Japan Collaborative Cohort Study Research Articles

Perceived Stress and Colorectal Cancer Incidence: The Japan Collaborative Cohort Study

Colorectal cancer is the third most common cancer worldwide, and many risk factors for colorectal cancer have been established. However, it remains uncertain whether psychological stress contributes to the onset of colorectal cancer. Therefore, we conducted a large-scale prospective cohort study to confirm the association between perceived stress and colorectal cancer incidence. We identified 680 cases of colon cancer and 330 cases of rectal cancer during a maximum of 21-year follow-up of 61,563 Japanese men and women. Cox regression analysis adjusted for potential confounders revealed a significant association of perceived stress with rectal cancer incidence but not with colon cancer incidence. This finding is partly consistent with that from only one previous study that addressed an association between perceived stress and the risk of colorectal cancer. However, studies on this topic are sparse and warrant further exploration.

No modifying effect of education level on the association between lifestyle behaviors and cardiovascular mortality: the Japan Collaborative Cohort Study

We examined the effect of education level on the association between healthy lifestyle behaviors and cardiovascular mortality in the Japanese population. A total of 42,647 community-based men and women aged 40–79 years were enrolled at baseline (1988–1990), followed through 2009. The components of the healthy lifestyle score included the intake of fruits, fish, and milk; body mass index; exercise; avoidance of smoking; moderate alcohol intake; and moderate sleep duration. During the 19.3 years of follow-up, 8,314 all-cause and 2,377 total cardiovascular mortality cases were noted. Inverse associations were observed between healthy lifestyle scores and total cardiovascular disease (CVD) for both the lower and higher education level groups. Multivariable hazard ratios (95% confidence interval) for CVD mortality from the highest to the lowest healthy lifestyle scores, and the population attributable fraction (95% CIs) without healthy lifestyle scores of 7–8 were 0.51 (0.33–0.52) and 42% (24–58%), and 0.38 (0.27–0.47) and 55% (36–69%) for the higher and lower education levels, respectively. Our findings suggest that the association between higher CVD mortality and lower education level can be explained by the individuals’ lower adherence to a healthy lifestyle; hence, lifestyle modification would be beneficial for the prevention of cardiovascular mortality, irrespective of the education level.

Insulin-like growth factor-1, IGF binding protein-3, and the risk of esophageal cancer in a nested case-control study.

AIMTo assess the relationship between serum levels of insulin-like growth factor-1 (IGF1)/IGF-binding protein-3 (IGFBP3) and the risk of esophageal carcinoma.METHODSWe assessed the relationship between the serum levels of these molecules and the risk of esophageal cancer in a prospective, nested case-control study of participants from the Japan Collaborative Cohort Study. A baseline survey was conducted from 1988 to 1990. Of the 110585 enrolled participants, 35% donated blood samples. Those who had been diagnosed with esophageal cancer were considered cases for nested case-control studies. A conditional logistic model was used to estimate odds ratios for the incidence of esophageal cancer associated with serum IGF1 and IGFBP3 levels.RESULTSThirty-one cases and 86 controls were eligible for the present assessment. The molar ratio of IGF1/IGFBP3, which represents the free and active form of IGF1, was not correlated with the risk of esophageal carcinoma. A higher molar difference between IGFBP3 and IGF1, which estimates the free form of IGFBP3, was associated with a decreased risk of esophageal carcinoma (P = 0.0146), and people in the highest tertile had the lowest risk (OR = 0.107, 95%CI: 0.017-0.669). After adjustment for body mass index, tobacco use, and alcohol intake, the molar difference of IGFBP3-IGF1 was inversely correlated with the risk of esophageal carcinoma (P = 0.0150).CONCLUSIONThe free form of IGFBP3, which is estimated by this molar difference, may be inversely associated with esophageal cancer incidence.

Transforming Growth Factor-β1 as a Predictor for the Development of Hepatocellular Carcinoma: A Nested Case–Controlled Study

BackgroundTransforming growth factor-β1 (TGF-β1) reportedly acts as a tumor suppressor in tumorigenesis. However, little is known as to how TGF-β1 concentrations change prior to the development of hepatocellular carcinoma (HCC) in humans. We examined the association between the serum TGF-β1 concentrations and death from HCC to determine whether the serum TGF-β1 can be a predictor of incident HCC. MethodsWe conducted a nested case-controlled study of participants in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk. We used a conditional logistic regression analysis to estimate the adjusted relative risks (aRRs) of death from HCC according to the serum TGF-β1 concentrations among 1940 participants including 83 patients with HCC and 1857 controls matched for age, sex, and hepatitis C virus (HCV)-antibody seropositivity. FindingsWhen serum TGF-β1 was modelled as a continuous variable, the aRR of death from HCC associated with a decrement of 7.9ng/mL (one standard deviation) in the serum TGF-β1 concentrations was 2.3 (95% CI 1.7–3.0, P<0.001) for all the subjects. The area under the receiver operating characteristic curve for the serum TGF-β1 concentrations was 0.78 (P<0.05). InterpretationOur finding suggests that TGF-β1 serves as a predictor for HCC.

Dietary Patterns and Risk of Esophageal Cancer Mortality: The Japan Collaborative Cohort Study

ABSTRACTSeveral case-control studies have associated dietary patterns with esophageal cancer (EC) risk, but prospective studies are scarce. We investigated dietary pattern and EC mortality risk associations by smoking status. Participants were 26,562 40- to 79-yr-old Japanese men, who enrolled in the Japan Collaborative Cohort Study between 1988 and 1990. Hazard ratios (HRs) and 95% confidence intervals (CIs) for EC mortality in nonsmokers and smokers were estimated using Cox proportional models. During follow-up (1988–2009), 132 participants died of EC. Using a baseline food frequency questionnaire and factor analysis, vegetable, animal, and dairy product food patterns were identified. EC risk decreased significantly with a higher factor score for the dairy product pattern (Ptrend = 0.042) and was more pronounced in smokers [multivariable HR (4th vs. 1st quartiles) = 0.57, 95% CI: 0.30, 1.09; Ptrend = 0.021]. Neither vegetable nor animal food patterns were significant overall; however, EC risk increased with a higher factor score for the animal food pattern in nonsmokers [multivariable HR (4th vs. 1st quartiles) = 6.01, 95% CI: 1.17, 30.88; Ptrend = 0.021], although the small number of events was a limitation. Our findings suggest a dairy product pattern may reduce EC risk in Japanese men, especially smokers.

Occupational physical activity in relation to risk of cardiovascular mortality: The Japan Collaborative Cohort Study for Evaluation for Cancer Risk (JACC Study)

We examined the association between patterns of occupational physical activity (OPA) and mortality from cardiovascular disease (CVD) in a Japanese population. A community-based, prospective cohort of 66,161 men and women aged 40–79years without a history of CVD or cancer at baseline (1988–1990) was followed until 2009. OPA was divided into four types: mostly sitting, sitting and standing (sitting/standing), mostly standing, and standing and walking (standing/walking). During follow-up for a median of 19.2years, 3728 deaths from CVD were registered. Compared with mostly sitting OPA, standing/walking OPA was not associated with a reduced risk of CVD mortality for all subjects, but it was associated with a 20% lower risk of CVD mortality among overweight individuals (body mass index ≥25kg/m2). Compared with mostly sitting OPA, mostly standing OPA was associated with an approximately 20% higher risk of CVD mortality, especially among overweight individuals or those with lower exercise (<2.5h/week). In conclusion, compared with mostly sitting OPA, standing/walking OPA is associated with lower CVD mortality among overweight individuals, while mostly standing OPA is associated with higher CVD mortality, especially in physically inactive individuals.

Prospective study of seaweed consumption and thyroid cancer incidence in women: the Japan collaborative cohort study.

Excess intake of iodine is a suspected risk factor for thyroid cancer. Previous epidemiological research from Japan reported that daily intake of seaweed was associated with a four-fold higher risk in postmenopausal women, whereas others reported a null association. A major source of iodine intake in Japan is from edible seaweeds, and it is reported to be among the highest in the world. We examined the association between seaweed intake frequency and the risk of thyroid cancer in women in the Japan Collaborative Cohort Study followed from 1988 to 2009. Seaweed intake, together with other lifestyle-related information was collected using a self-administered questionnaire at baseline. Seaweed intake frequency was categorized as follows: 1-2 times/week or less, 3-4 times/week, and almost daily. Hazard ratios and the 95% confidence intervals of thyroid cancer incidence according to seaweed intake frequency were estimated using Cox proportional hazards regression. During 447 876 person-years of follow-up (n=35 687), 94 new cases of thyroid cancer were identified. The crude incidence rate was 20.9 per 100 000 person-years. The hazard ratio of thyroid cancer in women who consumed seaweed daily compared with women who ate it 1-2 times/week or less was 1.15 (95% confidence interval: 0.69-1.90, P for trend=0.59). Further analyses did not indicate any association between seaweed intake and the risk of thyroid cancer on statistically adjusting for potential confounding variables as well as on stratification by menopausal status. The present study did not find an association between seaweed intake and thyroid cancer incidence in premenopausal or in postmenopausal women.

Weight Gain and Alcohol Drinking Associations with Breast Cancer Risk in Japanese Postmenopausal Women - Results from the Japan Collaborative Cohort (JACC) Study

We investigated four factors, height, weight gain since age 20, physical activity, and alcohol drinking, for associations with risk of breast cancer (BC) according to menopausal status, using the latest data of the Japan Collaborative Cohort Study (JACC Study). We confined the analysis to 24 areas available of cancer incidence information, excluding women with a previous diagnosis of BC. Baseline data were collected from 38,610 (9,367 premenopausal, and 29,243 postmenopausal) women during 1988 and 1990. The study subjects were followed-up at the end of 2009, and 273 (84 premenopausal, and 189 postmenopausal) cases of BC were newly diagnosed in 501,907 person-years. The Cox model was used to estimate a hazards ratio (HR) and its 95% confidence interval (CI) of BC risk. As a result of the multivariate analysis adjusting for age at baseline survey, age at menarche, number of live births, and, age at first delivery, weight gain since age 20 of 6.7 kg-9.9 kg, and ≥10.0 kg were significantly associated with increased risk for postmenopausal BC (HR=2.48, 95% CI 1.40-4.41, and, HR=2.94, 95% CI 1.84-4.70, respectively). Significantly increased trend of BC risk was also observed in weight gain since age 20 (p for trend, p<0.001). Amount of ethanol intake per day≥15.0 g was significantly associated with increased risk for postmenopausal BC in the multivariable-adjusted analysis (HR=2.74, 95% CI 1.32-5.70). Higher weight gain in adulthood and larger amounts of ethanol intake were significantly associated with increased risk of BC in Japanese postmenopausal women. None of the investigated factors were significantly associated with BC risk in Japanese premenopausal women.

Dietary patterns and breast cancer risk in a prospective Japanese study.

The association between dietary patterns and breast cancer has been inconsistent. This study examined associations between dietary patterns and risk of developing breast cancer among 23,172 women from the Japan Collaborative Cohort Study, including 119 incidences of breast cancer diagnosed during a median 16.9-year follow-up period. Factor analysis was conducted to obtain dietary patterns, and Cox proportional models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for breast cancer morbidity. Three dietary patterns were identified: ''vegetable pattern'' (vegetables, potatoes, seaweed, tofu, fruits, fresh fish, eggs, and miso soup); ''animal food pattern'' (meat, deep-fried foods, fried vegetables, fish paste and salt-preserved fish); and "dairy product pattern'' (milk, dairy products, fruits, coffee and tea). After adjusting for potential confounders, the vegetable and dairy product patterns were not significantly associated with risk of breast cancer. However, the animal food pattern was significantly associated with a decreased risk of breast cancer morbidity among premenopausal women by HR 0.47 for the 2nd tertile (95% CI 0.22-1.00) and HR 0.42 for the 3rd tertile (95% CI 0.18-0.93), compared with the bottom tertile (p for trend 0.04). We found no significant association between the vegetable and dairy product dietary patterns and breast cancer risk; however, an animal product diet may reduce risk of breast cancer among premenopausal Japanese women.

Abstract P211: Impact of Healthy Lifestyle Behaviors and Education Level on Cardiovascular Mortality: The Japan Collaborative Cohort Study

Introduction: Magnitude of impact of healthy lifestyle behaviors and education level on cardiovascular mortality is uncertain. Hypothesis: Impact of education on cardiovascular mortality is explained mostly by lifestyle behaviors Methods: The survey cohort was a total of 42,647 subjects (18,442 men and 24,205 women) aged 40-79 years with satisfactory information from 1988 to 1990, and followed up until the end of 2009. Education levels were sub-grouped into higher education (last school age of ≥16 years old) and lower education (&lt;16). We defined the healthy lifestyle score (fruits ≥1/day, fish ≥1/day, milk almost every day, exercise ≥5h/week and/or walking ≥0.5h/day, BMI 21-25kg/m2, ethanol intake &lt;46.0g/day, non-smoker, and sleep 5.5-7.5h/day, ranging 0 to 8), and calculated multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs) to determine the magnitude of impacts of healthy lifestyle behaviors and education level on cardiovascular mortality with persons who have lower education and 0-3 lifestyle score category as reference. Population attributable fraction (PAF) of lifestyle behaviors on cardiovascular mortality stratified by education level were also calculated. Results: During the 19.3 median years of follow-up, there were 8,314 total deaths and 2,377 CVD deaths. Compared with persons with lower education and 0-3 healthy lifestyle score category, those with lower education and 7-8 healthy lifestyles score category and those with higher education and 7-8 healthy lifestyle score category showed lower risk of mortality from total CVD. The respective multivariable-adjusted HRs (95% CI) were 0.37 (0.28-0.48) for those with lower education and 7-8 lifestyle score category, and 0.37 (0.30-0.46) for those with higher education and 7-8 lifestyle score category in total men and women, 0.25 (0.14-0.44) and 0.43 (0.31-0.59), respectively, for men, and 0.43 (0.31-0.60) and 0.36 (0.27-0.49), respectively, for women. PAF of CVD mortality for those who were not in the category of 7-8 lifestyle behavior were 40.1% in higher education group and 68.5% in lower education. Conclusions: More than 50% of risk reduction of cardiovascular mortality for those who have 7-8 healthy lifestyle score category compared to those who have 0-3 healthy lifestyles were found irrespective of education level which suggests large part of impact of education on cardiovascular mortality is explained by lifestyle behaviors.

Diabetes Mellitus and Risk of Colorectal Cancer Mortality in Japan: the Japan Collaborative Cohort Study

Objective:Our aim was to estimate whether diabetes mellitus (DM) may be associated with an increased risk of colorectal cancer (CRC) mortality in Japan.Methods:The Japan Collaborative Cohort (JACC) Study is a nationwide prospective study, initiated in 1988, which involves 110,585 subjects (age range: from 40 to 79 years; 46,395 males and 64,190 females). Our present analysis population comprised 96,081 (40,510 men and 55,571 women) who provided details on DM history. The questionnaire also included age, sex, weight, height, family history of CRC, smoking, drinking and exercise habits, and education. Cox proportional-hazard regression was used to estimate the hazard ratio (HR). We used SPSS 21 software to analyze all data.Results:Among the participants with DM, we followed up for 71,174 person-years and 640. deaths from CRC were confirmed; and, among the non-diabetic participants, 785 CRC deaths were identified during 1,499,324 person-years. After adjusting for multivariate confounding factors, such as age, sex, body mass index (BMI), family history of colorectal cancer, smoking habit, drinking habit, physical activity (sports and walking) and education, DM was associated with an increased risk of CRC death (HR 1.4, 95% confidence interval [CI] 1.0-2.0). Diabetic women, but not diabetic men, experienced increased mortality from CRC (HR 1.7, 95% CI 1.0-3.0).Conclusion:The risk of CRC mortality is significantly increased in both sexes and women with diabetes, but no significant increase was seen for diabetic men among Japanese.

Salty Food Preference and Intake and Risk of Gastric Cancer: The JACC Study.

BackgroundHigh sodium intake is a potential risk factor of gastric cancer. However, limited information is available on the relationship between salty food preference or intake and risk of gastric cancer. The aim of the present study was to determine the association between these variables among the Japanese population.MethodsBetween 1988 and 1990, 15 732 men and 24 997 women aged 40–79 years old with no history of cancer or cardiovascular disease completed a lifestyle questionnaire that included information about food intake. The subjects were enrolled in the Japan Collaborative Cohort (JACC) Study for Evaluation of Cancer Risk Sponsored by Monbusho. After a median follow-up of 14.3 years, 787 incident gastric cancers were documented. We examined the associations between salty food preference and intake and gastric cancer incidence using the Cox proportional hazard model.ResultsThe risk of gastric cancer among subjects with a strong preference for salty food was approximately 30% higher than among those who preferred normal-level salty food (hazard ratio [HR] 1.31; 95% confidence interval [CI], 1.02–1.67). The risk of gastric cancer in subjects who consumed 3 and ≥4 bowls/day of miso soup was approximately 60% higher than in those who consumed less miso soup (HR 1.67; 95% CI, 1.16–2.39 and HR 1.64; 95% CI, 1.11–2.42, respectively). Sodium intake correlated positively and linearly with risk of gastric cancer (P for trend = 0.002).ConclusionsThe present study showed that salty food preference, consumption of large quantities of miso soup, and high sodium intake were associated with increased risk of gastric cancer among Japanese people.

Bowel Movement Frequency, Laxative Use, and Mortality From Coronary Heart Disease and Stroke Among Japanese Men and Women: The Japan Collaborative Cohort (JACC) Study.

BackgroundThe associations of bowel movement frequency and laxative use with cardiovascular disease (CVD) are unclear.MethodsA total of 72 014 subjects (29 668 men and 42 346 women) aged 40 to 79 years, without a history of CVD or cancer, completed a lifestyle questionnaire at baseline between 1988 and 1990 that included information on bowel movement frequency (daily, every 2–3 days, or once every 4 or more days) and laxative use (yes or no), and were followed-up until 2009.ResultsDuring the subjects’ 1 165 569 person-years of follow-up, we documented 977 deaths from coronary heart disease (561 men and 416 women), 2024 from total stroke (1028 men and 996 women), 1127 from ischemic stroke (606 men and 521 women), and 828 from hemorrhagic stroke (388 men and 440 women). The prevalence of CVD risk factors, such as diabetes, stress, depression, and physical inactivity, was higher in laxative users and in those with a lower frequency of bowel movements. The multivariable HRs (95% confidence intervals [CIs]) of laxative users were as follows: 1.56 (95% CI, 1.21–2.03) for coronary heart disease and 1.37 (95% CI, 1.07–1.76) for ischemic stroke in men, and 1.27 (95% CI, 1.08–1.49) for total stroke, and 1.45 (95% CI, 1.17–1.79) for ischemic stroke in women. Similar results were observed even after the exclusion of deaths that occurred early in the follow-up period. A significant association between bowel movement frequency and mortality from CVD was not observed.ConclusionsConstipation could be a marker of exposure to CVD risk factors, and laxative use could be a risk factor for mortality from coronary heart disease and ischemic stroke.

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

BackgroundThere is increasing evidence suggesting that shift work involving night work may increase cancer risk.MethodsWe 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.ResultsDuring 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.ConclusionOur 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.

Prospective Cohort Study on Television Viewing Time and Chronic Obstructive Pulmonary Disease Mortality: Findings from the Japan Collaborative Cohort Study.

Prospective Cohort Study on Television Viewing Time and Chronic Obstructive Pulmonary Disease Mortality: Findings from the Japan Collaborative Cohort Study.

Employment situation and risk of death among middle-aged Japanese women

BackgroundFew studies have examined the health effects of employment situation among women, taking social and economic conditions into consideration. The objective of this research was to investigate the association of...

Stroke : Highlights of Selected Articles

<i>Stroke</i> : Highlights of Selected Articles

Milk drinking and mortality: findings from the Japan collaborative cohort study.

BackgroundFindings regarding the association between milk consumption and all-cause mortality reported by studies carried out in Western populations have been inconsistent. However, no studies have been conducted in Japan on this issue. The present study aimed to investigate the association of milk drinking with all-cause, cardiovascular, and cancer mortality in Japan.MethodsThe data were obtained from the Japan Collaborative Cohort (JACC) study. A total of 94 980 Japanese adults aged 40–79 years who had no history of cancer, stroke, or chronic cardiovascular diseases were followed between 1988 and 2009. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of mortalities were assessed using a Cox proportional hazard regression model and taking the lowest milk consumption group as the reference.ResultsDuring a median of 19 years of follow-up, there were 21 775 deaths (28.8% and 35.3% from cardiovascular diseases and cancer, respectively). Drinking milk 1–2 times a month was associated with lower all-cause mortality in men compared to those who never drank milk (multivariable-adjusted HR 0.92; 95% CI, 0.85–0.99). In women, those who drank 3–4 times a week also had a lower mortality risk compared with those who never drank milk (HR 0.91; 95% CI 0.85–0.98). Inverse associations between drinking milk and mortality from cardiovascular diseases and cancer were found only in men.ConclusionsDrinking milk at least 1–2 times a month was associated with lower all-cause mortality in men compared to never drinking milk. An inverse association was also found between drinking milk and mortality from both cardiovascular diseases and cancer. However, lower all-cause mortality in women was found only in those who drank milk 3–4 times/week.

Association of Body Mass Index and Mortality in Japanese Diabetic Men and Women Based on Self-Reports: The Japan Collaborative Cohort (JACC) Study.

BackgroundThe association between body mass index (BMI) and mortality among Asian diabetic people, especially with respect to the obesity paradox (ie, higher BMI is associated with lower mortality risk), remains unresolved.MethodsWe followed a cohort of 3851 self-reported Japanese diabetics (2115 men and 1736 women) in the Japan Collaborative Cohort Study from 1988–1990 through 2009. Individuals were aged 40 to 79 years and free from a history of cardiovascular disease, cancer, renal disease, or tuberculosis. BMI was grouped into the following four categories: <20.0, 20.0–22.9, 23.0–24.9, and ≥25.0 kg/m2.ResultsDuring 54 707 person-years of follow-up, 1457 deaths from all causes, 445 from cardiovascular disease, 421 from cancer, 43 from renal disease, and 148 from infectious disease were documented. Mortality from all causes, cardiovascular disease, cancer, and renal disease showed L-shaped associations with BMI. Compared to diabetics with BMI of 20.0–22.9 kg/m2, those with BMIs of 23.0–24.9 kg/m2 and ≥25.0 kg/m2 had lower risks of mortality from infectious disease (ie, obesity paradox). The multivariable HRs for mortality from infectious disease were 0.50 (95% confidence interval, 0.31–0.81) and 0.51 (95% confidence interval, 0.32–0.82) among participants with BMIs of 23.0–24.9 kg/m2 and ≥25.0 kg/m2, respectively. Similar results were observed after stratification by smoking status and age and exclusion of early deaths.ConclusionsWe observed L-shaped associations between BMI and mortality from all causes, cardiovascular disease, cancer, and renal disease, while the association between BMI and mortality from infectious disease manifested the obesity paradox.

Television viewing time and mortality from stroke and coronary artery disease among Japanese men and women -- the Japan Collaborative Cohort Study.

No study has examined the association between television (TV) viewing time and mortality from stroke and coronary artery disease (CAD) in Japanese. A total of 35,959 men and 49,940 women aged 40-79 years without a history of cardiovascular disease (CVD) and cancer were followed from 1988-1990 until 2009. During 19.2 median years of follow-up, there were 2,553 deaths from stroke, 1,206 from CAD and 5,835 from total CVD. Compared with viewing TV for <2 h/day, mortality from stroke, CAD and total CVD were higher for ≥6 h/day of TV viewing. The multivariable hazard ratios (HRs) for ≥6 h/day of TV viewing were 1.15 (95% confidence interval: 0.96-1.37) for stroke, 1.33 (1.03-1.72) for CAD and 1.19 (1.06-1.34) for total CVD. The corresponding HRs for each 1-h/day increment in TV viewing time were 1.01 (0.99-1.04), 1.04 (1.01-1.08) and 1.02 (1.01-1.04), respectively. The excess risk of mortality from CAD and total CVD was somewhat attenuated after further adjustment for potential mediators such as history of hypertension and diabetes: the multivariable HRs for ≥6 h/day of TV viewing were 1.24 (0.96-1.61) and 1.14 (1.02-1.28). The corresponding HRs for each 1-h/day increment in TV viewing time were 1.03 (1.00-1.07) and 1.01 (1.00-1.03). Prolonged TV viewing was associated with a small but significant increase in mortality from CAD and total CVD in Japanese.