Salivary diagnostic markers in males and females during rest and exercise
Published recently in The International Society of Sports Nutrition, research from our friends in New Zealand regarding Salivary diagnostic markers in males and females during rest and exercise.
Rutherfurd-Markwick K1,2, Starck C2,3, Dulson DK4, Ali A2,5.
School of Health Sciences, Massey University, Auckland, New Zealand.
Centre for Metabolic Health Research, Massey University, Palmerston North, New Zealand.
Riddet Institute Massey University, Palmerston North, New Zealand.
Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand.
School of Sport, Exercise and Nutrition Massey University, Auckland, New Zealand.
Saliva is a useful diagnostic tool for analysis in sports, exercise and nutrition research, as collection is easy and non-invasive and it contains a large number of analytes affected by a range of physiological and pathological stressors and conditions. This study examined key salivary electrolytes and stress and immune markers in males and females at rest and during exercise.
Unstimulated whole saliva from 20 healthy, recreationally active participants (8 males and 12 females) was analysed for flow rate, osmolality, sodium (Na+), potassium (K+), chloride (Cl-), secretory immunoglobulin A (SIgA), α-amylase activity and cortisol during both rest and moderate intensity (70% peak power) cycling exercise in a randomised crossover design. Each trial lasted 60 min and sampling was carried out at 15 and 45 min after the start of the trial. Saliva was collected using the gold-standard drool method; participants were required to provide at least 1 mL sample over 2 or 3-min period.
Females showed a greater response to steady-state exercise stress than males, with significant increases in osmolality (P < 0.001), α-amylase activity (P = 0.001) and secretion rate (P = 0.023) and SIgA secretion rate (P = 0.023), with trends for an increase in K+ (P = 0.053) and decrease in Cl- (P = 0.067). There were no differences between rest and exercise for any salivary analytes in males. In addition, females showed a trend for higher levels of cortisol than males at both rest (P = 0.099) and exercise (P = 0.070), as well as a higher heart rate (P < 0.001) and greater ratings of perceived exertion (P < 0.001) during the exercise trial. The coordination of the two stress response pathways (α-amylase vs cortisol) was positive in males (r = 0.799; P = 0.017) yet negative in females (r = -0.475; P = 0.036).
Males and females show a markedly different response to steady-state exercise stress as measured in unstimulated whole saliva.
Electrolytes; Hydration; Immune markers; Sex; Stress response
Further research into this area is planned by Professor Neil Walsh and his research group at Bangor University in the UK early next year. They plan to test endurance athletes both before and after the Snowdonia Marathon, one of Britains toughest marathons as they believe differences in how the body responds to stress could hold the key to the issue of ill-health. Prof Walsh said that “While general exercise boosts the immune system, endurance events cause a brief dip in our immunity levels, post-event,”
“Our hunch is that the way in which our body’s immune defence works during stress, like a marathon, is to some extent predictable. “It could be that hard-wired psychological characteristics can predict how our bodies respond.”
It will be interesting to read these findings when published
Stratech Scientific APAC, based in Sydney, supply an extensive range of Salivary Assays,
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