Nephrolithiasis, stone composition, meteorology, and seasons in Malta: Is there any connection?

Abstract

Context:The effect of seasons and meteorology on the incidence of nephrolithiasis has been studied in various regions around the globe, but seldom in the Mediterranean.Aims:This retrospective analysis aims at investigating these putative effects in the Maltese Islands, whose climate is typically Mediterranean, followed by a systematic review of the literature.Materials and Methods:Submission rate and chemical composition of all kidney stones after spontaneous passage or surgical removal between January 2009 and December 2011 were analyzed according to seasons and corresponding meteorology.Results:A total of 389 stones were analyzed. A higher stone submission rate was observed in summer compared to winter (31.6% vs. 20.8%, P = 0.0008) and in the warm period compared to the cold period (57.1% vs. 42.9%, P = 0.0001). Significant correlation was established between the monthly number of stones and mean monthly maximum temperature (r = 0.50, P = 0.002), mean monthly temperature (r = 0.49, P = 0.003) and mean monthly Humidex (r = 0.49, P = 0.007). Humidex was found to be an independent predictor for stone submission (β = 0.49, P = 0.007). The majority of stones contained calcium (83.3%), combined with oxalate (77.6%), phosphate (14.7%), and carbonate (2.8%). Some stones (11.8%) contained a mixture of >1 negatively charged molecules. Urate (11.6%), cysteine (4.6%), and ammonium-magnesium-phosphate (0.5%) constituted the rest. There was no association between chemical composition and seasons. Literature review included 25 articles. Higher ambient temperature and warm seasons were the most commonly encountered risk factors for both presentation and etiology of nephrolithiasis.Conclusions:A significant positive correlation was noted between ambient temperature and stone submission rate, which was significantly higher during the warm months in Malta.

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

“…In the present study, using humidity and temperature separately in our regression model, we did not find statistical difference among all types of stones concerning such parameters. Although not exactly comparable, our findings corroborated Buttigieg et al 11 , who observed no association between chemical composition and season, and also with a recent study on stone composition within the USA showing very few differences across all states according to climate 18 .…”

“…climate (including temperature and humidity levels) may account for the increase in urolithiasis across the world. However, there are scarce data investigating their association with kidney stone composition 11 . Brazil, given its continental size and huge coastal extension, possesses five different climates with a large range of temperature and humidity levels as a result of the territorial extension through the tropics.…”

“…O IDH médio de todas as cidades em conjunto foi de 0,780 ± 0,03. No entanto, indivíduos que vivem em regiões com IDH <0,800 apresentaram duas vezes a razão de chances de ter cálculo de estruvita do que aqueles que vivem em cidades com IDH > 0,800 (OR = 2,14; IC 95% 1, 11). Além disso, um aumento progressivo na frequência de cálculos de estruvita de 4,5 para 22,8% foi detectado em IDH> 0,800 até IDH <0,700.…”

Usefulness of Color Doppler for Non-dilatational Ureteral Stone

“…Increased incidence of nephrolithiasis is strongly associated with race or ethnicity, region of residence [36], association with temperature, various meteorological parameters, climates, and geographical locations [37]. Seasonal changes showed high urinary calcium saturation in males during summer and in females during early winter [38].…”

The impact of ambient temperature on the incidence of urolithiasis: a systematic review and meta-analysis

“…Only 24 articles were eligible under the full-text assessment (figure 1). Of these, 9 studies directly investigated the impact of ambient temperature on urolithiasis using RR (7-9, 14-19), 12 time-series studies evaluated the linear correlation between mean monthly temperature and incidence of urolithiasis (5,(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), and 6 time-series studies estimated the increased RR as mean daily temperature increased to evaluate the non-linear association (28)(29)(30)(31)(32)(33).…”