China has one of the highest carrier prevalences of hepatitis B virus (HBV) in the world: nearly 10% of the general population. The disease burden of HBV infection and hepatocellular carcinoma (HCC) is also believed to be among the world’s largest, and that of hepatitis C virus (HCV) infection is likely to be substantial as well. However, the epidemiology and measures to control HBV and HCV infection in China remain relatively unknown outside the country. We review the epidemiology of HBV and HCV infection, the disease burden of and risk factors for HCC, and current control measures against HBV and HCV infection in China. We also discuss the relevant literature and implications for future studies of hepatitis and HCC in China.
Background: We pooled data from 7 ongoing cohorts in Japan involving 353 422 adults (162 092 men and 191 330 women) to quantify the effect of body mass index (BMI) on total and cause-specific (cancer, heart disease, and cerebrovascular disease) mortality and identify optimal BMI ranges for middle-aged and elderly Japanese. Methods: During a mean follow-up of 12.5 years, 41 260 deaths occurred. The Cox proportional hazards model was used to estimate hazard ratios (HRs) for each BMI category, after controlling for age, area of residence, smoking, drinking, history of hypertension, diabetes, and physical activity in each study. A random-effects model was used to obtain summary measures. Results: A reverse-J pattern was seen for all-cause and cancer mortality (elevated risk only for high BMI in women) and a U- or J-shaped association was seen for heart disease and cerebrovascular disease mortality. For total mortality, as compared with a BMI of 23 to 25, the HR was 1.78 for 14 to 19, 1.27 for 19 to 21, 1.11 for 21 to 23, and 1.36 for 30 to 40 in men, and 1.61 for 14 to 19, 1.17 for 19 to 21, 1.08 for 27 to 30, and 1.37 for 30 to 40 in women. High BMI (≥27) accounted for 0.9% and 1.5% of total mortality in men and women, respectively. Conclusions: The lowest risk of total mortality and mortality from major causes of disease was observed for a BMI of 21 to 27 kg/m2 in middle-aged and elderly Japanese.
Background: Observation of early changes in fasting plasma glucose level induced by post-smoking cessation weight gain is useful in predicting the risks of diabetes mellitus (DM) and impaired fasting glucose (IFG). We investigated the effect of post-smoking cessation weight gain on early changes in the risk of a high fasting plasma glucose (IFG) level (≥100 mg/dL). Methods: In 946 subjects who underwent repeated health examinations after smoking cessation, changes in body mass index (BMI) and the odds ratio (OR) for IFG risk (adjusted for sex, age, BMI, fasting plasma glucose at year 1, and alcohol consumption) were calculated every year for 3 years after smoking cessation. Results: After smoking cessation, the rate of BMI increase significantly increased in quitters: 2.36% at year 2 (never smokers: 0.22%, current smokers: 0.39%) and 0.46% at year 3 (never smokers: 0.14%, current smokers: 0.32%). However, it decreased by 0.15% at year 4 (never smokers: 0.12%, current smokers: 0.26%). The ORs for quitters did not significantly increase at any time during the follow-up period. However, among quitters who had smoked at least 20 cigarettes per day, it was significantly higher (OR 1.51, 95% confidence interval 1.1–2.01 at year 1 and 1.71, 1.23–2.38 at year 2). Conclusions: The time course of the risk of IFG after smoking cessation was similar to that for the rate of BMI increase. In contrast to the findings of previous reports, the increase in IFG risk after smoking cessation was brief and disappeared in the absence of a significant increase in BMI.
Background: Prehypertension is common in China and is associated with an increased risk of cardiovascular disease. The present study estimated the current prevalence of prehypertension and its association with clustering of other modifiable cardiovascular risk factors (CRFs) among adults in suburban Beijing. Methods: A cross-sectional survey of a representative sample of 19 003 suburban adults aged 18 to 76 years was carried out in 2007. Questionnaire data and information on blood pressure, anthropometric characteristics, and laboratory measurements were collected. Results: The age-standardized prevalence of prehypertension was 35.7% (38.2% in men and 31.8% in women) among adults in suburban Beijing. The prevalence of overweight/obesity, diabetes, dyslipidemia, and physical inactivity was higher in participants with prehypertension (26.7%, 4.8%, 34.3%, and 60.4%, respectively) as compared with normotensive participants (15.9%, 2.7%, 20.5%, and 29.1%, respectively), and in participants with hypertension as compared with those with prehypertension. Overall, 85.3%, 49.8%, and 17.8% of prehypertensive men had 1 or more, 2 or more, and 3 or more CRFs (overweight/obesity, diabetes, dyslipidemia, current smoking, and physical inactivity). These proportions were higher than those in normotensive men (81.5%, 45.1%, and 13.4%) and lower than those in men with hypertension (91.7%, 56.4%, 19.2%). Similar results were found when women with prehypertension were compared with women who were normotensive or hypertensive. Conclusions: A high prevalence of prehypertension and clustering of other modifiable CRFs are common among prehypertensive adults in suburban Beijing. More-effective population-based lifestyle modifications are required to prevent progression to hypertension and reduce the increasing burden of cardiovascular disease in China.
Background: The validity of estimates of dietary intake calculated using a food frequency questionnaire (FFQ) depends on the specific population. The 138-item FFQ used in the 5-year follow-up survey for the Japan Public Health Center-based Prospective Study was initially developed for and validated in rural residents. However, the validity of estimates based on this FFQ for urban residents, whose diet and lifestyle differ from those of rural residents, has not been clarified. We examined the validity of ranking individuals according to level of dietary consumption, as estimated by this FFQ, among an urban population in Japan. Methods: Among 896 candidates randomly selected from examinees of cancer screening provided by the National Cancer Center, Japan, 144 participated in the study. In 2007–2008, at an average 2.7 years after cancer screening, participants were asked to respond to the questionnaire and to provide 4-day weighed diet records (4d-DRs) for use as the reference intake. Spearman correlation coefficients (CCs) between the FFQ and 4d-DR estimates were calculated, after correction for intraindividual variation of 4d-DRs. Results: The median (range) deattenuated CC for men and women was 0.57 (0.23 to 0.89) and 0.47 (0.08 to 0.94), respectively, across 45 nutrients and 0.51 (0.10 to 0.98) and 0.51 (−0.36 to 0.88) for 43 food groups. Conclusions: Although the FFQ was developed for a rural population, it provided reasonably valid measures of consumption for many nutrients and food groups in middle-aged screenees living in urban areas in Japan.
Background: The International Physical Activity Questionnaire (IPAQ) is a self-reported questionnaire for assessing physical activity and has been tested in 12 countries among adults aged 18 to 65 years. The present study evaluated the reliability and validity of the IPAQ among adults aged 65 years and older. Methods: The study included 164 men and 161 women selected from participants of the Fujiwara-kyo Study, a prospective cohort of elderly Japanese adults. To examine test–retest reliability, the participants were asked to complete the IPAQ twice, 2 weeks apart. The criterion validity of the IPAQ was tested by using an accelerometer. Results: Based on intraclass correlation coefficients, the reliability of the total IPAQ was 0.65 and 0.57 for men and women, respectively, aged 65 to 74 years and 0.50 and 0.56 for those aged 75 to 89 years. The Spearman correlation coefficients between total IPAQ score and total physical activity measured by accelerometer (TPA-AC) were 0.42 and 0.49 for men and women, respectively, aged 65 to 74 and 0.53 and 0.49 for those aged 75 to 89. Weighted kappa coefficients between total IPAQ score and TPA-AC were 0.49 and 0.39 for men and women, respectively, aged 65 to 74 and 0.46 and 0.47 for those aged 75 to 89. Conclusions: The reliability of the IPAQ was not sufficient, but the validity was adequate. Although there were some limitations with regard to repeatability and agreement in classification, the IPAQ was a useful tool for assessing physical activity among elderly adults.
Background: Current obesity is an established risk factor for endometrial cancer; however, the roles of weight gain during adulthood and obesity in early adulthood on endometrial cancer have not been elucidated. Here, we conducted a case-control study comprising 222 histologically diagnosed incident endometrial cancer cases and 2162 age- and menstrual-status matched non-cancer controls. Methods: Information on current body weight, weight and height at age 20 years, and lifestyle/environmental factors was obtained from a self-administered questionnaire. Subjects were classified into 3 groups according to change in body mass index (BMI, kg/m2) from age 20 years to enrollment (≤0 [reference], 0–3, and >3 kg/m2). The effects of adult BMI change and obesity in early adulthood were evaluated using an unconditional logistic regression model adjusted for potential confounders. Results: A high BMI at age 20 (BMI ≥25, BMI <25 as reference) was significantly positively associated with endometrial cancer risk (P = 0.005), as was a BMI increase during adulthood (0–3 BMI change, multivariate odds ratio [OR] = 1.28, 95% confidence interval [CI] = 0.88–1.87; >3 BMI change, OR = 2.02, 95% CI = 1.38–2.96; P-trend < 0.001). Parity and BMI at age 20 appeared to modify the effect of weight gain on cancer risk, albeit without statistical significance. This positive association of weight gain with risk was observed only for endometrioid adenocarcinoma. Conclusions: The results show that endometrial cancer is positively associated with obesity at age 20 and weight gain during adulthood among Japanese women.
Background: The objective of this study was to examine whether a widely available single-item measure of sleep disturbances is an acceptable alternative to a multi-item sleep questionnaire. Methods: Data were derived from Finnish Helsinki Health Study postal questionnaires administered in 2000–2002 (n = 7777, response rate 67%). The measures were the 4-item Jenkins Sleep Questionnaire (JSQ) on difficulties initiating and maintaining sleep, and nonrestorative sleep, and an item on sleep loss due to worry, from the General Health Questionnaire-12 (GHQ-12). Receiver operating characteristics (ROC) curve analyses were done to compare the predictive performance of the GHQ-12 item with the JSQ scale. Using the above 2 measures of sleep, logistic regression models were used to examine associations between sociodemographic factors, working conditions, health-related factors, and sleep disturbance. Results: The estimated area under the ROC curve was 0.68 among both women and men, which suggests that the ability of the GHQ-12 item to discriminate true positives from false positives was modest. However, the associations of sleep disturbance with its key determinants were largely similar using the GHQ-12 and the JSQ. Conclusions: A widely available, GHQ-12-based, single-item sleep measure was not an adequate substitute for a multi-item measure of overall sleep disturbance. Although the measures produced largely similar associations for key determinants of poor sleep, the discrepancies between responses must be considered when analyzing data from a measure that uses a single sleep item.
Background: Recent research has revealed the importance of neighborhood environment as a determinant of physical activity. However, evidence among elderly adults is limited. This study examined the association between perceived neighborhood environment and walking for specific purposes among Japanese elderly adults. Methods: This population-based, cross-sectional study enrolled 1921 participants (age: 65–74 years, men: 51.9%). Neighborhood environment (International Physical Activity Questionnaire Environmental Module) and walking for specific purposes (ie, transportation or recreation) were assessed by self-report. Multilevel logistic regression analyses with individuals at level 1 and neighborhoods at level 2 were conducted to examine the association between environment and walking, after adjustment for potential confounders. Results: Access to exercise facilities, social environment, and aesthetics were associated with total neighborhood walking. Odds ratios (95% CI) were 1.23 (1.00–1.51), 1.39 (1.14–1.71), and 1.48 (1.21–1.81), respectively. Regarding walking for specific purposes, social environment and aesthetics were consistent correlates of both transportation walking and recreational walking. Environmental correlates differed by specific types of walking and by sex. Transportation walking significantly correlated with a greater variety of environmental attributes. Sex differences were observed, especially for transportation walking. Bicycle lanes, crime safety, traffic safety, aesthetics, and household motor vehicles were significant correlates among men, while access to shops, access to exercise facilities, and social environment were important among women. Conclusions: Specific environment–walking associations differed by walking purpose and sex among elderly adults. Social environment and aesthetics were consistent correlates of both transportation walking and recreational walking. Improving these environmental features might be effective in promoting physical activity among elderly Japanese.
Background: It is not known whether chronic or past hepatitis C virus (HCV) infection contributes to the high mortality rate in hemodialysis patients. Methods: This prospective study of 1077 adult hemodialysis patients without hepatitis B virus infection used Poisson regression analysis to estimate crude and sex- and age-adjusted rates (per 1000 patient-years) of all-cause, cardiovascular, infectious disease-related and liver disease-related mortality in patients negative for HCV antibody (group A), patients positive for HCV antibody and negative for anti-HCV core antigen (group B), and patients positive for anti-HCV core antigen (group C). The relative risks (RRs) for each cause of death in group B vs group C as compared with those in group A were also estimated by Poisson regression analysis after multivariate adjustment. Results: A total of 407 patients died during the 5-year observation period. The sex- and age-adjusted mortality rate was 71.9 in group A, 80.4 in group B, and 156 in group C. The RRs (95% CI) for death in group B vs group C were 1.23 (0.72 to 2.12) vs 1.60 (1.13 to 2.28) for all-cause death, 0.75 (0.28 to 2.02) vs 1.64 (0.98 to 2.73) for cardiovascular death, 1.64 (0.65 to 4.15) vs 1.58 (0.81 to 3.07) for infectious disease-related death, and 15.3 (1.26 to 186) vs 28.8 (3.75 to 221) for liver disease-related death, respectively. Conclusions: Anti-HCV core antigen seropositivity independently contributes to elevated risks of all-cause and cause-specific death. Chronic HCV infection, but not past HCV infection, is a risk for death among hemodialysis patients.
Background: The aims of this study were to describe temporal patterns of injury-related mortality by sex, age group, and mechanism, and to identify changes in the leading causes of injury-related deaths in South Korea from 1996 through 2006. Methods: This retrospective, descriptive study analyzed national data on all injury-related deaths reported in official death certificates from 1996–2006. Incidence rates of fatal injuries are presented as crude and age-standardized rates per 100 000 population, and percentage changes in injury-related mortalities over the 11-year period were calculated with respect to intention, sex, and age. The 4 most common mechanisms (fall, poisoning, suffocation, and drowning) were then classified as unintentional injuries or suicides. Results: Overall injury-related mortality decreased 31.7% during the study period (1996–2006). Despite this overall decreasing trend, injury-related mortality increased among adults aged 65 years or older. In particular, injury-related mortality among women older than 80 years doubled since 1996. Suicide replaced transport as the leading cause of injury-related deaths between 2003 and 2006. With regard to intention, sex, and age, the most noticeable changes during the study period were increases in unintentional fall among elderly adults and suicidal fall among adolescents. Conclusions: The incidence rate for all injuries generally decreased from 1996–2006. However, the incidence rate of fall injuries increased among elderly adults, and suicide increased among adolescents. These findings suggest that further investigation of the characteristics and trends of injuries is necessary to develop and implement effective interventions.
Background: The present study used vital-statistics data to estimate the effect of maternal age and fertility treatment on the number and rate of multiple live births in Japan from 1974 through 2009. Methods: Japanese vital statistics published by the Ministry of Health, Labour and Welfare from 1974 to 2009 were gathered and reanalyzed with regard to maternal age class and plurality of live births. The numbers of spontaneous and iatrogenic multiple births during 1977–2009 were estimated, with the assumption that spontaneous multiple-birth rates according to maternal age class would be constant and equal to those of baseline values, ie, the means between 1974 and 1976. Results: During the 25-year period, multiple-birth rates according to maternal age class increased after the late 1980s. This tendency was obvious in women aged 35 to 39 years. The estimated numbers of iatrogenic multiple births remained nearly constant in women aged 20 to 24 years and greatly increased in women aged 30 to 34 and 35 to 39 years. The rate (per 1000 live births) of iatrogenic multiple births gradually increased from 0.7 (1977) to 1.3 (1986), then rapidly and markedly increased from 1.3 (1986) to 11.4 (2005), and finally decreased to 8.1 (2009). The estimated maximum percentage of iatrogenic multiple births was 50.0%, in 2004 and 2005. Conclusions: The rapid increases in Japan in the number and rate of multiples born to women older than 30 years are likely due to iatrogenic rather than spontaneous multiple births.