Case-control study for developing a novel evaluation of dry mouth using salivary biomarkers

日本的老年人口比例正在急剧增加，2003年65岁以上的人口约占总人口的19%，预计到2050年将达到32.3%。随着年龄的增长，口腔干燥是日本老年人最常见的口腔抱怨。我们研究了两种唾液应激激素与老年人口干症的关系。总共收集了140名受试者的唾液样本，并测定了嗜铬粒蛋白a （CgA）和皮质醇的水平。此外，还向同一研究对象提供了一份关于口干症（主观口腔干燥）、医疗条件和药物使用情况的医疗调查表。根据有无口干分为两组。口干症患者唾液CgA水平显著高于对照组（p<0.05），而两组间唾液皮质醇水平无显著差异。我们的研究结果还显示，接受药物治疗的口干组唾液CgA水平明显高于未接受药物治疗的口干组（p=0.025），并且当口干和接受药物治疗的受试者根据刺激唾液流量（<1.0 ml/min或【大于等于】1.0 ml/min）进行再划分时，唾液流量降低组的CgA水平显著高于未接受药物治疗组（p=0.016）。我们的研究结果表明，唾液CgA水平似乎可以作为老年患者口干症的生物标志物。

The percentage of aged people is increasing dramatically in Japan, with those over 65 years of age composing approximately 19% of the population in 2003 and predicted to reach 32.3% by 2050. In conjunction with aging, oral dryness is the most common oral complaint encountered in aged Japanese. We investigated the associations between two kinds of salivary stress hormones and xerostomia in elderly subjects. Saliva samples were collected from a total of 140 subjects and the levels of chromogranin A (CgA) and cortisol were determined. Further, a medical questionnaire regarding xerostomia (subjective oral dryness), medical conditions, and use of drugs was given to the same subjects. The subjects were divided into two groups according to the presence or absence of xerostomia. The level of salivary CgA was significantly higher in subjects with xerostomia (p<0.05), whereas no significant differences were found between the groups in regard to salivary cortisol levels. Our findings also showed that the level of salivary CgA was significantly higher in subjects in the xerostomia group who were receiving drugs than that in those in the group without xerostomia (p=0.025), and when the subjects with xerostomia and receiving drugs were subdivided according to stimulated salivary flow rate (<1.0 ml/min or 【greater than or equal】1.0 ml/min), the level of CgA was significantly higher in those with decreased salivary flow rate (p=0.016). Our results suggest that salivary CgA levels appear to serve as a biomarker of xerostomia in elderly patients.