This cross-sectional study investigated the relationship between periodontal condition and ultrasound-diagnosed non-alcoholic fatty liver disease (NAFLD) in a Japanese oral health check population. A total of 1226 consecutive participant were enrolled in the study. Abdominal ultrasonography was applied to diagnose NAFLD. Of the study participants, 339 (27.7%) had ultrasonography-diagnosed NAFLD. The participants with NAFLD had a significantly higher prevalence of probing pocket depth (PPD) ≥ 4 mm (86.7%) than those without NAFLD (72.9%) (p < 0.05). After adjusting for gender, age, Brinkman index, regular exercise habits, body mass index, number of teeth present, presence of periodontitis, blood pressure, and serum parameters, there was a statistically significant difference in the adjusted odds ratios of having PPD ≥ 4 mm for NAFLD (Odds ratio = 1.881, 95% confidence interval 1.184–2.987, p < 0.01). Having PPD ≥ 4 mm may be a risk factor for ultrasound-diagnosed NAFLD in this cross-sectional study of a Japanese oral health check population.

Endothelial disorders are related to various diseases. An initial endothelial injury is characterized by endothelial glycocalyx injury. We aimed to evaluate endothelial glycocalyx injury by measuring serum syndecan-1 concentrations in patients during comprehensive medical examinations. A single-center, prospective, observational study was conducted at Asahi University Hospital. The participants enrolled in this study were 1313 patients who underwent comprehensive medical examinations at Asahi University Hospital from January 2018 to June 2018. One patient undergoing hemodialysis was excluded from the study. At enrollment, blood samples were obtained, and study personnel collected demographic and clinical data. No treatments or exposures were conducted except for standard medical examinations and blood sample collection. Laboratory data were obtained by the collection of blood samples at the time of study enrolment. According to nonlinear regression, the concentrations of serum syndecan-1 were significantly related to age (p = 0.016), aspartic aminotransferase concentration (AST, p = 0.020), blood urea nitrogen concentration (BUN, p = 0.013), triglyceride concentration (p < 0.001), and hematocrit (p = 0.006). These relationships were independent associations. Endothelial glycocalyx injury, which is reflected by serum syndecan-1 concentrations, is related to age, hematocrit, AST concentration, BUN concentration, and triglyceride concentration.

Dental caries could be a risk factor for metabolic syndrome (MetS); however, there is limited evidence of such a relationship in the literature. This cross-sectional study investigated the relationships among dental caries experience, dietary habits, and MetS in Japanese adults. A total of 937 participants aged 40-74 years underwent a health check, including dental examination. Decayed, missing, and filled teeth (DMFT) were used as an index of caries experience. The mean DMFT score was 14, and 12% of the participants had MetS in this study. Multivariate logistic regression analyses showed that the prevalence of MetS was significantly related to DMFT (first vs. fourth quartile, odds ratio [OR] = 1.80; P < 0.05). In addition, the OR of DMFT for MetS was found to be greater in each successively higher DMFT quartile. The prevalence of MetS was significantly related to daily coffee consumption (OR = 0.51, P < 0.01), and the relationship between DMFT and MetS was noted after adjusting for daily coffee consumption. There appears to be a positive association between caries experience and MetS in Japanese adults. This relationship increased with the increase in DMFT regardless of dietary habits.

This study investigated the relationship between eating behavior and poor glycemic control in 5,479 Japanese adults with hemoglobin A1c (HbA1c) <6.5% who participated in health checks. Respondents to a 2013 baseline survey of eating behavior, including skipping breakfast and how quickly they consumed food were followed up until 2017. We defined poor glycemic control after follow-up as HbA1c ≥6.5%, or increases in HbA1c of ≥0.5% and/or being under medication to control diabetes. We identified 109 (2.0%) respondents who met these criteria for poor glycemic control. After adjusting for sex, age, smoking status, body mass index (BMI), and eating behavior, the risk of poor glycemic control was increased in males (odds ratio [OR], 2.38; 95% confidence interval [CI] 1.37–4.12; p < 0.01), and associated with being older (OR, 1.07; 95% CI, 1.04–1.11; p < 0.001), having a higher BMI (OR, 1.29; 95% CI 1.23–1.35; p < 0.001), skipping breakfast ≥3 times/week (OR, 2.44; 95% CI, 1.35–4.41; p < 0.01), and changing from eating slowly or at medium speed to eating quickly (OR, 2.11; 95% CI, 1.04–4.26; p < 0.05). In conclusion, Japanese adults who were male, older, had a high BMI, skipped breakfast ≥3 times/week and ate quickly were at increased risk for poor glycemic control.

An association between physical illness and sleep has been suggested. Disordered chewing might be a physical factor that is associated with sleep issues. This cross-sectional study aimed to determine whether chewing problems are associated with sleep in Japanese adults. Sleep and chewing issues were evaluated in 6,025 community residents using a self-reported questionnaire. The prevalence of poor sleep quality and sleeping for <6 h/day (short duration) were 15.6% and 29.4%, respectively. Multivariate logistic regression analyses showed that prevalence of poor sleep quality was significantly associated with self-reported medical history (odds ratio (OR), 1.30; p<0.001), self-reported symptoms (OR, 4.59; p<0.001), chewing problems (OR, 1.65; p<0.001), and poor glycemic control (OR, 1.43; p=0.035). The prevalence of short sleep duration was also significantly associated with female sex (OR, 1.23; p=0.001), self-reported symptoms (OR, 1.60; p<0.001), chewing problems (OR, 1.30; p=0.001), and being overweight (OR, 1.41; p<0.001). In conclusion, chewing problems were associated with poor sleep quality and short sleep duration among Japanese adults.