Objectives: This study aimed to determine the relationship between objective chewing ability and the nutritional status of Japanese community-dwelling elders. Design: A cross-sectional study. Participants: A total of 509 community-dwelling elders living in the Tokyo metropolitan area participated in a comprehensive survey conducted in October 2013. Measurements: The basic characteristics were sex, age, and body mass index. Undernutrition was examined through serum albumin levels. Chewing ability was examined through color-changeable xylitol gum by evaluating the color changes in chewing gum. Nutritional intake was examined using the semi-quantitative food frequency questionnaire. Results: In the poor chewing ability group, all nutrient intake levels were significantly low, except for carbohydrates, and intake levels for all food groups were significantly low, except for cereals, confectionery, sugars, seasonings, and spices. Additionally, after adjusting for covariates for sex, age, Tokyo Metropolitan Institute of Gerontology-Index of Competence (TMIG-IC) score, Mini-Mental State Examination (MMSE) score, body mass index (BMI), stroke, number of functional teeth, energy intake, and protein intake, chewing ability was found to be significantly associated with undernutrition. Conclusion: We concluded that chewing ability was closely associated with nutrient and different food groups’ intake, as well as undernutrition, among Japanese community-dwelling elders. Thus, to ensure comprehensive nutritional management, nutritionists and dentists should collaborate when treating the same patients.

Oral hypofunction, resulting from a combined decrease in multiple oral functions, may affect systemic-condition deterioration; however, few studies have examined the association between oral hypofunction and general health among older adults. In this cross-sectional study, we examined the relationship between oral hypofunction and sarcopenia in community-dwelling older adults. We included 878 adults (268 men and 610 women, mean age 76.5 ± 8.3 years). Tongue coating index, oral moisture, occlusal force, oral diadochokinesis (/pa/,/ta/,/ka/), tongue pressure, mas-ticatory function, and swallowing function were evaluated as indicators of oral hypofunction. Grip strength, gait speed, and skeletal muscle mass index were measured as diagnostic sarcopenia parameters. The association between oral hypofunction and sarcopenia was examined via logistic regression using sarcopenia as the dependent variable. Oral hypofunction prevalence was 50.5% overall, 40.3% in men, and 54.9% in women. The prevalence of sarcopenia was 18.6% overall, 9.7% in men, and 22.5% in women. A logistic regression showed oral hypofunction, age, body mass index, higher-level functional capacity, and serum albumin level were significantly associated with sarcopenia. Sarcopenia occurred at an increased frequency in patients diagnosed with oral hypofunction (odds ratio: 1.59, 95% confidence interval: 1.02–2.47); accordingly, oral hypofunction appears to be significantly associated with sarcopenia.

Background: Few studies have examined the state of oral function in older adults with sarcopenia. We assessed the oral functions of community‐dwelling older adults with sarcopenia from multiple perspectives to clarify their potentially low oral function.Methods: A total of 1517 (86.2%; 990 women, 527 men; mean age 76.1 ± 7.6 years) participants were included in this study. Grip strength, gait speed and skeletal muscle mass index were assessed, and sarcopenia was evaluated according to the criteria of the Asian Working Group for Sarcopenia 2019. The degree of tongue coating, oral moisture, occlusal force, tongue–lip motor function, tongue pressure, masticatory function and swallowing function were assessed. The criteria for oral hypofunction (a disease that is a combination of multiple low oral functions) were used to assess oral function. Statistical analyses were performed using Kolmogorov–Smirnov test, unpaired t‐test, Mann–Whitney U test, χ² test, and univariate and multivariable logistic regression analyses, with each oral function as the dependent variable and sarcopenia as one of the independent variables. The significance level was set at P < 0.05.Results: The prevalence rates of sarcopenia and severe sarcopenia were 14.2% and 3.8%, respectively. The prevalence of oral hypofunction was 39.9%. Compared with the robust group, the sarcopenia and severe sarcopenia groups tended to have a higher frequency of the following components (all P < 0.01): low occlusal force, low tongue–lip motor function, low tongue pressure, low masticatory function, low swallowing function and oral hypofunction. Univariate logistic regression analysis showed that sarcopenia was associated with low occlusal force, low tongue–lip motor function, low tongue pressure, low masticatory function, low swallowing function and oral hypofunction. The odds ratios and 95% confidence intervals of sarcopenia for each oral function were 2.62 [2.00, 3.43], 2.21 [1.69, 2.89], 3.66 [2.79, 4.81], 3.23 [2.46, 4.25], 1.66 [1.26, 2.20] and 3.59 [2.72, 4.72], respectively. Multivariable logistic regression analysis showed that sarcopenia was associated with low occlusal force (1.63 [1.10, 2.40]), low tongue pressure (2.28 [1.65, 3.15]), low masticatory function, (1.94 [1.27, 2.97]), low swallowing function (1.64 [1.17, 2.28]) and oral hypofunction (2.17 [1.52, 3.09]).Conclusions: This study demonstrated that multiple aspects of oral function were low among community‐dwelling older adults with sarcopenia. The potential decline in oral functions in older adults with sarcopenia may have been overlooked until now. This study indicates the need for dental perspectives in intervening with older adults with sarcopenia and the need to encourage them to see dental professionals.

Preventing social isolation is essential for promoting healthy aging. This study aims to 1) systematically review and synthesize the predictors of objectively measured social isolation from observational studies that have treated isolation as an outcome in community-dwelling older adults, and 2) overview previous studies in this area and reveal an agenda to develop future research. Peer-reviewed primary studies published in English or Japanese were identified from PubMed, ScienceDirect, PsycINFO, Igaku-Chuo-Zasshi, and CiNii. We followed the PRISMA statement. Risk of bias of included studies was assessed using the Newcastle-Ottawa Scale. Of the 1,161 studies identified, 10 were included in the review. Most studies were cross-sectional and published in the past 20 years. The risk of bias score ranged from 3 to 6 for the individual studies, indicating a moderate to high risk. The assessment measures for social isolation and proportion of isolated subjects varied greatly across studies. Findings on the predictors of social isolation from each study were clustered into four categories: socio-demographic factors, physical health factors, psychological and cognitive factors, and social and cultural factors. It was difficult to confirm these predictors conclusively because of the cross-sectional study design and a huge variety of assessment tools for social isolation. This result suggests the need to build consensus on the appropriate scales and standard cut-off points for assessing social isolation. Furthermore, longitudinal studies are urgently required. When considering predictors of social isolation, it is also essential to consider the regional and ethnic background of the samples studied.