Association between Self-Reported Chewing Status and Glycemic Control in Japanese Adults

Effect of periodontal therapy on glycaemic control in type 2 diabetes

AIM

This study aimed to elucidate the impact of periodontal therapy on glycaemic control in individuals with type 2 diabetes and various baseline blood glucose levels using a large-scale claims database from Japan.

MATERIALS AND METHODS

Using the JMDC Claims Database, we identified individuals with type 2 diabetes who underwent health check-ups in the fiscal years 2018 or 2019 and were followed up until the next year's health check-up. We conducted a weighted cohort analysis using stabilized inverse probability weights for treatment and censoring to estimate the effect of periodontal therapy on changes in haemoglobin A1c levels within a year. Analysis was done for different baseline haemoglobin A1c categories: 6.5%-6.9%, 7.0%-7.9% and ≥8.0%.

RESULTS

Of the 4279 insured persons included in the study, 957 received periodontal therapy. Overall, there was a tendency towards improved glycaemic control among those who received periodontal therapy. Participants with baseline haemoglobin A1c levels of 7.0%-7.9% who received periodontal therapy exhibited significantly better glycaemic control compared with those without dental visits (difference; -0.094 [95% confidence interval: -0.181 to -0.007]).

CONCLUSIONS

Periodontal therapy may improve glycaemic control in individuals with diabetes, especially in those with haemoglobin A1c levels ≥7.0%.

Longitudinal association of oral functions and dementia in Japanese older adults

The relationship between oral functions and dementia was examined in 7384 older adults (age ≥ 75 years) who visited a dental clinic in Gifu, Japan. Participants without dementia in a baseline survey in April 2018 were followed until March 2021. As oral functions, chewing function, tongue and lip function, and swallowing function were assessed by self-administered questionnaire, by oral diadochokinesis test, and by repetitive saliva swallowing test, respectively. The presence of systemic diseases was based on data obtained from the National Database of Health Insurance of Japan. At follow-up, 415 (6%) participants were diagnosed with dementia. Multivariate logistic regression analyses showed the presence of dementia at follow-up was associated with female (odds ratio [OR] 1.386; 95% confidence interval [CI] 1.117-1.719), age (OR 1.078; CI 1.056-1.101), regular dental checkups (absence; OR 1.452; CI 1.180-1.788), brushing frequency ≥ twice/day (absence; OR 1.510; CI 1.194-1.911), decayed teeth (presence; OR 1.328; CI 1.071-1.648), swallowing function (poor; OR 1.484; CI 1.135-1.939) at baseline. It was found that poor swallowing function was associated with the future onset of dementia.

Relationship between Chewing Status and Fatty Liver Diagnosed by Liver/Spleen Attenuation Ratio: A Cross-Sectional Study

This cross-sectional study investigated the relationship between chewing status and fatty liver among Japanese adults. Between April 2018 and March 2021, 450 individuals (352 males, 98 females; mean age 54.7 years) were recruited at the Asahi University Hospital Human Health Center. Chewing status was evaluated using a self-reported questionnaire. Liver/spleen (L/S) attenuation ratio < 0.9 on computed tomography was considered to indicate fatty liver, which was present in 69 participants (15%). Compared with participants without fatty liver, those with fatty liver had higher proportion of 25.0 (kg/m2) ≤ body mass index (BMI) (p < 0.001), higher serum hemoglobin A1c (HbA1c) (p < 0.001), higher systolic blood pressure (p < 0.001), higher diastolic blood pressure (p < 0.001), and lower serum high-density lipoprotein cholesterol (HDL cholesterol) (p = 0.011). Significant differences were also found in chewing status (p < 0.001) and eating speed (p = 0.011). Presence of fatty liver was positively associated with BMI (25.0 ≤; odds ratio [OR], 5.048; 95% confidence interval [CI], 2.550−9.992), serum HbA1c (OR, 1.937; 95% CI, 1.280−2.930), and chewing status (poor; OR, 8.912; 95% CI, 4.421−17.966) after adjusting for sex, age, BMI, serum HbA1c, systolic blood pressure, diastolic blood pressure, serum HDL cholesterol, chewing status, and eating speed. Poor chewing status was positively associated with L/S attenuation ratio. These results indicate a positive relationship between poor chewing status and fatty liver diagnosed by L/S attenuation ratio in Japanese adults.

Associations between self-reported masticatory dysfunction and frailty: A systematic review and meta-analysis

Background

Oral health is a key factor of overall health and closely associated with well-being and quality of life. Mastication is one the most important oral functions and may deteriorate with aging. Evidence on association between masticatory dysfunction and frailty in the literature is scarce and not coherent.

Methods

A search strategy was developed to conduct a systematic review of the literature in PubMed, CINAHL, and AMED in accordance with the PRISMA 2020 guidelines. We searched for studies published in 2000 or later that examined associations between self-reported masticatory dysfunction and frailty risk. The reference lists of the relevant articles were reviewed for additional studies. We calculated pooled odds ratios (OR) of association between self-reported masticatory dysfunction and the risk of frailty by fixed-effects meta-analysis. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess risk of bias. Publication bias was assessed by visually inspecting a funnel plot.

Results

A total of 285 studies were identified by the literature search. Among 5 studies selected for this review, 4 cross-sectional studies including a total of 7425 individuals were used for meta-analysis. The pooled results by a fixed-effects model showed that there was a significant association between self-reported masticatory dysfunction and frailty risk (pooled OR = 1.83, 95%CI = 1.55–2.18, p<0.00001). There was no evidence of publication bias observed.

Conclusions

This systematic review and meta-analysis highlighted pooled cross-sectional evidence that community-dwelling older people who report masticatory dysfunction are significantly more likely to be frail than those who do not. The limitations of this study are: inclusion of only cross-sectional studies, no gold standard to measure masticatory functions, self-reported information on masticatory function, and the limited number of included studies. More longitudinal studies are warranted for further understanding of the causal pathways and elucidate underlying mechanisms.

Registration: PROSPERO CRD42021277173