SODIUM AND POTASSIUM LEVELS OF HUMAN WHOLE STIMULATED SALIVA COLLECTED UNDER TWO FORMS OF STIMULATION FROM SUBJECTS IN A SELECT AGE GROUPING

¹ Research Dentistry Division, School of Aviation Medicine, USAF, Randolph Air Force Base, Texas

When a comparison was made between the results of salivary analyses on 402 males and 60 females stimulated by one small rubber band and 540 males and 116 females under three large rubber band stimulation, the following observations could be made:

1. Three rubber band stimulation produced a 75.0 per cent increase in flow rate for males and a 92.8 per cent increase for females. Flow rate increased with age in males between 17 and 20 years old under 1-RBS stimulation.

A significant volume difference attributable to sex was present in both studies. In the 1-RBS portion, the mean flow rate for females was 48.5 per cent of the mean for males while, under a 3-RBS stimulation, the female flow rate mean was 53.4 per cent of that found for males. Psychologic influences are offered as a partial explanation for this volume difference.

2. Potassium levels were not influenced by age under either form of stimulation. Under 3-RBS stimulation the difference attributable to sex was significant. Potassium and volume were found to be negatively correlated in both studies.

3. Sodium was found to increase with age in males between 17 and 20 years of age under 1-RBS stimulation. A significant difference in sodium levels was found between the sexes under 3-RBS stimulation. Sodium and volume were found to be positively correlated under each stimulus. This correlation was statistically significant in all instances except for females in the 3-RBS study.

4. The Na/K ratio (1-RBS) increased with age for males and no significant difference was found between the sexes. Under 3-RBS stimulation, no significant differences in Na/K with age were found, but the difference between the sexes was significant.

5. Correction formulas derived by Prader and his co-workers¹⁴ were applied in an attempt to adjust the sodium and Na/K values for varying rates of flow. The differences in the resulting Na_c and (Na/K)_c values between the studies were much smaller than the differences in the Na and Na/K values. These investigators did not derive formulas to correct the potassium values.

6. From the data of the present study, formulas were derived which corrected flow rates for the male participants to 6.6 ml./5 min. Differences in resulting Na_c, K_c and (Na/K)_c, values were small when the 2 studies were compared. These 3 formulas are offered as a means of reducing the distinct differences in Na, K, and Na/K mean values that are found associated with variations in means for rate of flow. Expressions based upon these corrected values would seem to be much more meaningful than statements based upon the uncorrected concentrations but it is to be emphasized that these statements are, at present, applicable only to mean values for large groups of subjects.