Renal analysis in 75 km ultra-marathon participants

Abstracts

OBJETIVO: Identificar alterações urinárias compatíveis com comprometimento renal em ultramaratonista e "pacer" (ciclista de apoio) ao longo de uma prova de 75 quilômetros. MÉTODOS: Para tal, utilizou-se teste de urina com fita reagente em quatro tempos diferentes, além de avaliação antropométrica. RESULTADOS: As medidas concernentes a ultramaratonista a classificaram como eutrófica, assim como o "pacer". Observou-se, assim, associação entre os momentos de esforço físico máximo e a detecção de alterações urinárias, definidas pela presença de hematúria e, por vezes, positivação da proteinúria. CONCLUSÃO: Foi possível ilustrar alteração transitória em dois indivíduos saudáveis submetidos a exercício intenso.

Esportes; Exercício; Atividade motora; Hematúria; Proteinúria; Rim; Nefropatia

ORIGINAL ARTICLE

Renal analysis in 75 km ultra-marathon participants^*

Análisis renal de corredora en la prueba de 75 kilómetros

Thiago Ribeiro Lopes^I; Gianna Mastroianni Kirsztajn^II

^INurse, post graduation in course - UNIFESP - São Paulo, Brazil

^IIMD, PhD, Nephrology Divison - UNIFESP - São Paulo, Brazil

Corresponding Author

ABSTRACT

OBJECTIVE: To identify urinary abnormalities, indicative of renal involvement, in 75 km ultra-marathon racer and pacer (cyclist that gives support to the racer).

METHODS: Renal analysis consisted of urine dipstick tests in four different times and anthropometric measures.

RESULTS: Both the racer and the pacer were in eutrophic conditions. There was an association between the capacity for maximum physical effort and detection of urinary abnormalities determined by the presence of hematuria and/or proteinuria.

CONCLUSION: Renal analysis allowed the identification of transitory renal involvement in both healthy individuals during intense exercise.

Keywords: Sports; Exercise/physiopathology; Motor activity; Hematuria; Proteinuria; Kidney/physiopathology; Kidney diseases

RESUMEN

OBJETIVO: Identificar alteraciones urinarias compatibles con compromiso renal en una corredora y un "pacer" (ciclista de apoyo) a lo largo de una prueba de 75 Kilómetros.

MÉTODOS: Para tal efecto, se utilizó un test de orina con cinta reactiva aplicado en cuatro tiempos diferentes, además de una evaluación antropométrica.

RESULTADOS: Las medidas concernientes a la corredora la clasificaron como eutrófica, así como el "pacer". Se observó que existe asociación entre los momentos de esfuerzo físico máximo y la detección de alteraciones urinarias, definidas por la presencia de hematuria y, a veces, proteinuria.

CONCLUSIÓN: Fue posible demostrar la alteración transitoria en dos individuos saludables sometidos a ejercicio intenso.

Descriptores: Deportes; Ejercicio/fisiopatologia; Actividad motora; Hematuria; Proteinuria; Riñón/fisiopatologia; Nefropatías

INTRODUCTION

In the last years, people presented an increasing interest in physical exercise practice, regardless of socio-economic status or age. Beneficial and well recognized aspects of these activities are related to quality of life and self esteem, in opposition to sedentarism, as well as increase of morbidity and mortality by chronic diseases⁽¹⁾. Nevertheless sport practice can present some undesirable effects, as systemic physiological alterations and common orthopedic lesions⁽²⁾.

Based on the review of different reports on renal disorders associated to physical activity, we observed that hematuria and proteinuria were documented in several groups of athletes^(2-7). Marathonists present predominantly urinary non glomerular bleeding, possibly due to bladder contusion, especially in shorter distance races, and glomerular hematuria in longer races⁽⁴⁾.

It is of note that hematuria and proteinuria due to "sports" do not use to progress as a chronic kidney disease, but the carriers should be followed closely to exclude significant underlying conditions that were not diagnosed at the first approach^(6,8).

So this study look for detecting eventual renal alterations secondary to the overload of physical exercise in two health subjects that performed an expressive effort in sports activities. The objective was to identify urinary abnormalities compatible with renal involvement in two athletes during a 75 km race.

METHODS

An ultramarathonist and her "pacer" (support cyclist) were observed and compared in a 75 km race, from Bertioga to Maresias (in the coast of the State of Sao Paulo). Both were submitted to the same "protocol" that consisted of: clinical evaluation and anthropometric measures a day before the race. Collection of random urine for dipstick test (ChoiceLine 10 Urinalysis - Roche), in four different times along the race- Time 1: 30 minutes before the start; Time 2: during a stop in the checking station 6 (Cantão da Jureia) after 4 hours and 23 minutes (43.6 km of race without intervals), for changing running shoes; Time 3: in the arriving station (Maresias), after 8 hours and 20 minutes of race; and Time 4: 4 hours after the end of the race (during the rest period). Hydration and nutritional supplementation was performed during the race.

The athletes gave their informed consent to participate of this study.

RESULTS

Based on anthropometric measures of abdominal circumference and cutaneous folds both athletes were classified as euthrofic. When asked about their ethnic origin they classified themselves as Caucasians. Other data about these subjects can be seen in Table 1.

In Table 2, the urinary test done before the race showed no urinary abnormalities (normal indexes). In all samples, urinary density, pH, white blood cells count and glucosuria were normal in both subjects, but hematuria was evident and it increased along the race, associated to positivity in the dipstick test for protein. The "pacer" presented less hematuria in the sample of time 3 than the ultramarathonist. The pacer had a stop after 69 km and he "rested" during 40 minutes before this collection. It was also observed that four hours after the end of the race, both were again without urinary abnormalities in the dipstick test.

Except for the urinary abnormalities no other alterations were detected.

DISCUSSION

First of all it is necessary to say that it was not possible to perform more complex exams for evaluation of renal function during this study due to a possible interference in the performance of the athletes along the race.

The urinary abnormalities observed in both cases indicate a possible role for physical exercise on renal physiology as previously established⁽⁹⁾. Some studies have shown proteinuria corresponding to a transitory increase in urinary protein excretion related to hemodynamic glomerular alterations that can occur during exercise or fever^(6,10). Similarly hematuria is seen in about 20% of marathon runners^(3,6). We believe that the same alterations can occur with ultramarathon participants, as documented here.

It is of note the excellent performance of the athletes in the resistance race, possibly due to previous adequate training, optimizing individual conditions and minimizing lesions (adequate nutritional supplementation to avoid hypoglycemia and to attenuate dehydration and eventual hyperthermia⁽¹¹⁾. In Addition it is important to emphasize that presenting urinary abnormalities during physical activity (race) does not mean that the individuals have or will develop permanent renal injury⁽¹²⁾.

It is possible to say the urine dipstick test is a practical instrument to explore possible pathophysiological mechanisms implicated in the urinary alterations seen in high intensity physical activities.

CONCLUSION

Studies related to the follow up of athletes in the course of physical activity are uncommon, and this study demonstrates of a transitory alteration in two health subjects submitted to intense exercise. In the present evaluation it was observed an association between the moments of maximal effort and the detection of urinary alterations, identified by positivity in the areas of hematuria and proteinuria in the dipstick. Studies with more subjects are certainly necessary to consolidate these findings in athletes that run in ultramarathons.

REFERENCES

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Publication Dates

• Publication in this collection
  09 Apr 2010
• Date of issue
  2009