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

日本的老年人比例正在急剧增加，2003年65岁以上的老年人约占总人口的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疾病。我们调查了两种唾液应激激素与老年人口干症的关系。唾液样本收集从总共140名受试者和嗜铬粒蛋白A（CgA）和皮质醇的水平进行了测定。此外，向相同受试者提供了关于口腔干燥症（主观口腔干燥）、医疗状况和药物使用的医学问卷。根据是否存在口干症，将受试者分为两组。口腔干燥症患者唾液CgA水平显著高于对照组（p<0.05），而两组唾液皮质醇水平无显著差异。我们的研究结果还表明，口干症组中接受药物治疗的受试者唾液CgA水平显著高于无口干症组（p=0.025），而当受试者口腔干燥症和接受药物根据刺激唾液流率细分（<1.0 ml/min或[大于或等于]1.0 ml/min），唾液流速降低者CgA水平显著升高（p=0.016）。我们的研究结果表明，唾液CgA水平似乎作为一个生物标志物的口干症的老年患者。

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.