It is well known that the salivary flow is reduced by aging but ionic composition changes associated to aging
have been less evaluated. To measure salivary and plasmatic [Na+], [K+] and [Cl-] and to correlate with age in healthy,
non-medicated subjects of any gender, 165 healthy participating subjects (over 15 years old) were asked to give sample of
5mL mix basal saliva in a plastic vial without any stimulation technique, additionally, 5mL of venous blood was collected.
Samples [Na+] and [K+] were measured by flame photometry (CorningTM M-405) and [Cl-] by voltametric chlorometry
(CorningTM M-920). Ionic concentrations were expressed as (X±DE; meq.L-1). All three ionic concentrations progresively
increased with age, with the lineal regression equation being: [Na+] mEq=17.76 + 0.26(Age); r=+0.42; F=31.5;
P=0.00001; [K+] mEq=13.2+0.15(Age); r=+0.32; F=16.5; P=0.00001; [Cl-] mEq=9.05+0.18(Age); r=+0.35; F=7.8;
P=0.0071. Age induced changes in salivary ionic concentrations were not associated to blood ionic changes. However, saliva
and blood [Na+] and [K+] were correlated (r=+0.25; F=4.49; P=0.04 and r=+0.30; F=6.98; P=0.01, respectively). Significant
association was found among salivary ions: [Na+] mEq=9.14+0.99[K+] (r=+0.79; F=95.2; P=0.000001); [Cl-]
mEq=0.95+0.56[Na+] (r=0.79; F=106.6; P=0.000001) and [Cl-] mEq=3.45+0.69[K+] (r=0.73; F=72.5; P=0.000001).
These results confirm and measure the impact of aging over the mixed and resting salivary secretion process and suggest
that local changes are not related to blood ionic composition.