Association between income inequality and dental status in Japanese older adults: Analysis of data from JAGES2013.

Objectives　Personal income affects dental status in older people. However, the impact of income inequality on dental status at the community level (junior high school district) is unclear. The purpose of this study was to examine the association between dental status and community level income inequity after adjust for individual socio-economic status in Japanese older adults, and to verify the relative income hypothesis, also known as the Wilkinson hypothesis.Methods　We used data from the Japan Gerontological Evaluation Study (JAGES) conducted in Niigata city. JAGES is a postal survey of functionally independent adults aged 65 years or older. We enrolled 4,983 respondents (response rate 62.3%) and used data on 3,980 of them after excluding incomplete data. We evaluated health condition and socio-economic status using questionnaires. The Gini coefficient, as an indicator of income inequality, was calculated by junior high school district (57 districts) based on the data from the questionnaire. Additionally, the Pearson's coefficient of correlation was calculated to evaluate the association between the mean number of remaining teeth and the community level Gini coefficient. Then we evaluated the mean number of remaining teeth among the groups stratified by the Gini coefficient conditions. Next, we conducted a multilevel analysis using an ordinal logistic regression model. The number of remaining teeth was set as the dependent variable, while sex, age, household size, education, smoking status, diabetes treatment, current living conditions, and equivalent income were used as independent variables at the individual level. The Gini coefficient and average equivalent income in the junior high school district were used as independent variables at the community level.Results　The Pearson's correlation coefficient for the relationship between the Gini coefficient and the mean number of remaining teeth in the junior high school district was -0.44 (P<0.01). Wider income disparity area (Gini coefficient≧0.35) revealed a significantly small number of remaining teeth (P<0.001). The multilevel analysis showed that a higher Gini coefficient and a lower average equivalent income at the community level were significantly associated with a lower number of remaining teeth, and with educational attainment, smoking status, current living conditions, and equivalent income at the individual level, after adjusting for sex and age. On the other hand, educational attainment at the individual level, and average equivalent income at the community level were not significant factors after adjusting for all individual level variables.Conclusion　This study showed that, in addition to individual socio-economic status, income inequality at the community level was significantly associated with number of remaining teeth in Japanese older adults. Although the precise mechanism of this association is still unclear, our result supports the relative income hypothesis.

Mild renal dysfunction on admission is an important prognostic predictor in patients with infective endocarditis: a retrospective single-center study.

OBJECTIVE: Infective endocarditis (IE) continues to be associated with high mortality. The aim of the present study was to identify prognostic predictors for short-term mortality in patients with IE. METHODS: We conducted a retrospective study of 119 consecutive patients with IE (mean age 58±17). Prognostic predictors for mortality at the early phase of admission were determined using a multivariate regression analysis, and a receiver operating characteristic (ROC) analysis was carried out to evaluate the predictive ability. RESULTS: Eleven of 119 patients died during hospital admission. In this non-survivor group, the clinical parameters at the time of admission, including serum creatinine (Cr), the estimated glomerular filtration rate (eGFR), the red blood cell count, the white blood cell count, the serum CRP level and heart rate, differed significantly from those observed in the survivors (all; p<0.05). According to a logistic regression analysis, an increase in log-serum Cr per one standard deviation (odds ratio=2.18, 95%CI=1.08-4.41) and a decrease in log-eGFR per one standard deviation (odds ratio=0.51, 95%CI=0.26-0.98) were significantly associated with in-hospital death. The area under the ROC curve for serum Cr to predict the outcome was 0.80, the sensitivity was 64% and the specificity was 85% at a cut-off value of 1.16 mg/dL. For eGFR, the area under the ROC curve was 0.77, the sensitivity was 64% and the specificity was 86% at a cut-off value of 47.5 mL/min./1.73 m(2). CONCLUSION: Mild renal dysfunction at the time of admission is an important predictor of early phase mortality in patients with IE.