Does poor dental health predict becoming homebound among older Japanese?

Background: Being homebound is an important risk factor of functional disability in older people. There is a possibility of bidirectional relationship between homeboundness and dental health. This prospective cohort study examined the association of dental health, which includes social function, on homeboundness in the future.

Poor Oral Health and Diet in Relation to Weight Loss, Stable Underweight, and Obesity in Community-Dwelling Older Adults: A Cross-Sectional Study From the JAGES 2010 Project.

Background: Involuntary weight loss and underweight increase the risks of mortality and disability in older people. However, the association and interaction of poor oral health and dietary intake with body mass index (BMI) have not been elucidated.

Methods: Data were analyzed for 96 794 respondents aged >65 years who were randomly selected from 31 Japanese municipalities in the Japan Gerontological Evaluation Study.

Influence of socioeconomic status on the association between body mass index and cause-specific mortality among older Japanese adults: The AGES Cohort Study.

Objective: Many studies have suggested a U-shaped curve for the association between body size and mortality risks, i.e., mortality risks increase in those who are both overweight and underweight.

Individual- and community-level social gradients of edentulousness.

Background: Community-level factors as well as individual-level factors affect individual health. To date, no studies have examined the association between community-level social gradient and edentulousness. The aim of this study was to investigate individual- and community-level social inequalities in edentulousness and to determine any explanatory factors in this association.

Social determinants of denture/bridge use: Japan gerontological evaluation study project cross-sectional study in older Japanese.

Background: Studies suggest that using a denture/bridge may prevent disability in older people. However, not all older people with few remaining teeth use a denture/bridge. This cross-sectional study aimed to examine the social determinants which promote denture/bridge use among older Japanese.

The relationship between consumption of tyrosine and phenylalanine as precursors of catecholamine at breakfast and the circadian typology and mental health in Japanese infants aged 2 to 5 years.

Background: This study aims to examine the relationship between tyrosine and phenylalanine intake at breakfast as precursors of dopamine, and scores on the Torsvall-Åkerstedt Diurnal Type Scale and of mental health in Japanese infants aged 2 to 5 years.

Results: An integrated questionnaire was administered to parents of 1,367 infants attending one of ten nursery schools governed by Kochi City or a kindergarten affiliated with the Faculty of Education at Kochi University (775 answers for analysis: 56.7%) in May and June 2008.

A tryptophan-rich breakfast and exposure to light with low color temperature at night improve sleep and salivary melatonin level in Japanese students.

Background: Epidemiological studies in Japan have documented an association between morning type and a tryptophan-rich breakfast followed by exposure to sunlight in children. The association may be mediated by enhanced melatonin synthesis, which facilitates sleep at night. However, melatonin is inhibited by artificial light levels with high color-temperature common in Japanese homes at night.

Dental status and incident falls among older Japanese: a prospective cohort study.

Objective: To examine if self-reported number of teeth, denture use and chewing ability are associated with incident falls.

Design: Longitudinal cohort study (the Aichi Gerontological Evaluation Study).

Setting: 5 Japanese municipalities.

Can breakfast tryptophan and vitamin B6 intake and morning exposure to sunlight promote morning-typology in young children aged 2 to 6 years?

This study tried to examine, from epidemiological and physiologic anthropological (Japanese culture on breakfast) points of view, the integrated effects of the amount of tryptophan and vitamin B6 intake and the following exposure to sunlight on the circadian typology and sleep habits in young Japanese children aged 2 to 6 years, using the newly-evaluated calculating system of tryptophan (Tryptophan Index 2009) and vitamin B6 intake (VitaminB6 Index 2009) at breakfast. The positive and significant correlation was shown between the Morningness-Eveningness (M-E) score and the Tryptophan Index and also the Vitamin B6 Index. This positive correlation between M-E score and amount of tryptophan intake was shown only by children who were exposed to sunlight for longer than 10min after breakfast.

Association between self-reported dental health status and onset of dementia: a 4-year prospective cohort study of older Japanese adults from the Aichi Gerontological Evaluation Study (AGES) Project.

Objectives: Studies have shown that people with cognitive impairment have poor dental health. However, the direction of causality remains unknown. This prospective cohort study aimed to determine the association between four self-reported dental health variables and dementia onset in older Japanese people.

Association between dental status and incident disability in an older Japanese population.

Objectives: To determine the association between dental health status and onset of functional disability in older Japanese people.

Design: Prospective cohort study.

Setting: Six Japanese municipalities.

Effect of birth season on circadian typology appearing in Japanese young children aged 2 to 12 years disappears in older students aged 18 to 25 years.

Several studies suggest that season of birth differentially affects the physiological characteristics of humans. Those living at relatively high latitude, such as Canada, Spain, and Italy (44°N-45°N), and born in the fall tended to be "morning-type" persons in comparison to those born in other seasons. There are relatively little data on the affect of season of birth on people residing at low latitude.

Neighborhood food environment and body mass index among Japanese older adults: results from the Aichi Gerontological Evaluation Study (AGES).

Background: The majority of studies of the local food environment in relation to obesity risk have been conducted in the US, UK, and Australia. The evidence remains limited to western societies. The aim of this paper is to examine the association of local food environment to body mass index (BMI) in a study of older Japanese individuals.

An integrated effect of protein intake at breakfast and morning exposure to sunlight on the circadian typology in Japanese infants aged 2-6 years.

Tryptophan (Trp) intake at breakfast promotes morning-typed circadian typology and higher sleep quality in Japanese children aged 0-6 yrs (Harada et al., 2007). This effect may be accelerated by morning exposure to sunlight, which has not yet been tested.

The different effects of vertical social capital and horizontal social capital on dental status: a multilevel analysis.

Few studies distinguish between the effects of different forms of social capital on health and of those that do none use physical indicators of health as an outcome variable. The objective of this study was to determine whether vertical and horizontal social capital had different associations with dental status of elderly Japanese. In this cross-sectional study, self-administered questionnaires were mailed to elderly individuals living in 25 Japanese communities in 2003.

Effects of meal habits and alcohol/cigarette consumption on morningness-eveningness preference and sleep habits by Japanese female students aged 18-29.

The relationship of meal habits and alcohol/cigarette consumption to circadian typology and sleep health in Japanese female students was studied from an epidemiological point of view. Questionnaires on Morningness-Eveningness by Torsvall and Akerstedt (1980), sleep habits, regularity of meal intake and meal amount, and style of alcohol and cigarette consumption were administered to 800 students aged 18-29 years, attending university or training schools for nutrition specialists (Aichi Prefecture, 35 degrees N). Points from ten questions were totaled to provide estimates of sleep habits given as the Unhealthy Sleep Index (UHSI).