Risk factors of cognitive impairment: Impact of decline in oral function

Occlusion dysfunction and Alzheimer's disease: Mendelian randomization study

Aim

Occlusion dysfunction (OD) is increasingly linked to Alzheimer's disease (AD). This study aimed to elucidate the causal relationship between OD and AD using Mendelian randomization (MR) analysis.

Materials and methods

Genome-wide association study (GWAS) meta-analysis data obtained from FinnGen, IEU Open GWAS, and UK Biobank (UKBB) was represented as instrumental variables. We validated the causal relationship between periodontal disease (PD), loose teeth (PD & occlusion dysfunction), dentures restoration (occlusion recovery), and AD.

Results

According to the MR analysis, PD and AD have no direct causal relationship (P = 0.395, IVW). However, loose teeth significantly increased the risk of AD progression (P = 0.017, IVW, OR = 187.3567, 95%CI = 2.54E+00-1.38E+04). These findings were further supported by the negative causal relationship between dentures restoration and AD (P = 0.015, IVW, OR = 0.0234, 95%CI = 1.13E-03-0.485).

Conclusion

The occlusion dysfunction can ultimately induce Alzheimer's disease. Occlusion function was a potentially protective factor for maintaining neurological health.

Impact of frailty severity and severe pain on cognitive function for community-dwelling older adults with arthritis: a cross-sectional study in Korea

Pain is a major symptom of arthritis in older adults, often leading to frailty and cognitive decline. However, few studies have investigated the relationship among pain, frailty, and cognitive function in older adults with arthritis. This study aimed to investigate the factors influencing cognitive function and the impact of frailty severity and pain on cognitive function in older adults with arthritis using a Korean population-based dataset. This cross-sectional descriptive study involved the secondary data of 1089 participants from the seventh and eighth waves of the Korean Longitudinal Study on Aging. We examined general characteristics, health behaviors, health conditions (including severe pain and frailty), and cognitive function. Participants were categorized based on the presence or absence of pain severity and frailty status as follows: robust, only severe pain, only prefrail, prefrail with severe pain, only frail, and frail with severe pain. Multiple linear regression analysis was performed to establish correlations between groups and cognitive function. The only-prefrail group was the largest (19.7%) among participants experiencing either pain or frailty. Advanced age, sex, level of education, and visual and hearing impairments were significantly associated with cognitive function. Compared to the robust group, only prefrail (β = -1.54, confidence interval [CI] = - 2.33; - 0.76), prefrail with severe pain (β = - 2.69, CI = - 3.52; - 1.87), only frail (β = - 4.02, CI = - 5.08; - 2.97), and frail with severe pain (β = - 5.03, CI = - 5.99; - 4.08) groups were associated with lower Mini-Mental State Examination scores. The study confirmed that severe pain alone does not significantly impact cognitive function in older adults with arthritis. To prevent cognitive decline in this group, assessment of both pain and frailty severity is essential to predict high-risk groups and provide appropriate interventions, such as transfer to hospitals or primary clinics according to the severity of pain and frailty.