Salivary diagnostic markers in males and females during rest and exercise

J Int Soc Sports Nutr. 2017 Aug 10;14:27. doi: 10.1186/s12970-017-0185-8. eCollection 2017.

Abstract

Background: 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.

Methods: 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.

Results: 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).

Conclusions: Males and females show a markedly different response to steady-state exercise stress as measured in unstimulated whole saliva.

Keywords: Electrolytes; Hydration; Immune markers; Sex; Stress response.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Biomarkers / analysis
  • Cross-Over Studies
  • Electrolytes / analysis*
  • Exercise / physiology*
  • Female
  • Heart Rate
  • Humans
  • Hydrocortisone / analysis
  • Immunity, Mucosal
  • Immunoglobulin A, Secretory / analysis
  • Male
  • Osmolar Concentration
  • Rest / physiology*
  • Saliva / chemistry*
  • Stress, Physiological
  • Young Adult
  • alpha-Amylases / analysis

Substances

  • Biomarkers
  • Electrolytes
  • Immunoglobulin A, Secretory
  • alpha-Amylases
  • Hydrocortisone