Association between dry eye and periodontal disease in community-dwelling Japanese adults: data from the Uonoma cohort study.

BACKGROUND: While research has explored the risk of periodontal disease in various eye conditions, the link between dry eye and periodontal disease remains underexplored, especially in Japanese adults. This study aims to investigate the association between dry eye and periodontal disease in community-dwelling Japanese adults. METHODS: This study is a subset of the Uonuma cohort study, which includes Japanese adults aged 40 years and older residing in the Uonuma area of Niigata Prefecture, Japan. Participants completed a self-administered, paper-based questionnaire. Statistical analyses, including the chi-square test, independent t test, ANOVA test, and logistic regressions, were employed to assess the association of periodontal disease with independent variables. RESULTS: Among 36,488 participants (average age 63.3 years, 47.4% men), 39.3% had a history of periodontal disease, and gender differences were statistically significant (p < 0.001). Significant associations were found between periodontal disease and dry eye diagnosis or symptoms. Univariable logistic regression revealed links between periodontal disease and age, gender, living status, alcohol consumption, remaining teeth, bite molar availability, and history of dry eye disease or symptoms. Multiple-adjusted regression found that doctor-diagnosed dry eye was associated with a higher likelihood of periodontal disease (odds ratio, 1.12; 95% confidence interval, 1.03-1.22). Participants who never experienced dryness or foreign body sensation had lower ORs of periodontal disease than those who always experienced such symptoms across all models. CONCLUSION: A significant correlation was found between dry eye and periodontal disease in Japanese adults. Regular check-ups, early detection, and effective management of both conditions are strongly recommended.

Association Between Low Kidney Function and Excess Weight Concerning Unfavourable Periodontal Health among Community-dwelling Older Japanese Women.

PURPOSE: To investigate the association of low renal function and overweight with poor periodontal condition in community-dwelling older Japanese women. MATERIALS AND METHODS: In total, 359 older women (age range: 55-74 years) participated in this study. Two periodontal parameters - the number of teeth with a probing pocket depth (PPD) or clinical attachment level (CAL) ≥ 4 mm - were used as the dependent variables. The principal independent variables were low renal function as defined by the estimated glomerular filtration rate (eGFR) and overweight as defined by the body mass index. Poisson regression analysis was used to calculate the ratio of means (RM). RESULTS: The RMs of the number of teeth with a PPD or CAL ≥ 4 mm in an adjusted model without an interaction term were 1.21- or 1.27-fold higher among those with an eGFR < 60, while those among the participants with an eGFR < 60 in the adjusted model with interaction terms for the number of teeth with a PPD or CAL ≥ 4 mm were 1.43- or 1.36-fold higher. In addition, increments of periodontal risk with low renal function and overweight showed a slightly smaller to negative trend. CONCLUSION: The present findings suggest a connection between unfavourable periodontal health and both renal function and being overweight among older Japanese women. A weak negative interaction was also found between poor renal condition and overweight in relation to periodontal condition.

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.

Association Between Oral Malodor and Dementia: An 11-Year Follow-Up Study in Japan.

Background: As infrequent social interaction is a potential risk of dementia, oral malodor may increase the risk of dementia, including Alzheimer's disease. Objective: This study investigated the association between malodor and dementia. Methods: We used the Japan Public Health Center-based Prospective Study data obtained at Yokote City. A total of 1,493 individuals aged 56 to 75 years underwent a dental examination and self-reported survey from May 2005 to January 2006. Follow-up for the onset of dementia was conducted using long-term care insurance data from 2006 to 2016. Hazard ratios of oral malodor on dementia were estimated by the Cox proportional hazards model. The inverse probability-weighted Cox model was used as a sensitivity analysis. Results: The study comprised 1493 participants (53.6% women) with a mean age of 65.6 (SD = 5.8) years old; at the end of the follow-up, 6.4% (n = 96) developed dementia, and the percentage was 20.7 in severe malodor group. Throughout 15274.133 person-years of follow-up, the average incidence rate for the onset of dementia per 1000 person-years was 6.29. The highest incidence rate was seen in participants with severe malodor (22.4 per 1000 person-years). After adjusting for confounders, compared to those with no malodor, there was a 3.8 (95% confidence interval: 1.5 to 9.4) times greater hazard of developing dementia in participants with severe malodor. The inverse probability weighted Cox model confirmed the same trend with an adjusted marginal hazard ratio of 4.4 (1.2 to 16.4). CONCLUSIONS: A significant association between oral malodor and the onset of dementia exists.

Association of Hyper-Low-Density Lipoprotein and Hypo-High-Density Lipoprotein Cholesterolemia with Low Saliva Flow Rates in Japanese Community-Dwelling Elders

Abstract Introduction The associations of low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein (HDL-C) with reduced saliva flow rates have not been previously reported. Objective The present study aimed to assess the association of cholesterolemia with reduced saliva flow rates in community-dwelling elderly subjects. Methods The present study analyzed 342 participants (170 males and 172 females aged between 78 and 79 years old). Unstimulated salivary flow rate (USFR) was assessed using a cotton roll method. Low-USFR was defined as 0.10 g/30 seconds. Stimulated salivary flow rate (SSFR) was assessed by having the participants chew tasteless gum for 3minutes. Low-SSFR was defined as 1.0 mL/minute. Blood samples were collected for the measurement of LDL-C, HDL-C, rheumatoid factor, hemoglobin A1c, and creatinine. To assess depression, the General Health Questionnaire 30 was used. A standardized questionnaire was completed, covering the current and previous medications of the participants and smoking status. We stratified the serum LDL-C levels of the participants as normal, moderate or severe hyper-LDL cholesterolemia and serum HDL-C levels as normal or hypo-HDL cholesterolemia. Multivariate logistic regression models were established and low-USFR or low-SSFR were set as dependent variables in the aforementioned models. Results After controlling for the effects of the other variables, the odds ratios (ORs) (95% confidence intervals [CIs]) for low-USFR were 2.25 (1.10-4.61) for moderate and 5.69 (1.55-20.8) for severe hyper-LDL cholesterolemia, while that of hypo-HDL cholesterolemia was 3.40 (1.33-8.69). Severe hyper-LDL cholesterolemia was also associated with low-SSFR with an OR of 3.89 (1.39-10.88). Conclusion Elderly patients with cholesterolemia have a risk of reduced salivary flow rate.

Low Body Mass Index as a Risk Factor for the Onset of Porosity of the Mandibular Bone in the Elderly

ABSTRACT Objective: To investigate whether a low body mass index (BMI) has a significant relationship with mandibular bone porosity progression by conducting a mandibular inferior cortex (MIC) classification in elderly Japanese people. Material and Methods: A total of 266 study subjects, aged 70 at baseline, were recruited for this study, conducted from 1998 to 2007. The subjects were divided into two groups according to changes in the MIC on serial panoramic radiographs during this nine-year study period: a no change group (MIC-NC) and a change group (MIC-C). All subjects in the MIC-C showed changes trending toward greater fragility. We evaluated the BMI at baseline. Logistic regression analysis was performed to assess the relationship between the MIC condition during the nine-year period (0: MIC-NC, 1: MIC-C) and BMI (kg/m2) adjusted for gender, current health status (CHS), and smoking habit (SH) at baseline. Results: The mean and standard deviations of the BMI at baseline in the MIC-NC and MIC-C were 22.8 ± 2.1 and 21.8 ± 2.5 kg/m2 for males and 23.1 ± 2.9 and 21.9 ± 2.4 kg/m2 for females. There was a significant relationship between the MIC condition and the BMI in both males (p=0.04) and females (p=0.01). The logistic regression analysis revealed a significant association between the MIC condition over the nine-year period and the BMI (OR=0.84, p=0.003), which was adjusted depending on the gender (OR=5.18, p=0.000), CHS (OR=0.53, p=0.015), and SH (OR=4.15, p=0.002) at baseline. Conclusion: A low BMI carries a risk of developing mandibular bone porosity by measuring the MIC condition in panoramic radiographs.