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.

A cross-sectional study of the association between periodontitis and physical activity in the Japanese population.

OBJECTIVE: The aim of this study was to determine whether physical activity (PA) is associated with periodontitis in the Japanese population. BACKGROUND: The potential association between PA and periodontitis has not been thoroughly investigated in the Japanese population. METHODS: We used cross-sectional data from the Japan Public Health Center-based Prospective Study for the Next-Generation Oral Health Study. Periodontitis was determined by a full-mouth periodontal examination. PA was assessed using a validated questionnaire. We performed multivariable ordinal logistic regression analyses to assess the association of total PA (the first quintile was set as the reference category) with periodontitis (three categories: no/mild, moderate, and severe), stratified by sex. The associations of periodontitis with domain- and intensity-specific PA were also studied in separate logistic regression models. RESULTS: This study included 2160 Japanese adults [1414 women and 746 men; mean (standard deviation) age 58.1 (9.6) years]. After adjusting for potential confounders, total PA was inversely associated with the presence and severity of periodontitis in women. The multivariable-adjusted odds ratios (95% confidence intervals) for periodontitis in the second to fifth quintiles (compared with the first quintile) of total PA were 0.81 (0.59-1.12), 0.74 (0.53-1.02), 0.77 (0.55-1.06), and 0.64 (0.46-0.89), respectively (p for trend = .01). We did not find different results when we further investigated the associations of periodontitis with domain- and intensity-specific PA. By contrast, PA was not associated with periodontitis in men. CONCLUSION: Total PA had an inverse, linear association with the presence and severity of periodontitis in Japanese women but not in Japanese men. Further prospective studies are required to determine the association between PA and periodontitis.

Changes in oral health status with dental intervention during the acute to subacute stages of stroke.

OBJECTIVES: To investigate the changes in oral health status with dental intervention during the acute and subacute stages of stroke and their associations with oral intake status. BACKGROUND: Oral health may deteriorate easily in patients following a stroke. However, data are scarce on the changes in oral health with dental intervention throughout the acute and subacute stages of stroke recovery. MATERIAL AND METHODS: We prospectively recruited 98 stroke patients who were admitted to an acute hospital and referred to a dental team and then could be followed at a subacute rehabilitation unit in the same hospital. Provided dental intervention, including oral health care and other general dental treatments, was recorded. Oral health was assessed with Oral Health Assessment Tool (OHAT), and the changes in OHAT score during the acute and subacute stages were statistically tested. Oral feeding status was examined using Functional Oral Intake Scale (FOIS). The cohort was divided into the non-oral feeding, dysphagia and regular diet groups based on FOIS score. Differences in OHAT among the oral intake groups were statistically tested. RESULTS: Gross OHAT score did not differ among the oral intake groups at the time of admission (mean ± standard deviation score: 6.5 ± 2.8 for non-oral diet, 5.6 ± 2.4 for dysphagia diet and 5.3 ± 2.1 for regular diet), but improved more in the regular diet group (2.4 ± 1.5) than in the other groups (5.8 ± 3.0 for non-oral diet and 4.0 ± 2.1 for dysphagia diet) at the last evaluation. Oral hygiene scores improved significantly in the acute stage, while scores for dentures and natural teeth ameliorated significantly in the subacute stage. CONCLUSION: Our findings suggest that appropriate dental intervention in the acute and subacute stages of stroke may contribute to improved oral health and oral food intake.

Career outcomes and satisfaction among graduates of a 4-year oral health and welfare baccalaureate program at Niigata University, Japan: A cross-sectional study.

OBJECTIVE: Globally, baccalaureate programs in dental hygiene are increasingly established. In addition, in Japan, many dental hygienists (DHs) and social workers (SWs) are prematurely leaving the workforce. This study aimed to investigate the most recent employment, career outcomes, reasons for a job change, and satisfaction with the job and undergraduate curriculum among graduates of the baccalaureate program at the Department of Oral Health and Welfare (DOHW), Faculty of Dentistry, Niigata University. METHODS: All 262 graduates (graduating classes 1-10) of the DOHW were invited to participate in this survey; an original self-administered questionnaire was distributed to those who consented. Responses were received from 114 (43.5%) graduates. RESULTS: Almost all respondents (89.5%) had dual licensure as both DH and certified SW. They were employed immediately after graduation (99.1%) and at the time of the survey (96.5%). Over 60% of them worked as DHs, mainly in hospitals. SWs mainly worked in administration. Among the 113 respondents who were employed, 39.8% changed jobs at least once. The main reasons for job selection were 'interest in job content' and 'flexible working hours'. Nearly 90% of the respondents felt satisfied or fairly satisfied with their job and their undergraduate education. CONCLUSIONS: A quality 4-year baccalaureate degree program in dental hygiene and social welfare positively influenced graduates' work continuity. Most graduates felt satisfied or fairly satisfied with their job and the undergraduate curriculum. Employment rates within each profession and the prevalence of hospital and administrative roles were higher than national averages. Long-term studies of graduates' career outcomes are warranted.

Interaction between serum vitamin C levels and smoking on the periodontal condition in older adults.

BACKGROUND AND OBJECTIVES: Several epidemiological studies have reported that smokers have a higher prevalence and severity of periodontal disease than do nonsmokers, and that smoking negatively affects nutritional status and is associated with a reduced intake of antioxidants, particularly vitamin C. The present investigation aimed to examine the relationship between serum vitamin C levels and smoking and its influence on the periodontal condition in older adults. MATERIALS AND METHODS: A total of 353 respondents met the inclusion criteria and were enrolled in the present study. The periodontal status of the study participants was determined through examinations of one or more residual teeth, which included a measurement of the probing pocket depth (PPD) and clinical attachment level (CAL) at six regions of each tooth. Blood samples were collected during the dental examinations and then sent to a laboratory to evaluate serum vitamin C and cotinine levels. A serum cotinine concentration of 100 ng/ml was considered a relevant threshold for active smoking. After dividing the participants into two groups according to serum cotinine levels, Poisson regression analysis was carried out to compare vitamin C levels with the prevalence rate ratio (PRR) for periodontal condition markers for each group based on serum cotinine levels. RESULTS: We evaluated differences in the PRR of serum vitamin C tertiles between participants with high (≥100 ng/ml) or low (<100 ng/ml) serum cotinine levels after adjusting for sex, the use of interdental brushes or dental floss, and the number of teeth. A negative tendency between the PRR of vitamin C tertiles for the PPD or CAL was seen for both groups. Especially, a bigger difference was observed in the group with high serum cotinine levels. The PRR of the first tertiles in the high serum cotinine group was 5.03, compared with 2.69 in the low serum cotinine group (relative risk: 1.9). CONCLUSION: The results of this study suggest a potential association between vitamin C levels and the periodontal condition, which may be influenced by smoking status.

Interaction between and impact of IL-6 genotype and alpha-tocopherol levels on periodontal condition in aging individuals.

BACKGROUND AND OBJECTIVES: Few studies have assessed the possible interaction between and impact of IL-6 variants and serum α-tocopherol levels on periodontal condition in older individuals. Here, we assessed the relationship between IL-6 variants and serum α-tocopherol levels on periodontal condition by considering effect modification. MATERIAL AND METHODS: Among the study participants, 359 who were 71 years of age underwent a dental examination, biochemical analysis, and interview. After dividing the participants into tertiles based on serum α-tocopherol levels, we conducted Poisson regression analysis to compare the prevalence rate ratio (PRR) for periodontal disease markers with the IL-6 genotype (rs1800796) based on each tertile adjusted by the number of teeth present (offset). RESULTS: The PRRs of the IL-6 genotype for periodontal condition (probing pocket depth [PPD], clinical attachment level [CAL], and bleeding on probing [BOP]) which were adjusted by the number of teeth present (offset) were 1.17 (P < .001), 1.37 (P < .001), and 1.08 (P = .048), respectively. In addition, a significant association was found between the reciprocal number of PRRs of the IL-6 genotype and three serum α-tocopherol levels. The adjusted PRRs (± standard error) of the IL-6 genotypes for PPD were 0.48 (0.12) for the first group (P < .001), 1.54 (0.04) for the second group (P < .001), and 2.11 (0.03) for the third group (P < .001); similar tendencies were seen for CAL and BOP. CONCLUSION: The results of this study suggest a potential association between the IL-6 genotype and periodontal condition in relation to serum antioxidant concentrations.

A 5-year longitudinal association between dietary fermented soya bean (natto) intake and tooth loss through bone mineral density in postmenopausal women: The Yokogoshi cohort study.

OBJECTIVE: In this 5-year cohort study, we aimed to determine whether the intake of natto, a fermented soya bean food product, has an indirect effect on tooth loss incidence through BMD changes among postmenopausal women. BACKGROUND: Evidence indicates (1) that natto has a beneficial effect on bone health and (2) that a decrease in bone mineral density (BMD) is associated with tooth loss. METHODS: The study recruited 435 postmenopausal women (average age = 64.2 years). Natto intake (exposure) was assessed at baseline using a food frequency questionnaire. Lumbar spine BMD and number of teeth were measured at baseline and 5-year follow-up. BMD change (mediator) and the number of teeth lost (outcome) over time were calculated. The mediation model consisted of these 3 variables. Mediation analysis was performed to test the indirect effect of the natto intake measured through BMD change on tooth loss. RESULTS: During the study, the mean number of teeth lost was 1.2 (standard deviation = 1.8), and the mean BMD decline was 2.5% (standard deviation = 7.1). After adjusting for potential confounders, increasing habitual natto intake was significantly indirectly associated with a lower incidence of tooth loss mediated by BMD change (incidence rate ratio of tooth loss among women with "≥1 pack/day" natto intake was 0.90 [95% confidence interval = 0.82-0.99] compared to those with natto consumption of "rarely"). CONCLUSIONS: Dietary natto intake is significantly indirectly associated with a lower incidence of tooth loss among postmenopausal women, and systemic bone density could be a mediator of this association.

Perioperative changes in knowledge and attitude toward oral health by oral health education.

OBJECTIVES: Perioperative oral health care can prevent postoperative complications, but it is also important to maintain oral health afterward to avoid later adverse events. This study examined (a) the relationship between knowledge and attitude toward oral health (KAOH) and oral/periodontal status (OPS) in patients receiving surgery, and (b) the changes in KAOH by perioperative oral health care and education. METHODS: Patients receiving surgery who visited our hospital's dental clinic beforehand were prospectively recruited. All participants received oral health care and education. In questionnaires assessing KAOH before and after surgery, respondent answers were generally classified as positive or negative. OPS was assessed before surgery. Associations between KAOH and OPS and perioperative changes in KAOH were statistically tested. RESULTS: A total of 507 patients answered the questionnaire before surgery, among whom 324 patients also completed it afterward. Preoperative OPS was significantly worse in the negative than in the positive KAOH group. Positive answers for KAOH increased significantly from 68.6% to 92.2% during the perioperative period. CONCLUSIONS: We found that patients with poor KAOH also had poor OPS, but KAOH could be improved by perioperative oral health care and education, suggesting that perioperative oral health management could improve oral health knowledge and attitudes.

Relationship between clinical periodontal parameters and changes in liver enzymes levels over an 8-year period in an elderly Japanese population.

AIMS: An association between periodontal disease and liver enzymes has been reported previously. This study examined the relationship between clinical periodontal parameters and changes in liver enzymes levels in 265 non-institutionalized Japanese elderly aged 72 years over 8 years. MATERIALS AND METHODS: The number of sites with probing pocket depth (PPD) ≥ 6 mm and clinical attachment level (CAL) ≥ 6 mm were measured. Changes in liver enzymes (alanine transaminase [ALT] and aspartate transaminase [AST]) was grouped based on any elevation of concentrations. The relationship was determined by logistic regression with adjustment for confounders. Interaction test and stratified analysis were then performed according to smoking status and alcohol drinking habits, separately. RESULTS: Elevation in ALT, but not AST, was significantly associated with PPD (odds ratio [OR] = 1.10) and CAL (OR = 1.03). A significant interaction of periodontal parameters on ALT was observed with smoking status, but not with alcohol drinking habit. The stratified analysis suggested that ALT was found to be significantly correlated with PPD (OR = 1.20) and CAL (OR = 1.04) to those who were smoker. CONCLUSION: The elevation in ALT levels might be associated with clinical periodontal parameters among non-institutionalized Japanese elderly, and this association was modified by smoking status.

Relationship between vitamin D receptor gene polymorphism and susceptibility to chronic kidney disease and periodontal disease in community-dwelling elderly.

OBJECTIVES: The aim of this study was to investigate the possible correlation between vitamin D receptor (VDR) gene polymorphism and susceptibility to chronic kidney disease (CKD) and periodontal disease. MATERIAL AND METHODS: This study analysed 345 participants, who were all 79 years of age. Kidney function levels were determined based on the estimated glomerular filtration rate (eGFR; non-reduced function: ≥60 and reduced function: <60 ml min-1  1.73 m-2 ). VDR TaqI genotyping was also studied. We calculated the periodontal inflamed surface area (PISA). After classifying participants into quartile groups according to eGFR or PISA values, the subjects were then split into two groups (highest quartile versus the other three groups combined). Multiple logistic regression analysis was performed to evaluate the odds ratios between the eGFR and VDR TaqI genotype with the different PISA groups. The eGFR was set as the dependent variable while the VDR TaqI genotype, HbA1C, gender, smoking habits and body mass index were defined as independent variables. RESULTS: A significant association was observed between the VDR TaqI genotype and eGFR in the PISA high group (odds ratio = 3.97, p = .027). CONCLUSION: Study results suggest that VDR TaqI genotype might be associated with CKD during inflammatory conditions caused by periodontal disease.

Effect of lifestyle on 6-year periodontitis incidence or progression and tooth loss in older adults.

AIM: To evaluate the longitudinal association of combined healthy lifestyle factors with incidence or progression of periodontitis and tooth loss in older adults. MATERIALS AND METHODS: This 6-year study included 374 Japanese 70-year olds with 7,157 teeth, from a source eligible baseline population of 554 individuals. Four lifestyle factors-cigarette smoking, physical activity, relative weight, and dietary quality-were scored as healthy (1 point) or unhealthy (0 point). Adding the individual scores generated the "healthy lifestyle score" (0-4 points). Multilevel mixed-effects logistic regression models were applied to evaluate tooth-specific associations between the baseline healthy lifestyle score and the incidence or progression of periodontitis (increase in clinical attachment loss ≥3 mm) and tooth loss. RESULTS: After 6 years, 19.0% of the teeth exhibited periodontitis incidence or progression and 8.2% were lost. Compared with a healthy lifestyle score of 0-1 (least healthy), the highest score (4 points) was associated with a significantly lower tooth-specific risk of periodontitis (adjusted odds ratio = 0.32; 95% confidence interval: 0.16-0.62) and tooth loss (adjusted odds ratio = 0.42; 95% confidence interval: 0.23-0.77). CONCLUSIONS: Simultaneous adherence to multiple healthy lifestyle factors significantly lowers the risk of incidence or progression of periodontitis and tooth loss in older adults.

Relationship between alcohol consumption and periodontal tissue condition in community-dwelling elderly Japanese.

OBJECTIVES: To examine the associations among alcohol consumption level, dietary intake and other lifestyle factors, and periodontal condition, in community-dwelling elderly Japanese of a specific age. BACKGROUND: The relationship between alcohol consumption level and periodontitis is a controversial issue. METHODS: Participants were 438 dentate elders aged 73 years from a larger cohort survey of elders in Niigata City, Japan. Data collected from oral examination of each participant, including number of the existing teeth, mean probing pocket depth and mean clinical attachment level (CAL) were used for the analyses. A semiquantitative food frequency questionnaire and a lifestyle habit questionnaire were used to assess food and alcohol consumption, smoking experience, frequency of tooth brushing, interdental brush use, and visits to a dental clinic during the previous year. Blood glucose control was assessed by the glycated haemoglobin (HbA1c) level. Body mass index was calculated from height and weight measurements. The relationships between each variable and the individual mean CAL were analysed by univariate and multivariate analyses. RESULTS: According to logistic regression analysis, the mean CAL was significantly associated with the number of existing teeth (odds ratio [OR] = 0.90; P < .001), being a heavy drinker (OR = 2.44; P < .05), and smoking experience (OR = 2.37; P < .01). CONCLUSION: This study showed that increased mean CAL was significantly associated with heavy drinking in community-dwelling elderly Japanese (aged 73 years) compared with non-drinking. Our results provide new evidence that high alcohol consumption is associated with an increased risk of periodontal disease and its progression.

Relationship between autoantibody associated with rheumatoid arthritis and tooth loss.

INTRODUCTION: This study evaluated the relationship between serum Rheumatoid Factor (RF) levels and tooth loss in a community-dwelling elderly Japanese women. It was hypothesised that women with high baseline RF levels would experience greater tooth loss over 10 years than age-matched women with lower baseline serum RF levels. MATERIALS AND METHODS: The study population consisted of 197 women aged 70 years with ≥12 teeth at baseline. One hundred and twenty-four participants completed a 10-year follow-up and were divided into 2 groups according to their baseline serum RF levels as follows: RF negative (<15 U/mL; n = 114) and RF positive (>15 U/mL; n = 10). Negative binomial regression was used to investigate the relationship between baseline RFs and tooth lost over the 10-year period. RF and its interaction with the baseline number of teeth were independent variables, with 9 other adjustment covariates. RESULTS: Baseline RFs were significantly associated with tooth loss (P = .035). In addition, a statistical interaction between baseline RFs and baseline number of teeth was identified (P = .023), modifying the association between RFs and tooth loss. The adjusted incidence rate ratio (IRR) for RF-positive participants with 21 baseline teeth was 1.88 (95% confidence interval (95% CI): 0.76, 4.65). IRRs obtained for participants who had 25 baseline teeth (3.02; 95% CI: 1.03, 8.83) or 30 baseline teeth (5.47; 95% CI: 1.29, 23.13) suggested that RF-positive participants with a high number of baseline teeth would exhibit greater tooth loss than RF-negative participants. CONCLUSION: High serum RF levels were associated with a greater IRR for future tooth loss in elderly Japanese women.

Hyposalivation and 10-year all-cause mortality in an elderly Japanese population.

OBJECTIVE: To evaluate the association of salivary flow rate with all-cause mortality among older Japanese adults. We hypothesised that hyposalivation would be a marker for mortality. BACKGROUND: Hyposalivation, which is an objectively measurable decrease in salivary flow, is highly prevalent among older adults. It is associated with malnutrition and poor general health. METHODS: The study population comprised 600 community-dwelling Japanese adults (306 men and 294 women), who were 70 years old at baseline. They underwent stimulated salivary flow rate (SSFR) measurements and were followed up during a 10-year study period. After stratification by sex, the hazard ratios of all-cause mortality were estimated using Cox proportional hazards regression analysis comparing groups with and without hyposalivation (ie, SSFR < 0.7 mL/min). RESULTS: The baseline prevalence of hyposalivation was 27.8% (85/306) among men and 47.3% (139/294) among women. During a mean (standard deviation) follow-up period of 104 (27) months, 80 deaths occurred: 60 (75.0%) deaths among men and 20 (25.0%) deaths among women. After adjusting for the number of remaining teeth, smoking status, exercise, hypoalbuminemia, diabetes and cardiovascular disease, hyposalivation at baseline was significantly associated with all-cause mortality among men (adjusted hazard ratio, 1.71; 95% confidence interval, 1.01-2.89). In contrast, no association between SSFR and all-cause mortality existed among women. CONCLUSION: Hyposalivation could be a marker for all-cause mortality among older community-dwelling Japanese men. Future studies investigating the association between SSFR and cause-specific mortality are warranted.

Relationship between renal function and periodontal disease in community-dwelling elderly women with different genotypes.

OBJECTIVES: The aim of this study was to examine the association between periodontal disease and renal function in elderly women with different genotypes. MATERIAL AND METHODS: A total of 332 postmenopausal never-smoking women were analysed. Poor renal function was defined as serum cystatin C > 0.91 mg/l. Periodontal disease markers such as periodontal inflamed surface area (PISA) were evaluated. Selected variables, including PISA quartile, body mass index (BMI), HbA1C and age in Arg allele carriers and non-carriers based on the beta-3 adrenergic receptor, or between Ala allele carriers and non-carriers based on peroxisome proliferator-activated receptor gamma, were analysed using multiple logistic regression analysis. RESULTS: The odds ratios of serum cystatin C level and PISA (fourth quartile) were significantly positive for both Arg (2.52; p = 0.035) and Ala allele non-carriers (2.36; p = 0.021). A significant association was also found between serum cystatin C level and BMI for both Arg (1.18; p = 0.001) and Ala allele non-carriers (1.12; p = 0.003). CONCLUSION: The results of this study suggest that periodontal inflammation might be associated with renal function. Furthermore, in both the Arg and Ala allele non-carriers, the associations between BMI and PISA for renal function became stronger.

Bidirectional relationship between renal function and periodontal disease in older Japanese women.

OBJECTIVES: The purpose of this study was to evaluate the reciprocal effects of chronic kidney disease (CKD) and periodontal disease. MATERIAL AND METHODS: A total of 332 postmenopausal never smoking women were enrolled, and their serum high-sensitivity C-reactive protein, serum osteocalcin and serum cystatin C levels were measured. Poor renal function was defined as serum cystatin C > 0.91 mg/l. Periodontal disease markers, including clinical attachment level and the periodontal inflamed surface area (PISA), were also evaluated. Logistic regression analysis was conducted to evaluate the relationships between renal function and periodontal disease markers, serum osteocalcin level and hsCRP level. The prevalence-rate ratios (PRRs) on multiple Poisson regression analyses were determined to evaluate the relationships between periodontal disease markers and serum osteocalcin, serum cystatin C and serum hsCRP levels. RESULTS: On logistic regression analysis, PISA was significantly associated with serum cystatin C level. The odds ratio for serum cystatin C level was 2.44 (p = 0.011). The PRR between serum cystatin C level and periodontal disease markers such as number of sites with clinical attachment level ≥6 mm was significantly positive (3.12, p < 0.001). Similar tendencies were shown for serum osteocalcin level. CONCLUSION: This study suggests that CKD and periodontal disease can have reciprocal effects.

Oral health and depression in older Japanese people.

OBJECTIVE: The aim of this study was to investigate the relationship between oral dysfunction and depressive symptoms in Japanese community-dwelling seniors. MATERIALS AND METHODS: Participants included 351 community-dwelling seniors (189 men, 162 women) aged 77 years. During dental examination, teeth and periodontal condition, including number of teeth, number of dental caries, pocket depth and clinical attachment level, were assessed, and unstimulated and stimulated salivary flow rates were measured. The General Health Questionnaire 30 (GHQ-30) was used to assess depression. The Tokyo Metropolitan Institute of Gerontology (TMIG) Index of Competence was used to assess activities of daily living. RESULTS: Multiple logistic regression analysis revealed that gender (odds ratio [OR] = 2.3), low unstimulated salivary flow rate (OR = 2.1), 'Complaint of mouth pain' (OR = 2.4), 'Complaint of physical disorders' (OR = 2.1), and the total TMIG Index of Competence score (OR = 2.0) were positively associated with the high GHQ-30 score. CONCLUSION: Subjective and objective oral dryness and oral pain are associated with depressive symptoms.

Cystatin C-based estimated glomerular filtration rate and periodontitis.

BACKGROUND AND OBJECTIVE: Accumulating evidence suggests that decreased kidney function characterised by low estimated glomerular filtration rate (eGFR) may be associated with periodontitis. Recent studies have suggested that the use of cystatin C strengthens the association between the eGFR and the risks of adverse outcomes in decreased kidney function. The aim of this cross-sectional study was to investigate the association of cystatin C-based eGFR (eGFRcys) and creatinine-based eGFR (eGFRcreat), the commonly used method to assess kidney function, with periodontitis in 502 Japanese women (average age, 68.6 years). MATERIALS AND METHODS: GFR was estimated from serum cystatin C and serum creatinine, respectively, using the Japanese equation for GFR. Participants were classified into five groups according to their eGFRcys and eGFRcreat values. Poisson regression models with robust error variance assessed the associations of eGFRcys and eGFRcreat with periodontitis. Tests for trends were performed by fitting the five-category eGFR variables in their continuous form to the regression models. RESULTS: Participants with eGFRcys < 50 ml/min/1.73 m(2) were at significantly higher risk of periodontitis compared with the reference group (≥90 ml/min/1.73 m(2) ) (adjusted relative risk = 2.12, 95% confidence interval = 1.12 to 4.02). Additionally, there was a trend towards a higher risk of periodontitis among participants with lower eGFRcys values (p for trend in the multivariable model = 0.008). In contrast, eGFRcreat did not show a significant association with periodontitis. CONCLUSION: The findings of this study of Japanese older women showed that eGFRcys had a stronger and more linear association with periodontitis than eGFRcreat.

PPARγ gene polymorphism, C-reactive protein level, BMI and periodontitis in post-menopausal Japanese women.

BACKGROUND: Several studies have reported inconsistent results regarding the association between the PPARγPro12Ala polymorphism and obesity. Obese individuals had higher C-reactive protein (CRP) levels compared with those of normal weight, and PPARγ activation could significantly reduce serum high-sensitive CRP level. We have previously suggested that the Pro12Ala polymorphism represents a susceptibility factor for periodontitis, which is a known risk factor for increased CRP level. OBJECTIVES: The aim was to investigate associations between PPARγ gene polymorphism, serum CRP level, BMI and/or periodontitis among post-menopausal Japanese women. MATERIALS AND METHODS: The final sample in this study comprised 359 post-menopausal Japanese women. Periodontal parameters, including PD, CAL and BOP, were measured per tooth. PPARγPro12Ala genotype was determined by PCR-RFLP. Hs-CRP value was measured by a latex nephelometry assay. RESULTS: No significant differences in age, BMI or periodontal parameters were found between the genotypes. The percentages of sites with PD ≥ 4 mm were significantly higher among the hsCRP ≥ 1 mg/l group than the hsCRP < 1 mg/l group (p = 0.003). Positive correlations were found between serum hsCRP levels and the percentages of sites with PD ≥ 4 mm (p = 0.043) in PPARγ Ala allele carriers, and BMI (p = 0.033) in non-carriers. After adjustment for model covariates, BMI was significantly associated with serum hsCRP level. CONCLUSION: The PPARγPro12Ala polymorphism was not independently associated with periodontitis, serum CRP level or BMI in post-menopausal Japanese women. However, serum hsCRP level correlated with periodontitis in Ala allele carriers, and with BMI in non-carriers.

Serum antibody to Porphyromonas gingivalis in metabolic syndrome among an older Japanese population.

BACKGROUND AND OBJECTIVE: Potentially significant associations between metabolic syndrome (MetS) and periodontal disease have been reported in recent studies; however, there is a dearth of literature regarding the relationship of MetS with serum antibody levels to periodontal pathogens. The aim of this cross-sectional study was to investigate the association between MetS and serum antibody to the periodontal pathogen Porphyromonas gingivalis (P. gingivalis) in 216 Japanese individuals aged 79 years. MATERIALS AND METHODS: Serum antibody levels to P. gingivalis were measured by enzyme-linked immunosorbent assay. An elevated serum antibody response was defined as the upper quartile and was considered as the outcome variable. A multivariable logistic regression model was used to evaluate the association of MetS defined by the modified National Cholesterol Education Program Adult Treatment Panel III criteria with an elevated antibody status. Adjustments for gender, income, education, smoking status, dental-care utilisation patterns and brushing frequency were considered. RESULTS: The prevalence of MetS was 22.2% (n = 48). Study participants with MetS were 2.9 times more likely to have an elevated serum antibody to P. gingivalis (adjusted odds ratio = 2.91, 95% confidence interval = 1.24-6.85) after simultaneous adjustment for other covariates. CONCLUSION: Our findings suggest an independent relationship between MetS and serum antibody levels to P. gingivalis in the Japanese elderly. Additional longitudinal epidemiologic studies with larger, more diversified samples and more complete information are needed to substantiate our findings.