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Dive into the research topics where Takehiro Michikawa is active.

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Featured researches published by Takehiro Michikawa.


Journal of Orthopaedic Science | 2009

One-leg standing test for elderly populations

Takehiro Michikawa; Yuji Nishiwaki; Toru Takebayashi; Yoshiaki Toyama

BackgroundThe one-leg standing (OLS) test is one of the balance tests used to diagnose musculoskeletal ambulation disability symptom complex (MARS), a condition newly defined by three professional Japanese medical societies in 2006 to help identify the symptoms of motor organ deterioration and establish preventive strategies. Although many studies have used the OLS test, none has shown conclusively that the test can be used as a practical marker of frailty among elderly people, especially in community settings. Based on the type of epidemiological study — i.e., descriptive epidemiology and analytical epidemiology (observational and intervention studies) — we reviewed evidence on three fundamental issues related to the OLS test: (1) testing procedures and reference values; (2) the associations between the OLS time and negative events; (3) improvement of the OLS time by intervention. These issues are key to any discussion of whether the OLS test can be used as a practical marker for predicting frailty in community-dwelling elderly populations.MethodsArticles were collected from MEDLINE databases using the search terms “one- leg standing” and the other names included in the same category.ResultsBecause various procedures are used to carry out the OLS test, the measured values for the OLS time varied widely from study to study. Some observational studies showed that the OLS time is related to negative events such as falls, declines in activity of daily living, and other morbidity. OLS times could be improved by several interventions.ConclusionsThis review suggests that the OLS test can be a tool for predicting frailty in community-dwelling elderly populations. However, our review should be interpreted with caution because we did not confirm the evidence level of each of the studies we selected. Further research on this topic is needed.


Ophthalmology | 2011

Prevalence and Risk Factors of Dry Eye Disease in Japan: Koumi Study

Miki Uchino; Yuji Nishiwaki; Takehiro Michikawa; Kazuhiro Shirakawa; Erika Kuwahara; Mutsuko Yamada; Murat Dogru; Debra A. Schaumberg; Tetsuya Kawakita; Toru Takebayashi; Kazuo Tsubota

OBJECTIVE To estimate the prevalence and risk factors of dry eye disease (DED) in a rural setting in Japan. DESIGN Cross-sectional study. PARTICIPANTS We included 3294 subjects, aged ≥ 40 years who were in the residential registry for Koumi town. INTERVENTION Subjects in a rural mountain area, Koumi town, completed questionnaires designed to detect dry eye diagnosis and risk factors. MAIN OUTCOME MEASURES Clinically diagnosed DED was defined as the presence of a previous clinical diagnosis of DED by ophthalmologists or severe symptoms of DED (both dryness and irritation constantly or often). Current symptoms of DED and possible risk factors such as age, gender, educational history, smoking history, alcohol drinking history, height and weight, visual display terminal (VDT) use, and contact lens (CL) wear, and past/current history of certain common systemic diseases were the main outcome measures. We used logistic regression analysis to examine associations between DED and other demographic factors. RESULTS Of the 3294 eligible residents, 2791 residents (85%) completed the questionnaire. The percentage of women with a composite outcome of clinically diagnosed DED or severe symptoms (21.6%; 95% confidence interval [CI], 19.5-23.9) was higher than that of men (12.5%; 95% CI, 10.7-14.5; P<0.001). A low body mass index (BMI; odds ratio [OR], 2.07; 95% CI, 0.98-4.39), CL use (OR, 3.84; 95% CI, 1.46-10.10), and hypertension (HT) (OR, 1.39; 95% CI, 0.94-2.06) were risk factors for DED in men. Use of a VDT (OR, 2.33; 95% CI, 1.12-4.85), CL use (OR, 3.61; 95% CI, 2.13-6.10), and myocardial infarction or angina were the risk factors (OR, 2.64; 95% CI, 1.51-4.62), whereas high BMI was a preventive factor (OR, 0.69; 95% CI, 0.48-1.01) for DED in women. CONCLUSIONS Among a Japanese cohort, DED leading to a clinical diagnosis or severe symptoms is prevalent. Use of CLs was a common dry eye risk factor in both genders. The condition is more prevalent in men with low BMI, HT, and in women with myocardial infarction or angina and VDT use. Relevant measures directed against the modifiable risks may provide a positive impact on public health and quality of life of Japanese. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any materials discussed in this article.


BMC Public Health | 2014

Rationale and study design of the Japan environment and children’s study (JECS)

Toshihiro Kawamoto; Hiroshi Nitta; Katsuyuki Murata; Eisaku Toda; Naoya Tsukamoto; Manabu Hasegawa; Zentaro Yamagata; Fujio Kayama; Reiko Kishi; Yukihiro Ohya; Hirohisa Saito; Haruhiko Sago; Makiko Okuyama; Tsutomu Ogata; Susumu Yokoya; Yuji Koresawa; Yasuyuki Shibata; Shoji F. Nakayama; Takehiro Michikawa; Ayano Takeuchi; Hiroshi Satoh

BackgroundThere is global concern over significant threats from a wide variety of environmental hazards to which children face. Large-scale and long-term birth cohort studies are needed for better environmental management based on sound science. The primary objective of the Japan Environment and Children’s Study (JECS), a nation-wide birth cohort study that started its recruitment in January 2011, is to elucidate environmental factors that affect children’s health and development.Methods/DesignApproximately 100,000 expecting mothers who live in designated study areas will be recruited over a 3-year period from January 2011. Participating children will be followed until they reach 13 years of age. Exposure to environmental factors will be assessed by chemical analyses of bio-specimens (blood, cord blood, urine, breast milk, and hair), household environment measurements, and computational simulations using monitoring data (e.g. ambient air quality monitoring) as well as questionnaires. JECS’ priority outcomes include reproduction/pregnancy complications, congenital anomalies, neuropsychiatric disorders, immune system disorders, and metabolic/endocrine system disorders. Genetic factors, socioeconomic status, and lifestyle factors will also be examined as covariates and potential confounders. To maximize representativeness, we adopted provider-mediated community-based recruitment.DiscussionThrough JECS, chemical substances to which children are exposed during the fetal stage or early childhood will be identified. The JECS results will be translated to better risk assessment and management to provide healthy environment for next generations.


Journal of Occupational Health | 2009

Effects of SO2 on respiratory system of adult Miyakejima resident 2 years after returning to the island.

Satoko Iwasawa; Yuriko Kikuchi; Yuji Nishiwaki; Makiko Nakano; Takehiro Michikawa; Tazuru Tsuboi; Shigeru Tanaka; Takamoto Uemura; Ai Ishigami; Hiroshi Nakashima; Toru Takebayashi; Mitsuru Adachi; Akihiro Morikawa; Kouichi Maruyama; Shoji Kudo; Iwao Uchiyama; Kazuyuki Omae

Effects of SO2 on Respiratory System of Adult Miyakejima Resident 2 Years after Returning to the Island: Satoko Iwasawa, et al. Department of Preventive Medicine and Public Health, School of Medicine, Keio University


Journal of Occupational Health | 2009

Causal Relationship between Indium Compound Inhalation and Effects on the Lungs

Makiko Nakano; Kazuyuki Omae; Akiyo Tanaka; Miyuki Hirata; Takehiro Michikawa; Yuriko Kikuchi; Noriyuki Yoshioka; Yuji Nishiwaki; Tatsuya Chonan

Causal Relationship between Indium Compound Inhalation and Effects on the Lungs: Makiko Nakano, et al. Department of Preventive Medicine and Public Health, School of Medicine, Keio University


Journal of the American Geriatrics Society | 2010

Hearing handicap predicts the development of depressive symptoms after 3 years in older community-dwelling Japanese.

Hideyuki Saito; Yuji Nishiwaki; Takehiro Michikawa; Yuriko Kikuchi; Kunio Mizutari; Toru Takebayashi; Kaoru Ogawa

OBJECTIVES: To examine the association between hearing handicap and depressive symptoms in older community‐dwelling Japanese.


Preventive Medicine | 2008

Gender difference in the relationships between vision and hearing impairments and negative well-being.

Sei Harada; Yuji Nishiwaki; Takehiro Michikawa; Yuriko Kikuchi; Satoko Iwasawa; Makiko Nakano; Ai Ishigami; Hideyuki Saito; Toru Takebayashi

OBJECTIVES To evaluate the association of hearing impairment, vision impairment and their combination (dual sensory impairment) with negative well-being such as depression, subjective poor health and the reduced functional ability in community-dwelling older adults, and to determine whether any association varies by gender. METHODS Between 2005 and 2006, we objectively examined vision and hearing impairment (using best-corrected visual acuity and pure-tone audiometric test) in 843 people aged 65 years and older (351 males, 492 females) in a rural Japanese town. Through a home visit interview survey using a structured questionnaire, we also collected information on depression (the five-item Geriatric Depression Scale), subjective poor health, and reduced functional activity (the Tokyo Metropolitan Institute of Gerontologys Index of Competence). RESULTS We observed gender differences in the association between sensory impairment and depression. Multiple logistic regression analysis revealed that hearing impairment in males (adjusted odds ratio: 2.22, 95% confidence interval; 1.07-4.61) and vision impairment in females (1.91, 1.14-3.21) were related to depression. Vision impairment and dual sensory impairment were also associated with subjective poor health and reduced functional activity in both sexes. CONCLUSIONS Sensory impairment is significantly associated with negative well-being in older persons, and its association with depression may differ between males and females.


Journal of Epidemiology | 2010

Prevalence and factors associated with tinnitus: A community-based study of Japanese elders

Takehiro Michikawa; Yuji Nishiwaki; Yuriko Kikuchi; Hideyuki Saito; Kunio Mizutari; Michiko Okamoto; Toru Takebayashi

Background The prevalence of tinnitus is reported to be high in older Western populations, and several risk factors have been suggested. However, community-based evidence on prevalence is limited and, to our knowledge, there is no such information from older non-Western populations. The purpose of this study was to determine the prevalence and factors associated with tinnitus in community-dwelling Japanese elders. Methods In this community-based cross-sectional study, 1320 residents of Kurabuchi Town aged 65 years or older (584 men and 736 women; participation proportion = 98.7%) were interviewed at home in 2006, and information on tinnitus and factors associated with tinnitus was collected. We estimated the prevalence of tinnitus by age group and sex and used a logistic regression model to investigate associated factors. Results The prevalence of tinnitus was 18.6% (men: 18.0%; women: 19.0%); there were no statistically significant differences by age group or sex. Hearing difficulty, depressive mood, prescribed medication, past/current history of coronary heart disease, and knee joint pain requiring medical consultation were associated with tinnitus. Conclusions These findings suggest that tinnitus is common in Japanese aged over 65 years. Because the factors associated with tinnitus in this cross-sectional study are potentially modifiable, they should be thoroughly investigated in a longitudinal study.


European Journal of Cancer Prevention | 2012

Seaweed consumption and the risk of thyroid cancer in women: the Japan Public Health Center-based Prospective Study.

Takehiro Michikawa; Manami Inoue; Taichi Shimazu; Norie Sawada; Motoki Iwasaki; Shizuka Sasazuki; Taiki Yamaji; Shoichiro Tsugane

Iodine is a suspected risk factor for thyroid cancer. Seaweed accounts for about 80% of Japanese people’s iodine intake. We examined the association between seaweed consumption and the risk of thyroid cancer in Japanese women. Women participating in the Japan Public Health Center-based Prospective Study (n=52 679; age: 40–69 years) were followed up for a mean of 14.5 years; 134 new thyroid cancer cases, including 113 papillary carcinoma cases, were identified. Seaweed consumption was assessed using a food-frequency questionnaire and divided into three categories: 2 days/week or less (reference); 3–4 days/week; and almost daily. The Cox proportional hazards model was applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Seaweed consumption was clearly associated with an increased risk of papillary carcinoma (HR for almost daily consumption compared with 2 days/week or less=1.71; 95% CI: 1.01–2.90; trend P=0.04). After stratification for menopausal status, an increased risk was observed in postmenopausal women (papillary carcinoma HR for almost daily consumption compared with 2 days/week or less=3.81, 95% CI: 1.67–8.68; trend P<0.01), but not in premenopausal women (HR=0.91, 95% CI: 0.44–1.91; trend P=0.76). This study identified a positive association between seaweed consumption and the risk of thyroid cancer (especially for papillary carcinoma) in postmenopausal women.


Journal of Epidemiology | 2015

The Japan Environment and Children's Study (JECS): A Preliminary Report on Selected Characteristics of Approximately 10 000 Pregnant Women Recruited During the First Year of the Study

Takehiro Michikawa; Hiroshi Nitta; Shoji F. Nakayama; Masaji Ono; Junzo Yonemoto; Kenji Tamura; Eiko Suda; Hiroyasu Ito; Ayano Takeuchi; Toshihiro Kawamoto

BACKGROUND The Japan Environment and Childrens Study (JECS) is an ongoing nationwide birth cohort study launched in January 2011. In this progress report, we present data collected in the first year to summarize selected maternal and infant characteristics. METHODS In the 15 Regional Centers located throughout Japan, the expectant mothers were recruited in early pregnancy at obstetric facilities and/or at local government offices issuing pregnancy journals. Self-administered questionnaires were distributed to the women during their first trimester and then again during the second or third trimester to obtain information on demographic factors, physical and mental health, lifestyle, occupation, environmental exposure, dwelling conditions, and socioeconomic status. Information was obtained from medical records in the first trimester and after delivery on medical history, including gravidity and related complications, parity, maternal anthropometry, and infant physical examinations. RESULTS We collected data on a total of 9819 expectant mothers (mean age = 31.0 years) who gave birth during 2011. There were 9635 live births. The selected infant characteristics (singleton births, gestational age at birth, sex, birth weight) in the JECS population were similar to those in national survey data on the Japanese general population. CONCLUSIONS Our final birth data will eventually be used to evaluate the national representativeness of the JECS population. We hope the JECS will provide valuable information on the impact of the environment in which our children live on their health and development.Background The Japan Environment and Children’s Study (JECS) is an ongoing nationwide birth cohort study launched in January 2011. In this progress report, we present data collected in the first year to summarize selected maternal and infant characteristics. Methods In the 15 Regional Centers located throughout Japan, the expectant mothers were recruited in early pregnancy at obstetric facilities and/or at local government offices issuing pregnancy journals. Self-administered questionnaires were distributed to the women during their first trimester and then again during the second or third trimester to obtain information on demographic factors, physical and mental health, lifestyle, occupation, environmental exposure, dwelling conditions, and socioeconomic status. Information was obtained from medical records in the first trimester and after delivery on medical history, including gravidity and related complications, parity, maternal anthropometry, and infant physical examinations. Results We collected data on a total of 9819 expectant mothers (mean age = 31.0 years) who gave birth during 2011. There were 9635 live births. The selected infant characteristics (singleton births, gestational age at birth, sex, birth weight) in the JECS population were similar to those in national survey data on the Japanese general population. Conclusions Our final birth data will eventually be used to evaluate the national representativeness of the JECS population. We hope the JECS will provide valuable information on the impact of the environment in which our children live on their health and development.

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Hiroshi Nitta

National Institute for Environmental Studies

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Shin Yamazaki

National Institute for Environmental Studies

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