The effect of prolonged aerobic exercise on serum adipokine levels during an ultra-marathon endurance race

HORMONES 2013, 12(2):275-282 Research paper The effect of prolonged aerobic exercise on serum adipokine levels during an ultra-marathon endurance race Nikolaos D. Roupas,1 Irene Mamali,2 Spyros Maragkos,3 Lydia Leonidou,4 Anastasia K. Armeni,1 George K. Markantes,1 Athanasios Tsekouras,2 George C. Sakellaropoulos,5 Kostas B. Markou,2 Neoklis A. Georgopoulos1 Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, 2Division of Endocrinology, Department of Internal Medicine, 3Department of Orthopedics, 4Division of Infectious Diseases, Department of Internal Medicine, 5Department of Medical Physics, University of Patras Medical School, Patras, Greece 1 Abstract OBJECTIVE: To evaluate the effect of prolonged intensive aerobic exercise and acute energy deficit (180 km ultra-marathon race) on serum leptin, adiponectin, resistin and visfatin levels and their association and interaction with serum cortisol and insulin levels in highly trained ultra-endurance runners. DESIGN: The study included 17 highly trained ultra-endurance male athletes (mean age 51.29±6.84 years and body mass index (ΒΜΙ) 23.51±1.90) participating in the 5th Olympian Race held in Greece on May 2010. Anthropometric values were assessed; Serum cortisol, insulin, leptin, adiponectin, resistin and visfatin levels were measured at baseline, post-exercise and ~20 hours after the end of the race. RESULTS: All hormonal values of the post-exercise and recovery status were corrected for plasma volume changes. The estimated energy deficit during the ultra-endurance event was about 5000 Kcal. At the end of the race serum resistin levels were elevated (p<0.001) and serum leptin levels were reduced (p<0.001) and failed to reach pre-exercise levels, although showing a tendency towards restoration. No significant changes were noted in serum adiponectin and visfatin levels. CONCLUSIONS: Ultra-endurance aerobic exercise and acute negative energy balance lead to an up-regulation of serum resistin levels and a down-regulation of serum leptin levels. Key words: Adiponectin, Adipose tissue, Athlete, Leptin, Resistin Address for correspondence: Neoklis A. Georgopoulos, Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology, University of Patras Medical School, University Hospital, 26500 Patras, Greece, Tel.: +302610999835, Fax: +302610993854, e-mail: Received 10-09-2012, Accepted 16-04-2013 Introduction Physical exercise represents a powerful stimulus to homeostasis, disturbs the energy balance, triggers metabolic changes and activates regulatory responses, establishing a new dynamic equilibrium. The maintenance of homeostasis involves adaptive changes in 276 N.D. Roupas ET AL central and peripheral regulatory mechanisms, a new steady state of glucoregulatory mechanisms, activation of the hypothalamic-pituitary-adrenal (HPA) axis and changes of the secretory role of adipose tissue. The hormonal and metabolic response depends on the intensity, the duration, the type of exercise and the individual training status.1 Attention is being increasingly focused on the role of adipose tissue as an active endocrine organ releasing a number of adipocyte-specific factors known as adipokines. Adipokines are involved in glucose homeostasis, energy balance, insulin action, reproductive function and inflammation process.2 Specifically, leptin is involved in the regulation of food intake, energy expenditure and insulin resistance (IR).2 Adiponectin is secreted exclusively from adipose tissue and is detected at high levels in serum, while also being involved in metabolism, IR, cardiovascular protection and inflammatory process.2 Visfatin is expressed in a variety of cell types and tissues, including adipose tissue, and is regarded as a novel insulin-mimetic, fat-secreted regulatory factor involved in pro-inflammatory and immunomodulating processes.3 Finally, resistin has been described as a product of the adipose tissue, participating in the pathogenesis of IR, adipogenesis and inflammation.2 Materials and methods The present study included 17 highly trained ultramarathon endurance male athletes participating in the 5th Olympian Race held in Greece on 28 and 29 of May, 2010. The Olympian Race is an ultra-marathon endurance race (180 km of continuous running) held every two years in Greece. The goal of the participants is to complete the race within the 28-hour time limit. The race starts on Friday at 1430 hrs in the Ancient Stadium of Nemea and successful competitors reach the Ancient Stadium of Olympia on Saturday no later than at 1830 hrs. The trail races have special rules and specifications and comprise the largest possible part of the route on roads and paths over mountainous terrain and the fewest possible paths on tar roads. The athletes have free access to food and drink (including carbohydrate-rich foods and drinks) at 20 checkpoints throughout the race. Sixty (60) ultra-endurance athletes participated in the 5th Olympian Road. All of them were invited to be enrolled in the study, but only 25 agreed to participate. Among the 60 athletes who started the race, only 40 managed to reach the finishing point within the acceptable time period of 28 hrs and 17 of these were participants of the present study. The influence of prolonged intensive aerobic exercise has been studied in regard to serum leptin response and regulation,4 while no data exist regarding the homeostasis of adiponectin, visfatin and resistin during strenuous exercise of long duration. All athletes participated voluntarily in every part of the study, providing samples or data for each of the variables measured and informed consent was obtained. The anthropometric features and the training history of the participants are shown in Table 1. The aim of the present study was to evaluate the effect of prolonged intensive aerobic exercise and acute energy deficit (ultra-marathon endurance race of 180 km distance) on serum leptin, adiponectin, resistin and visfatin levels. Moreover, the study attempted to assess the association of the specific adipokines with serum cortisol and insulin levels in highly trained marathon runners, considering the reported data on their relationship with stress response and insulin resistance.2,3 Finally, the results of this study aimed at providing further evidence on the role of the specific adipokines in energy homeostasis and the response to exercise stress. The athletes were evaluated three times: on the morning of the race (baseline values, at 0800hrs before breakfast - fasting samples), at the finishing line (post-exercise values, around 1500 hrs, within a few minutes after the end of the running race – nonfasting samples) and on the next morning (recovery values, at 08:00hrs before breakfast, within 17-22 hrs after the end of the race - fasting samples). The study protocol included noninvasive clinical and laboratory investigations as well as the completion of a questionnaire. The cl (...truncated)