The Effect of Oral Adenosine Triphosphate (ATP) Supplementation on Anaerobic Exercise in Healthy Resistance-Trained Individuals: A Systematic Review and Meta-Analysis.

Adenosine triphosphate (ATP) is an energy and signaling molecule. It is synthesized endogenously and can be taken as an oral supplement. This review aimed to identify the effects of oral ATP supplementation on anaerobic exercise in healthy resistance-trained adults. A systematic review and meta-analysis were performed based on the Preferred Reporting Items of Systematic Reviews and Meta-Analysis (PRISMA) criteria. The inclusion criteria were articles published from 2000 to 2022, with anaerobic variables (maximal strength, maximum repetitions, and maximum anaerobic power) measurable in healthy adults with experience in resistance training, only randomized placebo-controlled clinical trials (RCTs), and with the acute (a single dose 30 min to 24 h before the tests) and/or chronic (>1 day) oral supplementation of ATP. A total of five RCTs with 121 adult men were included. The oral ATP supplementation achieved significantly greater gains in maximal strength compared with the placebo (PL) (MD = 8.13 kg, 95%CI [3.36-12.90], p < 0.001). Still, no differences were observed in the maximum number of repetitions or the maximum anaerobic power. Furthermore, 400 mg of ATP showed improvement in anaerobic exercise regardless of the duration of the supplementation protocol. In conclusion, supplementation with 400 mg of ATP doses can improve maximal muscle strength in resistance-trained men.

Computed tomographic characterization of urinary stones in patients with urolithiasis from Southeast Mexico.

Urolithiasis (UL) is a severe public health concern in southeastern Mexico. Computed tomography (CT) is the first-line diagnostic method for patients with suspected UL. The present study aimed to characterize stones in the entire urinary system using CT and to contribute to personalized treatment in patients with UL. Patients >18 years of age with suspected UL were enrolled. Characteristics of UL included stone size, location (kidney, ureters, and bladder), composition of the stone in Hounsfield units (HU), presence of staghorn stone(s), and obstructive uropathy. Patients were stratified according to sex and age to determine whether stone size and HU were dependent on hormonal factors in females and on prostatic hyperplasia in males. The Mann-Whitney U test was used to compare median values. Frequencies are expressed as percentages and were analyzed using the Mantel-Haenszel chi-squared test. A total of 1150 patients were included in this study, of whom 744 (64.7 %) had UL in only 1 anatomical location in the urinary system, and 406 (35.3 %) had stones in ≥2 anatomical locations. Localization and stone size differed between males and females (p < 0.05). Additionally, males exhibited differences in HU (p = 0.024) and frequency of obstructive uropathy (p = 0.10) when stratified according to age (≤50 and > 50 years). In addition, females exhibited statistical differences in HU (p = 0.010) and kidney stone size (p = 0.047) dependent on age (≤47 and > 47 years). In conclusion, findings suggest that HU and stone size differ in different anatomical structures of the urinary system. In addition, differences in stone size and composition may be associated with age and sex.

Estimates of Agreement Between Three Low-cost and One High-cost Bioelectrical Impedance Analyzers using Classical and Contemporary Dancers.

The aim of this study was to determine the concordance between the estimates of three low-cost and one high-cost electrical bioimpedance equipment (BIA) in classical and contemporary dancers. Participation in the study included 28 subjects (15 men and 13 women) 18 to 35 years old, who perform classical and/or modern dance, thrice weekly, from 60 to 120 min per session, for 10 years or more. Those who presented any disease, consumed drugs, supplements or multivitamins; had prostheses, surgical metal parts or pacemakers, had problems maintaining the correct anatomical positions for taking measurements, and pregnant women were excluded. Their body composition was determined with 3 low-cost BIA equipment (OMRON HBF-306C, SKULPT CHISEL and BEURER BF 1000) and one high-cost equipment (SECA mBCA 515). The results indicated that in men, SKULTP in its "complete" modality had the highest agreement with SECA (CCC=0.73, 95% CI=0.46-0.88) for body fat percentage (%BF); in women, OMRON in its "normal" modality had the highest agreement with SECA (CCC=0.85, 95% CI=0.62-0.94) for %BF; while BEURER had poor concordances (CCC=0.86-0.03) for the rest of the estimates in its different modalities, in both sexes. It is concluded that the lower cost equipment (SKULPT and OMRON) were the most consistent with SECA for %BF in normal weight dancers. BEURER had the lowest agreements with SECA, in all its modalities, as well as inconsistent estimates for all parameters. Therefore, there was no relationship between the cost of the low-cost impedance equipment and its agreement with those of a high-cost one.

Recurrence of Nephrolithiasis and Surgical Events Are Associated with Chronic Kidney Disease in Adult Patients.

Background and objective: Nephrolithiasis (NL) is a public health problem in the population of Southeast Mexico because of its high prevalence and recurrence. The evolution of this pathology can result in renal damage and may even cause chronic kidney disease (CKD), leading to a reduced glomerular filtration rate (GFR), decreased kidney function, and kidney loss in advanced stages. However, few studies support this evidence in the population. The present study aimed to determine risk factors associated with CKD in adult patients in an endemic population of Mexico. Materials and methods: A case-control study was carried out with patients diagnosed with NL. Additionally, the clinical information of patients (age, weight, height, blood pressure, comorbidities, and time of progress of NL), characteristics of the stones (number, location, and Hounsfield units), and biochemical parameters were collected. Results: The recurrence of NL was associated with CKD (OR 1.91; 95% CI 1.37−2.27; p = 0.003). In addition, male sex (p = 0.016), surgical history (p = 0.011), bilateral kidney stones (p < 0.001), and urinary tract infections (p = 0.004) were other factors associated with CKD. Interestingly, thirty-two patients younger than 50 years old with >2 surgical events presented a significant decrease in GFR (p < 0.001). Conclusions: The recurrence of NL and the number of surgical events were risk factors associated with CKD in patients with NL treated in our population.

Implementation of a Technique Based on Hounsfield Units and Hounsfield Density to Determine Kidney Stone Composition.

Hounsfield units (HU) are a measure of radiodensity, related to the density of a tissue and the composition of kidney stones. Hounsfield density is what is related to the composition of kidney stones. In the standard acquisition method, these measures are arbitrary and dependent on the operator. This study describes the implementation of a technique based on the HU and Hounsfield density to predict the stone compositions of patients with nephrolithiasis. By conventional percutaneous nephrolithotomy, thirty kidney stone samples corresponding to the cortex, middle, and nucleus were obtained. The HU were obtained by CT scanning with a systematic grid. Hounsfield density was calculated as the HU value divided by the stone's greatest diameter (HU/mm). With that method and after analyzing the samples by IR-spectroscopy, anhydrous uric acid and ammonium magnesium phosphate were identified as the compounds of kidney stones. Additionally, anhydrous uric acid, magnesium ammonium phosphate, and calcium oxalate monohydrate were identified via Hounsfield density calculation. The study identified HU ranges for stone compounds using a systematic technique that avoids bias in its analysis. In addition, this work could contribute to the timely diagnosis and development of personalized therapies for patients with this pathology.

Acute kidney injury associated with intestinal infection by Cyclospora cayetanensis in a kidney transplant patient. A case report.

This study shows a clinical case report of a kidney transplant patient who traveled from Mexico to The Netherlands and ate green vegetables in an international food restaurant. After 5 days, he started having diarrhea, nausea, colic, and a physical feeling of malaise. The patient only received symptomatic treatment after showing the characteristic symptoms of traveler's diarrhea. When he returned to Mexico, the clinical picture worsened, and he was hospitalized. Clinical analyses indicated dehydration and acute kidney injury stage II. Coproparasitoscopic study showed the presence of Cyclospora cayetanensis. Parenteral solutions, gastric mucosal protector, ciprofloxacin, and a soft diet were administrated as treatment. The patient was discharged 72 h later with an improvement of the kidney function.

Metabolic syndrome and urolithiasis: a case-control study. / Síndrome metabólico y litiasis urinaria en adultos: estudio de casos y controles.

BACKGROUND: The estimate for metabolic syndrome (MS) worldwide is above 20%; MS it has been linked to urolithiasis. OBJECTIVE: To determine the association between the components of MS as risk factors for urolithiasis in the adult population of Yucatán, Mexico. METHOD: Case-control study with a sample size of 85 subjects per group, paired by age and sex; patients with urolithiasis (stones > 5 mm) and controls without urolithiasis. Diagnosis was verified by ultrasound. Blood pressure, weight, height, waist circumference, serum triglycerides, HDL cholesterol, glycemia, and urinalysis were determined. International Diabetes Federation criteria were used for the MS diagnosis. Subjects with kidney damage, endocrinopathies and consumption of steroid drugs were excluded. Descriptive statistics, association analysis and risk calculation were performed. RESULTS: One hundred and seventy subjects were included, 83.5% were women and 52.4% presented MS. Was observed an association between urolithiasis and MS (odds ratio [OR]: 2.7; 95% confidence interval [95% CI]: 1.4-5.1; p = 0.001), hypertriglyceridemia (OR: 1.9; 95% CI: 1.06-3.66; p = 0.021) and high blood pressure (OR: 2.5; 95% CI: 1.2-4.8; p = 0.004). The analysis showed that a higher quantity of MS components increases the risk of urolithiasis (p = 0.004). CONCLUSIONS: MS increased in 2.7-fold the risk of urolithiasis. Hypertriglyceridemia and high blood pressure are MS components that increased the risk of urolithiasis.

INTRODUCCIÓN: El síndrome metabólico (SM) tiene una prevalencia mayor del 20% en todo el mundo, y se le ha relacionado con la urolitiasis. OBJETIVO: Determinar la asociación entre los componentes del SM como factores de riesgo para urolitiasis en población adulta de Yucatán, México. MÉTODO: Estudio de casos y controles con un tamaño muestral de 85 sujetos por grupo, pareados por edad y sexo. Los casos con urolitiasis (litos > 5 mm) y los controles sin urolitiasis fueron comprobados mediante ecografía. Se determinaron la presión arterial, el peso, la talla, la circunferencia de la cintura, la trigliceridemia, el colesterol-HDL y la glucemia; se realizó uroanálisis. Para el diagnóstico de SM se siguieron los criterios de la Federación Internacional de Diabetes. Se excluyeron los sujetos con daño renal, endocrinopatías y consumo de medicamentos esteroideos. Se realizaron estadística descriptiva, análisis de asociación y cálculo del riesgo. RESULTADOS: De las 170 personas incluidas, el 83.5% fueron mujeres y el 52.4% presentaban SM. Se observó asociación entre la urolitiasis y el SM (razón de momios [RM]: 2.7; intervalo de confianza del 95% [IC95%]: 1.4-5.1; p = 0.001), la hipertrigliceridemia (RM: 1.9; IC95%: 1.06-3.66; p = 0.021) y la hipertensión arterial (RM: 2.5; IC95%: 1.2-4.8; p = 0.004). El análisis mostró que, a más cantidad de componentes del SM, mayor es el riesgo de urolitiasis (p = 0.004). CONCLUSIONES: El SM incrementa 2.7 veces el riesgo de urolitiasis; de los componentes del SM, la hipertrigliceridemia y la hipertensión incrementan el riesgo de urolitiasis.

[Obesity as a risk factor for metabolic disorders in adults with urolithiasis]. / Obesidad como factor de riesgo para alteraciones metabólicas en adultos con litiasis urinaria.

BACKGROUND: Yucatán ranks first in the prevalence of urinary calculi (UL), and above the national average of obesity (OB). The aim of the study was to determine whether there is an association between obesity and metabolic disorders (MD) in patients with UL. METHODS: In a case-control design, 197 patients were studied with and without UL. Weight and height were measured; urine calcium, phosphate, magnesium, uric acid, oxalates, citrates and sodium were quantified. RESULTS: 197 subjects, 62 men and 135 women were studied; 114 subjects with UL and 83 without UL. Hyperuricosuria was more frequent in obese patients without UL. Hypocitraturia was the most frequent MD in patients both with and without OB, with and without UL. There was a positive trend towards a greater number of MD as weight increased. Urinary sodium excretion in patients with OB was significant. CONCLUSIONS: Obesity is a risk factor for MD in patients with UL. Strategies must be implemented to spread awareness on the influence of obesity on UL, and how it can be modified by diet.

Introducción: Yucatán ocupa el primer lugar en la prevalencia de litiasis urinaria (LU), y supera la media nacional de obesidad (OB). El objetivo del estudio fue conocer si existe una asociación entre la obesidad y las alteraciones metabólicas (AM) en pacientes con LU. Métodos: mediante un diseño de casos y controles, se estudiaron 197 pacientes con y sin LU. Se midió peso y talla; en orina se cuantificó calcio, fosfato, magnesio, ácido úrico, oxalatos, citratos y sodio. Resultados: se estudiaron 197 sujetos, 62 hombres y 135 mujeres; 114 sujetos con LU y 83 sin LU. La hiperuricosuria fue más frecuente en pacientes obesos sin LU. La hipocitraturia fue la AM de mayor frecuencia tanto en pacientes con, como sin OB, con y sin LU. Existió una tendencia positiva a un mayor número de AM en función del incremento de peso. Fue significativa la excreción de sodio urinario en los pacientes con OB. Conclusiones: la obesidad es factor de riesgo para AM en pacientes con LU. Deben implementarse estrategias que concienticen sobre la influencia de la obesidad en la LU, y como ésta puede ser modificada por la alimentación.

[Relationship between body fat and creatinine clearence in adults with and without diabetes mellitus]. / Relación entre grasa corporal y depuración de creatinina en adultos con y sin diabetes mellitus.

BACKGROUND: Obesity is a risk factor for renal damage. This study aimed to determine the relationship between body fat percent and creatinine clearance in adult patients with and without type 2 diabetes mellitus (T2DM). METHODS: An observational prospective cross-correlation study was carried out among adults with and without T2DM between 18 and 60 years of age. It was determined the time of evolution with T2DM, as well as fat percentage (FP), body mass index (BMI), creatinine clearance (Cockroft-Gault [CrCCG]), glycemia and micro/macroalbuminuria. The correlation between CrCCG and FP was determined by Spearman's test. RESULTS: 174 subjects were included in this study. Obesity by BMI and FP in subjects with and without T2DM was similar. Of the studied subjects, 12.6 % didn't have kidney damage and 50.7 % had increased risk of renal disease; the frequencies for stages 1-4 of kidney damage were 12.0, 20.1, 4.0 and 0.6 %, respectively. Spearman's test showed a direct relationship between FP and CrCCG, higher in diabetics (r = 0.418, p < 0.0001) than in non-diabetics (p = 0.327, p < 0.0001). CONCLUSIONS: The FP was correlated directly with the CrCCG in subjects with and without T2DM; therefore, we can conclude that the greater the kidney damage, the smaller the fat porcentage in the study sample.

Introducción: la obesidad es un factor de riesgo para daño renal. El objetivo del estudio fue conocer la relación entre el porcentaje de grasa corporal (PG) y la depuración de creatinina en pacientes adultos con y sin diabetes mellitus 2 (DM2). Métodos: estudio observacional, prospectivo, transversal de correlación. Se evaluaron adultos entre 18 y 60 años, con y sin DM2. Se determinó el tiempo de evolución con DM2, el PG, el índice de masa corporal (IMC), la depuración de creatinina (Cockroft-Gault [DCrCG]), la glicemia y la micro/macroalbuminuria. Mediante la prueba de Spearman se determinó la correlación entre DCrCG y PG. Resultados: se incluyeron 174 sujetos. La frecuencia de obesidad por IMC y PG en sujetos con y sin DM2 fue similar. El 12.6 % no tuvo daño renal y el 50.7 % tuvo riesgo aumentado de enfermedad renal. Las frecuencias para los estadios 1 a 4 fueron 12.0, 20.1, 4.0 y 0.6 %, de forma respectiva. La prueba de Spearman mostró relación directa entre PG y DCrCG, mayor en diabéticos (r = 0.418 frente a r = 0.327, p < 0.0001). Conclusiones: el PG corporal se correlacionó en forma directa con la DCrCG en sujetos con y sin DM2; se infiere que a mayor daño renal, menor grasa tiene la población evaluada.

Metabolic abnormalities and polymorphisms of the vitamin D receptor (VDR) and ZNF365 genes in children with urolithiasis.

Composition of urinary stones in children from Yucatán, México, is calcium and uric acid. Polymorphisms in VDR and ZNF365 genes have been associated to calcium and uric acid lithiasis, respectively. We evaluated the association of polymorphisms TaqI and FokI of VDR gene and Ala62Thr of ZNF365 gene with the metabolic disorders (MD) in children with urolithiasis (UL). We included 109 children with UL. Creatinine, calcium, phosphorus, magnesium, uric acid, oxalates and citrates were measured in fresh urine. Urinary indices were calculated for determining the MD. VDR and ZNF365 polymorphisms were determined by PCR-RFLP. Genotype frequencies were compared with the frequency of MD and with the averages of excretion of the analytes, using the statistical package STATA 11.0. The most frequent MD were hypocitraturia (35.8 %) and hyperuricosuria (22.9 %). The comparison of genotype frequencies with the frequency of MD did not show significant differences (p > 0.05). The comparison of the urinary excretion averages of analytes with respect to the genotype showed that GG homozygotes have higher concentrations of uric acid and citrate than AG heterozygotes (p = 0.03), and that fF heterozygotes have lower concentrations of citrate (p = 0.009). Hypocitraturia and hyperuricosuria were the most common metabolic disorders. The frequency of MD is not associated with polymorphisms. However, in children with urolithiasis of Yucatan, GG homozygotes excrete higher concentrations of uric acid and citrates, and fF heterozygotes have lower concentrations of citrates.

[Kidney function in marginalized population: a pilot study]. / Función renal en un grupo marginado de la población. Estudio piloto.

BACKGROUND: Chronic kidney disease (CKD) is a public health problem; more than 6 % of worldwide population suffers from it. Low education and socioeconomic status, as well as limited access to medical care increase the probability of kidney damage. The objective was to evaluate and classify renal function in Yucatan's marginalized population. METHODS: A transversal descriptive survey was carried out among non-hospitalized adults of a general hospital. The study population included marginalized subjects (confirmed by socioeconomic survey), without oedema, pregnancy or diabetes mellitus. Renal function was evaluated by glomerular filtration rate. Patients were staged according to KDOQI guidelines. Likewise, weight, height, body mass index (BMI), fat percentage and blood pressure were measured. The results were compared between gender groups as well as rural and urban population. RESULTS: 165 subjects were included (83 % female). High risk of kidney damage was observed in 44.2 % of patients; 1.8 %, 49.1 %, and 4.8 % were in stages 1 to 3, respectively. There was no difference when comparing data between different groups. CONCLUSIONS: This study found high prevalence of CKD in Yucatan's marginalized population.

INTRODUCCIÓN: la enfermedad renal crónica (ERC) es un problema de salud pública. A nivel mundial, más del 6 % de la población la padece. Tener un nivel educativo y socioeconómico bajo, así como acceso limitado a los servicios médicos incrementan la probabilidad de daño renal. Los objetivos de esta investigación fueron evaluar y clasificar la función renal de la población marginada de Yucatán. MÉTODOS: estudio observacional, prospectivo, transversal, descriptivo, en una muestra no probabilística consecutiva, en adultos del área de consulta externa de un hospital general. Se incluyeron sujetos marginados (confirmado por encuesta socioeconómica), sin edema, embarazo ni diabetes mellitus. Se realizaron pruebas de función renal; se calculó filtrado glomerular y se estadificaron las enfermedades de los pacientes, según guías KDOQI. Se determinó peso, talla, índice de masa corporal (IMC), porcentaje de grasa y presión arterial. Se compararon los resultados entre grupos por sexo y por población rural y urbana. RESULTADOS: se incluyeron 165 sujetos (83 % mujeres). El 44.2 % presentó un riesgo alto de daño renal; 8, 49.1 y 4.8 % estuvieron en estadios del 1 al 3, respectivamente. No hubo diferencia cuando se compararon los datos entre los diferentes grupos estudiados. CONCLUSIONES: se encontró alta prevalencia de ERC en la población marginada de Yucatán.

Epidemiología y clínica de la litiasis urinaria en niños / Epidemiological and clinical characteristics of urolithiasis in children

Establecer las características clínicas y demográficas de los pacientes pediátricos con litiasis urinaria (LU) de Yucatán, México. Métodos: Mediante diseño prospectivo y longitudinal se estudiaron todos los menores de 16 años con diagnóstico de LU, durante un período de 9 años; se registraron los datos clínicos, las alteraciones metabólicas, el tratamiento instituido, las complicaciones, las recurrencias, etcétera. Resultados: Se observaron 69 casos nuevos por año, con un aumento de la tasa de prevalencia del 19% en relación con lo informado en años previos. En los 474 pacientes estudiados se observó una relación varones: mujeresde 1:1.6, con edades desde 3 hasta 180 meses, con predominio de lactantes y escolares. Las alteraciones metabólicas más frecuentes fueron hiperuricosuria, hipercalciuria e hipocitraturia. El 27% tuvo sobrepeso u obesidad y el 32.7% talla baja. El 63.9% tuvo antecedente familiar y el 20.8% antecedente personal positivo de LU. El 7.1% se asoció con malformaciones urinarias. El 7.8% de los cálculos fueron hallazgos, detectándose en más de un sitio anatómico en el 29.1% de los casos. El cuadro clínico varió desde casos asintomáticos, hasta casos con datos clínicos de insuficiencia renal aguda o crónica. Conclusiones: Deben diseñarse programas de prevención, diagnóstico y tratamiento oportunos para disminuir la incidencia y complicaciones en niños con LU de Yucatán...

[Changes in body composition according to kidney damage in patients with type 2 diabetes mellitus]. / Modificaciones en la composición corporal según el daño renal en pacientes con diabetes mellitus tipo 2.

OBJECTIVE: To know the relationship between total body composition and the stage of kidney damage, according to the K/DOQI classification, in patients with type 2 diabetes mellitus (T2DM). METHODS: Under a correlation design, adults with T2DM were studied. Age, evolution time, fat and lean mass, fat percentage, total water, body index mass (BMI), creatinine clearance by Cockroft-Gault (CrCCG), glucose, HbA1c, proteinuria and microalbuminuria were determined. T test to compare independent means and Spearman correlation were used. RESULTS: The study included 60 men (23.4%) and 196 women (76.6%). There were no differences by gender when comparing age, BMI, duration of T2DM, blood glucose and HbA1c. The analysis showed a direct relationship between BMI (r = 0.281), the amount of fat mass (r = 0.360), lean tissue (r = 0.158), and water (r = 0.176) with the CrCCG (p < 0.0001). The biggest change in body composition, due to fat mass, was observed in chronic kidney disease stages 1-3, in which BMI had a good correlation with fat mass (r = 0.80, p < 0.001). CONCLUSIONS: Fat mass is inversely related to the stage of kidney damage in patients with T2DM.

Heavy metal quantification in renal tissue of patients in the state of yucatan and its association with urolithiasis.

A possible cause associated with urinary lithiasis (UL) is the bioaccumulation of heavy metals in the kidney. The aim of this study was to evaluate the content of Cu, Pb, and Cd in kidney tissues removed from patients with nephrological problems and associate it with UL. Samples of 50 kidney sections from patients were analyzed. Results were statistically analyzed using a fixed effects model including the overall mean, the effect of the health status of patients (with or without UL), gender (male and female), the interaction between both factors and the random error (NID (0, σ (2))). Cu level was 8.8 ± 4.4 mg/kg (mean ± DS) and 25.5% of samples had levels above normal. Lead content in 97.9% of the samples (3.6 ± 1.5 mg/kg) was above normal. All results of Cd (13.2 ± 16.6 mg/kg) were below the maximum permissible limits. There was no difference in the amount of heavy metals on patients with or without UL (P > 0.05) nor depending on the gender (P > 0.05). It was concluded that there is no apparent relationship between a very elevated level of Cu or Pb in the kidney on the development of UL.

[Nephrolithiasis as a nephrectomy surgical indication. A multicentric study]. / Nefrolitiasis como indicación de nefrectomía. Estudio multicéntrico.

BACKGROUND: urolithiasis is endemic in Yucatan, Mexico, and its complications are abscesses and renal exclusion which end up in a nephrectomy. Our objective in this paper was to know the nephrectomy indications in Yucatecan population. METHODS: the nephrectomies from four concentrations hospitals of the Health Services, were analyzed. Patients older than 18 years were included; surgical indication, evolution time of the disease, and associated illnesses were registered. The diagnosis was confirmed by laboratory, X-rays or anatomopathological study. Statistics were t Student test and chi(2). RESULTS: 206 (70.5 %) women and 86 (29.5 %) men were included; they were 48 + or - 14 years of age with an evolution time 40 + or - 70 months. Nephrolithiasis was observed in 59.6 %, renal tumors 21.9 %, hydronephrosis 7.9 % and abscess 3.4 %. No cases with nephrolithiasis had metabolic studies. The cases with lithiasis (n = 174) had a longer evolution time and were younger at the time of the surgical procedure (p < 0.05) than those not related to lithiasis (n = 118). CONCLUSIONS: nephrolithiasis is the most frequent indication for nephrectomy in the Yucatecan population which differs from others reports.

[Four years experience in the follow up of nursing children with urolithiasis]. / Litiasis urinaria en lactantes. Seguimiento a cuatro años.

OBJECTIVE: to describe clinical data, metabolic profile, treatment and evolution of a nursing children cohort with urolithiasis. METHODS: using a descriptive, prospective and longitudinal design, were registered all patients with urolithiasis, of Pediatric Division at the Hospital General "Agustín O'Horán," in Yucatan, Mexico. We included all patients who were 36 months old and younger. We did not include children with malformations or associated disease which causes urolithiasis. Clinical and metabolic profiles, evaluation of the applied treatment as well as an evolution by four years period were done. RESULTS: 63 patients were recruited with ages ranging from 2 to 36 months; 39 (61.9 %) were male. The most common clinical signs were crying upon urination (49.2 %), urinary retention (31.7 %), hematuria (30.2 %), and pollakiuria (28.6 %). Calculus were most frequently located in the kidney (58.7 %). The most common complications were acute urinary tract infection (61.9 %), malnutrition (47.6 %) and acute renal failure (12.7 %). Documented metabolic alterations included hyperuricosuria (57.1 %), hypomagnesiuria (11.1 %) and hypercalciuria (9.5 %). CONCLUSIONS: urolithiasis should be suspected in children with crying upon urination and urinary symptoms; it should be considered among the different causes of renal failure; hyperuricosuria was the most frequent metabolic alteration.