Hideko Takahashi

Green tea consumption is associated with depressive symptoms in the elderly

BACKGROUND Green tea is reported to have various beneficial effects (eg, anti-stress response and antiinflammatory effects) on human health. Although these functions might be associated with the development and progression of depressive symptoms, no studies have investigated the relation between green tea consumption and depressive symptoms in a community-dwelling population. OBJECTIVE The aim of this study was to investigate the relations between green tea consumption and depressive symptoms in elderly Japanese subjects who widely consumed green tea. DESIGN We conducted a cross-sectional study in 1058 community-dwelling elderly Japanese individuals aged >or=70 y. Green tea consumption was assessed by using a self-administered questionnaire, and depressive symptoms were evaluated by using the 30-item Geriatric Depression Scale with 2 cutoffs: 11 (mild and severe depressive symptoms) and 14 (severe depressive symptoms). If a participant was consuming antidepressants, he or she was considered to have depressive symptoms. RESULTS The prevalence of mild and severe and severe depressive symptoms was 34.1% and 20.2%, respectively. After adjustment for confounding factors, the odds ratios (95% CI) for mild and severe depressive symptoms when higher green tea consumption was compared with green tea consumption of <or=1 cup/d were as follows: 2-3 cups green tea/d (0.96; 95% CI: 0.66, 1.42) and >or=4 cups green tea/d (0.56; 95% CI: 0.39, 0.81) (P for trend: 0.001). Similar relations were also observed in the case of severe depressive symptoms. CONCLUSION A more frequent consumption of green tea was associated with a lower prevalence of depressive symptoms in the community-dwelling older population.

Factors Associated With Psychological Distress in a Community-Dwelling Japanese Population: The Ohsaki Cohort 2006 Study

Background In Asia, there has been no population-based epidemiological study using the K6, a 6-item instrument that assesses nonspecific psychological distress. Methods Using cross-sectional data from 2006, we studied 43 716 (20 168 men and 23 548 women) community-dwelling people aged 40 years or older living in Japan. We examined the association between psychological distress and demographic, medical, lifestyle, and social factors by using the K6, with psychological distress defined as 13 or more points out of a total of 24 points. Results The following variables were significantly associated with psychological distress among the population: female sex, young and old age, a history of serious disease (hypertension, diabetes mellitus, stroke, myocardial infarction, or cancer), current smoking, former alcohol drinking, low body mass index, shorter daily walking time, lack of social support (4 of 5 components), and lack of participation in community activities (4 of 5 components). Among men aged 40 to 64 years, only “lack of social support for consultation when in trouble” and a history of diabetes mellitus remained significant on multivariate analysis. Among men aged 65 years or older, age was not significantly associated with psychological distress, and the significant association with current smoking disappeared on multivariate analysis. Among women aged 40 to 64 years, a history of stroke was not associated with psychological distress. Among women aged 65 years or older, the significant association with current smoking disappeared on multivariate analysis. Conclusions A number of factors were significantly associated with psychological distress, as assessed by the K6. These factors differed between men and women, and also between middle-aged and elderly people.

The Ohsaki Cohort 2006 Study: Design of Study and Profile of Participants at Baseline

Background Large-scale cohort studies conducted in Japan do not always include psychosocial factors as exposures. In addition, such studies sometimes fail to satisfactorily evaluate disability status as an outcome. Methods This prospective cohort study comprised 49 603 (22 438 men and 27 165 women) community-dwelling adults aged 40 years or older who were included in the Residential Registry for Ohsaki City, Miyagi Prefecture, in northeastern Japan. The baseline survey, which included psychosocial factors, was conducted in December 2006. Follow-up of death, immigration, cause of death, cancer incidence, and long-term care insurance certification was started on 1 January 2007. Results The response rate was 64.2%. In general, lifestyle-related conditions in the study population were similar to those of the general Japanese population; however, the proportion of male current smokers was higher in the cohort. The association between age and the proportion of those reporting psychological distress showed a clear U-shaped curve, with a nadir at age 60 to 69 years in both men and women, although more women were affected by such distress than men. The proportion of those who reported a lack of social support was highest among those aged 40 to 49 years. Most men and women surveyed did not participate in community activities. Among participants aged 65 years or older, 10.9% of participants were certified beneficiaries of the long-term care insurance system at baseline. Conclusions The Ohsaki Cohort 2006 Study is a novel population-based prospective cohort study that focuses on psychosocial factors and long-term care insurance certification.

Impact of physical activity and performance on medical care costs among the Japanese elderly

Aim:  Physical activity (PA) is known to be inversely associated with medical care costs. The amount of PA is strongly associated with the level of physical performance among the elderly population. Therefore, it is possible that known relation between PA and medical care merely shows the relation between physical performance and medical care. To know whether PA itself relates to medical care, considering physical performance is necessary. The aim of this study was to ascertain the impact of PA on medical care expenditure by considering the physical performance in an elderly community‐dwelling population.

Time spent walking and risk of colorectal cancer in Japan: the Miyagi Cohort study.

Higher levels of physical activity have been consistently associated with a lower risk of colon cancer in earlier epidemiological studies. The specific benefits of walking, however, remain relatively unexplored. In 1990, 20 519 men and 21 469 women in Japan completed a self-administered questionnaire including a question on time spent walking per day. During 7 years of follow-up, 260 cases of colorectal cancer were documented in 305 790 person-years. We used the Cox proportional hazards regression model to estimate the relative risk of incident cancer (colorectal, colon, and rectal) according to three levels of walking. Time spent walking was inversely associated with risk of colorectal cancer incidence in men. Compared with men who walked 0.5 h or less per day, the multivariate relative risks were 1.06 (95% confidence interval 0.72–1.57) for men who walked between 0.5 and 1 h per day, and 0.57 (95% confidence interval 0.38–0.83) for men who walked 1 h or more per day (P for trend=0.003). Time spent walking per day was associated with a lower risk of colon cancer in Japanese men but not in women, and there was no association between time spent walking and the risk of rectal cancer.

Serum C-Reactive Protein Even at Very Low (<1.0 mg/l) Concentration Is Associated with Physical Performance in a Community-Based Elderly Population Aged 70 Years and Over

Background: Although several studies have reported that C-reactive protein (CRP) is associated with physical performance, few studies have evaluated the relationships between CRP and physical performance among subjects who had a very low range of CRP. Therefore, it is still unclear whether a lower CRP is favorably associated with physical performance even within a very low range. Objective: The aim of this study was to investigate the relationships between CRP and physical performance among a Japanese population with a low serum CRP concentration (CRP <1.0 mg/l). Methods: We designed a cross-sectional survey for 775 persons aged 70 years and older living in Japan. High-sensitivity CRP was measured using a nephelometric method. The subjects whose serum CRP concentrations were higher than 10.0 mg/l were excluded. Physical performance was assessed using a 10-meter maximum walk test, leg extension power, and a timed ‘up and go’ test. Results: The median value (interquartile range) of CRP was 0.55 (0.29–1.20) mg/l. After adjustment for potential confounding factors, an inverse relation of CRP with the 10-meter maximum walk test and leg power was observed in all subjects (p for trend = 0.10 and 0.04, respectively). For subjects who had a CRP <1.0 mg/l, these inverse relations were unchanged (p for trend = 0.03 and 0.02, respectively). Conclusions: Serum CRP concentration is favorably related to physical performance, even within a very low range in a community-based elderly population aged 70 years and over. The findings suggest that maintaining as low CRP levels as possible may potentially maintain better physical performance.

Effects of the autonomic ganglion blocking agent hexamethonium on vasodilator responses mediated by the parasympathetic ganglion on the chorda tympani pathway of the cat

We investigated the pharmacological properties of a parasympathetic ganglion (a chorda tympani ganglion) that mediates vasodilator responses in the lower lip induced by electrical stimulation of the distal cut end of the chorda tympani or facial nerve root of the cat. These responses were suppressed by prior treatment with the autonomic ganglion blocking agent hexamethonium. We compared the effects of three doses of hexamethonium (1, 3 and 10 mg/kg, i.v.) on the chorda tympani ganglion with their effects on three large ganglia; the otic, submandibular and pterygopalatine ganglia that mediate vasodilator responses. Experiments were conducted on 20 cats weighing 1-3 kg which had been anesthetized with a mixture of urethane (100 mg/kg, i.v.) and chloralose (50 mg/kg, i.v.) then artificially ventilated (pancuronium bromide 0.2 mg/kg per h, i.v.). The chorda tympani ganglions sensitivity to hexamethonium was similar to that of the otic ganglion but differed from the sensitivities of submandibular and pterygopalatine ganglia. We speculate that transmission through the chorda tympani ganglion is pharmacologically similar to the otic ganglion, although its precise location has yet to be determined.

Pentylenetetrazole-induced parasympathetic blood flow increase in the lower lip of the cat

The pentylenetetrazole (30 mg/kg i.v.)-induced blood flow increase in cat lip was more marked on the sympathectomized side than on the intact side (P < 0.01). This difference is probably dependent on the degree of simultaneous activation of the sympathetic nerve elicited by pentylenetetrazole administration. The blood flow increases were markedly suppressed by prior treatment with hexamethonium (10 mg/kg i.v.), an autonomic ganglion blocker (P < 0.01). Combined section of the facial and glossopharyngeal nerve roots completely abolished the blood flow increases elicited by pentylenetetrazole administration (P < 0.01), but section of either the facial or glossopharyngeal nerve root alone failed to produce complete abolition (P < 0.05). These results indicate that the relevant parasympathetic vasodilator fibers originate not only from the glossopharyngeal, but also the facial nerves and that both participate in pentylenetetrazole-induced vasodilatation in the cat lower lip.