Longitudinal study of stimulated whole saliva in an elderly population.

The aim of this investigation, which is part of the longitudinal gerontologic population study in Gothenburg (H-70), was to examine the effect of aging on salivary flow. Three 70-yr-old cohorts, born in 1901/02, 1906/07, and 1911/12, were studied both cross-sectionally and longitudinally. Representative subsamples (n = 931) were followed up to 82 yr in the first and up to 75 yr in the second and third cohorts. Whole saliva secretion was stimulated by paraffin wax chewing for 5 min and all sampling was carried out in the morning after an overnight fast. The mean secretion rate was 1.24 for men and 0.94 ml/min for women at the age of 70 (all cohorts pooled). The percentage values for extremely low secretion rate (< 0.2 ml/min) were 2 and 6%, respectively. Neither the cross-sectional nor the longitudinal comparison showed any decrease in secretion rate on a group basis either in the age interval 70-82 yr in the first or between 70 and 75 yr in the other two cohorts. However, an increased prevalence of complaints of mouth dryness was found, especially among women. The main conclusion from this study is that there is no decline on a population basis in paraffin-wax-stimulated salivary flow with increasing age.