Mari Oyama

Long-term effects of the Niigata-Chuetsu earthquake in Japan on acute myocardial infarction mortality: an analysis of death certificate data

Objective: To determine if the Niigata-Chuetsu earthquake of October 2004 increased long-term mortality from acute myocardial infarction (AMI). Design: A comparative study of mortality rates before and after the earthquake, as well as between the disaster and control areas, by analysing death certificate data from 1 October 1999 to 30 September 2007. Setting: The disaster area and a control area in Niigata Prefecture (n = 2 448 025 in 1 October 2004) in Japan. Population: The total population of Niigata Prefecture observed for five years (12 333 429 person-years) before and three years (7 279 076 person-years) after the earthquake. Main outcome measures: Mortality from AMI (ICD-10, I21 and I22). Results: Overall mortality rates from AMI five years before and three years after the earthquake in the disaster area were 47.3 and 53.9 per 100 000 person-years, respectively. Change (+6.6 or +14.0%) was significantly different (p = 0.0008), compared to the control area, where mortality rates were 42.5 and 42.6 per 100 000 person-years, respectively, and was not significantly different (p = 0.9028). In men, a change in AMI mortality before and after the earthquake in the disaster area was +7.1 per 100 000 person-years (+13.4%, p = 0.0172), and +2.0 (+4.2%, p = 0.2362) in the control area. In women, a change in AMI mortality in the disaster area was +6.2 per 100 000 person-years (+14.9%, p = 0.0184) and −1.6 (−4.2%, p = 0.2735) in the control area. Conclusions: The Niigata-Chuetsu earthquake significantly increased long-term mortality from AMI in both men and women. Clinicians and policymakers in public health must recognise the need for long-term prevention of AMI in earthquake disaster areas.

Effect of low-dose calcium supplements on bone loss in perimenopausal and postmenopausal Asian women: A randomized controlled trial

Current standard‐dose calcium supplements (eg, 1000 mg/d) may increase the risk for cardiovascular events. Effectiveness of lower‐dose supplements in preventing bone loss should thus be considered. This study aimed to assess whether calcium supplements of 500 or 250 mg/d effectively prevent bone loss in perimenopausal and postmenopausal Japanese women. We recruited 450 Japanese women between 50 and 75 years of age. They were randomly assigned to receive 500 mg of calcium (as calcium carbonate), 250 mg of calcium, or placebo daily. Medical examinations conducted three times over a 2‐year follow‐up period assessed bone mineral density (BMD) of the lumbar spine and femoral neck. One‐factor repeated measures ANOVA was used for statistical tests. Subgroup analyses were also conducted. Average total daily calcium intake at baseline for the 418 subjects who underwent follow‐up examinations was 493 mg/d. Intention‐to‐treat analysis showed less dramatic decreases in spinal BMD for the 500‐mg/d calcium supplement group compared to the placebo group (1.2% difference over 2 years, p = 0.027). Per‐protocol analysis (≥80% compliance) revealed that spinal BMD for the 500‐mg/d and 250‐mg/d calcium supplement groups decreased less than the placebo group (1.6%, p = 0.010 and 1.0%, p = 0.078, respectively), and that femoral neck BMD for the 500‐mg/d calcium supplement group decreased less relative to the placebo group (1.0%, p = 0.077). A low‐dose calcium supplement of 500 mg/d can effectively slow lumbar spine bone loss in perimenopausal and postmenopausal women with habitually low calcium intake, but its effect on the femoral neck is less certain. Calcium supplementation dosage should thus be reassessed. (Clinical Trials Registry number: UMIN000001176).

Low calcium intake is associated with increased bone resorption in postmenopausal Japanese women: Yokogoshi Study.

OBJECTIVE Low Ca intake is common among Japanese women, but its effect on bone metabolism has not been fully elucidated. The aim of the present study was to determine the relationship between Ca intake and serum markers of bone turnover in postmenopausal Japanese women. DESIGN A cross-sectional study. SETTING A community setting. SUBJECTS Subjects were 595 home-dwelling postmenopausal Japanese women. Ca intake was assessed by a validated FFQ. Serum type I collagen cross-linked N-telopeptides (NTX) and osteocalcin were measured as markers of bone turnover. The relationships between demographic characteristics, lifestyles, serum Ca, vitamin D and intact serum parathyroid hormone and bone turnover were also assessed. RESULTS The average age of the subjects was 64.5 (sd 5.8) years and the mean Ca intake was 527 (sd 160) mg/d. Ca intake was significantly associated with serum NTX (P = 0.0104), but not with serum osteocalcin. Mean serum NTX concentration in the lowest quartile of Ca intake (<417 mg/d) was significantly higher than in the fourth, referent quartile. Among these Japanese postmenopausal women, very low Ca intake (less than approximately 400 mg/d) was associated with increased bone resorption but not bone formation. CONCLUSIONS Increased bone resorption may be one mechanism by which this Ca-depleted population normalizes bone metabolism and prevents osteoporosis.

Evidence that genetic variants of metabolic detoxication and cell cycle control are not related to gallbladder cancer risk in Chilean women.

Background and aims High consumption of red chili pepper has been shown to be a risk factor for gallbladder cancer (GBC) in Chilean women. However, genetic factors in addition to this and other environmental factors may also be associated with an increased risk of GBC. We aimed to examine the associations of cytochrome P450 1A1 (CYP1A1), glutathione S-transferase class mu (GSTM1), and tumor protein p53 (TP53) polymorphisms with the risk of GBC in Chilean women. Methods A hospital-based case-control study of 57 patients with GBC, 119 patients with gallstones, and 70 controls was conducted. The statuses of the polymorphisms CYP1A1 rs4646903, CYP1A1 rs1048943, and TP53 rs1042522 were assayed using Custom Taqman® SNP Genotyping Assays and TaqMan®SNP Genotyping Assay. GSTM1 deletion polymorphism was detected by allele-specific PCR analysis. Results No significant differences in the genotypic or allelic frequencies in the CYP1A1, GSTM1, and TP53 polymorphisms were found between the three groups. Conclusion These genetic variants were not related to an increased risk of GBC in Chilean women. Other polymorphisms, such as red-chili-pepper-related polymorphisms, may contribute to the development of GBC in Chilean women.

Nutritional and biochemical parameters associated with 6-year change in bone mineral density in community-dwelling Japanese women aged 69 years and older: The Muramatsu Study

OBJECTIVE Predictors of bone loss in elderly Asian women have been unclear. This cohort study aimed to assess lifestyle, nutritional, and biochemical predictors of bone loss in elderly Japanese women. METHODS Subjects included 389 community-dwelling women aged 69 y and older from the Muramatsu cohort initiated in 2003; follow-up ended in 2009. We obtained data on physical characteristics, osteoporosis treatment (with bisphosphonates or selective estrogen receptor modulators), physical activity, calcium intake, serum 25-hydroxyvitamin D, undercarboxylated osteocalcin, serum albumin, and bone turnover markers as predictors. The outcome was a 6-y change in forearm BMD (ΔBMD). Osteoporosis treatment was coded as 0 for none, 1 for sometimes, and 2 for always during the follow-up period. Stepwise multiple linear regression analysis was used to identify independent predictors of ΔBMD. RESULTS Mean age of the subjects was 73.3 y. Mean values of ΔBMD and Δweight were -0.019 g/cm(2) (-5.8%) and -2.2 kg, respectively. Stepwise multiple linear regression analysis revealed baseline BMD (β = -0.137, P < 0.0001), osteoporosis treatment (β = 0.0068, P = 0.0105), serum albumin levels (β = 0.0122, P = 0.0319), and Δweight (β = 0.0015, P = 0.0009) as significant independent predictors of ΔBMD. However, none of the other nutritional or biochemical indices were found to be significant predictors of ΔBMD. CONCLUSIONS Our findings indicate that adequate general nutrition and appropriate osteoporosis medication, rather than specific nutritional regimens, may be effective in preventing bone loss in elderly women.