Background: Physical exercise activates the hypothalamo-pituitary-adrenal (HPA) axis and induces the body's inflammatory response. Due to contemporary dietary habits and increased energy expenditure, athletes are susceptible to depletion of magnesium ions. The aim of our study was to investigate, through assessment of plasma ACTH, serum IL-6, and salivary/serum cortisol levels, if chronic magnesium supplementation might reduce damaging stress effects in amateur rugby players.
Methods: Rugby players (N=23) were randomly assigned to intervention and control group. Basal samples were collected before intervention group started a 4-week-long supplementation with magnesium (500 mg Mg/d). Blood and saliva sampling were done a day before the match (Day-1), on the morning of competition (Game), and during a six-day-long recovery period (Day1, Day3 and Day6). ACTH, serum/salivary cortisol, IL-6 and total/differential leukocytes counts were determined at each time point.
Results: There was a statistically significant increase in ACTH concentration in intervention group compared to control group, while reductions in cortisol concentrations between the two groups were the greatest at Day-1 (p < 0.01) and at the day of competition (Game) (p < 0.01). Our results revealed that magnesium completely abolished the increase in IL-6 level noted in control group on Day1 and Day3 vs. Day-1 (p < 0.01) and also diminished the rise in neutrophil/lymphocyte ratio in intervention group vs. control group (p < 0.01).
Conclusions: These results suggest the possibly important influence magnesium supplementation might have on the change of parameters of HPA axis activity and reduction of immune response activation following strenuous physical exercise such as a rugby game.
Uvod: Fizičko vežbanje aktivira hipotalamo-hipofizno-nad-bubrežnu (HPA) osovinu i indukuje inflamatorni odgovor organizma. Sportisti su, zbog savremenih navika u ishrani i povećanog utroška energije, posebno podložni nastanku deplecije jona magnezijuma. Cilj naše studije bio je da se, praćenjem nivoa ACTH, serumskog IL-6 i nivoa salivarnog/serumskog kortizola, ispita da li hronična suplementacija magnezijumom može da smanji štetne efekte stresa kod amaterskih ragbi igrača.
Metode: Ragbi igrači (N=23) nasumice su podeljeni u interventnu i kontrolnu grupu. Bazalni uzorci su prikupljeni pre nego što je interventna grupa započela suplementaciju magnezijumom (500 mg Mg/dan). Krv i saliva su uzorkovani dan pre utakmice (Day-1), na dan takmičenja (Game) i tokom 6 dana perioda oporavka (Day1, Day3 and Day6). ACTH, serumski/salivarni kortizol, IL-6 kao i ukupan/diferencijalni broj leukocita su određeni u svakoj tački vremena.
Rezultati: Uočen je statistički značajan porast u koncentraciji ACTH u interventnoj grupi u poređenju sa kontrolnom grupom, dok je sniženje nivoa kortizola, između ispitivanih grupa bilo najveće dan pre utakmice (Day-1) (p<0,01) i na dan utakmice (Game) (p<0,01). Naši rezultati su pokazali da je magnezijum u potpunosti poništio porast IL-6 koji je primećen u kontrolnoj grupi prvog (Day1) i trećeg dana (Day3) posle utakmice u odnosu na dan pre utakmice (Day-1) (p<0,01) i doveo do sniženja odnosa između neutrofila i limfocita u interventnoj grupi u odnosu na kontrolnu (p<0,01).
Zaključak: Ovi rezultati ukazuju na potencijalno značajan uticaj koji suplementacija magnezijumom može imati na parametre aktivnosti HPA osovine i na smanjenje aktivacije imunog odgovora nakon napornog fizičkog vežbanja kao što je ragbi utakmica.
Keywords: ACTH; IL-6; amateur rugby; magnesium supplementation; serum/saliva cortisol.