Nocturia in the elderly in relation to thirst, dry mouth and dry eyes

To assess the relationship between nocturia, thirst and the perception of dryness in the eyes and mouth in a group of elderly men and women.

The study comprised 6103 elderly men and women recruited by a questionnaire from a group of pensioners (n=10216; response rate 61.3%). The age of the men and the women was 73.0 (6.0) and 72.6 (6.7) years, respectively. The questionnaire included questions on their health, diseases and symptoms, drugs, sleep habits and the number of nocturnal voiding episodes.

Dryness of the eyes increased from 6.5% in men without nocturnal micturition to 15.8% (p < 0.05) in those with > three nocturnal voids, and correspondingly from 9.9% to 33.1% (p < 0.0001) in women. Dryness of the mouth increased similarly from 15.7% to 37.3% (p < 0.001) in the men and from 17.0% to 56.7% (p < 0.0001) in the women. Multiple logistic regression analyses revealed that dry eyes and dry mouth increased with increasing nocturnal micturition independently of the influence of age, sex, analgesics and the use of diuretics.

Nocturia is associated with a significant increase in the occurrence of dry eyes and dry mouth among the elderly. The results may indicate that nocturnal polyuria is an overlooked pathogenetic mechanism in these symptoms.