Effect of Underwater Exercise on Salivary Metabolites of Older Persons With Disability

Background/Aim: Underwater exercise is aimed at preventing aging, maintaining, and improving motor function, and improving physical function. However, its rehabilitation effects have not been well evaluated. In order to gain insight into the molecular basis of its rehabilitation effects, possible changes in the salivary metabolites of four older persons with disability (mean age: 72.5 years) during underwater exercise were investigated. Materials and Methods: Halitosis was measured by Breathtron; salivary bacterial number by bacterial counter; amino acids by amino acid analyzer; 8-oxoguanine by ELISA; and intracellular metabolites by capillary electrophoresis, time-of-flight mass spectrometry, liquid chromatography, and triode quadrupole mass spectrometry. Results: Underwater exercise induced apparent declines in two major salivary amino acids (glycine and proline) and bacterial numbers in the cheek mucosa and salivary, without apparent changes in the halitosis and urine 8-oxoguanine concentration. Older subjects showed higher concentrations of most of 166 metabolites compared to young volunteers (mean age: 38.8 years old). Fifteen compounds were significantly reduced with the progression of underwater exercise. Conclusion: Improvement of upright balance function with underwater exercise is correlated with several salivary components.