Low back pain is an important public health issue across the world. However, it is unclear whether socioeconomic status (SES) is associated with low back pain. This study determines an association between SES and low back pain among older people. We used cross-sectional data derived from the year 2013 across 30 Japanese municipalities. The survey was conducted between October 2013 to December 2013. Functionally independent community-dwelling older adults aged 65 and above (n = 26,037) were eligible for the study. Multilevel Poisson regression analysis with a robust variance estimator was used to examine the association between SES and low back pain. Self-reported low back pain in the past year was used as a dependent variable. Educational attainment, past occupation, equivalized household income, wealth, and subjective economic situation represented SES and were separately analyzed as independent variables, adjusted for covariates including age and sex. The prevalence of low back pain was 63.4%. Overall, lower SES were more likely to suffer from low back pain compared with that for the highest. First, as for the educational attainment, the prevalence ratio (PR) (95% credible interval (CI)) for the lowest level was 1.07 (1.02–1.12). Second, as for the past occupation, the PR (95% CI) for the blue-collared workers compared with professionals was 1.06 (1.01–1.11). Third, as for the equalized household income, the PRs (95% CI) for lower middle and the lowest income levels were 1.08 (1.02–1.13) and 1.16 (1.10–1.23), respectively. Fourth, as for the wealth, the PRs (95% CI) for lower middle and the lowest wealth levels were 1.11 (1.04–1.19) and 1.18 (1.11–1.27), respectively. Fifth, as for the subjective economic situation, the PRs (95% CI) for lower middle and the lowest financial conditions were 1.18 (1.10–1.26) and 1.32 (1.22–1.44), respectively. Significant socioeconomic inequalities were observed in low back pain among older individuals in Japan. Policymakers and clinicians must understand the nature of these inequalities.

Epidemiological studies of the association between coffee consumption and dementia have yielded inconsistent results. Therefore, we investigated the association between coffee consumption and incident risk of dementia in an elderly Japanese population. 23,091 subjects aged ≥65 y living in Ohsaki City, northeastern Japan, responded to the baseline survey in 2006. Of these, we analyzed 13,137 subjects who gave informed consent and were not disabled at baseline. The outcome was the incidence of disabling dementia defined by usage of the Long-term Care Insurance database. We used the Cox proportional hazards regression model for multivariate analysis. During 5.7 y of follow-up period, we identified 1,107 cases of incident dementia. Overall, coffee consumption was significantly associated with a lower risk of incident dementia. The multivariate-adjusted HRs for the incidence of dementia according to coffee consumption categories (never, occasionally, 1-2 cups/d, and ≥3 cups/d) were 1.00, 0.73 (95% CI, 0.62–0.86), 0.72 (95% CI, 0.61–0.84), and 0.82 (95% CI, 0.65–1.02; p for trend = 0.009), respectively. In addition, this significant inverse association was more remarkable among women, non-smokers, and non-drinkers. Coffee consumption is significantly associated with a lower risk of incident dementia.

BackgroundAlthough the feasibility of randomized trials for investigating the long-term association between oral health and cognitive decline is low, deriving causal inferences from observational data is challenging. We aimed to investigate the association between poor oral status and subjective cognitive complaints (SCC) using fixed-effects model to eliminate the confounding effect of unobserved time-invariant factors.MethodsWe used data from Japan Gerontological Evaluation Study (JAGES) which was conducted in 2010, 2013, and 2016. β regression coefficients (95% confidence intervals) were calculated using fixed-effects models to determine the effect of deteriorating oral status on developing SCC. Onset of SCC was evaluated using the Kihon Checklist-Cognitive function score. Four oral status variables were used: awareness of swallowing difficulty, decline in masticatory function, dry mouth, and number of teeth.Results13,594 participants (55.8% women) without SCC at baseline were included. The mean age was 72.4 (SD = 5.1) for men and 72.4 (SD=4.9) for women. Within the 6-year follow-up, 26.6% of men and 24.9% of women developed SCC. The probability of developing SCC was significantly higher when participants acquired swallowing difficulty (β= 0.088; 0.065-0.111 for men, β= 0.077; 0.057-0.097 for women), decline in masticatory function (β=0.039; 0.021-0.057 for men, β= 0.030; 0.013-0.046 for women), dry mouth (β= 0.026; 0.005-0.048 for men, β= 0.064; 0.045-0.083 for women), and tooth loss (β= 0.043; 0.001-0.085 for men, β= 0.058; 0.015-0.102 for women).ConclusionsThe findings suggest that good oral health needs to be maintained to prevent the development of SCC, which increases the risk for future dementia.

Background: The trend of the diffusion of heated tobacco products (HTPs) is a great concern because HTPs have become available worldwide. This study examined the sociodemographic characteristics of HTPs users in Japan, which were first launched.Methods: This cross-sectional study used data from an online survey conducted in 2017. A total of 4,926 participants, aged 20–69 years, were included. The dependent variable was the type of tobacco products used. The independent variables were age and equivalent income. Two analyses estimated the odds ratios (ORs) for 1) being smokers compared to “non-smokers”, and 2) being “HTP smokers” compared to “only combustible cigarette smokers.” Analyses were stratified by sex. Educational attainment and occupation were also used in the sensitivity analyses.Results: The percentages of “non-smokers,” “only combustible cigarette smokers,” and “HTP smokers” were 82.8%, 14.2%, and 3.0%, respectively. When compared to the oldest participants (aged 60–69), the youngest participants (aged 20–29) tended to be “HTP smokers” (OR=7.90 (95% CI=3.09–20.22) for men and 9.28 (2.14–40.28) for women). Compared to participants with the lowest incomes (<2 million), those with the highest incomes (≥4 million) tended to use HTPs (OR=2.93 (95% CI=1.56–5.49) in men and 1.82 (0.73–4.54) in women). These trends were consistent when analyses included only smokers. There were consistent results in other SES measurements; educational attainment and occupation.Conclusions: Younger or more affluent people tended to use HTPs, although smoking rates among these populations were generally lower. New tobacco control efforts are required.

Recent epidemiological studies of the association between coffee consumption and the risk of bladder cancer have yielded conflicting results. The aim of the present study was to examine the association between coffee consumption and the incidence of bladder cancer on the basis of pooled data from two cohort studies carried out in Miyagi Prefecture, northeastern Japan. We delivered self-administered questionnaires inquiring about the frequency of coffee consumption and other lifestyle factors in 1990 for the Miyagi Cohort Study and in 1994 for the Ohsaki Cohort Study. We followed 73 346 individuals from both cohorts and identified 274 cases of bladder cancer during 17.6 years for the Miyagi Cohort Study and 13.3 years for the Ohsaki Cohort Study. The multivariate-adjusted hazard ratios (95% confidence intervals) of bladder cancer incidence for the individuals who drank coffee occasionally, 1–2 cups/day, and 3 or more cups/day compared with never drinkers were 1.22 (0.90–1.66), 0.88 (0.61–1.26), and 0.56 (0.32–0.99), respectively (P _trend=0.04). The inverse association remained even after stratification for smoking status. These data indicate that there is a significant inverse association between coffee consumption and the risk of bladder cancer.

This study examined the associations between area-level unemployment rates and lower back pain using large-scale data provided by the Japanese working population. We analyzed data from a nationally representative, repeated, cross-sectional study across three waves from 2010, 2013, and 2016 in 47 Japanese subnational level areas. Workers aged 18–64 years (n = 962,586) were eligible to participate in the study. A multilevel logistic model was used to examine the association between the unemployment rate and lower back pain. The self-report of lower back pain was a dependent variable. The prefecture-level unemployment rate was analyzed as an independent variable, adjusted for individual-level covariates (e.g., gender, age, socioeconomic status). After adjusting for all covariates, the main effect of the prefecture-level unemployment rate was statistically significant: the odds ratio (OR) (95% credible interval (CrI)) was 1.01 (1.002, 1.03). Additionally, the OR (95% CrI) for the interaction between gender and the prefecture-level unemployment rate was 1.02 (1.01, 1.03) indicating that women were more affected by area-level employment status than men. In conclusion, a significant association between the unemployment rate and lower back pain was observed in the Japanese working population. Women were more sensitive to the unemployment rate.