Relationship between tooth loss, low masticatory ability, and nutritional indices in the elderly: a cross-sectional study.

BACKGROUND: Low masticatory ability and the resulting decrease in intake of masticable foods can result in undernutrition. The present study investigated the relationship between tooth loss, low masticatory ability, and nutritional indices in the elderly. METHODS: The data analyzed in this study were retrieved from the baseline data of the 2007 Fujiwara-kyo study, a prospective cohort study of community-dwelling elderly individuals. Subjects included 1591 men and 1543 women, both with a median age of 71 years. The maximum occlusal force was measured as an objective index of masticatory ability. Foods were divided into five groups based on hardness: Group 1 (bananas, etc.), 0.53 kg; Group 2 (boiled rice, etc.), 1.22 kg; Group 3 (raisins, etc.), 2.93 kg; Group 4 (raw carrots, etc.), 4.38 kg; and Group 5 (beef jerky), 6.56 kg. To obtain a subjective index of masticatory ability, a questionnaire-based survey was conducted to determine whether subjects could masticate foods within each group. As nutritional indices, serum albumin levels and body mass index (BMI) data were used. RESULTS: The median number of teeth was 21. The proportion of subjects for whom all five food groups were masticable showed a significant decrease in the number of teeth in both males and females. Logistic regression analysis showed that, after adjustment for confounders, no significant relationships were observed between the number of teeth and the masticatory ability with nutritional indices in males. In females, a maximum occlusal force of 100 to 300 N (OR = 1.65; 95% CI = 1.06-2.55) or less than 100 N (OR = 1.95; 95% CI = 1.15-3.31) showed a significant correlation with serum albumin levels below 4.4 g/dL (reference: 500 N or more). In addition, the masticability of all five food groups showed a significant correlation with BMI < 21.0 kg/m2 (OR = 0.62; 95% CI = 0.46-0.85) in females. CONCLUSIONS: A low number of teeth was associated with low masticatory ability in both males and females. Low masticatory ability was associated with low plasma albumin levels and low BMI in females. Not smoking, maintaining grip strength, preventing cancer, and masticatory ability are important for preventing undernutrition.

Effects of Tooth Loss and the Apolipoprotein E ɛ4 Allele on Mild Memory Impairment in the Fujiwara-kyo Study of Japan: A Nested Case-Control Study.

BACKGROUND: Several studies have suggested that periodontal disease can exacerbate the pro-inflammatory status of the brain. Tooth loss is one of the alternative evaluation indices of periodontal disease. There are few data on the relationship between tooth loss and memory impairment, depending on the apolipoprotein E (APOE) ɛ4 genotype. OBJECTIVE: To determine if tooth loss is associated with mild memory impairment (MMI) and if this association is modified by the presence of the APOEɛ4 allele. METHODS: A nested case-control study was conducted from 2007 to 2012 in Japan. Five hundred and thirty-seven Japanese subjects aged 65 years and over who were cognitively intact at baseline were analyzed. MMI at follow-up was evaluated. RESULTS: The median number of teeth at baseline was significantly lower in MMI participants (n = 179) than in controls (n = 358) (MMI: median 21.0, interquartile range 10.0-25.0 versus controls: 24.0, 14.0-27.0). After adjustment for demographics, vascular risk factors, and APOEɛ4 allele, the multivariate adjusted odds ratio (OR) of ≤8 teeth was 1.97 (95% confidence interval [CI], 1.13-3.44) compared to 25-32 teeth. Participants with both the presence of at least 1 APOEɛ4 allele and ≤8 teeth had a higher risk of MMI compared with those with neither (OR, 2.82; 95% CI, 1.15-6.91). Those with either risk factor alone did not have a higher risk of MMI. CONCLUSIONS: A lower number of teeth is related to risk of MMI. This may be primarily true for those individuals with an APOEɛ4 allele.

Association of Tooth Loss With Development of Swallowing Problems in Community-Dwelling Independent Elderly Population: The Fujiwara-kyo Study.

BACKGROUND: Tooth loss induces changes to the anatomy of the oral cavity. We hypothesized that tooth loss may disturb smooth swallowing in healthy elderly people. The purpose of this study was to investigate the effect of tooth loss on the development of swallowing problems in an independent elderly population. METHODS: This was a 5-year prospective cohort study conducted in Nara, Japan. Included in this analysis were 1,988 community residents aged 65 years or older without swallowing problems at baseline. The participants were classified into quartile groups according to the number of remaining teeth at the baseline survey: 0-12, 13-22, 23-26, and 27-32 teeth. A decrease in the number of teeth during the survey was calculated by subtracting follow-up number from baseline number. Main outcome was the development of swallowing problems at follow-up. RESULTS: During follow-up, 312 individuals developed swallowing problems. After adjustment for confounding factors by multiple logistic regression analysis, the odds ratios for developing swallowing problems in participants with 13-22 or 0-12 teeth were 2.42 (95% confidence interval [CI], 1.61-3.63) and 2.49 (95% CI, 1.68-3.69), respectively, compared to participants with 27-32 teeth, demonstrating a significant relationship. The odds ratio of per 1 tooth decrease over 5 years was 1.08 (95% CI, 1.02-1.13), showing a significant association. CONCLUSIONS: Swallowing problems due to aging are more likely to develop in individuals with fewer teeth.

Association between tooth loss and the development of mild memory impairment in the elderly: the Fujiwara-kyo Study.

BACKGROUND: Tooth loss may be a modifiable risk factor for memory disorders, but the causal relationship has not been evaluated sufficiently. OBJECTIVE: This 5-year prospective cohort study investigated the effect of tooth loss on the development of mild memory impairment (MMI) among the elderly. METHODS: Data are from the baseline and follow-up examinations of 2,335 community residents who were cognitively intact at baseline. The number of remaining teeth at baseline was classified as zero, 1-8, 9-16, 17-24, and 25-32. The main outcome for the analysis was the development of MMI at follow-up. RESULTS: After adjustment for potential confounding factors in multivariable logistic regression analysis, the odds ratio of per 1 tooth loss at baseline was 1.02 (95% confidence interval, 1.00-1.03). The odds ratio of edentulism for MMI was 2.39 (1.48-3.86) compared to 25-32 teeth. The odds ratio of becoming edentulous compared to retaining 1-8 teeth in the 1-8 teeth group at baseline was 4.68 (1.50-14.58). CONCLUSION: Tooth loss predicts the development of MMI among the elderly.

Association between depressive symptoms and metabolic syndrome in Japanese community-dwelling older people: a cross-sectional analysis from the baseline results of the Fujiwara-kyo prospective cohort study.

OBJECTIVE: Metabolic syndrome contains many risks for medical diseases such as cardiovascular disease and diabetes, which might precipitate depressive symptoms in the older people. However, the association between depressive symptoms and metabolic syndrome in Japanese community-dwelling older people is unclear. This study was performed to answer this important question. METHODS: Cross-sectional analyses were performed on 3796 community-dwelling independent older people (≥ 65 years, 1911 men and 1885 women) from the 2007-2008 baseline examination of the Fujiwara-kyo study, a prospective cohort study on successful aging. Depressive symptoms were assessed using the 15-item short form of the Geriatric Depression Scale and metabolic syndrome was defined according to the 2005 International Diabetes Federation. Covariates were social supports, negative life events, health behavior, education, cognitive function, anthropometric status, and others. Multiple logistic regression analyses were performed to determine the relationships between depressive symptoms and these variables. RESULTS: The prevalence of depressive symptoms (Geriatric Depression Scale-15 ≥ 6) and metabolic syndrome were 14.8% and 16.6%, respectively. Significant protective factors against depressive symptoms were higher education, more opportunity for drinking of alcohol, better social supports, and more walking daily. Metabolic syndrome was statistically associated with depressive symptoms (adjusted odds ratio = \ 1.32, 95% confidence interval = 1.03-1.68). Other risk factors significantly associated with depressive symptoms were sleep disturbance, visual or hearing impairment, and negative life events. CONCLUSIONS: The present study showed an association between metabolic syndrome and depressive symptoms in ambulatory Japanese older people, as in western countries.

Relationship of tooth loss to mild memory impairment and cognitive impairment: findings from the Fujiwara-kyo study.

BACKGROUND: This cross-sectional study investigated the relationship between the number of remaining teeth to mild memory impairment (MMI), which is a preclinical stage of dementia, and to cognitive impairment. METHODS: The subjects were aged 65 years or older and were grouped according to their score for the Mini-Mental State Examination (MMSE), the three-word delayed recall test in the MMSE, and the Geriatric Depression Scale into the control group (n = 3,696), the MMI group (n = 121), and the low MMSE score (23 or lower) group (n = 214). We collected data on the number of remaining teeth, the length of the edentulous period, health-related lifestyle, medical history, blood pressure, height, and body weight. Fasting venous blood samples were also obtained. RESULTS: Multiple logistic regression analysis, adjusted for depressive symptoms, age, sex, length of education, and other explanatory variables, revealed that the odds ratios of 0-10 remaining teeth to 22-32 remaining teeth were 1.679 (95% CI 1.073-2.627) for MMI and 2.177 (95% CI 1.510-3.140) for a low MMSE score. A significant relationship was also found between the length of the edentulous period and the risk of a low MMSE score (odds ratio 3.102, 95% CI 1.432-6.720) (15 years or more/less than 15 years). CONCLUSIONS: Our findings suggest that tooth loss is associated with cognitive function.