Association of Self-reported Height Loss and Kyphosis with Loss of Teeth in Japanese Elderly
Study background: Height loss and kyphosis are useful surrogate markers of osteoporotic vertebral fractures in the elderly. Loss of teeth in the elderly also is associated with osteoporosis. These imply the possibility that self-reported these indices may be associated with loss of teeth in the elderly. This study aimed to clarify the associations of self-reported height loss and kyphosis with number of teeth lost in Japanese elderly. Subjects and Methods: Among patients who visited dispensing pharmacies in Matsumoto, Japan, 307 patients (75 men and 232 women) aged 50–97 years participated in the study. They completed a structured questionnaire including covariates related to loss of teeth. Self-reported height loss and kyphosis were simply defined as three categories: no; mild-to-moderate; severe. Results: Analyses of covariance adjusted for covariates revealed that there were no significant differences in the numbers of teeth lost in total, or during the past 1 year among the three self-reported height loss categories. Significant differences were observed in the total numbers of teeth lost among the three self-reported kyphosis categories (p<0.001). Subjects who were conscious of severe kyphosis had significantly larger number of teeth lost (mean ± SEM, 16.1 ± 1.8) than those who were conscious of no kyphosis (8.7 ± 0.6, p<0.001) and mild-to-moderate kyphosis (8.3 ± 0.7, p<0.001). Furthermore, there were significant differences in the number of teeth lost during the past 1 year among the three self-reported kyphosis categories (p=0.031). Subjects who were conscious of severe kyphosis had significantly greater number of teeth lost during the past 1 year (0.9 ± 0.2) than those who were conscious of no kyphosis (0.3 ±0.1, p=0.03). Conclusions: Our results suggest that Japanese elderly with self-reported severe kyphosis may lost more teeth than those without self-reported severe kyphosis.