Stesura Seveso 189Archivio Italiano di Urologia e Andrologia 2021; 93, 2 ORIGINAL PAPER No conflict of interest declared. INTRODUCTION Obesity is considered a risk factor for urinary stone for- mation. A recent meta-analysis based on 7 large cohorts in the United States, China and Japan computed a relative risk for kidney stone formation of 1.21 per 5 units of increment in body mass index (BMI) (1). This scientific evidence is robust although it is mainly dependent on observations collected from cohorts in the United States. For this reason, one might question the extension of these findings to other countries. In fact, the population of the United States is characterized by a dietary pattern that contains important risk factors for stone formation (a high animal protein load, a significant acid load due to lack of fruit and vegetable consumption). Furthermore, morbid obesity (BMI ≥ 40) is much more prevalent in the population of the United States than in any other country excluding Pacific Islands (2). In fact, the prevalence of morbid obesity in the United States is high and is constantly increasing. From 2000 to 2010 the prevalence rate of a BMI > 40 increased by 70% (from 3.9% to 6.6%) and the prevalence of BMI > 50 has increased even more (from 0.27 to 0.55%) (3). Morbid obesity levels are also increasing in other countries but with much lower rates (< 2%) (4-6). Morbid obesity or type III obesity has a different impact on health than mod- erate obesity by increasing the risk and severity of many cardiovascular and non-cardiovascular comorbidities. Particularly, it was observed that 98% of subjects with morbid obesity have at least one lithogenic risk factor identified on 24-hour urine collection (7). The obese pop- ulation of the United States is therefore a different popula- Objective: To collect evidence on the rate of obesity in renal stone formers (RSFs) living in different climatic areas and consuming different diets. Materials and methods: Data of adult renal stone formers were retrospectively collected by members of U-merge from 13 participant centers in Argentina, Brazil, Bulgaria (2), China, India, Iraq (2), Italy (2), Nigeria, Pakistan and Poland. The following data were collected: age, gender, weight, height, stone analysis and procedure of stone removal. Results: In total, 1689 renal stone formers (1032 males, 657 females) from 10 countries were considered. Average age was 48 (±14) years, male to female ratio was 1.57 (M/F 1032/657), the average body mass index (BMI) was 26.5 (±4.8) kg/m2. The obesity rates of RSFs in different countries were significantly different from each other. The highest rates were observed in Pakistan (50%), Iraq (32%), and Brazil (32%), while the lowest rates were observed in China (2%), Nigeria (3%) and Italy (10%). Intermediate rates were observed in Argentina (17%), Bulgaria (17%), India (15%) and Poland (22%). The age-adjusted obesity rate of RSFs was high- er than the age-adjusted obesity rate in the general population in Brazil, India, and Pakistan, whereas it was lower in Argentina, Bulgaria, China, Italy, and Nigeria, and similar in Iraq and Poland. Conclusions: The age-adjusted obesity rate of RSFs was not higher than the age-adjusted obesity rate of the general popu- lation in most countries. The relationship between obesity and the risk of kidney stone formation should be reconsidered by further studies carried out in different populations. KEY WORDS: Urinary calculi; Obesity; Diet, Body mass index. Submitted 1 April 2021; Accepted 25 May 2021 Obesity rates in renal stone formers from various countries Elenko Popov 1, 2, Murtadha Almusafer 1, 3, Arben Belba 1, 4, Jibril O. Bello 1, 5, Kamran Hassan Bhatti 1, 6, Luca Boeri 1, 7, Kaloyan Davidoff 1, 2, BM Zeeshan Hameed 1, 8, Adam Haliński 1, 9, Ita Pfeferman Heilberg 1, 10, Hongyi Hui 1, 11, Kremena Petkova 1, 12, Bapir Rawa 1, 13, Fernanda Guedes Rodrigues 10, Iliya Saltirov 1, 12, Francisco R. Spivacow 1, 14, Alberto Trinchieri 1, Noor Buchholz 1 1 U-merge Ltd.* (Urology for emerging countries), London, UK; 2 Acibadem City Clinic Tokuda Hospital, Sofia, Bulgaria; 3 College of Medicine, University of Basrah, Basrah, Iraq; 4 Ospedale Santo Stefano, Prato & Casa di Cura Villa Donatello, Sesto Fiorentino, Italy; 5 Department of Surgery, Urology Unit, University of Ilorin Teaching Hospital, Nigeria; 6 Urology Department, Hamad Medical Corporation, Doha, Qatar; 7 Department of Urology, IRCCS Ca’ Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy; 8 Department of Urology, Kasturba Medical College, Manipal, Karnataka, India; 9 Private Medical Center "Klinika Wisniowa" Zielona Gora, Poland; 10 Nephrology Division, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil; 11 Department of Urology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; 12 Department of Urology and Nephrology, Military Medical Academy, Sofia, Bulgaria; 13 Smart Health Tower, Sulaymaniyah, Kurdistan region, Iraq; 14 Instituto de Investigaciones Metabólicas (IDIM), Buenos Aires, Argentina. * U-merge Ltd. (Urology in Emerging Countries) is an academic urological platform dedicated to facilitate knowledge transfer in urology on all levels from developed to emerging countries. U-merge Ltd. is registered with the Companies House in London/ UK. www.u-merge.com DOI: 10.4081/aiua.2021.2.189 Summary Archivio Italiano di Urologia e Andrologia 2021; 93, 2 E. Popov, M. Almusafer, A. Belba, et al. 190 tion from obese populations observed in other countries in that it includes a higher percentage of morbid obese sub- jects. On the other hand, rates of overweight and obesity in a population consuming a Mediterranean diet were not different in renal stone formers with respect to a control population matched by age and gender (8) suggesting a prevalent role of the dietary pattern for the risk of stone formation (9). The aim of the present study was to collect more evi- dence on the rate of obesity in renal stone formers living in different climatic areas and consuming different diets. Age and sex adjusted rates of obesity in stone formers from different countries were compared with already known obesity rates for each corresponding country. MATERIALS AND METHODS Data were collected by 13 participating centers in Argentina, Brazil, Bulgaria (n = 2), China, India, Iraq (n = 2), Italy (n = 2), Nigeria, Pakistan and Poland under the umbrella of U-merge. Each participating center collected retrospectively data of consecutively observed adult (> 18 years) renal stone former patients (RSFs) by review- ing charts of patients who passed spontaneously a stone or had extracorporeal or endourological treatment for stone removal. For each patient, the following informa- tion was collected: age, gender, weight, height, stone analysis (optional), procedure of removal (spontaneous passage, SWL, PNL, URS, open surgery). Any method of stone analysis was accepted, but the methodology had to be known and registered. Excel files containing anonymised data from each patient and numbered consecutively were mailed to the coordinating center (U- merge scientific office). Each center retained the list of the corresponding names of the participants in their own original files at their institution. BMI was computed from weight and height of each subject. Obesity was defined as a body mass index (BMI) ≥ 30 kg/m2. Tables reporting the number of subjects with obesity for each age and sex group were built. The obesity rates of RSFs in different countries were adjusted by the age distribution in the general population of each country, in order to compare them with age adjusted obesity rates in the general pop- ulation of the corresponding country obtained from esti- mated worldwide trends in obesity by NCD Risk Factor Collaboration (NCD-RisC) (2). Briefly, RSFs of each coun- try were grouped by sex and class age. Age and sex spe- cific rate of obesity of RSFs of each subgroup was multi- plied by the corresponding age and sex specific weight of that country. The weights used in the age-adjustment of obesity data are the proportion of the population of each country within each age and sex group according to the estimates prepared by the Population Division of the Department of Economic and Social Affairs (DESA) of the United Nations Secretariat (10). The weighted rates are then summed across the age and sex groups to give the age and sex adjusted rate of obesity for RSFs of each country (Table 1). Age adjusted obesity rates of male and female RSFs from each country were compared with age adjusted obesity rate of male and female general popula- tion obtained from estimated worldwide trends in obesi- ty by NCD-RisC (2). Finally, obesity rates in RSFs with stones of different chemical composition were calculated. Statistical analysis was carried out using the Statistical Package for the Social Sciences (SPSS). Chi square analysis was used to compare rates of obesity in different groups. Mean values of age and BMI were compared by one-way ANOVA, and differences between groups were evaluated by post hoc Bonferroni analysis. A p-value < 0.05 was considered statistically significant. RESULTS In total, 1689 renal stone formers (1032 males, 657 females) from 10 countries (Argentina, Brazil, Bulgaria, China, India, Iraq, Italy, Nigeria, Pakistan, Poland) were con- sidered. Most of the cases were observed in the period 2016-2019. Only the series from Argentina included patients observed over a longer period from 2005 to 2017. Average age was 48 (±14) years, male to female ratio was 1.57 (M/F 1032/657), average BMI was 26.5 (±) 4.8 kg/m2). Average age, M/F ratio and average BMI in series from different countries are shown in Table 2. The aver- age age values in the different series were significantly different (p = 0.000). The highest average age was observed in patients from Table 2. Mean age, M/F ratio and mean BMI of RSFs from different countries. Argentina Brazil Bulgaria China India Iraq Italy Nigeria Pakistan Poland N° 300 216 183 90 33 246 428 31 50 112 M 179 (60%) 114 (53%) 112 (61%) 59 (66%) 26 (79%) 154 (63%) 267 (62%) 17 (55%) 41 (82%) 63 (56%) F 121 (40%) 102 (47%) 71 (39%) 31 (34%) 7 (21%) 92 (37%) 161 (38%) 14 (45%) 9 (18%) 49 (44%) Age 45 +/-11 42 +/-12 50 +/-13 51 +/-13 48 +/-11 46 +/-14 56 +/-14 44 +/-14 38 +/-8 48 +/-14 BMI 25.8 +/-4.4 28.3 +/-5.8 26.2 +/-3.8 24.2 +/-2.9 26.0 +/-4.2 28.3 +/-4.7 25.1 +/-4.3 26.2 +/-2.4 30.4 +/-6.7 26.7 +/- 4.6 UA % 11% § - 29% * 6% * 34% * - 16% § - 25% * 33% * BMI = Body Mass Index; UA% = Rate of Uric Acid containing stones; § Present series; * Other series from the same institution. Table 1. An example of computation of age-adjusted obesity rate (Italy-males). Class age Obesity rate in RSF Weight of class ages in Italy (5) Age adjusted 18-39 1/29 = 0.034 0.30 0.010 40-59 17/130 = 0.130 0.38 0.049 > 60 9/108 = 0.083 0.32 0.026 TOTAL 27/267 = 0.101 1.00 0.085 10.1% 8.5% Italy, while the lowest average age was observed in patients from Pakistan. The average age of patients from Italy was significantly higher than that of patients from Bulgaria (p = 0.000), Iraq (p = 0.000), Pakistan (p = 0.000), Nigeria (p = 0.000), Poland (p = 0.000), Argentina (p = 0.000) and Brazil (p = 0.000). The average age of patients from Pakistan was significantly lower than that of patients from Bulgaria (p = 0.000), Iraq (p = 0.003), China (p = 0.000), India (p = 0.039), Italy (p = 0.000), Poland (p = 0.000) and Argentina (p = 0.046). The average age of patients from Bulgaria and China was significantly higher than that of patients from Pakistan (p = 0.000 and p = 0.000), Argentina (p = 0.007 and p = 0.007) and Brazil (p = 0.000 and p = 0.000) and the average age of patients from Brazil was higher than that of patients from Poland (p = 0.002) and Iraq (p = 0.005). Male to female ratio was in favor of men in all countries, with the percentage of men ranging from 53 to 63% in most countries except Pakistan and India where males accounted for 82 and 79%, respectively. The average BMI values of patients in different countries were significantly different (p = 0.000). In particular, the average BMI was highest in patients from Pakistan, Iraq and Brazil. The average BMI of patients in Pakistan was significantly higher than that of patients in Bulgaria (p = 0.000), China (p = 0.000), India (p = 0.001), Italy (p = 0.000), Nigeria (p = 0.004), Poland (p = 0.000), Argentina (p = 0.000) and Brazil (p = 0.000). The average BMI of patients in Iraq was significantly higher than the average BMI of patients in Bulgaria (p = 0.000), China (p = 0.000), Italy (p = 0.000) and Argentina (p = 0.000). The average BMI of Brazilian patients was intermediate, being higher than that of patients in Bulgaria (p = 0.001), China (p = 0.000), Italy (p = 0.000) and Argentina (p = 0.000). The lowest average BMI value was observed in patients from China being lower than that of Bulgaria (0.0024) and Poland (p = 0.007). Crude and age-adjusted obesity rates in male and female RSFs from different countries in comparison of age- adjusted obesity rates in the male and female general population are shown in Table 3. In both, males and females, the age-adjusted rate of obesity in RSFs was higher than the age-adjusted rate of obesity in the gener- al population in Brazil, India, and Pakistan, whereas it was lower in Argentina, Bulgaria, China, Italy, and Nigeria, and similar in Iraq and Poland. The obesity rates of RSFs were significantly different from country to country. The highest rates were observed in Pakistan (50%), Iraq (32%), and Brazil (32%), while the lowest rates were observed in China (2%), Italy (10%), and Nigeria (3%). Intermediate rates were observed in Argentina (17%), Bulgaria (17%), India (15%), and Poland (22%). These differences were maintained when obesity rates were adjusted by age in reference to a pool of all series. In a sample of 666 patients (409 males and 257 females) with stone analysis, obesity rate was 13.3% (61/456) for calcium oxalate stones, 4.7% (1/21) for cal- cium phosphate, 8.5% (6/70) for mixed calcium phos- phate/calcium oxalate, 18.8% (13/69) for uric acid, 20.8% (5/24) for mixed calcium oxalate/uric acid. No obese patients were observed for infection (struvite) (0/21) and cystine stones (0/5). Mean age (56±14 vs 50±14 years, p = 0.000), mean BMI (27.2±4.6 vs 25.0±4.2, p = 0.000) and obesity rates 18/86 (21%) vs 75/580 (13%) were higher in patients who formed uric acid-containing stones than in those of patients forming other type of stones. In the present series, rate of uric acid containing stones was 16% in Italy and 11% in Argentina and, from data of other series collected in the same centers participating to the present study, 29% in Bulgaria, 6% in China, 34% in India, 25% in Iraq, 25% in Pakistan and 33%in Poland DISCUSSION In 2006, a prospective study of 3 large cohorts demon- strated that a BMI > 30 is associated with an increased risk of kidney stone formation for both, men and women (11). Some authors emphasized the presence of high rates of obesity in RSFs in some countries, whilst other authors did not confirm this finding in other countries (Table 4) (8, 12-20). 191Archivio Italiano di Urologia e Andrologia 2021; 93, 2 Obesity rates in renal stone formers Table 3. Crude and age-adjusted obesity rates in male and female RSFs from different countries in comparison of age-adjusted obesity rates in male and female general population. Country Gender RSFs RSFs obesity RSFs obesity General population obese/total rate (crude) rate (adjusted) obesity rate 2016 Argentina T 51/300 (17%) 17% M 32/179 (18%) 17.8% 15.9% 28.2% F 19/121 (16%) 15.7% 15% 30.1% Brazil T 70/216 (32%) M 36/114 (31%) 31.5% 32.5% 19.2% F 34/102 (33%) 33.3% 31.9% 26.4% Bulgaria T 32/183 (17%) M 18/112 (16%) 16.0% 15.3% 26.3% F 14/71 (19%) 19.7% 17.7% 25.2% China T 2/90 (2%) M 1/59 (2%) 1.6% 1.5% 6.1% F 1/31 (3%) 3.2% 3.3% 6.8% India T 5/33 (15%) M 3/26 (11%) 11.5% 11.0% 2.8% F 2/7 (28%) 28.5% 59.5% 5.3% Iraq T 78/246 (32%) M 45/154 (29%) 29.2% 22.5% 24.3% F 33/92 (36%) 35.8% 32.3% 38.3% Italy T 43/428 (10%) M 27/267 (10%) 10.1% 8.5% 20.9% F 16/161 (10%) 9.9% 9.5% 20.4% Nigeria T 1/31 (3%) M 17 0 0 4.8% F 1/14 (7%) 7.1% 4.5% 13.6% Pakistan T 25/50 (50%) M 20/41 (49%) 48.7% 20.7% 6.2% F 5/9 (55%) 55.5% 24.1% 11.7% Poland T 25/112 (22%) M 18/63 (28%) 28.5% 27.9% 24.6% F 7/49 (14%) 14.2% 14.6% 23.2% TOTAL T 332/1689 (20%) M 200/1032 (19%) F 132/657 (20%) Archivio Italiano di Urologia e Andrologia 2021; 93, 2 E. Popov, M. Almusafer, A. Belba, et al. 192 The assessment of the significance of the obesity rate in a given population on one hand, and the comparison of obesity rates in different populations on the other hand are complex because one must take into account the age and gender distribution of the population as well as the chemical composition of the stones. Our study shows that obesity rates among RSFs in dif- ferent countries range between 0 and 48.7% in men, and 7.1% and 55.5% in women. These differences are main- tained after age adjustment according to the general pop- ulation’s age distribution, with rates ranging between 0 and 32.5% in men, and 3.3% and 59.5% in women, respectively. These wide oscillations can be explained by the different age distributions in different countries, but also by dif- ferent spectra of stone composition, dietary patterns and different climatic conditions. In general, the rate of obesity tends to increase with increasing age, so it is possible that in populations with an older age distribution there may be a higher preva- lence of obesity. To the contrary, in this study, series with higher average ages, such as those observed in Italy, Bulgaria and China, had the lowest obesity rates among both, men (1.6-16%) and women (3.2-15.7%), respec- tively. On the other hand, the ranking of obesity rates in differ- ent countries does not vary after the rates have been adjusted by age taking as a reference the pooled popula- tion of all the series. Another potential determinant of obesity rate among RSFs is the type of stone. Obesity tends to be more fre- quent in uric acid stone formers (21). Uric acid stones have a different prevalence in different countries. In our series obesity rates were higher in Pakistan, Iraq and Brazil. The former two have reported a higher fre- quency of uric acid stones (22, 23), which was also observed in some parts of Brazil (24). In contrast, the lowest obesity rates were observed in countries where the frequency of uric acid stones is low, such as China, Nigeria and, to a lesser extent, Italy (25-27). One of the major determinants of the epidemiology of uric acid stones is climate, as higher environmental tem- peratures and humidity increase skin loss of fluids result- ing in a reduction in urinary volumes, a decrease of pH values and, consequently, an increased urinary saturation for uric acid (28, 29). In fact, in our study, the countries with the highest rates of uric acid stones are character- ized by higher environmental temperatures (30). The finding of obesity rates in RSFs equal to or even lower than those observed in the general population of most countries can be explained by the interaction of several factors specific to each population. Obesity is the result of the imbalance between dietary energy intake and energy expenditure that is modulated by the individual genetic characteristics that affect the absorption and metabolism of nutrients. In Table 5 the different patterns of dietary energy intake, levels of physical activity and consumption of healthy and unhealthy foods in the general population of countries involved in the present study are summarized (31-33). In countries with the lowest dietary energy intake, such as India, Pakistan and Nigeria, the lowest obesity rates were observed, but also in China, where dietary energy intake has an intermediate value, the obesity rate is low in view of the high levels of physical activity. In other countries with intermediate energy intake values Table 4. Obesity rates of RSFs of different countries (from the highest to the lowest). Author, year Country N° Obesity rate Overweight Semins, 2010 United States 1935 M+1322 F 49.9%-49.0% 34.1%-20% Abu Ghazaleh and Budair, 2013 Jordan 8346 42.3 % 25.8% Chou, 2011 Taiwan 907 38.8% 33.5% Saenz, 2012 Spain 346 28.6% 43.6% Funes, 2016 Paraguay 73 23.3 39.7% Negri, 2008 Argentina 799 20.3% 40.6% Siener, 2004 Germany 527 9.9% 44.6% Daudon, 2006 France 1931 M+F 8.4%-13.5% 27.1%-19.6% Trinchieri, 2016 Italy 1698 8.3% 31.9% Oda, 2014 Japan 238 M+82 F 2.1%-0% 24.4%-12.2% Table 5. Rates of obesity, estimated energy intake, levels of physical inactivity and quality of dietary pattern of the general population in countries involved in this surveycomparison of age-adjusted obesity rates in male and female general population. Country Obesity Energy Physical Quality of dietary pattern (NCD-RiskCo) intake inactivity (NutriCoDE) M-F Kcal/day (FAO) * (WHO) Argentina 28.2-30.1 3030 41.6% (T) Healthy foods very low 37.6% (M) Unhealthy foods low/mod 45.3% (F) Brazil 19.2-26.4 3120 47.9% (T) Healthy foods moderate 40.4% (M) Unhealthy foods high 53.3% (F) Bulgaria 26.3-25.2 2760 38.6% (T) Healthy foods moderate 35.6% (M) Unhealthy foods low/moderate 41.4% (F) China 6.1-6.8 2990 14.1% (T) Healthy foods low 16.0% (M) Unhealthy foods low 12.2% (F) India 2.8-5.3 2360 34.0% (T) Healthy foods low 24.7% (M) Unhealthy foods very low 43.9% (F) Iraq 24.3-38.3 - 52.0%(T) Healthy foods moderate 39.5% (M) Unhealthy foods low/moderate 64.6% (F) Italy 20.9-20.4 3650 41.4% (T) Healthy foods low/mododrate 36.2% (M) Unhealthy foods moderate 46.2% (F) Nigeria 4.8-13.6 2710 27.1% (T) Healthy foods moderate 24.7% (M) Unhealthy foods low 29.6% (F) Pakistan 6.2-11.7 2280 33.7% (T) Healthy foods very low 24.4% (M) Unhealthy foods low 43.3% (F) Poland 24.6-23.3 3410 32.5% (T) Healthy foods low/moderate 31.5% (M) Unhealthy foods high/moderate 33.4% (F) 193Archivio Italiano di Urologia e Andrologia 2021; 93, 2 Obesity rates in renal stone formers but reduced levels of physical activity, such as Brazil and Argentina, high obesity rates are observed similarly to those of countries with higher energy intakes, such as Italy and Poland. Finally, the highest levels of obesity were observed in Iraq where lowest levels of physical activity were reported. Obesity rate in RSFs was higher than in the general pop- ulation in Brazil, which is, a country with a high con- sumption of unhealthy foods (34, 35). The other two countries where obesity rates were increased in RSFs, namely Pakistan and India, are not characterized by a high consumption of unhealthy foods, but have a low consumption of healthy foods such as fruits, vegetables, beans and legumes, nuts and seeds, whole grains, milk, total polyunsaturated fatty acids, fish, plant omega-3s, and dietary fibers (33). Admittedly, our study has some limitations such as the retrospective study format, the small number of subjects observed in some countries, the heterogeneous nature of data, the variability in the population pattern and nature of cohorts and the availability of the chemical examina- tion of the stones only in some series Particularly, series observed in some areas of large coun- tries are representative only for those specific areas, notably Shanghai (China), Lagos (Nigeria), Pakpattan (Pakistan) and Manipal (Karnataka-India) and obesity rates cannot be translated to populations of countries with several million inhabitants. In fact, the populations of these countries are made up of different ethnicities with different genetic characteristics and different culture and religion influencing eating habits and lifestyle. In conclusion, obesity rates among patients with urinary stones are variable in different countries. 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Correspondence Elenko Popov, MD shennyp@yahoo.com Kaloyan Davidoff, MD shennyp@yahoo.com Acibadem City Clinic Tokuda Hospital - Sofia, Bulgaria Murtadha Almusafer, MD dralmusafer@yahoo.com College of Medicine, University of Basrah - Basrah, Iraq Kamran Hassan Bhatti, MS Urology kamibhatti92@gmail.com Urology Department, Hamad Medical Corporation - Doha, Qatar Arben Belba, MD arbenbelba@gmail.com Ospedale Santo Stefano, Prato and Casa di Cura Villa Donatello, Sesto Fiorentino, Florence, Italy Jibril O. Bello, MD jabarng@yahoo.com Department of Surgery, Urology Unit, University of Ilorin Teaching Hospital - Ilorin, Nigeria Luca Boeri, MD dr.lucaboeri@gmail.com Department of Urology, IRCCS Ca’ Granda Ospedale Maggiore Policlinico University of Milan, Milan, Italy Adam Haliński, MD adamhalinski@gmail.com Private Medical Center "Klinika Wisniowa" - Zielona Gora, Poland BM Zeeshan Hameed, MD zeeshanhameedbm@gmail.com Department of Urology, Kasturba Medical College - Manipal, Karnataka, India Ita Pfeferman Heilberg, MD ita.heilberg@gmail.com Fernanda Guedes Rodrigues, MSci RD fernanda.gr91@gmail.com Nephrology Division, Universidade Federal de São Paulo (UNIFESP) - São Paulo, Brazil Hongyi Hui, MD 1095340463@qq.com Department of Urology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China Kremena Petkova, MD dr_petkova@yahoo.com Iliya Saltirov, MD saltirov@vma.bg Department of Urology and Nephrology, Military Medical Academy - Sofia, Bulgaria Bapir Rawa, MD dr.rawa@yahoo.com Smart Health Tower - Sulaymaniyah , Kurdistan region, Iraq Francisco R. Spivacow, MD frspivacow@gmail.com Instituto de Investigaciones Metabólicas (IDIM) - Buenos Aires, Argentina Alberto Trinchieri, MD alberto.trinchieri@gmail.com U-merge Ltd. (Urology for emerging countries), Scientific Office - Athens, Greece & School of Urology, University of Milan - Milan, Italy Noor Buchholz, MD (Corresponding Author) noor.buchholz@gmail.com U-merge Ltd. (Urology for emerging countries), Scientific Office - Athens, Greece