Longitudinal Evaluation of Multi-phasic, Odontological and Nutritional Associations in Dentists (LEMONADE Study): study design and profile of nationwide cohort participants at baseline

Effects of oral health-related quality of life on total mortality: a prospective cohort study

BACKGROUND

The effects of oral health on mortality have been reported; however, the association between mortality and Oral Health-Related Quality of Life (OHQOL) is unknown. We investigated the effect of OHQOL on total mortality in a cohort consisting of dentists.

METHODS

In this cohort study, we analyzed data from the Longitudinal Evaluation of Multi-phasic, Odonatological and Nutritional Associations in Dentists study. We conducted a baseline survey of general and oral health factors. We called for 31,178 participants and collected responses from 10,256 participants. We followed up with 10,114 participants (mean age ± standard deviation, 52.4 ± 12.1 years; females, 8.9%) for 7.7 years, until March 2014, to determine the average total mortality. OHQOL was assessed using the General Oral Health Assessment Index (GOHAI). The total score was divided into quartiles (Q1 ≤ 51.6, Q2 = 51.7-56.7, Q3 = 56.8-59.9, and Q4 = 60.0), with higher GOHAI scores indicating better OHQOL (score range, 12-60). The association between OHQOL and total mortality was analyzed using the Cox proportional hazards model.

RESULTS

We documented 460 deaths. Males with low GOHAI scores possessed a remarkably high risk of total mortality. The multivariate adjusted-hazard ratios (aHRs), were 1.93 (95% confidence interval [CI], 1.07 - 3.48) for Q1, 1.69 (95% CI, 0.90 - 3.17) for Q2, and 0.65 (95% CI, 0.29 - 1.46) for Q3, relative to Q4 (trend p = 0.001). The aHRs in the multivariate model with all background variables were 1.69 (95% CI, 1.15-2.46) for Q1, 1.53 (95% CI, 1.04-2.27) for Q2, and 1.09 (95% CI, 0.71-1.70) for Q3, relative to Q4 (trend p = 0.001). In females, there was no significant association between the quartiles, in both the multivariate-adjusted model (trend p = 0.52) and multivariate-adjusted model with all background variables (trend p = 0.79).

CONCLUSIONS

A lower OHQOL indicated an increased risk of total mortality in dentists. OHQOL may be used as an indicator for selecting treatment plans and personalized care interventions, thus contributing to increased healthy life expectancy.

TRIAL REGISTRATION

Aichi Cancer Center, Nagoya University Graduate School of Medicine, and Hiroshima University (Approval numbers: 33, 632-3, 8-21, and E2019-1603).

Influence of black rice (Oryza sativa L.) bran derived anthocyanin-extract on growth rate, immunological response, and immune-antioxidant gene expression in Nile tilapia (Oreochromis niloticus) cultivated in a biofloc system

This study investigated the effects of dietary supplementation with anthocyanin extracted from black rice bran (AR) on the growth rate, immunological response, and expression of immune and antioxidant genes in Nile tilapia raised in an indoor biofloc system. A total of 300 Nile tilapia fingerlings (15.14 ± 0.032 g) were maintained in 150 L tanks and acclimatized for two weeks. Five experimental AR diets (0, 1, 2, 4, and 8 g kg^-1) with various anthocyanin doses were used to feed the fish. We observed that the growth and feed utilization of fish fed with different dietary AR levels increased significantly after eight weeks (p < 0.05). In addition, the serum immunity of fish fed AR diets was much greater than that of those fed non-AR diets (p < 0.05). However, there were little or no difference in between fish fed AR enriched diets and the control AR-free diet (p > 0.05). After eight weeks, fish fed AR-supplemented diets had significantly higher mRNA transcript levels in immune (interleukin [IL]-1, IL-8, and liposaccharide-binding protein [LBP]) and antioxidant (glutathione transferase-alpha [GST-α] and glutathione reductase [GSR]) genes compared to control fish fed the AR-free diet, with the greatest enhancement of mRNA transcript levels (in the case of IL-8 by up to about 5.8-fold) in the 4 g kg^-1 AR diet. These findings suggest that dietary inclusion of AR extract from black rice bran at 4-8 g kg^-1 could function as a herbal immunostimulant to enhance growth performance, feed consumption, and immunity in Nile tilapia.

Plant Growth-Promoting Rhizobacteria With ACC Deaminase Activity Enhance Maternal Lateral Root and Seedling Growth in Switchgrass

Switchgrass, a C4 plant with high potential as a bioenergy source, is unsteady in yield under sub-optimal conditions. Bacteria containing 1-aminocyclopropane-1-carboxylate synthase (ACC) deaminase can promote plant growth. We isolated bacteria containing ACC deaminase activity from switchgrass rhizosphere using an orthogonal matrix experimental design with four factors (bacterial liquid concentration, bacterial liquid treatment time, nitrogen content, and NaCl) to quantitatively investigate the effects and pairwise interactions on the seedling growth. Pseudomonas sp. Y1, isolated from the switchgrass cv. Blackwell rhizomes was selected. We optimized the inoculation bacterial concentration, treatment time, NaCl, and nitrogen concentration for the seedling growth. The optimal bacterial concentration, treatment time, NaCl, and nitrogen content was 0.5-1.25 OD at 600 nm, 3 h, 60-125 mM and 158 mg L-1, respectively. Pseudomonas sp. Y1 significantly increased the total root length, root surface, shoot length, and fresh and dry weight through an effective proliferation of the number of first-order lateral roots and root tips. This indicated that Pseudomonas sp. Y1 has a higher potential to be used as a plant growth-promoting rhizobacteria bacteria.

Tooth loss and pneumonia mortality: A cohort study of Japanese dentists

Although associations between oral health and pneumonia have been reported in previous studies, particularly in the institutionalized elderly, few prospective studies have investigated the association between oral condition and pneumonia among community-dwelling people and whether the findings among inpatients or patients in nursing homes are applicable to the general population is still unclear. The oral bacteria propagated in the periodontal regions may drop into the lung and increase the risk of pneumonia. We, therefore, investigated the association of tooth loss with mortality from pneumonia in a cohort study of Japanese dentists. Members of the Japan Dental Association (JDA) participated in the LEMONADE (Longitudinal Evaluation of Multi-phasic, Odontological and Nutritional Associations in Dentists) Study. From 2001 to 2006, they completed a baseline questionnaire on lifestyle and health factors including the number of teeth lost (excluding third molars). We followed 19,775 participants (mean age ± standard deviation, 51.4 ± 11.7 years; 1,573 women [8.0%] and 18,202 men [92.0%]) for mortality from pneumonia (ICD-10, J12-J18). Mortality data were collected via the fraternal insurance program of the JDA. The hazard ratios (HRs) were estimated with adjustment for sex, age, body mass index, smoking status, physical activity and diabetes history. During the median follow-up period of 9.5 years, we documented 68 deaths from pneumonia. Participants who were edentulous at baseline were at significantly increased risk of mortality from pneumonia. The multivariable-adjusted HRs were 2.07 (95% confidence interval [CI], 1.09-3.95) for the edentulous and 1.60 (95% CI, 0.83-3.10) for loss of 15-27 teeth relative to loss of 0-14 teeth (trend p = 0.026). The HR per one tooth loss was also significant; 1.031 (95% CI, 1.004-1.060). In conclusion, a large number of teeth lost may indicate an increased risk of mortality from pneumonia in community-dwelling populations.

Declining rates of tobacco use in the Japanese medical profession, 1965-2009

Background

Although there has been a downward trend in smoking rates among medical doctors in recent years, rates have been higher among Japanese doctors when compared internationally.

Methods

We extensively reviewed all published English- and Japanese-language articles that reported the smoking rates of Japanese doctors.

Results

A total of 36 articles were examined, most of which had been conducted as postal surveys, usually by a national, prefectural, or local medical association. Sample sizes ranged from 17 to 11 773, and response rates ranged from 33% to 91%. National surveys conducted between 1965 and 2009 suggest that there has been a statistically significant (P < 0.0001) decline in smoking rates among Japanese doctors (from around 68% to 16% among males and from 19% to 5% among females).

Conclusions

Overall, the published data reveal a significant decline in smoking rates among Japanese doctors since 1965, especially among men. Although less than one-fifth of Japanese male doctors now smoke, more work needs to be done in tobacco control to help further reduce the burden of smoking, especially in medical schools.

Necessity and readiness for smoking cessation intervention in dental clinics in Japan

BACKGROUND

The necessity and readiness for smoking cessation intervention in dental clinics was assessed by investigating smoking status and stage of behavior change in patients and the attitudes of dentists toward the effects of smoking on their patients, respectively.

METHODS

A self-administered questionnaire was mailed to 1022 dentists randomly selected from the Japanese Dental Association database. The questionnaire survey consisted of 1 section for dentists and 1 for patients aged 20 years or older and was scheduled to be completed at the dentists' clinics on a designated day in February 2008.

RESULTS

The response rate to the questionnaire was 78.2% from among target dental clinics and 73.7% and 74.7% for patient and dentist questionnaires, respectively. Data from 11,370 patients and 739 dentists were analyzed. The overall smoking prevalence among the patients (25.1%) was similar to that reported by the National Health and Nutrition Examination Survey, and young female patients had a markedly higher smoking prevalence. More than 70% of patients who smoked were interested in quitting. Although the prevalence of current smoking among dentists (27.1%) was significantly higher than that reported among Japanese physicians (15.0%), approximately 70% of dentists were concerned about the effects of smoking on patient health and prohibited smoking inside their clinic.

CONCLUSIONS

Many smokers who were interested in quitting, particularly young women, visited dental clinics, and most dentists believed that smoking was harmful for their patients. These results indicate that smoking cessation intervention in dental settings is necessary and that dentists are ready to provide such interventions.