Association between shift work and the risk of death from biliary tract cancer in Japanese men

Background: There is increasing evidence suggesting that shift work involving night work may increase cancer risk. Methods: We examined the association between working rotating shifts and the risk of death from biliary tract cancer among Japanese men who participated in the Japan Collaborative Cohort Study. Of the 46, 395 men recruited, 22, 224 men aged 40-65 at baseline (1988-1990) who reported working full-time or were self-employed were included in the present analysis. The study subjects were followed through December 31, 2009. Information regarding occupation and lifestyle factors was collected using a self-administered questionnaire. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95 % confidence interval (CI) for the risk of death from biliary tract cancer in relation to shift work. Results: During a mean 17-year follow-up, we observed 94 biliary tract cancer deaths, including 23 deaths from gallbladder cancer and 71 deaths from extrahepatic bile duct cancer. Overall, shift work was associated with a statistically non-significant increase in the risk of biliary tract cancer, with an HR of 1.50 (95 % CI: 0.81-2.77), among rotating shift workers. When the analysis was limited to extrahepatic bile duct cancer, a significant association appeared, with a multivariable-adjusted HR of 1.93 (95 % CI: 1.00-3.72) for rotating shift workers. Conclusion: Our data indicate that shift work may be associated with increased risk of death from extrahepatic bile duct cancer in this cohort of Japanese men. The association with gallbladder cancer remains unclear because of the small number of deaths

Sleep duration and risk of breast cancer : The JACC Study

PurposeThe evidence on beneficial or adverse effects of sleep duration on risk of breast cancer remains controversial and limited, especially in Asia.MethodsA prospective study of 34,350 women aged 40-79years in whom sleep duration, and menstrual and reproductive histories were determined by a self-administered questionnaire. The follow-up period was from 1988 to 2009, and hazard ratios (HRs) with 95% confidence intervals (CIs) of breast cancer incidence were calculated for shorter sleep duration in reference to sleep duration of 8h/day by Cox proportional hazard models.ResultsDuring 19.2-year median follow-up (236 cases), we found a significant inverse association between sleep duration and risk of breast cancer, especially among postmenopausal women and women with low parity (nulliparous and women with <3 children); the multivariable HRs (95% CIs) among postmenopausal women who reported 7h/day and 6h/day of sleep in reference to 8h/day were 1.49 (0.81-2.76) and 1.98 (1.08-3.70) (P for trend=0.028), respectively, and the corresponding values among women with low parity were 1.50 (0.96-2.35) and 1.76 (1.01-2.79) (P for trend=0.018).ConclusionsShort sleep duration was associated with increased risk of incident breast cancer, especially among postmenopausal women and women with low parity

Self-Reported Eczema in Relation with Mortality from Cardiovascular Disease in Japanese : the Japan Collaborative Cohort Study

Aim: Previous studies suggested a positive association between eczema and cardiovascular disease (CVD), probably through enhanced systemic inflammation. However, several studies reported null findings about eczema and CVD, so the evidence is still controversial. Methods: We asked 85,099 participants (35,489 men and 49,610 women), aged 40 to 79 years, without a history of CVD or cancer at baseline between 1988 and 1990, to complete a lifestyle questionnaire, including information eczema frequency (seldom, sometimes or often). Results: During the 6,389,818 person-years of follow-up, there were 1,174 deaths from coronary heart disease (CHD), 979 from heart failure, 366 from cardiac arrhythmia, 2,454 from total stroke, 1,357 from ischemic stroke, 1,013 from hemorrhagic stroke, and 201 from aortic aneurysm or dissection. The multivariable-adjusted model showed that individuals who "sometimes" or "often" had eczema had 0.82 (95%confidence interval (CI): 0.69-0.97) or 1.26 (95%CI: 1.01-1.56) times the risk of mortality from CHD, respectively, compared to those who "seldom" did. Individuals who "often" had 1.30 (95%CI: 1.05-1.61) times the risk of mortality from CHD, compared to those who "seldom or sometimes" did. There was no association of eczema with mortality from other CVD, or no interaction between eczema and sex or age, in relation to any CVD mortality risk. Conclusions: Self-reported frequent eczema was associated with increased risk of mortality from CHD, but not other major CVD, in a Japanese general population. Since steroid usage was not considered, future studies should include it as a potential confounding factor

Television Viewing Time and Breast Cancer Incidence or Japanese Premenopausal and Postmenopausal Women : The JACC Study

Purpose The evidence on effects of TV viewing time among premenopausal and postmenopausal women for breast cancer risk remains controversial and limited. Materials and Methods A prospective study encompassing 33,276 (17,568 premenopausal, and 15,708 postmenopausal) women aged 40-79 years in whom TV viewing time, menstrual, and reproductive histories were determined by a self-administered questionnaire. The follow-up was from 1988 to 2009 and hazard ratios (HRs) with 95% confidence intervals (as) of breast cancer incidence were calculated for longer TV viewing time in reference to shorter TV viewing time by Cox proportional hazard models. Results During 16.8-year median follow-up, we found positive associations between TV viewing time and breast cancer incidence with a borderline significant trend among total women and a significant trend among postmenopausal women. Among total women, the multivariable HRs (95% Cis) for risk of breast cancer in reference to = 4.5 hr/day (p for trend=0.053) and among postmenopausal women, the corresponding risk estimates were 1.10 (0.42-2.88), 2.54 (1.11-5.80), and 2.37 (0.926.10) (p for trend=0.009), respectively. Conclusion Prolonged TV viewing time was associated with increased risk of breast cancer, especially among postmenopausal women