MO302: The Correlation Between Serum and Urinary NGAL With Redox Biomarkers in Post-Ultramarathon Amateur Athletes

Abstract

Abstract BACKGROUND AND AIMS Few studies have investigated the physiological alterations provoked by ultramarathon competition, particularly those related to redox balance, kidney function and NGAL regulation. A better understanding of the dynamics of these biomarkers during ultramarathons could be useful in the search of new biomarkers in the context of exercise physiology. Thus, the aim of this study was to evaluate the relationship between oxidative stress and NGAL levels in blood and urine of amateur athletes before and after a 100-km ultramarathon. METHOD The sample was composed of seven athletes between the ages of 21 and 60 years, submitted to anthropometric evaluation, ergoespirometric testing, urine and blood sampling, biochemical and hormonal measurements, body weight measurement and subjective perception of effort (SPE)—–the perception was evaluated through a scale from 6 to 19 [1], along with verification of competition duration, besides the heart rate (HR), energy expenditure and oxygen consumption (VO2) during the event. The duration, the energy expenditure and the average HR of the competition were measured by a frequency meter (Polar, m200). The data provided was analyzed by the Polar Flow app platform. RESULTS The sample had an average BMI of 25.75 ± 3.20, a body fat percentage of 18.54% ± 4.35% and a VO2max of 48.87 ± 4.78. In the pre-competition period, no significant correlations (P > .05) were found between NGAL levels, in blood and urine and blood and urine biomarkers. In relation to the results obtained after competition, there were no significant correlations among of the NGAL levels and plasma biomarkers, except for the serum creatinine level (P < .05). The average duration of the competition (the average finishing time of the competitors) was 820.60 min (±117.00), during which the mean energy consumption was 2209.72 kcal (+951.97) and energy expenditure was 7837.16 kcal (+195.71), with an average HR of 127.85 (±12.02). CONCLUSION The data presented here did not support our initial hypothesis that the ultramarathon would cause oxidative stress and acute kidney injury. In addition, there was no significant correlation between oxidative stress biomarkers and NGAL in serum and urine, which suggests that NGAL is more sensitive to the inflammatory process than ROS levels.