Daytime napping and the risk of gastric cancer: the JACC Study.

BACKGROUND: Gastric cancer is a major cause of morbidity and mortality in Japan and worldwide. Emerging literature has suggested unfavorable health outcomes associated with daytime napping. Herein, we aimed to investigate the association between daytime napping and the risk of gastric cancer among Japanese people. METHODS: This prospective cohort study included 49,037 participants, aged 40-79 years, from the Japan Collaborative Cohort Study (JACC Study). Participants with positive cancer history and those who reported night or rotational shift work were excluded. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident gastric cancer among daytime nappers. RESULTS: Within 650,040 person-years (median = 13.7 years) of follow-up, 1,164 participants developed gastric cancer. Daytime napping was associated with the increased risk of gastric cancer in the multivariable-adjusted model: HR (95% CI) = 1.14 (1.01, 1.29). The excess risk did not significantly differ across sexes, age groups (<65 and ≥65 years), and employment status (employed and unemployed) (p-interactions > 0.40). However, sleep duration modified this effect: HRs (95% CIs) = 1.66 (1.23, 2.23) in sleep duration ≤6 h/night versus 1.06 (0.93, 1.21) in sleep duration >6 h/night (p-interaction = 0.006). CONCLUSION: Daytime napping was associated with increased gastric cancer risk, especially among those who reported short sleep duration.

Associations of different isomeric forms of serum lycopene with cardiovascular disease and all-cause mortality.

Background: The effect of serum lycopene on the progression of cardiovascular diseases (CVDs) and their longevity remains a controversial topic. The purpose of this study was to evaluate the associations of different isomeric forms of serum lycopene with CVD and all-cause mortality in the American population. Methods: The National Health and Nutrition Examination Survey (NHANES) is a large population survey to investigate public health in the US. We analyzed data from 2003-2006 linked with mortality data obtained in 2015. Cox proportional hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated to assess the risk of CVD and all-cause mortality caused by serum lycopene. Results: Among 7452 participants (aged 20-85 years, 46.7% male), 298 died from CVDs among the total 1213 deaths during a median follow-up of 10.7 years. Serum lycopene is a protective factor for all-cause and CVD mortality. In multivariable-adjusted models, the hazard ratio (with 95% confidence intervals) associated with Q4 compared to Q1 of serum total-lycopene, trans-lycopene and cis-lycopene was 0.49 (0.38,0.63), 0.49 (0.39,0.63) and 0.55 (0.43,0.70) for all-cause mortality (Ptrend<0.05), and was 0.53 (0.32,0.96), 0.48 (0.32,0.72) and 0.63 (0.41,0.97) for CVD mortality (Ptrend<0.05). The subgroup analyses showed that different isomeric forms of lycopene showed varied associations with CVD and all-cause mortality based on age, drinking status, history of hypertension and diabetes. Conclusions: Serum lycopene concentration was significantly associated with the risk of CVD and all-cause mortality. Cis-lycopene had a U-shaped relationship with mortality, while trans-lycopene had an inverse relationship with it.

Dietary Manganese Intake and Risk of Liver Cancer in Japanese Men and Women: The JACC Study.

We explored the association between dietary manganese intake and the risk of liver cancer in 14,517 men and 21,583 women who participated in the Japan Collaborative Cohort Study for Cancer Risk Assessment. We assessed dietary manganese intake using a food frequency questionnaire and incident liver cancer by reviewing cancer registries. According to manganese intake, we estimated the liver cancer risk by Cox regression analyses. During the 513,657 person-year follow-ups within a median of 17.9 years of 36,100 participants, there were 239 incident cases of liver cancer. The multivariable hazard ratio (HR) (95% confidence interval [CI]; P-trend) for liver cancer risk in the highest vs. the lowest quintiles of dietary manganese intake was 0.56 (0.32-0.99; 0.04) in men and 1.16 (0.56-2.40; 0.79) in women; P-interaction = 0.06. The history of liver disease modified the observed association in men (P-interaction = 0.02), in which the multivariable HR (95%CI) of liver cancer risk comparing the highest vs. lowest quintiles of dietary manganese intake was 0.32 (0.14-0.74) in Japanese men without a history of liver disease, while it was 1.54 (0.62-3.79) in men with a history of liver disease. In conclusion, a higher dietary manganese intake was associated with a lower risk of liver cancer in men without a history of liver disease.

Association Between Mode of Delivery and Postpartum Depression: The Japan Environment and Children's Study (JECS).

BACKGROUND: Postpartum depression (PPD) has been associated with adverse health outcomes, including maternal suicide. Mode of delivery has been suggested to be a risk factor for PPD, but no large cohort study has examined the association between mode of delivery and PPD. We aimed to examine the association between mode of delivery and risks of PPD at 1 and 6 months after childbirth. METHODS: In a nationwide study of 89,954 mothers with a live singleton birth, we examined the association between mode of delivery and risks of PPD. PPD was evaluated using the Edinburgh Postnatal Depression Scale (≥13) at 1 and 6 months after childbirth. Odds ratios (ORs) with 95% confidence intervals (CIs) of PPD were calculated using multivariable logistic regression analyses after adjustment of antenatal physical, socioeconomic, and mental factors. RESULTS: Among 89,954 women, 3.7% and 2.8% had PPD at 1 and 6 months after childbirth, respectively. Compared with unassisted vaginal delivery, cesarean section (CS) was marginally associated with PPD at 1 month but not at 6 months; adjusted ORs were 1.10 (95% CI, 1.00-1.21) and 1.01 (95% CI, 0.90-1.13), respectively. The association with PPD at 1 month was evident in women with antenatal psychological distress (adjusted OR 1.15; 95% CI, 1.03-1.28). The observed associations were attenuated after adjusting for infant feeding method. CONCLUSION: Women who had antenatal psychological distress and underwent CS delivery may be regarded as a target for monitoring PPD.

Vitamin K Intake and Risk of Lung Cancer: The Japan Collaborative Cohort Study.

BACKGROUND: Limited reports from prospective human studies investigated the possible role of vitamin K in the development of lung cancer although vitamin K's anticarcinogenic activities were verified from several in vitro and in vivo studies. We investigated the associations between total vitamin K intake from food and the development of lung cancer based on this large prospective cohort study. METHODS: A validated food frequency questionnaire was used to examine vitamin K intake among 42,166 (16,341 men and 25,825 women) at the Japan Collaborative Cohort Study's baseline (1988-1990). Hazard ratios (HRs) and 95% confidence intervals (CIs) of incident lung cancer were calculated using the Cox proportional hazard regression method based on vitamin K consumption quartiles. RESULTS: 430 cases (308 males and 122 women) of lung cancer were documented during a total of 564,127 person-years of follow-up (median follow-up, 14.6 years). Vitamin K consumption was shown to be inversely related to lung cancer risk; the multivariable hazard ratio [HR] for the highest versus lowest quartiles was 0.67 (95% confidence interval [CI], 0.46-0.96; P for trend = 0.010). This relationship appears to be stronger in males (HR 0.62; 95% CI, 0.40-0.96; P for trend = 0.016) than in females (HR 0.82; 95% CI, 0.42-1.61; P for trend = 0.39) (P for interaction = 0.012), and in ever smokers (HR 0.57; 95% CI, 0.36-0.91; P for trend = 0.006) than in never smokers (HR 0.79; 95% CI, 0.40-1.55; P for trend = 0.37) (P for interaction = 0.30). The individuals' age, body mass index, or alcohol consumption status had no effect on the observed connection. CONCLUSION: Vitamin K consumption reduces the risk of lung cancer. More research is needed to clarify the molecular processes behind this connection.

Work and Family Conflicts, Depression, and "Ikigai": A Mediation Analysis in a Cross-cultural Study Between Japanese and Egyptian Civil Workers.

BACKGROUND: Total work-family conflicts (TWFCs) could associate with mental health, and having ikigai (a purpose of life) may mediate this association. METHODS: In a cross-cultural study of 4,792 Japanese Aichi Workers' Cohort study participants and 3,109 Egyptian civil workers, the Midlife Development in the United States (MIDUS) questionnaire measured TWFCs and the Center for Epidemiological Studies Depression (CES-D) 11-item scale measured depression. We used logistic regression models to estimate odds ratios (ORs) of having depression and a high-ikigai across levels of TWFCs (low, moderate, and high), and the PROCESS macro of Hayes to test the mediation effect. RESULTS: The prevalence of high TWFCs, depression, and having a high ikigai were 17.9%, 39.4%, and 70.1% in Japanese women, 10.5%, 26.8%, and 70.1% in Japanese men, 23.7%, 58.2%, and 24.7% in Egyptian women, and 19.1%, 38.9%, and 36.9% in Egyptian men, respectively. Compared with participants with low TWFCs, the multivariable ORs of depression in Japanese women and men with high TWFCs were 4.11 (95% confidence interval [CI], 2.99-5.65) and 5.42 (95% CI, 4.18-7.02), and those in Egyptian women and men were 4.43 (95% CI, 3.30-5.95) and 4.79 (95% CI, 3.53-6.48), respectively. The respective ORs of having a high-ikigai were 0.46 (95% CI, 0.33-0.64) and 0.40 (95% CI, 0.31-0.52) in Japanese women and men and were 0.34 (95% CI, 0.24-0.48) and 0.28 (95% CI, 0.20-0.39) in Egyptian women and men. No interaction between TWFCs and country was observed for the associations with depression or ikigai. Ikigai mediated (up to 18%) the associations between the TWFCs and depression, especially in Egyptian civil workers. CONCLUSION: TWFCs were associated with depression, and having low ikigai mediated these associations in Japanese and Egyptian civil workers.

Daytime napping and risk of liver cancer: A large population-based prospective cohort study.

INTRODUCTION AND OBJECTIVES: Liver cancer is a major cause of morbidity and mortality in Japan and worldwide. Daytime napping is a common behavior, especially among older adults, that was related in previous research to unfavorable health conditions. Herein, we investigated the association between daytime napping and liver cancer risk. MATERIALS AND METHODS: In this prospective cohort study, data from 51,185 participants aged 40-79 years and registered in the Japan Collaborative Cohort Study (JACC Study) were analyzed. Incident cases of liver cancer were diagnosed using cancer registries, hospital records, and death certificates. Daytime napping was assessed using the JACC baseline self-administered questionnaire. We used the Cox regression to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident liver cancer among participants in the age categories of the 40s, 50s, 60s, and 70s who reported daytime napping compared with their counterparts who did not. RESULTS: Within 669,734 person-years of follow-up, 341 participants developed liver cancer. Daytime napping was associated with a higher risk of liver cancer among participants who were in their 60s and 70s of age after adjusting for sex: HRs (95% CIs) 1.88 (1.35-2.61) and 1.96 (1.18-3.26), lifestyle and medical history: 1.76 (1.27-2.47) and 1.82 (1.07-3.09), and history of liver diseases: 1.66 (1.18-2.34) and 1.72 (1.01-2.94), respectively. No associations were detected among participants from the 40s and 50s age groups. CONCLUSIONS: Daytime napping was associated with a higher risk of liver cancer among older adults.

Walking time, sports activity, job type, and body posture during work in relation to incident colorectal cancer: the JACC prospective cohort study.

PURPOSE: An inverse association between physical activity and colorectal cancer (CRC) has been suggested. We aimed to assess the specific and combined effects of leisure-time and occupational physical activities on CRC risk among Japanese adults. METHODS: Using Cox proportional hazard models, we tested whether walking time, sports activity, body posture during work, and job type-or the combination of these variables-were associated with CRC incidence in a prospective cohort of 26,897 Japanese adults aged 40-79 years. RESULTS: During a median 17-year follow-up (1990-2009) period, we ascertained 423 incident cases of CRC (267 colon and 156 rectum cancer). Time spent walking suggested a dose-response inverse relationship with CRC risk (p-trend = 0.051). Manual labor was associated with lower CRC risk when compared to office work with HRs (95% CIs) of 0.74 (0.56-0.97) for CRC and 0.68 (0.48-0.96) for colon cancer. Compared to sitting, moving during work tended to be inversely associated with rectal cancer risk, especially after censoring early incident cases within 3 years after baseline; HR (95% CI) = 0.63 (0.40-0.99). Combining walking and job type suggested mutual and synergistic benefits on the risk of colon cancer (p-interaction = 0.03). Compared to office workers walking < 1 h/day, the HR (95% CI) of colon cancer was 0.48 (0.23-0.98), 0.61 (0.42-0.89), and 0.59 (0.41-0.87) in office workers walking ≥ 1 h/day, non-office workers walking < 1 h/day, and non-office workers walking ≥ 1 h/day, respectively. CONCLUSION: The time spent walking, job type, and posture during work were independently associated with the reduced incident CRC risk among Japanese men and women.

Smoking Cessation, Weight Gain, Cardiovascular Risk, and All-Cause Mortality: A Meta-analysis.

INTRODUCTION: Quitting smoking usually results in weight gain, rising the concern that weight gain after smoking cessation may attenuate the benefits of smoking quitting on cardiovascular health. AIMS AND METHODS: We aimed to examine the risk of cardiovascular disease (CVD) among smoking quitters compared with smokers, stratified by post-cessation weight change. We searched PubMed, Scopus, and Web of Science for eligible studies published before September 2020. Cohort studies examining the relative risk of CVD among smoking quitters stratified by post-cessation weight change, with smokers being treated as the reference, were included. Two investigators extracted the key characteristics of each included study using a standard electronic form. RESULTS: We identified nine studies for this meta-analysis. Compared with smokers, the pooled RRs (95% confidence interval) of CVD among quitters with weight gain and among those without were 0.74 [0.66, 0.83] and 0.86 [0.80, 0.92], with no evidence of heterogeneity between studies being observed. Moreover, the associations appeared to be significantly stronger among quitters with weight gain than those without, particularly in the analysis of coronary heart disease (CHD) and stroke (pooled RRs = 0.65 [0.59, 0.71] vs. 0.79 [0.71, 0.88] for CHD and 0.67 [0.62, 0.73] vs. 0.76 [0.72, 0.81] for stroke, respectively; p for interaction <.05). CONCLUSIONS: Smoking cessation was associated with a significantly lower risk of CVD and all-cause mortality, regardless of post-cessation weight gain. A greater risk reduction among quitters with weight gain than those without merits further investigations. IMPLICATIONS: Quitting smoking usually results in weight gain and increases the risk of type 2 diabetes. We found that the risk reduction in CVD and all-cause mortality associated with smoking cessation was greater in quitters with weight gain than that in quitters without, especially in CHD and stroke. Despite weight gain and increased risk of type 2 diabetes, quitting smoking remains effective in the prevention of CVD.

Night Work, Rotating Shift Work, and the Risk of Cancer in Japanese Men and Women: The JACC Study.

BACKGROUND: Limited epidemiological evidence has suggested a positive relationship between night shift work and the risk of cancer. Herein, we investigated the prospective association between different forms of work schedule and the risk of numerous cancers and all-cause cancer among Japanese men and women. METHODS: This cohort study included 45,390 working men and women aged 40-79 years and registered in the Japan Collaborative Cohort Study (JACC Study). The Cox proportional hazards models were used to calculate the hazard ratios (HRs) and their 95% confidence intervals (CIs) for incident cancer among those who reported engagement in night work and rotating shift work for their longest occupations compared with day work. RESULTS: Within a median follow-up duration of 14.2 years, 2,283 (9.4%) men and 1,309 (4.5%) women developed cancer. Among men, rotating shift work was significantly associated with increased risk of esophageal cancer (HR 2.47; 95% CI, 1.42-4.31) and decreased risk of liver cancer (HR 0.54; 95% CI, 0.30-0.98). Also, rotating shift work tended to be associated with the increased risk of prostate cancer (HR 1.42; 95% CI, 0.95-2.12). Night work and rotating shift work were not related to the risk of all-cause cancer in either sex. CONCLUSION: Rotating shift work might contribute to the increased risk of esophageal cancer and prostate cancer and the decreased risk of liver cancer among Japanese men.

Alcohol Consumption and Risk of Gastric Cancer: The Japan Collaborative Cohort Study.

BACKGROUND: Alcohol consumption is a potential risk factor for gastric cancer. However, findings from cohort studies that examined the relationship between alcohol consumption and gastric cancer risk among Japanese population are not conclusive. METHODS: A total of 54,682 Japanese men and women participating in the Japan Collaborative Cohort study completed a questionnaire, including alcohol consumption information. The Cox proportional hazard model was used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: After a median 13.4-year follow-up, we documented 801 men and 466 women incident cases of gastric cancer. Alcohol consumption was associated with increased risk of gastric cancer among men (HRs in ex-drinkers and current alcohol consumption of <23 g, 23-<46 g, 46-<69 g, and ≥69 g/d categories versus never drinkers were 1.82; 95% CI, 1.38-2.42, 1.41; 95% CI, 1.10-1.80, 1.47; 95% CI, 1.17-1.85, 1.88; 95% CI, 1.48-2.38, and 1.85; 95% CI, 1.35-2.53, respectively, and that for 10 g increment of alcohol consumption after excluding ex-drinkers was 1.07; 95% CI, 1.04-1.10). The association in men was observed for cardia and non-cardia gastric cancer (HRs in the highest alcohol consumption category versus never drinkers were 9.96; 95% CI, 2.22-44.67 for cardia cancer and 2.40; 95% CI, 1.64-3.52 for non-cardia cancer). However, no such trend was observed in women. CONCLUSIONS: Alcohol consumption is associated with increased risk of gastric cancer among Japanese men, regardless of anatomical subsite of the cancer.

The apparent inverse association between dietary carotene intake and risk of cardiovascular mortality disappeared after adjustment for other cardioprotective dietary intakes: The Japan collaborative cohort study.

BACKGROUND AND PURPOSE: An effect of dietary carotenes on risk of cardiovascular disease (CVD) is uncertain. We aimed to investigate whether the association between dietary carotenes intake and risk of CVD mortality will persist after controlling for the intakes of potential cardioprotective dietary factors that correlate with dietary alpha- and/or beta-carotenes. METHODS AND RESULTS: We followed up a total of 58,646 Japanese between 1988 and 1990 and 2009. We used a food frequency questionnaire (FFQ) to determine the dietary intakes of carotenes, and estimated the hazard ratios (HRs) and 95% confidence intervals (CIs) of CVD mortality in relation to carotene intake by the proportional hazard regression developed by David Cox. During 965,970 person-years of follow-up (median 19.3 years), we identified 3388 total CVD deaths. After adjusting for demographic and lifestyle factors, dietary intakes of alpha-carotene were significantly associated with the reduced risk of mortality from coronary heart disease (CHD); adjusted HR (95% CI) in the highest versus lowest quintiles of intake was 0.75 (0.58-0.96; P-trend = 0.02) and dietary intakes of beta-carotene were significantly associated with the reduced risk of mortality from CVD, CHD, and other CVD; adjusted HRs (95% CIs) were 0.88 (0.79-0.98; P-trend = 0.04), 0.78 (0.61-0.99; P-trend = 0.01), and 0.81 (0.67-0.98; P-trend = 0.04), respectively. However, after further adjusting for the dietary intakes of potassium, calcium, vitamins C, E, or K, these associations disappeared. CONCLUSIONS: -Dietary alpha- and beta-carotene intakes were not associated with risk of CVD mortality after controlling for intakes of other potential cardioprotective nutrients.

The Influencing Factors of Sleep Quality Among Chinese Junior and Senior High School Adolescents During the COVID-19 Pandemic.

BACKGROUND: Since coronavirus disease 2019 (COVID-19) outbreak, its terrible infectiousness has caused great panic, anxiety and poor sleep quality to the vulnerable adolescent populations. METHODS: This cross-sectional online survey recruited 10 569 Chinese junior and senior high school adolescents during 31 January to 9 February 2020. Basic socio-demographic information, Pittsburgh Sleep Quality Index (PSQI), Self-rating Anxiety Scale (SAS) and Fear of negative evaluation (FNE) were included in the survey. The χ2 and logistic regression analyses were used to identify factors correlated with poor sleep quality. RESULTS: The prevalence of poor sleep quality was 18.6% in the Chinese adolescent population. The average score of PSQI was 3.39 (SD = 2.64), which was significantly correlated with scores for anxiety (r = 0.50, p < 0.01), and FNE (r = 0.36, p < 0.01). Adjusted logistic regression indicated that gender (females) and education (senior high school) were associated with poor sleep quality, while living in Hubei Province and time spent on the COVID-19 information were inversely associated with poor sleep quality. Having a family member or friend infected/suspected and spending time on electronics were associated with higher odds of having poor sleep quality. Adolescents with anxiety were 8 times, and those with FNE were three times more likely than ones without anxiety or FNE to have poor sleep quality. In addition, the number of meals, exercise time and diet quality were also significantly associated with sleep quality. (p < 0.05). CONCLUSIONS: Poor sleep quality was common during the COVID-19 pandemic in Chinese adolescents. Understanding several factors associated with the poor sleep quality will offer some important insights into determining potential interventions to improve sleep quality during the COVID-19 pandemic.

Effects of strawberry intervention on cardiovascular risk factors: a meta-analysis of randomised controlled trials.

We conducted a meta-analysis of randomised controlled trials (RCT) to examine the effects of strawberry interventions on cardiovascular risk factors. We searched multiple databases including PubMed, Web of Science and Scopus to identify eligible studies published before 19 May 2019. The endpoints were blood pressure, total cholesterol (TC), HDL-cholesterol, LDL-cholesterol, TAG, fasting blood glucose, endothelial function and inflammatory factors. Pooled analyses were performed using random- or fixed-effects models according to a heterogeneity test. We also conducted sub-group analyses by baseline endpoint levels. We included eleven RCT in this meta-analysis (six for blood pressure, seven for lipid profile, seven for fasting blood glucose and six for C-reactive protein (CRP)). Overall, the strawberry interventions significantly reduced CRP levels by 0·63 (95 % CI -1·04, -0·22) mg/l but did not affect blood pressure, lipid profile or fasting blood glucose in the main analyses. Our analysis stratified by baseline endpoint levels showed the strawberry interventions significantly reduced TC among people with baseline levels >5 mmol/l (-0·52 (95 % CI -0·88, -0·15) mmol/l) and reduced LDL-cholesterol among people with baseline levels >3 mmol/l (-0·31 (95 % CI -0·60, -0·02) mmol/l). There was little evidence of heterogeneity in the analysis and no evidence of publication bias. In summary, strawberry interventions significantly reduced CRP levels and may improve TC and LDL-cholesterol in individuals with high baseline levels.

Maternal total energy, macronutrient and vitamin intakes during pregnancy associated with the offspring's birth size in the Japan Environment and Children's Study.

Maternal diet during pregnancy can influence fetal growth; however, the available evidence is controversial. We aimed to assess whether maternal diet of Japanese women in mid-pregnancy can affect their offspring's birth size via collection of questionnaire and medical record data. The studied sample was a large cohort of paired mothers and their singleton offspring (n 78 793) from fifteen areas all over Japan who participated in the Japan Environment and Children's Study. The mid-pregnancy intakes of total energy, macronutrients and vitamins were lower than the recommended intakes for pregnant Japanese women. Maternal total energy intake was positively associated with the offspring's birth weight; there was a 10-g mean difference in the offspring's birth weight of mothers in the lowest (3026 g) v. highest (3036 g) quartiles of energy intake. Carbohydrate intake was positively associated with the offspring's birth length (mean difference of 0·7 cm) and inversely associated with the ponderal index (mean difference of 0·8 g/cm3). Offspring of mothers in the highest v. lowest quartiles of total dietary fibre intake were on average 9 g heavier and had 0·3 cm longer birth length and 0·2 cm longer head circumference. The highest in reference to lowest intake quartile of vitamin C was associated with 13 g and 0·7 cm mean differences in the offspring's birth weight and length, respectively. Several other associations were evident for maternal intakes of vitamins and the offspring's birth size. In conclusion, maternal dietary intakes of energy, dietary fibre, carbohydrate and vitamins during pregnancy were associated with the offspring's birth size.

Factors Associated With Family Member's Spanking of 3.5-year-old Children in Japan.

BACKGROUND: Spanking can cause adverse psychological development and biological functional changes in children. However, spanking is widely used by parents in Japan. This study explored the risk factors for family member's spanking of 3.5-year-old children using nationwide population data in Japan. METHODS: Surveys were administered to family members in Japan who had a child in 2001 (first cohort) or in 2010 (second cohort), and the data when their child was 0.5, 1.5, and 3.5 years old were used. We used multivariate binary and ordinal logistic regression analyses to examine the associations between risk factors and spanking children at 3.5 years of age, which was subcategorized into frequencies of never, sometimes, and always spanking, presented with odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Among 70,450 families, 62.8% and 7.9% sometimes and always spanked their children, respectively. Children in the second cohort were spanked less frequently compared with those in the first cohort, and fathers who responded to the questionnaire spanked children less frequently than mothers who responded. Identified associated factors for spanking were male child, presence of siblings of the child, not living in a two-parent household, not living in a three-generation household, younger parents, parents with lower education, no outside work or unstable work, and lower family income. CONCLUSIONS: We found a high prevalence of spanking and its associated factors. Approaching those with lower socioeconomic factors and promoting fathers' involvement in parenting may be important public health strategies for reducing and preventing spanking.

Impact of intention and feeling toward being pregnant on postpartum depression: the Japan Environment and Children's Study (JECS).

Pregnancy intention is reported to be associated with the risk of postpartum depression (PPD), but the impact of feelings toward being pregnant on PPD is unknown. We aimed to examine whether feelings toward being pregnant are associated with PPD at 1 month after childbirth. In our nationwide study between 2011 and 2014 in Japan, we used multivariate logistic regression analyses to examine the associations between pregnancy intention and feelings toward being pregnant with PPD [Edinburgh Postnatal Depression Scale (EPDS score > 9 or > 12)] among Japanese women. Among 92,431 women, 14.0 and 5.4% had PPD with EPDS scores > 9 and > 12, respectively. Compared with women who felt very happy to be pregnant, those whose pregnancy was unintended but happy, unintended and confused, those who felt troubled, and those who felt no emotion toward being pregnant had increased risks of PPD [multivariable odds ratios (95% confidence intervals (CIs)) = 1.17 (1.11-1.22), 1.39 (1.29-1.49), 1.74 (1.42-2.14), and 1.58 (1.22-2.02), respectively, for EPDS score > 9]. Those associations were more evident without antenatal possible mental illness (K6 score < 13). Women whose pregnancy was unintended should be regarded as targets for the early detection and prevention of PPD irrespective of whether they felt happy or confused.

Age-Period-Cohort Analysis of Stroke Mortality Attributable to High Sodium Intake in China and Japan.

Background and Purpose- The aim of this study is to assess the long-term trends in stroke mortality attributable to high sodium intake in China and Japan during the period 1990 to 2016. Methods- The mortality data were obtained from the GBD study (Global Burden of Disease) 2016 and were analyzed using an age-period-cohort method. Results- The age-standardized mortality rates showed declining trends for high sodium intake-related stroke mortality. The overall net drifts per year were -3.1% for Chinese men and -5.0% for Chinese women; and -4.6% for Japanese men and -5.7% for Japanese women. The local drift values were below zero in all age groups for both sexes in both countries, and all local drift values of female participants were below their counterparts of male participants. The longitudinal age curves of high sodium intake-attributable stroke mortality increased rapidly for both sexes in China, whereas those of Japanese were slowly rising. The period and cohort rate ratios were found to have similar downward patterns for both sexes in both countries, with a quicker decline for women than for men (significantly with P<0.05 for all). Conclusions- The age-standardized mortality rates, the period effect and the cohort effect of stroke mortality attributable to high sodium intake in China and Japan have been declining in both sexes and all age groups from 1990 to 2016. Consequently, sodium-reduction strategies are of low cost and effective for the prevention of stroke. It is necessary to educate the nation with the correct knowledge on healthy diet and techniques to reduce salt consumption.

Sleep duration and risk of breast cancer: The JACC Study.

PURPOSE: The evidence on beneficial or adverse effects of sleep duration on risk of breast cancer remains controversial and limited, especially in Asia. METHODS: A prospective study of 34,350 women aged 40-79 years 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 ≥ 8 h/day by Cox proportional hazard models. RESULTS: During 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 7 h/day and ≤ 6 h/day of sleep in reference to ≥ 8 h/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). CONCLUSIONS: Short sleep duration was associated with increased risk of incident breast cancer, especially among postmenopausal women and women with low parity.

Among the water-soluble vitamins, dietary intakes of vitamins C, B2 and folate are associated with the reduced risk of diabetes in Japanese women but not men.

Recent studies have shown that micronutrients are involved in the pathology of type 2 diabetes. Antioxidant effects of vitamins C and B2 and homocysteine-lowering effects of vitamins B6, folate and B12 may have protective roles. However, a few reports have investigated the association between dietary water-soluble vitamin intakes and risk of diabetes. In a prospective study encompassing 19 168 healthy Japanese men and women aged 40-79 years, we examined the associations between dietary intakes of water-soluble vitamins, determined by a validated self-administered FFQ, with the risk of 5-year cumulative incidence of type 2 diabetes by using the logistic regression model. Within the 5-year period, there were 494 self-reported new cases of diabetes. Higher dietary intakes of vitamins C, B2 and folate were associated with lower risk of incident diabetes only in women, whereas no associations of dietary intakes of vitamins B1, B3, B5, B6 and B12 were observed in either sex. The multivariable OR in the highest v. the lowest quartile of intakes among women were 0·61 (95 % CI 0·44, 0·94; P-trend = 0·04) for vitamin C, 0·56 (95 % CI 0·34, 0·93; P-trend = 0·03) for vitamin B2 and 0·70 (95 % CI 0·46, 0·98; P-trend = 0·03) for folate. Other than that for sex (P 0·10. In conclusion, higher dietary intakes of vitamins C, B2 and folate, but not other water-soluble vitamins, were associated with reduced risk of type 2 diabetes in Japanese women.