The number of remaining teeth as a risk indicator of cognitive impairment: A cross-sectional clinical study in Sado Island

UCP2 polymorphisms, daily step count, and number of teeth associated with all-cause mortality risk in Sado City: A hospital-based cohort study

Objective

Uncoupling protein 2 (UCP2) is an ion/anion transporter in the mitochondrial inner membrane that plays a crucial role in immune response, regulation of oxidative stress, and cellular metabolism. UCP2 polymorphisms are linked to chronic inflammation, obesity, diabetes, heart disease, exercise efficiency, and longevity. Daily step count and number of teeth are modifiable factors that reduce mortality risk, although the role of UCP2 in this mechanism is unknown. This study aimed to assess the possible effects of UCP2 polymorphisms on the association between daily step count and number of teeth with all-cause mortality.

Methods

This study was conducted as a cohort project involving adult Japanese outpatients at Sado General Hospital (PROST). The final number of participants was 875 (mean age: 69 y). All-cause mortality during thirteen years (from June 2008 to August 2021) was recorded. The functional UCP2 genotypes rs659366 and rs660339 were identified using the Japonica Array®. Survival analyses were performed using multivariate Cox proportional hazard models.

Results

There were 161 deaths (mean observation period: 113 months). Age, sex, daily step count, and the number of teeth were significantly associated with mortality. In females, UCP2 polymorphisms were associated with mortality independent of other factors (rs659366 GA compared to GG + AA; HR = 2.033, p = 0.019, rs660339 C T compared to CC + TT; HR = 1.911, p = 0.029). Multivariate models, with and without UCP2 genotypes, yielded similar results. The interaction terms between UCP2 genotype and daily step count or number of teeth were not significantly associated with mortality.

Conclusion

The effects of UCP2 polymorphisms on the association between daily step count or the number of teeth and all-cause mortality were not statistically significant. In females, UCP2 polymorphisms were significantly associated with all-cause mortality. Our findings confirmed the importance of physical activity and oral health and suggested a role of UCP2 in mortality risk independently with those factors.

Rehabilitation with dental prostheses and its influence on brain activity: A systematic review

STATEMENT OF PROBLEM

The consequences of edentulism depend on its complexity and are far-reaching, but limited evidence regarding its association with neurologic health is available.

PURPOSE

The purpose of this systematic review was to establish the relationship between oral prosthetic rehabilitation and the regional increase in brain activity.

MATERIAL AND METHODS

This systematic review was registered in the International Prospective Register of Systematic Reviews (CRD42021262247), and the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline was followed. Randomized clinical trials, prospective studies comparing the brain activity of patients rehabilitated with and without the use of dental prostheses, and studies that analyzed the human brain by using noninvasive techniques were used as inclusion criteria. The risk of bias in each study was assessed by using the Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I).

RESULTS

The search was carried out in the PubMed/MEDLINE, Embase, Cochrane Library, and https://clinicaltrials.gov databases up to June 2021. After a search conducted by 2 reviewers, 8 articles were included in the review. A regional increase in blood flow and regional cerebral activity during dental prosthesis use was identified in the studies.

CONCLUSIONS

A positive association was found between the different types of prosthetic rehabilitation and brain function. Prostheses may preserve and restore neurological health.

Associations of oral health status and swallowing function with cognitive impairment in the aging population: a cross-sectional study

BACKGROUND

The purpose of this study was to investigate the relationships of oral health status and swallowing function with cognitive impairment in community-dwelling older adults from Changsha, Hunan Province, China.

METHODS

In this cross-sectional study, we analyzed the data of 215 participants aged ≥ 50 years which were retrieved from the Xiangya and Panasonic mild cognitive impairment (MCI) Study, a community-based study conducted among the residents of the urban areas of Hunan province in China. Demographic information of all participants was collected. We determined oral function by evaluating oral hygiene, oral dryness, occlusal force, tongue pressure, chewing function, swallowing function, remaining teeth number, and other indicators. The mini-mental state examination (MMSE) was used to screen for cognitive function. The relationship between each oral function evaluation item and cognitive function was investigated using correlation analysis. The associations between oral health status and swallowing function with cognitive impairment were inferred using multiple regression analysis.

RESULTS

The general characteristics of participants showed statistically significant correlation coefficients in number of teeth remaining (p = 0.003) and number of teeth lost (p < 0.0001). Almost half of the 25 participants (48%) were aged from 70-80 years. Only 25 older adults (11.6% of the participants) were determined to have cognitive impairment by MMSE sores less than 24. Tongue pressure in male participants was the only significant independent variable that was associated with cognitive impairment (p = 0.01971). The results indicate that male participants with lower MMSE scores had a relative deficiency in tongue pressure.

CONCLUSIONS

In this cross-sectional study, the oral health status and swallowing function of participants were in relatively good condition and showed low correlations with cognitive impairment. However, lower tongue pressures were associated with lower MMSE scores in males, indicating it could serve as a novel oral function index for evaluating cognitive impairment.

The Relationship of Coronary Artery Calcium and Clinical Coronary Artery Disease with Cognitive Function: A Systematic Review and Meta-Analysis

AIM

Coronary artery disease (CAD) and cognitive impairment are common in the elderly, with evidence for shared risk factors and pathophysiological processes. The coronary artery calcium (CAC) score is a marker of subclinical CAD, which may allow early detection of individuals prone to cognitive decline. Prior studies on associations of CAC and clinical CAD with cognitive impairment had discrepant results. This systematic review aims to evaluate the association of (sub)clinical CAD with cognitive function, cognitive decline, and diagnosis of mild cognitive impairment (MCI) or dementia.

METHODS

A systematic search was conducted in MEDLINE, Embase, and Web of Science until February 2019, supplemented with citations tracking. Two reviewers independently screened studies and extracted information including odds ratios (ORs) and hazard ratios (HRs).

RESULTS

Forty-six studies, 10 on CAC and 36 on clinical CAD, comprising 1,248,908 participants were included in the systematic review. Studies about associations of (sub)clinical CAD with cognitive function and cognitive decline had heterogeneous methodology and inconsistent findings. Two population-based studies investigated the association between CAC and risk of dementia over 6-12.2 years using different CAC scoring methods. Both found a tendency toward higher risk of dementia as CAC severity increased. Meta-analysis in 15 studies (663,250 individuals) showed an association between CAD and MCI/dementia (pooled OR 1.32, 95%CI 1.17-1.48) with substantial heterogeneity (I²=87.0%, p＜0.001). Pooled HR of CAD for incident MCI/dementia over 3.2-25.5 years in six longitudinal studies (70,060 individuals) was 1.51 (95%CI 1.24-1.85), with low heterogeneity (I²=14.1%, p=0.32). Sensitivity analysis did not detect any study that was of particular influence on the pooled OR or HR.

CONCLUSIONS

Limited evidence suggests the CAC score is associated with risk of dementia. In clinical CAD, risk of MCI and dementia is increased by 50%, as supported by stronger evidence.