The Age-related Changes Of The Saliva Flow Rate And Secretory Leukocyte Protease Inhibitor Content In Healthy Adults

Background Why the elderly is susceptible to mucosal diseases has been a hot spot of gerontology in recent years ? Lots of studies have demonstrated that saliva plays an important role in it with respect to both the volumn produced and the reactive constituents it contains. Although numerous studies on the saliva flow rate, the effect of aging on it remains unclear and conflicting observations exist in the literature. Secretory leukocyte protease inhibitor(SLPI) is thought to play a critical role in mucosal defenses,however, the age-related changes of salivary SLPI production have not been assessed systematically in an aged cohort.Purpose To investigate the age-related change of salivary gland function with regard to salivary flow rates and SLPI production of 98 healthy individuals. Methods (1) To collect unstimulated and stimulated whole saliva and stimulated parotid saliva of healthy individuals in four age groups and calculate the flow rate; (2)To determine SLPI concentration and time-unit content in stimulated whole saliva using ELISA kits.Results (1)The mean flow rate of unstimulated whole saliva decreased with aging; In the older groups, the mean flow rate and SLPI time-unit content of stimulated whole saliva were significantly less than that of the young group; ofstimulated parotid saliva, no age-related decline in the mean value was observed; (2)no age-related change was observed on SLPI concentration in stimulated whole saliva but the time-unit content was inclined to decrease with aging.Conclusions The age-related change of salivary flow rate and SLPI content may contribute to the impairment of host salivary defenses and delayed wound healing, thus lead to the increased risk of oral mucosal diseases recognized among the elderly.