology, prevalence, and trends from 11 different countries in the past 2 years [6 ▪▪ ,12,13 ▪ ,14 ▪ ,15,16 ▪▪ ,17,18 ▪ ,19–26,27 ▪ ,28–33].…”

“…Whereas, in northeastern China, there were more struvite stones, which was attributed to the low socioeconomic status and low healthcare accessibility in this region [28]. Similarly, struvite stones were more prevalent in low human development index (HDI) areas in Brazil [25].…”

Vascular Calcification Is Associated with Fetuin-A and Cortical Bone Porosity in Stone Formers

“…Nephrolithiasis represents a common disorder with a lifetime cumulative incidence of 5–10% and a progressively increasing prevalence worldwide [ 1 , 2 ], affecting all ages, sexes, and races, but frequently occurring between the 2nd and 4th decades of life [ 3 ]. Lithogenesis is characterized by an imbalance between the solubility and precipitation of minerals in the urine influenced by several factors, including climate, social-economic status, eating habits, obesity, genetic inheritance, and metabolic disorders [ 2 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. It is well established that stone formers (SF) exhibit a reduction of bone mineral density (BMD) [ 12 , 13 ], which may be exacerbated under low calcium intake [ 14 ], and histomorphometric studies have reported low bone formation and increased bone resorption [ 15 , 16 , 17 ].…”