Alterations of body mass index and body composition in atomic bomb survivors.

OBJECTIVE: Obesity, underweight, sarcopenia and excess accumulation of abdominal fat are associated with a risk of death and adverse health outcomes. Our aim was to determine whether body mass index (BMI) and body composition, assessed with dual-energy X-ray absorptiometry (DXA), are associated with radiation exposure among atomic bomb (A-bomb) survivors. DESIGN: This was a cross-sectional study conducted in the Adult Health Study of the Radiation Effects Research Foundation. SUBJECTS: We examined 2686 subjects (834 men and 1852 women), aged 48-89 years (0-40 years at A-bomb exposure), for BMI analysis. Among them, 550 men and 1179 women underwent DXA in 1994-1996 and were eligible for a body composition study. RESULTS: After being adjusted for age and other potential confounding factors, A-bomb radiation dose was associated significantly and negatively with BMI in both sexes (P=0.01 in men, P=0.03 in women) and appendicular lean mass (P<0.001 in men, P=0.05 in women). It was positively associated with trunk-to-limb fat ratio in women who were less than 15 years old at the time of exposure (P=0.03). CONCLUSIONS: This is the first study to report a significant dose response for BMI and body composition 50 years after A-bomb radiation exposure. We will need to conduct further studies to evaluate whether these alterations affect health status.

Historical height loss, vertebral deformity, and health-related quality of life in Hiroshima cohort study.

UNLABELLED: Height loss and vertebral deformity had independent effects on health-related quality of life evaluated by the European quality-of-life five-domain questionnaire (EQ-5D) in a cohort of 2,021 elderly Japanese men and women. Height loss aggravated EQ-5D more strongly than vertebral deformity in all domains, with different patterns. INTRODUCTION: Vertebral deformity reduces the activities of daily living and quality of life, and elevates mortality. Height loss is taken to be a sign of vertebral deformity, although other factors could also cause height loss. In this study, we examined the difference in EQ-5D between elderly with height loss and with vertebral deformity. METHODS: The subjects were 2,021 men and women aged 57-101 years from the Hiroshima Cohort who underwent health examinations in 2002-03 and responded to the EQ-5D. Vertebral deformity was assessed semi-quantitative methods using lateral chest and spine radiographs. Height was measured during the routine biennial examinations, which have been conducted since 1958. We used linear regression analyses, ordered polytomous logistic regression analyses, and Bonferroni tests. RESULTS: Eighty three men and 314 women had prevalent vertebral deformity. The mean height loss was 2.2 cm for men and 3.9 cm for women. Height loss > or =4 cm (P < 0.01) and vertebral deformity (P = 0.04) were independent risk factors for low EQ-5D scores, after adjustment for sex and age. CONCLUSIONS: The present study showed that height loss and vertebral deformity affected EQ-5D significantly and independently in the elderly.

Heel bone ultrasound predicts non-spine fracture in Japanese men and women.

A number of prospective studies in the USA and Europe have demonstrated that quantitative ultrasound (QUS) measurements predict fracture risk. To our knowledge, there has been no such study in a Japanese population, and very few studies have measured the prognostic value of QUS measurements among men, even in the USA and Europe. We performed a three-center prospective study to investigate the relationship between baseline heel QUS measurements and non-spine fracture risk. There were 4,028 subjects (1,004 men and 3,024 women), 67.5+/-8.9 years [mean +/- standard deviation (SD)] of age), who underwent heel QUS (Achilles device) at three centers between 1993 and 2000. In 2002, the subjects were mailed a standardized questionnaire that asked about their history of fracture. The mean follow-up period was approximately 5 years. The Achilles measured speed of sound (SOS) and broadband ultrasound attenuation (BUA). We used Cox regression analysis to determine the hazard ratio (HR), using weighted coefficients. SOS, BUA, and stiffness index (SI) predicted self-reported hip, wrist, and total non-spine fractures. After we had adjusted for age, gender, and weight, the HRs of total non-spine fracture were 1.54 [95% confidence interval (CI) 1.39-1.69], 1.53 (1.37-1.70), and 1.80 (1.62-1.98) for 1 SD decrease in SOS, BUA, and SI, respectively. In men, SOS and SI also predicted total non-spine fractures with HRs similar to those in women. The HR of prediction for hip fracture by SOS and SI was better in the short term than in the long term, and the prediction for hip, wrist, and non-spine fracture remained significant between 5 to 10 years of follow-up. Measurements obtained from heel QUS predicted non-spine fracture in Japanese men and women, and the HRs of Japanese of both genders was similar to the risk ratio (RR) of Caucasian men and women. QUS parameters can predict hip, wrist, and non-spine fracture up to 10 years.

Mortality of rheumatoid arthritis in Japan: a longitudinal cohort study.

OBJECTIVE: To determine the mortality risk of Japanese patients with rheumatoid arthritis, taking into account lifestyle and physical factors, including comorbidity. METHODS: 91 individuals with rheumatoid arthritis were identified during screening a cohort of 16 119 Japanese atomic bomb survivors in the period 1958 to 1966. These individuals and the remainder of the cohort were followed for mortality until 1999. Mortality risk of the rheumatoid patients was estimated by the Cox proportional hazards model. In addition to age and sex, lifestyle and physical factors such as smoking status, alcohol consumption, blood pressure, and comorbidity were included as adjustment factors for the analysis of total mortality and for analysis of mortality from each cause of death. RESULTS: 83 of the rheumatoid patients (91.2%) and 8527 of the non-rheumatoid controls (52.9%) died during mean follow up periods of 17.8 and 28.0 years, respectively. The age and sex adjusted hazard ratio for mortality in the rheumatoid patients was 1.60 (95% confidence interval, 1.29 to 1.99), p < 0.001. Multiple adjustments, including for lifestyle and physical factors, resulted in a similar mortality hazard ratio of 1.57 (1.25 to 1.94), p < 0.001. Although mortality risk tended to be higher in male than in female rheumatoid patients, the difference was not significant. Pneumonia, tuberculosis, and liver disease were significantly increased as causes of death in rheumatoid patients. CONCLUSIONS: Rheumatoid arthritis is an independent risk factor for mortality. Infectious events are associated with increased mortality in rheumatoid arthritis.

Rates of change in spinal bone density among Japanese women.

To determine the rates of change in bone mineral density (BMD) at the spine in healthy Japanese women, longitudinal measurements of spinal BMD using dual X-ray absorptiometry were collected from 984 women over 17 years of age (mean age 51.6) at eight medical research centers. They were followed up for 20.9 months on average without any treatment influencing bone and calcium metabolism. Measurements of BMD obtained by two different scanners were converted into standardized BMD (sBMD) values. The multiple linear regression model predicts that spinal sBMD increases up to about 23 years of age: the estimated average rates of increases were 0.13%/year for women aged 20 years. After the age of 23, the sBMD began decreasing: the rates of loss increased by 0.045%/year for each year increase in age among premenopausal women. In perimenopausal women, the rate of loss was 2. 1%/year. In postnatural menopausal women, the rates of loss decreased exponentially with increasing years since menopause. The rates of loss increased by 0.04%/year for 1 kg decrease in body weight or by 0.1%/year for 1 kg/m2 decrease in body mass index. No significant differences in changes in sBMD were found between scanners and between centers after multiple adjustment. We conclude that the rates of change in spinal sBMD are associated with age in premenopausal women, and with years since menopause and weight or BMI in postmenopausal women. Caution is needed, however, when using data from different densitometers to evaluate rates in bone loss in multicenter trials.

Electrophoretic variants of blood proteins in Japanese. IV. Prevalence and enzymologic characteristics of glucose-6-phosphate dehydrogenase variants in Hiroshima and Nagasaki.

Electrophoretic screening of glucose-6-phosphate dehydrogenase (EC 1.1.1.49, G6PD) was conducted one sample of 9,260 children born to the atomic bomb survivors in Hiroshima (Honshu) and Nagasaki (Kyushu). The prevalence of electrophoretic variants was 0.11% in males and 0.42% in females in Hiroshima, and 0.16% in males and 0.31% in females in Nagasaki. Enzymologic characteristics of 10 variants obtained from three males and seven hemizygous fathers of heterozygous females were examined. As a result, three new types of G6PD variants were identified among five variants detected in Hiroshima, and three new types among five variants in Nagasaki. All the variants except one belonged to Class 3, as defined by Yoshida et al. (1971).

A phylogeny for the principal alleles of the human phosphoglucomutase-1 locus.

The results of phosphoglucomutase-1 (PGM1) typings by starch gel electrophoresis and subtypings by isoelectric focusing are presented for a sample of Japanese. A distinction made on the basis of isoelectric focusing (termed "+" and "-") is nonrandomly associated with each of the products of the four most common electrophoretic alleles (PGM1(1), PGM1(2), PGM1(3), and PGM1(7). The isoelectric trait cosegregates with the allele; the degree of nonrandomness of the association varies from allele to allele. Thus, the four alleles become eight. On the basis of these facts plus the additive nature of the pI differences between allele products and the geographical distribution of the alleles, an allele phylogeny can be constructed. This postulates that the eight alleles may be explained by three nucleotide substitutions involving the stem allele plus four intragenic recombinations between these substitutions. The potential of intragenic recombination as a cause of mutation has been insufficiently appreciated.