Tetsuya Ohira

Prof. Tetsuya Ohira

Department of Epidemiology, Fukushima Medical University School of Medicine
orcid

Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2009 in Hypertension
Verified
Journal Article
Closed access
TOTetsuya Ohira
Tetsuya Ohira
TTTakeshi Tanigawa
Takeshi Tanigawa
MTMinako Tabata
Minako Tabata
HIHironori Imano
Hironori Imano
AKAkihiko Kitamura
Akihiko Kitamura
HIHiroyasu Iso
Hiroyasu Iso
We sought to examine effects of habitual alcohol intake on ambulatory blood pressure (BP), heart rate (HR), and HR variability among Japanese men. Subjects were 539 men aged 35 to 65 years from rural and urban communities. Ambulatory BP and HR were monitored with an automated, portable, noninvasive multibiomedical recorder. Power spectral analysis of the RR intervals on the ECG was performed every 5 minutes. Compared with nondrinkers, moderate drinkers (alcohol intake 23 to 45 g/d) and heavy drinkers (alcohol intake ≥46 g/d) showed higher age- and field-adjusted mean values of systolic and diastolic BPs during the morning and while awake, but there were no differences in BPs over 24-hour periods and while asleep among the alcohol intake categories. Alcohol intake was positively associated with mean values of sleep-morning differences and daytime variability in BPs, HRs while awake and asleep, and low frequency:high frequency ratio while asleep. The results were virtually unchanged after adjustment for body mass index, smoking, and diabetes mellitus. Compared with the nondrinkers, age- and field-adjusted odds ratios of the morning BP surge (excess elevation of BP in the morning: morning systolic BP minus sleep systolic BP ≥37 mm Hg) for light (alcohol intake 0 to 22 g/d), moderate, and heavy drinkers were 0.96 (95% CI: 0.34 to 2.78), 1.68 (95% CI: 0.64 to 4.38), and 2.73 (95% CI: 1.12 to 6.67), respectively. Habitual alcohol intake was associated with increased BP in the morning, HR while awake and asleep, and sympathetic activity while asleep, which may explain some of the mechanisms of the relationship between heavy alcohol intake and risk of cardiovascular diseases.

1 September 2016 in Hypertension
Verified
Journal Article
Closed access
TOTetsuya Ohira
Tetsuya Ohira
MHMitsuaki Hosoya
Mitsuaki Hosoya
SYSeiji Yasumura
Seiji Yasumura
HSHiroaki Satoh
Hiroaki Satoh
HSHitoshi Suzuki
Hitoshi Suzuki
YSYoshisada Shibata
Yoshisada Shibata
On March 11, 2011, the Great East Japan Earthquake occurred in Japan, with a nuclear accident subsequently occurring at the Fukushima Daiichi Nuclear Power Plant. The disaster forced many evacuees to change particular aspects of their lifestyles. This study assessed the hypothesis that evacuation may have increased the risk of hypertension among residents in Fukushima. A longitudinal study examined data collected from 31 252 Japanese participants aged 40 to 74 years sourced from general health checkups conducted in 13 communities between 2008 and 2010. Follow-up examinations were conducted from 2011 through 2013. A total of 21 989 participants (follow-up proportion, 70.4%) received follow-up examinations. Mean blood pressure significantly increased in both evacuees and nonevacuees after the disaster, with greater changes in blood pressure among the former. The changes in systolic and diastolic blood pressure among the evacuees and nonevacuees were +5.8/3.4 versus +4.6/2.1 mm Hg ( P <0.01/ P <0.0001) for men and +4.4/2.8 versus +4.1/1.7 mm Hg ( P =0.33/ P <0.0001) for women, respectively. Evacuation was associated with an increased risk of hypertension among men, and the age-adjusted hazard ratios of evacuation for incidence of hypertension were 1.24 (95% confidence interval, 1.11–1.39; P <0.001) for men and 1.05 (95% confidence interval, 0.94–1.17; P =0.37) for women, respectively. For men, after adjustment for confounding variables, the hazard ratio slightly decreased to 1.20, but the association was essentially unchanged. Blood pressure increased among residents, especially evacuees, in the evacuation zone of Fukushima prefecture after the Great East Japan Earthquake. Evacuation may be associated with an increased risk of hypertension among men in the 2 years after the disaster.

1 May 2016 in American Journal of Preventive Medicine
Verified
Journal Article
Open access
TOTetsuya Ohira
Tetsuya Ohira
MHMitsuaki Hosoya
Mitsuaki Hosoya
SYSeiji Yasumura
Seiji Yasumura
HSHiroaki Satoh
Hiroaki Satoh
HSHitoshi Suzuki
Hitoshi Suzuki
MAMasafumi Abe
Masafumi Abe
The Great East Japan Earthquake occurred on March 11, 2011, with a nuclear accident subsequently occurring at the Fukushima Daiichi Nuclear Power Plant. The government ordered a mandatory evacuation from the high radioactive concentration area in Fukushima, which might have forced many evacuees to change particular aspects of their lifestyles. This study assessed the hypothesis that mean body weight and the proportion of overweight/obese individuals would increase among evacuees after versus before the disaster. A longitudinal study examined data collected from 41,633 Japanese participants (mean age, 67 years) sourced from general health checkups conducted in 13 communities between 2008 and 2010. Follow-up examinations were conducted from June 2011 through March 2013. A total of 27,486 participants (12,432 men and 15,054 women; follow-up proportion, 66%) received follow-up examinations after the disaster, with an average follow-up of 1.6 years. Mean body weight significantly increased in both evacuees (n=9,671) and non-evacuees (n=17,815) after the disaster, with greater changes in body weight among evacuees than non-evacuees (+1.2 kg vs +0.3 kg, p<0.001). The proportion of overweight/obese people also increased among evacuees after the disaster, and evacuation was associated with an increased risk of being overweight, despite adjustments for confounding variables. The proportions of overweight evacuees before and after the disaster were 31.8% and 39.4%, respectively, whereas proportions among non-evacuees were 28.3% and 30.3%, respectively. Body weight and the proportion of overweight/obese people increased among residents, especially evacuees, in the evacuation zone of Fukushima prefecture after the Great East Japan Earthquake.

5 December 2022 in Journal of Epidemiology
Verified
Journal Article
Open access
PDF file
SYSeiji Yasumura
Seiji Yasumura
TOTetsuya Ohira
Tetsuya Ohira
TITetsuo Ishikawa
Tetsuo Ishikawa
HSHiroki Shimura
Hiroki Shimura
ASAkira Sakai
Akira Sakai
KKKenji Kamiya
Kenji Kamiya
The Fukushima Health Management Survey (FHMS) was established in response to the Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011. The primary objectives of the study are to monitor residents’ long-term health and promote their future well-being, and to determine the health effects of long-term low-dose radiation exposure. This special issue summarizes the results and current status of the FHMS and discusses the challenges and future directions of the FHMS. The FHMS, a cohort study of all people who were residents in Fukushima Prefecture at the time of the accident, consists of a Basic Survey, Thyroid Ultrasound Examination, Comprehensive Health Check, Mental Health and Lifestyle Survey, and Pregnancy and Birth Survey. The radiation exposure was estimated based on the behavioral records examined using the Basic Survey. Although the response rate was low in the Basic Survey, the representativeness of the radiation exposure data was confirmed using additional surveys. There appears to be no relationship between the radiation exposure and risk of thyroid cancer, although more thyroid cancer cases were detected than initially expected. The ongoing Comprehensive Health Check and Mental Health and Lifestyle Survey have provided evidence of worsening physical and mental health status. The Pregnancy and Birth Survey showed rates of preterm delivery, low birth weight, and congenital abnormalities similar to the national average. Considering the above evidence, the Fukushima Prefectural Government decided to end the Pregnancy and Birth Survey at the end of March 2021, as recommended by the Prefectural Oversight Committee. The framework of the FHMS has not changed, but the FHMS needs to adapt according to the survey results and the changing needs of the eligible residents and municipalities.

2 July 2015 in International Journal of Cardiology
Verified
Journal Article
Closed access
PDF file
HSHitoshi Suzuki
Hitoshi Suzuki
TOTetsuya Ohira
Tetsuya Ohira
YTYasuchika Takeishi
Yasuchika Takeishi
MHMitsuaki Hosoya
Mitsuaki Hosoya
SYSeiji Yasumura
Seiji Yasumura
MAMasafumi Abe
Masafumi Abe

1 August 2016 in Medicine
Verified
Journal Article
Open access
TOTetsuya Ohira
Tetsuya Ohira
HTHideto Takahashi
Hideto Takahashi
SYSeiji Yasumura
Seiji Yasumura
AOAkira Ohtsuru
Akira Ohtsuru
SMSanae Midorikawa
Sanae Midorikawa
FGFukushima Health Management Survey Group
Fukushima Health Management Survey Group
The 2011 Great East Japan Earthquake led to a subsequent nuclear accident at the Fukushima Daiichi Nuclear Power Plant. In its wake, we sought to examine the association between external radiation dose and thyroid cancer in Fukushima Prefecture. We applied a cross-sectional study design with 300,476 participants aged 18 years and younger who underwent thyroid examinations between October 2011 and June 2015. Areas within Fukushima Prefecture were divided into three groups based on individual external doses (≥1% of 5 mSv, <99% of 1 mSv/y, and the other). The odds ratios (ORs) and 95% confidence intervals of thyroid cancer for all areas, with the lowest dose area as reference, were calculated using logistic regression models adjusted for age and sex. Furthermore, the ORs of thyroid cancer for individual external doses of 1 mSv or more and 2 mSv or more, with the external dose less than 1 mSv as reference, were calculated. Prevalence of thyroid cancer for the location groups were 48/100,000 for the highest dose area, 36/100,000 for the middle dose area, and 41/100,000 for the lowest dose area. Compared with the lowest dose area, age-, and sex-adjusted ORs (95% confidence intervals) for the highest-dose and middle-dose areas were 1.49 (0.36-6.23) and 1.00 (0.67-1.50), respectively. The duration between accident and thyroid examination was not associated with thyroid cancer prevalence. There were no significant associations between individual external doses and prevalence of thyroid cancer. External radiation dose was not associated with thyroid cancer prevalence among Fukushima children within the first 4 years after the nuclear accident.