E. Ghezzi

The purpose of this study was to determine, through use of cross-sectional and longitudinal data, whether hypothyroidism and its treatment with thyroid hormones have a significant effect on the production of stimulated parotid flow rates. From the Baltimore Longitudinal Study of Aging (NIA, NIH), subjects with hypothyroidism taking and not taking thyroid replacement therapy were evaluated for the production of 2% citrate-stimulated parotid saliva in a cross-sectional and longitudinal investigation. Comparisons were made with nonmedicated healthy control subjects. Cross-sectional analyses revealed that stimulated parotid flow rates were not significantly different between healthy controls, subjects with hypothyroidism on thyroid replacement therapy, and subjects with hypothyroidism not on thyroid replacement therapy. In general, longitudinal analyses revealed no significant differences over time in stimulated parotid flow rates between healthy controls and subjects with hypothyroidism. Hypothyroidism and the concomitant use of thyroid replacement therapy do not cause significant changes in the production of stimulated parotid saliva.

... Output of saliva was determined gravimetrically and reported as mL/min per gland. Xerostomic Questionnaire. ... Applied linear statistical models. Boston: Irwin. ↵ Olsen JG,Salih MA, Harrison JL, Herrera I, Luther MF, Kalu DN, et al. (1997). ...

Salivary hypofunction is associated with oral and pharyngeal disorders and requires early diagnosis and intervention. Large variability in salivary flow rates within and between individuals has been reported, which has impaired the establishment of standard values. The objective of this study was to determine variations in stimulated parotid and submandibular flow rates over 6 hours and to define salivary hypofunction. Pooled mean, standard deviation, and coefficient of variation values for four collection time periods were obtained from 36 healthy males and females (18 young, ages 20-38; 18 older, ages 60-77). The results demonstrated 27-44% variation in salivary flow rates over time. Overall, there were no significant age or gender differences in variability between and within salivary flow rates at all collection time periods. The results suggest that a 45% range in salivary flow rates could be considered normal salivary variation, and values below 45% of normal levels could be used to define salivary hypofunction.