Publications (49)216.23 Total impact
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Article: Radiation risk of individual multifactorial diseases in offspring of the atomic-bomb survivors: a clinical health study.
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ABSTRACT: There is no convincing evidence regarding radiation-induced heritable risks of adult-onset multifactorial diseases in humans, although it is important from the standpoint of protection and management of populations exposed to radiation. The objective of the present study was to examine whether parental exposure to atomic-bomb (A-bomb) radiation led to an increased risk of common polygenic, multifactorial diseases-hypertension, hypercholesterolaemia, diabetes mellitus, angina pectoris, myocardial infarction or stroke-in the first-generation (F1) offspring of A-bomb survivors. A total of 11 951 F1 offspring of survivors in Hiroshima or Nagasaki, conceived after the bombing, underwent health examinations to assess disease prevalence. We found no evidence that paternal or maternal A-bomb radiation dose, or the sum of their doses, was associated with an increased risk of any multifactorial diseases in either male or female offspring. None of the 18 radiation dose-response slopes, adjusted for other risk factors for the diseases, was statistically significantly elevated. However, the study population is still in mid-life (mean age 48.6 years), and will express much of its multifactorial disease incidence in the future, so ongoing longitudinal follow-up will provide increasingly informative risk estimates regarding hereditary genetic effects for incidence of adult-onset multifactorial disease.Journal of Radiological Protection 03/2013; 33(2):281-293. · 1.39 Impact Factor -
Article: The Association Between Chronic Kidney Disease and Cardiovascular Disease Risk Factors in Atomic Bomb Survivors.
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ABSTRACT: Atomic bomb (A-bomb) radiation is associated with cardiovascular disease (CVD) and metabolic CVD risk factors. Chronic kidney disease (CKD) is also known to be a risk factor for CVD and little is known whether CKD is associated with A-bomb radiation. To examine whether CKD is associated with CVD risk factors or with A-bomb radiation in A-bomb survivors, we classified renal dysfunction in 1,040 A-bomb survivors who were examined in 2004-2007 as normal [n = 121; estimated glomerular filtration rate (eGFR) ≥90 ml/min/1.73 m(2)]; mild (n = 686; eGFR 60-89 ml/min/1.73 m(2)); moderate (n = 217; eGFR 30-59 ml/min/1.73 m(2)); or severe (n = 16; eGFR <30 ml/min/1.73 m(2)). Also, we diagnosed subjects in the moderate and severe renal dysfunction groups as having CKD (n = 233; eGFR <59 ml/min/1.73 m(2)). After adjusting for age, gender, and smoking and drinking habits, we looked for an association between renal dysfunction and hypertension, diabetes mellitus (DM), hyperlipidemia, and metabolic syndrome (MetS), and between renal dysfunction and A-bomb radiation. Hypertension [odds ratio (OR), 1.57; 95% confidence interval (CI), 1.12-2.20, P = 0.009]; DM (OR, 1.79; 95% CI, 1.23-2.61, P = 0.002); hyperlipidemia (OR, 1.55; 95% CI, 1.12-2.14, P = 0.008); and MetS (OR, 1.86; 95% CI, 1.32-2.63, P < 0.001) were associated with CKD (moderate/severe renal dysfunction), and hyperlipidemia and MetS were also associated with mild renal dysfunction. CKD (OR/Gy, 1.29; 95% CI, 1.01-1.63, P = 0.038) and severe renal dysfunction (OR/Gy, 3.19; 95% CI, 1.63-6.25, P < 0.001) were significantly associated with radiation dose. CKD associated with radiation may have played a role in the development of CVD among A-bomb survivors.Radiation Research 11/2012; · 2.68 Impact Factor -
Article: Relationship between anthropometric factors, radiation exposure, and colon cancer incidence in the Life Span Study cohort of atomic bomb survivors.
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ABSTRACT: PURPOSE: We examined colon cancer risk in atomic bomb survivors to investigate whether excess body weight after the bombings alters sensitivity to radiation effects. METHODS: Of the 56,064 Japanese atomic bomb survivors with follow-up through 2002 with self-reported anthropometric data obtained from periodic mail surveys, 1,142 were diagnosed with colon cancer. We evaluated the influence of body mass index (BMI) and height on radiation-associated colon cancer risk using Poisson regression. RESULTS: We observed a similar linear dose-response relationship for the 56,064 subjects included in our analysis and the entire cohort of Japanese atomic bomb survivors [excess relative risk (ERR) per Gray (Gy) = 0.53, 95 % confidence interval (CI) 0.25-0.86]. Elevation in earliest reported BMI, BMI reported closest to colon cancer diagnosis, and time-varying BMI were associated with an elevated risk of colon cancer [relative risk (RR) per 5 kg/m(2) increase in BMI = 1.14, 95 % CI 1.03-1.26; RR = 1.16, 95 % CI 1.05-1.27; and RR = 1.15, 95 % CI 1.04-1.27, respectively]. Height was not significantly related to colon cancer risk. Inclusion of anthropometric variables in models had little impact on radiation risk estimates, and there was no evidence that sensitivity to the effect of radiation on colon cancer risk depended on BMI. CONCLUSIONS: Radiation exposure and BMI are both risk factors for colon cancer. BMI at various times after exposure to the atomic bombings does not significantly influence the relationship between radiation dose and colon cancer risk, suggesting that BMI and radiation impact colon cancer risk independently of each other.Cancer Causes and Control 10/2012; · 2.88 Impact Factor -
Article: Radiation dose and cataract surgery incidence in atomic bomb survivors, 1986-2005.
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ABSTRACT: Purpose: To examine the incidence of clinically important cataracts in relation to lens radiation doses between 0 and approximately 3 Gy to address risks at relatively low brief doses. Materials and Methods: Informed consent was obtained, and human subjects procedures were approved by the ethical committee at the Radiation Effects Research Foundation. Cataract surgery incidence was documented for 6066 atomic bomb survivors during 1986-2005. Sixteen risk factors for cataract, such as smoking, hypertension, and corticosteroid use, were not confounders of the radiation effect on the basis of Cox regression analysis. Radiation dose-response analyses were performed for cataract surgery incidence by using Poisson regression analysis, adjusting for demographic variables and diabetes mellitus, and results were expressed as the excess relative risk (ERR) and the excess absolute risk (EAR) (ie, measures of how much radiation multiplies [ERR] or adds to [EAR] the risk in the unexposed group). Results: Of 6066 atomic bomb survivors, 1028 underwent a first cataract surgery during 1986-2005. The estimated threshold dose was 0.50 Gy (95% confidence interval [CI]: 0.10 Gy, 0.95 Gy) for the ERR model and 0.45 Gy (95% CI: 0.10 Gy, 1.05 Gy) for the EAR model. A linear-quadratic test for upward curvature did not show a significant quadratic effect for either the ERR or EAR model. The linear ERR model for a 70-year-old individual, exposed at age 20 years, showed a 0.32 (95% CI: 0.17, 0.52) excess risk at 1 Gy. The ERR was highest for those who were young at exposure. Conclusion: These data indicate a radiation effect for vision-impairing cataracts at doses less than 1 Gy. The evidence suggests that dose standards for protection of the eye from brief radiation exposures should be 0.5 Gy or less. © RSNA, 2012 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12111947/-/DC1.Radiology 08/2012; 265(1):167-74. · 5.73 Impact Factor -
Article: A prospective follow-up study of the association of radiation exposure with fatal and non-fatal stroke among atomic bomb survivors in Hiroshima and Nagasaki (1980-2003).
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ABSTRACT: Use of medical radiotherapy has increased markedly in recent decades. Whether the consequence includes an increased risk of cardiovascular disease remains to be determined. The purpose of this study was to examine the association between radiation exposure and the incidence of stroke among Japanese atomic bomb survivors. A prospective follow-up study. Radiation exposure from the atomic bombing was assessed in 9515 subjects (34.8% men) with 24-year follow-up from 1980. Subjects were free of prevalent stroke when follow-up began. Stroke events and the underlying cause of death were reviewed to confirm the first-ever stroke. Subtypes (ischaemic and haemorrhagic events) were categorised based on established criteria according to the definitions of typical/atypical stroke symptoms. Overall mean radiation dose (±SD) in units of gray (Gy) was 0.38±0.58 (range: 0-3.5). During the study period, 235 haemorrhagic and 607 ischaemic events were identified. For men, after adjusting for age and concomitant risk factors, the risk of haemorrhagic stroke rose consistently from 11.6 to 29.1 per 10 000 person-years as doses increased from <0.05 to ≥2 Gy (p=0.009). Incidence also rose within the dose range <1 Gy (p=0.004) with no dose threshold. In women, the risk of haemorrhagic stroke rose with increasing radiation exposure but not until doses reached a threshold of 1.3 Gy (95% CI 0.5 to 2.3). Among women, for doses <1.3 Gy, differences in stroke risk were modest (13.5 per 10 000 person-years), while it increased to 20.3 per 10 000 person-years for doses that ranged from 1.3 to <2.2 Gy and to 48.6 per 10 000 person-years for doses that were higher (p=0.002). In both sexes, dose was unrelated to ischaemic stroke. While the risk of haemorrhagic stroke increases with rising radiation exposure for both sexes, effects in women are less apparent until doses exceed a threshold at 1.3 Gy.BMJ open. 01/2012; 2(1):e000654. -
Article: Radiation dose associated with renal failure mortality: a potential pathway to partially explain increased cardiovascular disease mortality observed after whole-body irradiation.
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ABSTRACT: Whole-body and thoracic ionizing radiation exposure are associated with increased cardiovascular disease (CVD) risk. In atomic bomb survivors, radiation dose is also associated with increased hypertension incidence, suggesting that radiation dose may be associated with chronic renal failure (CRF), thus explaining part of the mechanism for increased CVD. Multivariate Poisson regression was used to evaluate the association of radiation dose with various definitions of chronic kidney disease (CKD) mortality in the Life Span Study (LSS) of atomic bomb survivors. A secondary analysis was performed using a subsample for whom self-reported information on hypertension and diabetes, the two biggest risk factors for CRF, had been collected. We found a significant association between radiation dose and only our broadest definition of CRF among the full cohort. A quadratic dose excess relative risk model [ERR/Gy(2) = 0.091 (95% CI: 0.05, 0.198)] fit minimally better than a linear model. Within the subsample, association was also observed only with the broadest CRF definition [ERR/Gy(2) = 0.15 (95% CI: 0.02, 0.32)]. Adjustment for hypertension and diabetes improved model fit but did not substantially change the ERR/Gy(2) estimate, which was 0.17 (95% CI: 0.04, 0.35). We found a significant quadratic dose relationship between radiation dose and possible chronic renal disease mortality that is similar in shape to that observed between radiation and incidence of hypertension in this population. Our results suggest that renal dysfunction could be part of the mechanism causing increased CVD risk after whole-body irradiation, a hypothesis that deserves further study.Radiation Research 12/2011; 177(2):220-8. · 2.68 Impact Factor -
Article: Risk for progression to overt hypothyroidism in an elderly Japanese population with subclinical hypothyroidism.
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ABSTRACT: Few population-based studies report the changes with time in thyroid function tests in patients with subclinical hypothyroidism. We compared the risk for developing overt hypothyroidism in patients with subclinical hypothyroidism and euthyroid controls from the same population of elderly Japanese. We also sought associations of selected parameters with the development of overt hypothyroidism in the subclinical hypothyroid and euthyroid groups. We measured thyrotropin (TSH) and free thyroxine (T4) levels at baseline examinations performed from 2000 to 2003 in the cohort of Japanese atomic-bomb survivors and identified 71 patients with spontaneous subclinical hypothyroidism (normal free T4 and TSH >4.5 mIU/L without a history of thyroid treatment, mean age 70 year) and 562 euthyroid controls. We re-examined TSH and free T4 levels an average of 4.2 years later (range, 1.9-6.9). The risk for progression to overt hypothyroidism was significantly increased in subclinical hypothyroid patients (7.0%) compared with control subjects (1.6%) after adjusting for age and sex (odds ratio, 4.56; p=0.009). Higher baseline TSH levels were associated with progression from subclinical to overt hypothyroidism (p=0.02) in the multivariate analysis, including age, sex, antithyroid peroxidase antibody, and ultrasonography (US) findings. The analysis using binary TSH data suggested that a TSH level >8 mIU/L was a predictive value for development of overt hypothyroidism (p=0.005). On the other hand, serum TSH levels spontaneously normalized in 38 (53.5%) of the patients with subclinical hypothyroidism. In the multivariate analysis, normalization of TSH levels was associated with lower baseline TSH levels (p=0.004) and normal and homogenous thyroid US findings (p=0.04). Atomic-bomb radiation dose was not associated with subclinical hypothyroidism or its course. Subclinical hypothyroidism was four times more likely to be associated with development of overt hypothyroidism than euthyroid controls in the sample population of Japanese elderly. TSH levels in half of the patients normalized spontaneously when assessed after an average follow-up period of 4.2 years. Baseline TSH level and thyroid US findings are potential predictors of future thyroid function in subclinical hypothyroidism.Thyroid: official journal of the American Thyroid Association 08/2011; 21(11):1177-82. · 2.60 Impact Factor -
Article: Incidence and prognostic value of early repolarization pattern in the 12-lead electrocardiogram.
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ABSTRACT: Early repolarization pattern is a common ECG finding characterized by J-point elevation and QRS notching or slurring in the inferior and/or lateral leads, yet little is known about its incidence and long-term prognosis in Asian populations. We reviewed all the ECG records of the 5976 atomic-bomb survivors who were examined at least once during our biennial health examination in Nagasaki, Japan, between July 1958 and December 2004. We defined early repolarization pattern as ≥0.1-mV elevation of the J point or ST segment, with notching or slurring in at least 2 inferior and/or lateral leads. We assessed unexpected, cardiac, and all-cause death risk by Cox analysis. We identified 1429 early repolarization pattern cases (779 incident cases) during follow-up, yielding a positive rate of 23.9% and an incidence rate of 715 per 100 000 person-years. Early repolarization pattern had an elevated risk of unexpected death (hazard ratio, 1.83; 95% confidence interval, 1.12 to 2.97; P=0.02) and a decreased risk of cardiac (hazard ratio, 0.75; 95% confidence interval, 0.60 to 0.93; P<0.01) and all-cause (hazard ratio, 0.85; 95% confidence interval, 0.78 to 0.93; P<0.01) death. In addition, both slurring and notching were related to higher risk of unexpected death (hazard ratio, 2.09; 95% confidence interval, 1.06 to 4.12; P=0.03), as was early repolarization pattern manifestation in both inferior and lateral leads (hazard ratio, 2.50; 95% confidence interval, 1.29 to 4.83; P<0.01). Early repolarization pattern is associated with an elevated risk of unexpected death and a decreased risk of cardiac and all-cause death. Specific early repolarization pattern morphologies and location are associated with an adverse prognosis.Circulation 06/2011; 123(25):2931-7. · 14.74 Impact Factor -
Article: Lymphocyte subset characterization associated with persistent hepatitis C virus infection and subsequent progression of liver fibrosis.
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ABSTRACT: This study aims to deepen the understanding of lymphocyte phenotypes related to the course of hepatitis C virus (HCV) infection and progression of liver fibrosis in a cohort of atomic bomb survivors. The study subjects comprise 3 groups: 162 HCV persistently infected, 145 spontaneously cleared, and 3,511 uninfected individuals. We observed increased percentages of peripheral blood T(H)1 and total CD8 T cells and decreased percentages of natural killer (NK) cells in the HCV persistence group compared with the other 2 groups after adjustment for age, gender, and radiation exposure dose. Subsequently, we determined that increased T(H)1 cell percentages in the HCV persistence group were significantly associated with an accelerated time-course reduction in platelet counts-accelerated progression of liver fibrosis-whereas T(C)1 and NK cell percentages were inversely associated with progression. This study suggests that T(H)1 immunity is enhanced by persistent HCV infection and that percentages of peripheral T(H)1, T(C)1, and NK cells may help predict progression of liver fibrosis.Human immunology 06/2011; 72(10):821-6. · 2.55 Impact Factor -
Article: Impact of radiation and hepatitis virus infection on risk of hepatocellular carcinoma.
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ABSTRACT: In cohort studies of atomic bomb survivors and Mayak nuclear facility workers, radiation-associated increases in liver cancer risk were observed, but hepatitis B virus (HBV) and hepatitis C virus (HCV) infections were not taken strictly into account. We identified 359 hepatocellular carcinoma (HCC) cases between 1970 and 2002 in the cohort of atomic bomb survivors and estimated cumulative incidence of HCC by radiation dose. To investigate contributions of radiation exposure and hepatitis virus infection to HCC risk, we conducted a nested case-control study using sera stored before HCC diagnosis in the longitudinal cohort of atomic bomb survivors. The study included 224 HCC cases and 644 controls that were matched to the cases on gender, age, city, and time and method of serum storage, and countermatched on radiation dose. The cumulative incidence of HCC by follow-up time and age increased significantly with radiation dose. The relative risk (RR) of HCC for radiation at 1 Gy was 1.67 (95% confidence interval: 1.22-2.35) with adjustment for alcohol consumption, body mass index (BMI), and smoking habit, whereas the RRs for HBV or HCV infection alone were 63 (20-241) and 83 (36-231) with such adjustment, respectively. Those estimates changed little when radiation and hepatitis virus infection were fit simultaneously. The RR of non-B, non-C HCC at 1 Gy was 1.90 (1.02-3.92) without adjustment for alcohol consumption, BMI, or smoking habit and 2.74 (1.26-7.04) with such adjustment. CONCLUSION: These results indicate that radiation exposure and HBV and HCV infection are associated independently with increased HCC risk. In particular, radiation exposure was a significant risk factor for non-B, non-C HCC with no apparent confounding by alcohol consumption, BMI, or smoking habit.Hepatology 04/2011; 53(4):1237-45. · 11.66 Impact Factor -
Article: Lifetime risk of stroke and impact of hypertension: estimates from the adult health study in Hiroshima and Nagasaki.
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ABSTRACT: Very few reports have been published on lifetime risk (LTR) of stroke by blood pressure (BP) group. This study included participants in the Radiation Effects Research Foundation Adult Health Study who have been followed up by biennial health examinations since 1958. We calculated the LTR of stroke for various BP-based groups among 7847 subjects who had not been diagnosed with stroke before the index age of 55 years using cumulative incidence analysis adjusting for competing risks. By 2003, 868 subjects had suffered stroke (512 (58.9%) were women and 542 (62.4%) experienced ischemic stroke). BP was a significant factor in determining risk of stroke for men and women, with distributions of cumulative risk for stroke significantly different across BP groups. The LTR of all-stroke for normotension (systolic BP/diastolic BP < 120/80 mm Hg), prehypertension (120-139/80-89 mm Hg), stage 1 hypertension (140-159/90-99 mm Hg) and stage 2 hypertension (> 160/100 mm Hg) were 13.8-16.9-25.8-25.8% in men and 16.0-19.9-24.0-30.5% in women, respectively (P < 0.001 among BP groups in both sexes). The estimates did not differ significantly (P = 0.16) between normotensive and prehypertensive subjects. One in five Japanese atomic bomb survivor subjects experienced stroke over their lifetime from the age of 55 years. Long-term stroke risks were elevated in those with hypertension (> 140/90 mm Hg) at any of the index ages of 45, 55, 65 and 75 years.Hypertension Research 02/2011; 34(5):649-54. · 2.58 Impact Factor -
Article: Biomarkers of radiosensitivity in a-bomb survivors pregnant at the time of bombings in hiroshima and nagasaki.
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ABSTRACT: Purpose. There is evidence in the literature of increased maternal radiosensitivity during pregnancy. Materials and Methods. We tested this hypothesis using information from the atomic-bomb survivor cohort, that is, the Adult Health Study database at the Radiation Effects Research Foundation, which contains data from a cohort of women who were pregnant at the time of the bombings of Hiroshima and Nagasaki. Previous evaluation has demonstrated long-term radiation dose-response effects. Results/Conclusions. Data on approximately 250 women were available to assess dose-response rates for serum cholesterol, white blood cell count, erythrocyte sedimentation rate, and serum hemoglobin, and on approximately 85 women for stable chromosome aberrations, glycophorin A locus mutations, and naïve CD4 T-cell counts. Although there is no statistically significant evidence of increased radiosensitivity in pregnant women, the increased slope of the linear trend line in the third trimester with respect to stable chromosome aberrations is suggestive of an increased radiosensitivity.ISRN obstetrics and gynecology 01/2011; 2011:264978. -
Article: Association of human T lymphotropic virus type I with Sjogren syndrome.
Annals of the rheumatic diseases 11/2010; 69(11):2056-7. · 8.11 Impact Factor -
Article: Metabolic cardiovascular disease risk factors and their clustering in subclinical hypothyroidism.
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ABSTRACT: A possible association between subclinical hypothyroidism and cardiovascular disease (CVD) has been reported. Monitoring of atomic-bomb survivors for late effects of radiation exposure at the Radiation Effects Research Foundation has provided the opportunity to examine associations between subclinical hypothyroidism and metabolic CVD risk factors. The objective of the study was to evaluate associations between subclinical hypothyroidism and metabolic CVD risk factors, and a cluster of these factors. This was a cross-sectional study of 3549 subjects (mean age 70 years; 1221 men and 2328 women) between 2000 and 2003 comprising 306 subjects with subclinical hypothyroidism and 3243 control euthyroid subjects in Japan. We investigated associations between subclinical hypothyroidism and metabolic CVD risk factors such as hypertension, diabetes mellitus, dyslipidaemia and hyperuricaemia, and a cluster of these factors. Subclinical hypothyroidism was not significantly associated with either hypertension, diabetes mellitus or hyperuricaemia defined by taking into account the use of medications in both men and women, but in men it was associated with dyslipidaemia (P = 0.02). We observed a significantly increased odds ratio (OR) for the presence of three or more metabolic CVD risk factors in men with subclinical hypothyroidism after adjusting for age, body mass index (BMI), and smoking status [OR: 1.83, 95% confidence interval (CI): 1.13-2.94, P = 0.01]. The significant associations remained after an additional adjustment for atomic-bomb radiation dose. There appears to be a significant increase in a cluster of metabolic CVD risk factors among people with subclinical hypothyroidism.Clinical Endocrinology 05/2010; 72(5):689-95. · 3.17 Impact Factor -
Article: Fatty liver incidence and predictive variables.
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ABSTRACT: Although fatty liver predicts ischemic heart disease, the incidence and predictors of fatty liver need examination. The objective of this study was to determine fatty liver incidence and predictive variables. Using abdominal ultrasonography, we followed biennially through 2007 (mean follow-up, 11.6+/-4.6 years) 1635 Nagasaki atomic bomb survivors (606 men) without fatty liver at baseline (November 1990 through October 1992). We examined potential predictive variables with the Cox proportional hazard model and longitudinal trends with the Wilcoxon rank-sum test. In all, 323 (124 men) new fatty liver cases were diagnosed. The incidence was 19.9/1000 person-years (22.3 for men, 18.6 for women) and peaked in the sixth decade of life. After controlling for age, sex, and smoking and drinking habits, obesity (relative risk (RR), 2.93; 95% confidence interval (CI), 2.33-3.69, P<0.001), low high-density lipoprotein-cholesterol (RR, 1.87; 95% CI, 1.42-2.47; P<0.001), hypertriglyceridemia (RR, 2.49; 95% CI, 1.96-3.15; P<0.001), glucose intolerance (RR, 1.51; 95% CI, 1.09-2.10; P=0.013) and hypertension (RR, 1.63; 95% CI, 1.30-2.04; P<0.001) were predictive of fatty liver. In multivariate analysis including all variables, obesity (RR, 2.55; 95% CI, 1.93-3.38; P<0.001), hypertriglyceridemia (RR, 1.92; 95% CI, 1.41-2.62; P<0.001) and hypertension (RR, 1.31; 95% CI, 1.01-1.71; P=0.046) remained predictive. In fatty liver cases, body mass index and serum triglycerides, but not systolic or diastolic blood pressure, increased significantly and steadily up to the time of the diagnosis. Obesity, hypertriglyceridemia and, to a lesser extent, hypertension might serve as predictive variables for fatty liver.Hypertension Research 04/2010; 33(6):638-43. · 2.58 Impact Factor -
Article: LTA 252GG and GA genotypes are associated with diffuse-type noncardia gastric cancer risk in the Japanese population.
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ABSTRACT: There are limited numbers of reports on the association of lymphotoxin-alpha (LTA) genotypes with gastric cancer. A nested case-control study was carried out in the longitudinal cohort of atomic bomb survivors using stored sera before diagnosis (mean, 2.3 years) and blood cells. Enrolled were 287 cases with noncardia gastric cancer of diffuse and intestinal types and three controls per case selected from cohort members matched on age, gender, city, and time and type of serum storage and counter-matched on radiation dose. LTA 252GG and GA genotypes were associated with the prevalence of Helicobacter pylori IgG seropositivity and higher antibody titer against H. pylori cytotoxin-associated gene A (CagA) protein in controls and they were an independent risk factor for noncardia gastric cancer of diffuse type (RR = 2.8 (95% CI: 1.3-6.3), p = .01, and RR = 2.7 (95% CI: 1.5-4.8), p < .001), but not for intestinal type, after adjusting for H. pylori IgG seropositivity, CagA antibody titers, chronic atrophic gastritis, smoking, and radiation dose. Cessation of smoking (RR = 0.4 (95% CI: 0.2-0.7), p < .001) and never smoking (RR = 0.4 (95% CI: 0.3-0.6), p < .001) were both protective for future noncardia gastric cancer. Radiation dose was associated with noncardia gastric cancer in subjects with both the LTA 252G-allele and never smoking/quit smoking histories (RR = 3.8 (95% CI: 1.7-5.9), p = .009). The LTA 252 genotype is associated with noncardia gastric cancer of diffuse type in Japan and interacted with radiation dose.Helicobacter 12/2009; 14(6):571-9. · 3.15 Impact Factor -
Article: Men with Brugada-like electrocardiogram have higher risk of prostate cancer.
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ABSTRACT: Elevated plasma testosterone levels are thought to play a role in the male preponderance of cases of Brugada syndrome (BS) and the development of prostate cancer. The 34 Brugada-like electrocardiogram (ECG) cases were identified among 2,681 male survivors of the atomic bomb who had undergone at least 1 biennial health examination between July 1958 and December 1999 in Nagasaki, Japan. They were followed for incident prostate cancer from July 1958 through December 2004, and the risk of prostate cancer for Brugada-like ECG, age, smoking habit, and radiation exposure was analyzed using Cox proportional hazards analysis. Among the men with or without Brugada-like ECG there were 4 (11.8%) and 54 (2.0%) cases of prostate cancer, respectively. With age adjustment there was a higher risk of prostate cancer for Brugada-like ECG (relative risk (RR): 5.42, 95% confidence interval (CI) 1.96-15.00, P=0.001). With further adjustment for smoking habit and radiation dose, Brugada-like ECG remained a significant risk factor for prostate cancer (RR: 6.47, 95%CI 1.97-21.21, P=0.002). Brugada-like ECG confers a higher risk of prostate cancer independent of age, smoking habit, and radiation exposure. Men with a Brugada-like ECG should be regularly examined for prostate cancer and vice versa, especially elderly subjects.Circulation Journal 12/2008; 73(1):63-8. · 3.77 Impact Factor -
Article: Cardiovascular disease risk among atomic bomb survivors exposed in utero, 1978-2003.
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ABSTRACT: Given the well-documented association of in utero radiation exposure with childhood cancer and developmental impairments, the possibility of effects on adult onset diseases is an important issue. The objectives of the present study were to examine the effects of atomic bomb radiation dose on the incidence of hypertension, hypercholesterolemia and cardiovascular disease (myocardial infarction and stroke) among survivors exposed in utero and to compare their risk estimates with those of survivors exposed in childhood (<10 years old) at the time of the bombing. A total of 506 participants exposed in utero and 1,053 participants exposed in childhood were followed during 1978-2003 with biennial clinical examinations. There were no significant radiation dose effects for any diseases in the entire in utero-exposed cohort or in trimester-of-exposure subgroups, though there was a suggestion of an increased risk when fatal and nonfatal cardiovascular disease cases were combined. Positive radiation dose effects were found for hypertension and cardiovascular disease in the childhood-exposure cohort, but there were no statistically significant differences in the relative risks when we compared the two cohorts. Since the in utero cohort was under age 60 at the latest examination, continued follow-up is needed to document cardiovascular disease risk more fully.Radiation Research 09/2008; 170(3):269-74. · 2.68 Impact Factor -
Article: White blood cell count, especially neutrophil count, as a predictor of hypertension in a Japanese population.
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ABSTRACT: Although several studies have shown that high WBC count is a risk factor for hypertension, the relationship between WBC count and the incidence of hypertension in Japanese is poorly understood, as are the effects of WBC components on that relationship. Our objective was to verify in a Japanese population whether WBC or differential WBC count predicts hypertension incidence. A total of 9,383 initially hypertension-free subjects (3,356 men and 6,027 women), whose WBC counts were within the normal range (3,000 to < 10,000 cells/mm3), were followed from 1965 to 2004. During this 40-year follow-up, 4,606 subjects developed hypertension. After adjusting for conventional risk factors, including smoking status, we found that elevated WBC count was associated with hypertension incidence in a Cox regression model with both fixed and time-varying covariates for women. For men, elevated WBC count was a significant risk factor for hypertension only in the time-varying Cox-regression covariate. We also observed a significant association between increased neutrophil count and hypertension incidence among women. In a fully adjusted model, the relative risks of hypertension incidence, from the lowest to the highest quartiles of neutrophil count, were 1.00, 1.18, 1.28, and 1.22 in women (p for trend < 0.001). In conclusion, elevated WBC count predicted an increased incidence of hypertension in Japanese, especially among females. Moreover, neutrophils were the major WBC component contributing to the increased risk.Hypertension Research 07/2008; 31(7):1391-7. · 2.58 Impact Factor -
Article: Thyroid diseases in atomic bomb survivors exposed in utero.
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ABSTRACT: The objective of the study was to evaluate the association of thyroid disease with radiation dose in atomic bomb survivors exposed in utero. This was a cross-sectional study. The study was conducted in atomic bomb survivors in Hiroshima and Nagasaki, Japan. Participants included 328 atomic bomb survivors exposed in utero (mean age 55.2 yr, 162 males) who participated in the thyroid study at the Radiation Effects Research Foundation. Examinations were conducted between March 2000 and February 2003. The relationships of various thyroid conditions to atomic bomb radiation dose were measured. Among the 319 participants excluding nine participants whose exposure radiation dose was not estimated, the mean maternal uterine radiation dose was 0.256 Gy. We observed no significant dose-response relationship for the prevalence of solid thyroid nodules (odds ratio at 1 Gy, 2.78; 95% confidence interval 0.50-11.80, P = 0.22), but the risk estimate was similar to the estimate for childhood exposures. The prevalence of cysts and autoimmune thyroid diseases was not associated with radiation dose (P > 0.30). We could not evaluate the dose response for malignant tumors or benign nodules due to the small number of cases. We did not observe a statistically significant linear dose response to radiation for thyroid nodules or autoimmune thyroid diseases 55-58 yr after participants' in utero exposure. However, the risk estimate for solid thyroid nodules was similar for those exposed in utero and those exposed in childhood. Because the study had limited statistical power to detect moderately sized effects, further studies are needed for a definitive conclusion.Journal of Clinical Endocrinology & Metabolism 06/2008; 93(5):1641-8. · 6.50 Impact Factor
Top co-authors
Top Journals
Institutions
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2011
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University of Rochester
- Department of Community and Preventive Medicine
Rochester, NY, USA
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2005–2010
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Nagasaki University
Nagasaki-shi, Nagasaki-ken, Japan
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2002–2009
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Radiation Effects Research Foundation
Hiroshima-shi, Hiroshima-ken, Japan
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