Explanation for the Japanese paradox: prevention of increase in coronary heart disease and reduction in stroke

Household dietary salt consumption and mortality from cardiovascular diseases: an ecological panel analysis in Japan

Background

Epidemiological evidence has shown that lower salt intake reduces hypertension-related disease mortality. Japan has experienced a drastic decrease in cardiovascular mortality, although this varies across regions. This regional variation does not necessarily match the local patterns of reported average salt intake. In this study, we examined population-level risk factors for hypertension-related disease mortality, focussing on the average household dietary consumption of salt intake sources.

Methods

We prepared an ecological panel dataset, with prefecture as the unit of analysis, by referring to public statistics and market research data from 2012 to 2015. We collected prefectural averages of household dietary consumption related to salt intake and other nutrients that may affect hypertension control. We used demographic characteristics, medical care availability and local economy indices as covariates. Panel data analysis with fixed-effects modelling was performed, regressing prefectural-level mortality from ischaemic heart diseases, subarachnoid and intracerebral haemorrhage and cerebral infarction on dietary consumption and the selected covariates.

Results

We confirmed the average household consumption of salt equivalents of discretional salt intake sources to be positively but only weakly associated with mortality from ischaemic heart diseases and cerebral infarction. Household expenditure on processed foods was positively associated with ischaemic heart disease mortality.

Conclusions

These findings may suggest that the reduction of salt in processed foods, in addition to individual behavioural change, could be useful for decreasing mortality from ischaemic heart diseases in the Japanese population. Ecological factors related to decreasing cerebrovascular disease mortality in the context of the ageing Japanese population require further investigation.

Expert panel consensus recommendations for ambulatory blood pressure monitoring in Asia: The HOPE Asia Network

Hypertension is an important public health issue because of its association with a number of significant diseases and adverse outcomes. However, there are important ethnic differences in the pathogenesis and cardio-/cerebrovascular consequences of hypertension. Given the large populations and rapidly aging demographic in Asian regions, optimal strategies to diagnose and manage hypertension are of high importance. Ambulatory blood pressure monitoring (ABPM) is an important out-of-office blood pressure (BP) measurement tool that should play a central role in hypertension detection and management. The use of ABPM is particularly important in Asia due to the specific features of hypertension in Asian patients, including a high prevalence of masked hypertension, disrupted BP variability with marked morning BP surge, and nocturnal hypertension. This HOPE Asia Network document summarizes region-specific literature on the relationship between ABPM parameters and cardiovascular risk and target organ damage, providing a rationale for consensus-based recommendations on the use of ABPM in Asia. The aim of these recommendations is to guide and improve clinical practice to facilitate optimal BP monitoring with the goal of optimizing patient management and expediting the efficient allocation of treatment and health care resources. This should contribute to the HOPE Asia Network mission of improving the management of hypertension and organ protection toward achieving "zero" cardiovascular events in Asia.

Disabled life expectancy with and without stroke: a 10-year Japanese prospective cohort study

PURPOSE

A stroke is a debilitating condition that can cause lifelong disability, severely limiting the ability of individuals to perform daily activities. In Japan, strokes are the fourth leading cause of death; however, no previous studies have examined the influence of strokes on a disabled or disability-free life for older Japanese residents. This study aims to address this gap.

METHODS

The study used data from the Nihon University Japanese Longitudinal Study of Aging (NUJLSOA) and incidence-based multistate life tables to estimate disabled and disability-free life expectancy based on the stroke status of Japanese residents aged 65 and older.

RESULTS

Japanese stroke survivors aged 65 who experienced an initial disability-free state could expect to live approximately 3 fewer total years of life, 4-5 fewer years in a disability-free state, and 1-2 more years in a disabled state compared to those without history of a stroke (p < 0.05). For those disabled at the beginning of the survey interval, the differences between individuals with and without stroke history were also similar to those disability-free at the beginning of the survey interval (2-4 and 5-6 fewer total and disability-free years, respectively) (p < 0.05). The same pattern was observed for older age groups.

CONCLUSION

Older adults who have experienced a stroke could experience a shorter total life expectancy, shorter disability-free life expectancy, and longer disabled life expectancy than those who have not experienced a stroke. These results can inform policymakers and rehabilitation practitioners on stroke survivor long-term care needs and their post-stroke health status.

Hypercholesterolemia and Lifetime Risk of Coronary Heart Disease in the General Japanese Population: Results from the Suita Cohort Study

Aim: Lifetime risk (LTR) is a measure of disease burden, which presents the probability of occurrence of a specific disease in the remaining lifetime of a group of people for a given index age. This measure is useful for presenting the risk dynamics of a disease at the population level, which constitutes important public health information toward prevention. To date, there have been no studies investigating the LTR for coronary heart diseases (CHDs) in relation to hypercholesterolemia in Asian populations. Therefore, we estimated the LTR of CHDs according to serum low-density lipoprotein cholesterol (LDL-C).

Methods: The participants included in this study were 2,559 men and 2,848 women, enrolled in the Suita Cohort Study of urban residents followed up from 1989 to 2007 for a total of 69,823 person-years. We estimated the sex- and index-age-specific LTR for the first CHD event among participants with or without hypercholesterolemia (LDL-C ≥ 160 mg/dL), accounting for the competing risk for mortality.

Results: For men with hypercholesterolemia, the LTR was 47.2% (95% confidence interval [CI]: 29.3–65.1%) and 44.5% (95% CI: 21.4–68.5%) for those aged 45 and 75, respectively. The LTRs of women with hypercholesterolemia were also higher than of those without hypercholesterolemia. However, their LTRs were lower for all index ages compared to men. These results did not differ for hypercholesterolemia defined by non-high-density lipoprotein cholesterol.

Conclusions: The presence of hypercholesterolemia increases the LTR for CHDs in the Japanese population, especially in men. This estimate can be used in preventive knowledge translation efforts at the population level.

Association of taller stature with lower cardiovascular disease mortality in Asian people: a systematic review

Background

Adult height can serve as a disease marker. While taller stature has been reported to be linked to a decreased risk of cardiovascular disease (CVD), an influence of the height on CVD is not fully understood in specific populations of Asia, which has a lower incidence of CVD and lower stature than Western populations.

Methods

We conducted a systematic review using original articles of prospective cohort studies published in English, via the PubMed database, on the relationship between the height and mortality of CVD, including cerebrovascular disease, in Asian people.

Results

We selected four studies on heart/coronary disease and five studies on cerebrovascular disease. Regarding heart/coronary disease, two studies showed that taller stature was associated with a decreased mortality of heart disease in men or cardiovascular disease in women. The hazard ratios of other studies had not shown a clear significance but a decreased direction of taller stature to the mortality. Regarding cerebrovascular disease, most studies showed that taller stature was associated with a decreased mortality of total cerebrovascular diseases or stroke. In two studies, taller stature showed a decreased mortality of ischemic or hemorrhagic stroke.

Conclusions

Overall, adult height may be inversely predictive to the mortality of CVD, in particular cerebrovascular disease, in Asian people. While this seems to be a similar trend to that of Westerns, further studies are warranted.

Cardiovascular Risk Assessment Chart by Dietary Factors in Japan - NIPPON DATA80

BACKGROUND

Many studies show that dietary factors such as vegetables, fruit, and salt are associated with cardiovascular disease (CVD) risk. However, a risk assessment chart for CVD mortality according to combinations of dietary factors has not been established.Methods and Results:Participants were 9,115 men and women aged 30-79 years enrolled in the National Nutritional Survey of Japan in 1980 with a 29-year follow-up. Dietary intake was assessed using a 3-day weighed dietary record at baseline. Cox regression models were used to estimate the hazard ratio (HR) of CVD mortality stratified by vegetables, fruit, fish, and salt consumption. HRs of CVD mortality according to combinations of dietary factors were color coded on an assessment chart. Higher intakes of vegetables, fruit, and fish, and lower salt intake were associated with lower CVD mortality risk. HRs calculated from combinations of dietary factors were displayed using 5 colors corresponding to the magnitude of the HR. People with the lowest intake of vegetables, fruit, and fish, and higher salt intake had a HR of 2.87 compared with those with the highest intake of vegetables, fruit, and fish, and lower salt intake.

CONCLUSIONS

Vegetables, fruit, fish, and salt intake were independently associated with CVD mortality risk. The assessment chart generated could be used in Japan as an educational tool for CVD prevention.

New risk prediction model of coronary heart disease in participants with and without diabetes: Assessments of the Framingham risk and Suita scores in 3-year longitudinal database in a Japanese population

The Framingham Risk Score (FRS) has been reported to predict coronary heart disease (CHD), but its assessment has been unsuccessful in Asian population. We aimed to assess FRS and Suita score (a Japanese CHD prediction model) in a Japanese nation-wide annual health check program, participants aged 40-79 years were followed up longitudinally from 2008 to 2011. Of 35,379 participants analyzed, 1,234 had new-onset CHD. New-onset CHD was observed in diabetic men [6.00%], non-diabetic men [3.96%], diabetic women [5.51%], and non-diabetic women [2.86%], respectively. Area under the curve (AUC) of receiver operating characteristic (ROC) curve for CHD prediction were consistently low in Suita score (TC), FRS (TC) and NCEP-ATPIII FRS (TC), suggesting that these scores have only a limited power. ROC, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA) and Hosmer-Lemeshow goodness-of-fit test did not show clear differences between Suita score (TC) and FRS (TC). New models combining waist circumference ≥85 cm in men or proteinuria ≥1+ in women to Suita score (TC) was superior in diabetic men and women. New models could be useful to predict 3-year risk of CHD at least in Japanese population especially in diabetic population.

Differences of patients' characteristics in acute type A aortic dissection - surgical data from Belgian and Japanese centers

Background

It is well known that there are major differences between the Japanese and Western population regarding the incidence of ischemic heart disease and stroke. The purpose of this study was to evaluate differences of patients’ characteristics between Belgian and Japanese cohort with acute type A aortic dissection.

Methods

In 487 patients (297 male patients, mean age 61.9 ± 12.2 yrs) who underwent surgery for acute type A aortic dissection, baseline preoperative and intraoperative data were collected. Belgian patients (n = 237) were compared to Japanese patients (n = 250). Clinical data included patient demographics, history, status at presentation, imaging study results and intraoperative findings.

Results

The Japanese cohort had significantly more women (48.8% vs. 28.7%, p < 0.0001), lower BMI (24.2 vs. 26.4, p < 0.0001) and lower prevalence of hypertension (49.2% vs. 65.8%, p = 0.0002). More DeBakey type I dissections and less type III dissections with retrograde extension were reported in Belgium than in Japan (77.2% vs. 48.4%, p < 0.0001, 3.4% vs. 38.7%, p < 0.0001, respectively). More entries were found in the ascending aorta (78.5% vs. 58.5%, p < 0.0001) and aortic arch (24.9% vs. 13.7%, p = 0.0018) in Belgian patients than in Japanese patients, who had more entries in the descending aorta or undetected entries.

Conclusions

In acute type A aortic dissection, Belgian patients reveal striking differences from Japanese patients regarding gender distribution, entry tear location and type of dissection. Japanese women are more likely to develop acute type A aortic dissection than Belgian women. (234 words).

Two-Year Survival After First-Ever Stroke in a General Population of 1.4 Million Japanese - Shiga Stroke Registry

BACKGROUND

Stroke is one of the leading causes of disability and mortality in Japan. The aim of the present analysis was to determine the non-acute survival rate after first-ever stroke using data from a large-scale population-based stroke registry in Japan. Methods and Results: Shiga Stroke Registry is an ongoing population-based registry of stroke, which covers approximately 1.4 million residents of Shiga Prefecture in central Japan. A total of 2,176 first-ever stroke patients, who were registered in 2011, were followed up until December 2013. The 2-year cumulative survival rates were estimated using Kaplan-Meier method according to index stroke subtype. Cox proportional hazards models were used to assess predictors of all-cause death. During a 2-year follow-up period, 663 patients (30.5%) died. The 2-year cumulative survival rate after first-ever stroke was 69.5%. There was heterogeneity in 2-year cumulative survival according to stroke subtype: lacunar infarction, 87.2%; large artery infarction, 76.1%; cardioembolic infarction, 55.4%; intracerebral hemorrhage, 65.9%; and subarachnoid hemorrhage, 56.7%. Older age, male sex, medical history, higher Japan coma scale score on admission, and stroke subtype were associated with risk of all-cause death in ≤2 years.

CONCLUSIONS

In the present population-based stroke registry with a real-world setting in Japan, 2-year cumulative mortality after first-ever stroke is still high (>30%), particularly for cardioembolic infarction, subarachnoid hemorrhage and intracerebral hemorrhage.

A longitudinal study of the association of the eicosapentaenoic acid/arachidonic acid ratio derived from fish consumption with the serum lipid levels: a pilot study

It has been demonstrated that regular fish consumption is associated with a reduced mortality from atherosclerotic cardiovascular disease (ASCVD). However, data are scarce regarding the correlation between the changes in the serum eicosapentaenoic acid/arachidonic acid (EPA/AA) ratio associated with regular fish consumption and the changes in the serum lipid profile variables. This study was designed as a hospital-based longitudinal study to investigate the relationship between the changes in the serum EPA/AA ratio and changes of the serum lipid levels in patients with one or more risk factors for ASCVD. In 475 patients followed-up for at least 1 year, univariable and multivariable regression analyses conducted after adjustments for the risk factors of ASCVD revealed that the absolute change of the EPA/AA ratio (∆EPA/AA ratio) was independently and significantly associated with the changes of the serum levels of low-density lipoprotein cholesterol (LDL-C) (β = - 0.129, p = 0.005), triglyceride (TG) (β = - 0.108, p = 0.019), non-high-density lipoprotein cholesterol (non-HDL-C) (β = - 0.149, p = 0.001), and TG/HDL-C ratio, a marker of the LDL particle size (β = - 0.104, p = 0.02), while not being correlated with any other lipid parameters. On the other hand, while the ∆ docosahexaenoic acid (DHA)/AA ratio was inversely correlated with the changes of the serum HDL-C level and positively correlated with the changes of the TG/HDL-C ratio, possibly serving to promote development of atherosclerosis. The results suggest that an increase of the EPA/AA ratio might be associated with decrease of the serum levels of LDL-C, TG and non-HDL-C levels, as well as with an increase of the TG/HDL-C ratio, which represents increased LDL particle size, all of which play a role in the development of ASCVD. A high EPA/AA ratio, but not DHA/AA ratio, derived from fish consumption might reduce the risk of ASCVD through reducing the risk of development of atherosclerosis.Clinical Trial Registration Information: UMIN ( http://www.umin.ac.jp/ ), Study ID: UMIN000010603.

Associations between Socioeconomic Status and the Prevalence and Treatment of Hypercholesterolemia in a General Japanese Population: NIPPON DATA2010

AIM

To investigate associations between socioeconomic status (SES) and the prevalence and treatment status of hypercholesterolemia in a general Japanese population.

METHODS

In 2010, we established a cohort study of 2417 adults (age 20-91 yr) from 300 randomly selected areas across Japan who participated in the National Health and Nutrition Survey of Japan. We cross-sectionally examined an association between SES and (1) prevalence of hypercholesterolemia in 2417 participants (999 men and 1418 women) and (2) not receiving medication for hypercholesterolemia in 654 participants (215 men and 439 women). SES included employment status, marital status, length of education, and household expenditures. Hypercholesterolemia was defined as a total serum cholesterol level of ≥6.21 mmol/L (240 mg/dL) or the use of lipid-lowering medications.

RESULTS

The overall prevalence of hypercholesterolemia was 21.5% in men and 31.0% in women. In men, the lowest quintile of household expenditures was associated with a higher prevalence of hypercholesterolemia (28.3%) compared with the upper 4 quintiles (19.9%) (multivariable-adjusted odds ratio 1.66; 95% confidence interval [CI] 1.16-2.38). Among participants with hypercholesterolemia, 55.4% of men and 55.1% of women were not receiving medication. Unmarried men were more likely to be untreated (75.0%) than married men (50.9%) (multivariable-adjusted odds ratio 2.53;95%CI 1.05-6.08). SES had no significant effects in women.

CONCLUSION

In a general population of Japanese men, low household expenditures were associated with a higher prevalence of hypercholesterolemia, and unmarried men with hypercholesterolemia were less likely to receive medication.

The JAGUAR Score Predicts 1-Month Disability/Death in Ischemic Stroke Patient Ineligible for Recanalization Therapy

BACKGROUND AND PURPOSE

Most available scoring system to predict outcome after acute ischemic stroke (AIS) were established in Western countries. We aimed to develop a simple prediction score of 1-month severe disability/death after onset in AIS patients ineligible for recanalization therapy based on readily and widely obtainable on-admission clinical, laboratory and radiological examinations in Asian developing countries.

METHODS

Using the Shiga Stroke Registry, a large population-based registry in Japan, multivariable logistic regression analysis was conducted in 1617 AIS patients ineligible for recanalization therapy to yield ß-coefficients of significant predictors of 1-month modified Rankin Scale score of 5-6, which were then multiplied by a specific constant and rounded to nearest integer to develop 0-10 points system. Model discrimination and calibration were evaluated in the original and bootstrapped population.

RESULTS

Japan Coma Scale score (J), age (A), random glucose (G), untimely onset-to-arrival time (U), atrial fibrillation (A), and preadmission dependency status according to the modified Rankin Scale score (R), were recognized as independent predictors of outcome. Each of their β-coefficients was multiplied by 1.3 creating the JAGUAR score. Its area under the curve (95% confidence interval) was .901 (.880- .922) and .901 (.900- .901) in the original and bootstrapped population, respectively. It was found to have good calibration in both study population (P = .27).

CONCLUSIONS

The JAGUAR score can be an important prediction tool of severe disability/death in AIS patients ineligible for recanalization therapy that can be applied on admission with no complicated calculation and multimodal neuroimaging necessary, thus suitable for Asian developing countries.

Association of Coronary Artery Calcification with Estimated Coronary Heart Disease Risk from Prediction Models in a Community-Based Sample of Japanese Men: The Shiga Epidemiological Study of Subclinical Atherosclerosis (SESSA)

AIM

The clinical significance of coronary artery calcification (CAC) is not fully determined in general East Asian populations where background coronary heart disease (CHD) is less common than in USA/Western countries. We cross-sectionally assessed the association between CAC and estimated CHD risk as well as each major risk factor in general Japanese men.

METHODS

Participants were 996 randomly selected Japanese men aged 40-79 y, free of stroke, myocardial infarction, or revascularization. We examined an independent relationship between each risk factor used in prediction models and CAC score ≥100 by logistic regression. We then divided the participants into quintiles of estimated CHD risk per prediction model to calculate odds ratio of having CAC score ≥100. Receiver operating characteristic curve and c-index were used to examine discriminative ability of prevalent CAC for each prediction model.

RESULTS

Age, smoking status, and systolic blood pressure were significantly associated with CAC score ≥100 in the multivariable analysis. The odds of having CAC score ≥100 were higher for those in higher quintiles in all prediction models (p-values for trend across quintiles ＜0.0001 for all models). All prediction models showed fair and similar discriminative abilities to detect CAC score ≥100, with similar c-statistics (around 0.70).

CONCLUSIONS

In a community-based sample of Japanese men free of CHD and stroke, CAC score ≥100 was significantly associated with higher estimated CHD risk by prediction models. This finding supports the potential utility of CAC as a biomarker for CHD in a general Japanese male population.

Stroke, cerebrovascular diseases and vascular cognitive impairment in Africa

With increased numbers of older people a higher burden of neurological disorders worldwide is predicted. Stroke and other cerebrovascular diseases do not necessarily present with different phenotypes in Africa but their incidence is rising in tandem with the demographic change in the population. Age remains the strongest irreversible risk factor for stroke and cognitive impairment. Modifiable factors relating to vascular disease risk, diet, lifestyle, physical activity and psychosocial status play a key role in shaping the current spate of stroke related diseases in Africa. Hypertension is the strongest modifiable risk factor for stroke but is also likely associated with co-inheritance of genetic traits among Africans. Somewhat different from high-income countries, strokes attributed to cerebral small vessel disease (SVD) are higher >30% among sub-Saharan Africans. Raised blood pressure may explain most of the incidence of SVD-related strokes but there are likely other contributing factors including dyslipidaemia and diabetes in some sectors of Africa. However, atherosclerotic and cardioembolic diseases combined also appear to be common subtypes as causes of strokes. Significant proportions of cerebrovascular diseases are ascribed to various forms of infectious disease including complications of human immunodeficiency virus. Cerebral SVD leads to several clinical manifestations including gait disturbance, autonomic dysfunction and depression. Pathological processes are characterized by arteriolosclerosis, lacunar infarcts, perivascular spaces, microinfarcts and diffuse white matter changes, which can now all be detected on neuroimaging. Except for isolated cases of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy or CADASIL, hereditary arteriopathies have so far not been reported in Africa. Prevalence estimates of vascular dementia (2-3%), delayed dementia after stroke (10-20%) and vascular cognitive impairment (30-40%) do not appear to be vastly different from those in other parts of the world. However, given the current demographic transition in both urban and rural settings these figures will likely rise. Wider application of neuroimaging modalities and implementation of stroke care in Africa will enable better estimates of SVD and other subtypes of stroke. Stroke survivors with SVD type pathology are likely to have low mortality and therefore portend increased incidence of dementia.

The Influence of the Japanese Nationwide Cardiovascular Prevention System Health Guidance on Smoking Cessation Among Smokers: A Propensity Score Matching Analysis

Aim: We investigated whether 2 types of personalized health guidance (repeated and single counseling) in the Japanese nationwide cardiovascular prevention system promoted smoking cessation among smokers.

Methods: The study included 47,745 Japanese smokers aged 40 to 74 years classified into 2 personalized health guidance schemes. After a 1-year follow-up, we compared the rates of smoking cessation between individuals who had received counseling (“supported”) and those who had not received counseling (“unsupported”). Using propensity score matching analysis, we estimated the average treatment effect (ATE) of each approach on smoking cessation after balancing out the characteristics between the supported and unsupported groups. The propensity score regression model included age, medical insurance type, weight gain since the age of 20 years, exercise, eating habits, alcohol intake, quality of sleep, readiness to modify lifestyle, willingness to receive support, and body mass index.

Results: In the repeated counseling scheme, the age-adjusted rates of smoking cessation in the supported and unsupported groups were 8.8% and 6.3% for males, and 9.8% and 9.1% for females respectively. In the single counseling scheme, the corresponding rates were 8.4% and 7.3% for supported and unsupported males, and 11.0% and 11.7% for supported and unsupported females respectively. The ATE of repeated counseling was + 2.64% (95% confidence interval: + 1.51% to + 3.77%) for males and + 3.11% (−1.85% to +8.07%) for females. The ATE of single counseling was +0.61% (−1.17% to +2.38%) for males and −1.06% (−5.96% to +3.85%) for females.

Conclusions: In the Japanese cardiovascular prevention system, repeated counseling may promote smoking cessation among male smokers.

Blood pressure, heart rate, and double product in a pooled cohort: the Japan Arteriosclerosis Longitudinal Study

OBJECTIVE

To identify the characteristics of blood pressure (BP), heart rate (HR), and double product in a Japanese population sample.

METHODS

We pooled individual records from 1999 to 2005 for 111 007 participants in 25 community-based cohorts and seven worksite-based cohorts. The data were analyzed to provide information on BP, HR, and double product according to age-sex groups and use of antihypertensive medication.

RESULTS

Average BP was 130/77 mmHg among men and women combined. Among untreated individuals, SBP increased with age, whereas DBP reached a ceiling around the age of 60 years. The average SBP of treated participants was around 140 mmHg, irrespective of age, whereas DBP decreased linearly with age, and 56.4% of treated participants had a BP of 140/90 mmHg or over. HR did not differ across age groups or treatment status. The double product, also called the rate-pressure product, calculated by multiplying the SBP and the HR, increased with age among untreated individuals, whereas it first decreased and then increased with age among treated individuals.

CONCLUSION

Based on these collaborative data, insufficient BP control in Japan, where the average life expectancy is the longest in the world, was seen.

Direct adjustment for confounding by smoking reduces radiation-related cancer risk estimates of mortality among male nuclear workers in Japan, 1999-2010

A causal relationship between protracted exposure to low-dose rate radiation and health effects remains unclear despite extensive international studies of nuclear workers. One potential reason is that radiation epidemiological studies that adjust for tobacco smoking, which heavily influences mortality, have been limited. In the present study, we examined radiation-related cancer risk by directly assessing the possible confounding effect of smoking, using data from two questionnaire surveys performed among Japanese nuclear workers in 1997 and 2003. Mortality follow-up was carried out for 71 733 male respondents for an average of 8.2 years during the observation period of 1999-2010. The mean cumulative dose was 25.5 mSv at the end of the follow-up period. Estimates of excess relative risk per Sv (ERRs/Sv) were obtained by Poisson regression. By adjusting for smoking directly on the basis of a linear dose-response model, we quantified the confounding effects of smoking on radiation risks. Statistically significant ERRs/Sv were found for all causes, all diseases, all non-cancer diseases, and liver cancer: 0.97 (90% confidence interval: 0.23, 1.78), 1.32 (0.40, 2.34), 1.87 (0.47, 3.49), and 4.78 (0.09, 11.68), respectively, without adjustment for smoking. However, the ERRs/Sv were no longer statistically significant after adjustment for smoking: 0.45 (-0.22, 1.19), 0.77 (-0.08, 1.72), 1.28 (-0.03, 2.79), and 3.89 (-0.46, 10.34), respectively. The ERRs/Sv for all cancers excluding leukaemia and lung cancer were not significant before adjustment for smoking, but declined after adjustment for smoking. The present study demonstrates that in this cohort of workers, smoking heavily distorts radiation risk estimates of mortality. The possibility of confounding by smoking depends on how strongly smoking is correlated with radiation exposure. If a correlation between smoking and radiation dose is suggested, smoking is an important confounder when assessing the radiation and health risks.

Association of extremely high levels of high-density lipoprotein cholesterol with cardiovascular mortality in a pooled analysis of 9 cohort studies including 43,407 individuals: The EPOCH-JAPAN study

BACKGROUND

The effect of very high or extremely high levels of high-density lipoprotein cholesterol (HDL-C) on cardiovascular disease (CVD) is not well described. Although a few recent studies have reported the adverse effects of extremely high levels of HDL-C on CVD events, these did not show a statistically significant association between extremely high levels of HDL-C and cause-specific CVD mortality. In addition, Asian populations have not been studied.

OBJECTIVE

We examine the impact of extremely high levels of HDL-C on cause-specific CVD mortality using pooled data of Japanese cohort studies.

METHODS

We performed a large-scale pooled analysis of 9 Japanese cohorts including 43,407 participants aged 40-89 years, dividing the participants into 5 groups by HDL-C levels, including extremely high levels of HDL-C ≥2.33 mmol/L (≥90 mg/dL). We estimated the adjusted hazard ratio of each HDL-C category for all-cause death and cause-specific deaths compared with HDL-C 1.04-1.55 mmol/L (40-59 mg/dL) using a cohort-stratified Cox proportional hazards model.

RESULTS

During a 12.1-year follow-up, 4995 all-cause deaths and 1280 deaths due to overall CVD were identified. Extremely high levels of HDL-C were significantly associated with increased risk of atherosclerotic CVD mortality (hazard ratio = 2.37, 95% confidence interval: 1.37-4.09 for total) and increased risk for coronary heart disease and ischemic stroke. In addition, the risk for extremely high HDL-C was more evident among current drinkers.

CONCLUSION

We showed extremely high levels of HDL-C had an adverse effect on atherosclerotic CVD mortality in a pooled analysis of Japanese cohorts.

Prevalence of Cardiovascular Disease and Its Risk Factors in Primary Aldosteronism: A Multicenter Study in Japan

There have been several clinical studies examining the factors associated with cardiovascular disease (CVD) in patients with primary aldosteronism (PA); however, their results have left it unclear whether CVD is affected by the plasma aldosterone concentration or hypokalemia. We assessed the PA database established by the multicenter JPAS (Japan Primary Aldosteronism Study) and compared the prevalence of CVD among patients with PA with that among age-, sex-, and blood pressure-matched essential hypertension patients and participants with hypertension in a general population cohort. We also performed binary logistic regression analysis to determine which parameters significantly increased the odds ratio for CVD. Of the 2582 patients with PA studied, the prevalence of CVD, including stroke (cerebral infarction, cerebral hemorrhage, or subarachnoid hemorrhage), ischemic heart disease (myocardial infarction or angina pectoris), and heart failure, was 9.4% (stroke, 7.4%; ischemic heart disease, 2.1%; and heart failure, 0.6%). The prevalence of CVD, especially stroke, was higher among the patients with PA than those with essential hypertension/hypertension. Hypokalemia (K⁺ ≤3.5 mEq/L) and the unilateral subtype significantly increased adjusted odds ratios for CVD. Although aldosterone levels were not linearly related to the adjusted odds ratio for CVD, patients with plasma aldosterone concentrations ≥125 pg/mL had significantly higher adjusted odds ratios for CVD than those with plasma aldosterone concentrations <125 pg/mL. Thus, patients with PA seem to be at a higher risk of developing CVD than patients with essential hypertension. Moreover, patients with PA presenting with hypokalemia, the unilateral subtype, or plasma aldosterone concentration ≥125 pg/mL are at a greater risk of CVD and have a greater need for PA-specific treatments than others.

Diabetes and lifetime risk of coronary heart disease

INTRODUCTION

Epidemiological estimate lifetime risk (LTR) is a measure that expresses the probability of disease in the remaining lifetime for individuals of a specific index age. These estimates can be useful for general audience targeted knowledge translation activities against diabetes. There are only a few reports on lifetime of impact of diabetes on coronary heart disease (CHD) events.

METHODS

The Suita Study, a cohort study of cardiovascular diseases (CVD), was established in 1989. We included all participants who were CVD free at baseline. Age (in years) was used as the time scale. Age-specific incidence rates were calculated with person-year method within ten-year bands. We estimated the sex and index-age specific LTR of first-ever CHD with taking the competing risk of death into account.

RESULTS

We followed 5559 participants without CHD history during 1989-2007 for 71,745.4 person-years. At age 40 years the competing risk of death adjusted LTR for all CHD were 16.61% for men without diabetes and 21.06% for men with diabetes. Therefore the LTD for CHD was higher by 4.45% for men with diabetes compared to men without. The competing risk adjusted LTR of CHD at 40 years of aged women was 9.18% for without diabetes and 14.21% for with diabetes. This increased LTR of CHD for diabetic patients were observed among both men and women across all index ages.

CONCLUSION

In this urban community based population we observed that diabetes has significant effect on the residual LTR of CHD among both men and women of middle age. This easy understandable knowledge can be used as important indexes to assist public health education and planning.

Detection of Left Ventricular Thrombus by Cardiac Magnetic Resonance in Embolic Stroke of Undetermined Source

BACKGROUND AND PURPOSE

We aimed to use contrast-enhanced cardiac magnetic resonance (CE-CMR) imaging to elucidate the prevalence of left ventricular (LV) thrombus in patients suspected of embolic stroke of undetermined source (ESUS) with previous myocardial infarction or LV dysfunction (LV ejection fraction [LVEF] <50%).

METHODS

We prospectively investigated 797 consecutive patients who presented to our hospital with acute ischemic stroke between 2014 and 2015. Patients with myocardial infarction or LVEF<50% underwent CE-CMR imaging. ESUS was diagnosed according to proposal criteria based on transthoracic echocardiography findings.

RESULTS

The prevalence of ESUS was 22% (178 of 797) on initial diagnosis. Among 60 patients with myocardial infarction or LVEF<50%, the stroke subtypes were as follows: small artery disease, 17% (10 of 60); large artery atherosclerosis, 5% (3 of 60); cardioembolic stroke, 49% (29 of 60); ESUS, 23% (14 of 60); and undetermined causes other than ESUS, 6% (4 of 60). Of 60 patients examined via CE-CMR, LV thrombus was confirmed in 12 patients, whereas only 1 had been detected on transthoracic echocardiography (P=0.04). Importantly, 29% (4 of 14) of patients with ESUS had LV thrombus. A prediction model based on CE-CMR findings showed higher performance in LV thrombus detection, permitting a net improvement of 0.46 (95% confidence interval, 0.08-0.82; P=0.016) in cardioembolic stroke reclassification. Compared with patients without LV thrombus, those with LV thrombus had lower LVEF (median: 26% versus 40%; P=0.003). Notably, 42% (5 of 12) of patients with LV thrombus had LVEF≥30%.

CONCLUSIONS

When ESUS-suspected patients have myocardial infarction or LV dysfunction, CE-CMR may help improve detection of cardioembolic stroke and provide relevant information for anticoagulation therapy.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02251665.

Two-Year Follow-Up of Vascular Events in Peripheral Arterial Disease Treated With Antiplatelet Agents: A Prospective Observational Multicenter Cohort Study (SEASON)

The present analysis was intended to evaluate the real-world management of peripheral arterial disease (PAD) in Asia, and to explore cardiovascular events in patients with PAD undergoing antiplatelet therapy over 2 years of follow-up. The Surveillance of cardiovascular Events in Antiplatelet-treated arteriosclerosis Obliterans patients in JapaN (SEASON) registry is a prospective observational multicenter study of cardiovascular events in antiplatelet-treated patients with PAD in Japan. The SEASON registry included 11,375 patients who were scheduled to receive treatment for PAD. Two analysis populations were defined: a real-world population (RWP; n = 10,322) and a definite PAD population (DPP; n = 3992) who had ankle-brachial pressure index (ABPI) <0.9 and intermittent claudication, or a history of lower limb revascularization. The primary outcome measure was the rate of the composite of cerebrovascular, cardiovascular, and peripheral vascular events. The composite event rates (95% confidence interval) were 3.28 (3.00-3.57) and 5.71 (5.13-6.34) events per 100 patient-years in the RWP and DPP groups, respectively. Fontaine IV classification and ABPI <0.4 at baseline were both identified as strong risk factors for vascular events. These findings contribute to understanding the situation for real-world patients with PAD receiving antiplatelet therapy.

Influence of family history on the willingness of outpatients to undergo genetic testing for salt-sensitive hypertension: a cross-sectional study

OBJECTIVES

It is unclear whether family medical history influences the willingness to undergo genetic testing. This study aimed to determine how family history affected the willingness to undergo genetic testing for salt-sensitive hypertension in patients with and without hypertension.

DESIGN

Cross-sectional study using a self-administered questionnaire.

SETTING

Six primary care clinics and hospitals in Japan.

PARTICIPANTS

Consecutive 1705 outpatients aged >20 years, 578 of whom had hypertension.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome variable was the willingness to undergo genetic testing to determine the risk of salt-sensitive hypertension, and the secondary variables were age, sex, education level, family history and concerns about hypertension. Factors associated with a willingness to undergo genetic testing were evaluated in patients with and without hypertension using a logistic regression model.

RESULTS

In the hypertension and non-hypertension groups, 323 (55.9%) and 509 patients (45.2%), respectively, were willing to undergo genetic testing. This willingness was related with a high level of education (adjusted OR (ad-OR): 1.81, 95% CI 1.12 to 2.93), family history of stroke (1.55, 1.04 to 2.31) and concerns about hypertension (2.04, 1.27 to 3.28) in the hypertension group, whereas in the non-hypertension group, it was influenced by education level (ad-OR: 1.45, 95% CI 1.13 to 1.86), family history of hypertension (1.52, 1.17 to 1.98) and concerns about hypertension (2.03, 1.53 to 2.68).

CONCLUSIONS

The influence of family history on the willingness to undergo genetic testing for risk of salt-sensitivity hypertension differed between participants with and without hypertension. In particular, participants without hypertension wished to know their likelihood of developing hypertension, whereas those with hypertension were interested to know the risk of stroke (a complication of hypertension). Family history could help better counsel patients about genetic testing on the basis of their medical history.

Trends in Policy on the Prevention and Control of Non-Communicable Diseases in Japan

Abstract-For the past decades Japan has remained number one in a range of population health metrics including the world's longest healthy life expectancy. While this was achieved through various socioeconomic factors besides public health interventions, health promotion policies to prevent and control non-communicable diseases (NCDs) played a major role. Japan introduced its first comprehensive national plan to prevent and control NCDs in 1978 and has revised the plan every decade since. These 10-year policy packages were instrumental in galvanizing stakeholders, while adapting to changing social, behavioral, and epidemiological trends. In this article, we provide an overview of trends in policy on the prevention and control of NCDs in Japan with a focus on successes and challenges especially due to a rapidly aging population. Through this review we aim to share the lessons learned in Japan for other countries tackling or expecting to be challenged by NCDs. These lessons include the role of multisectoral approaches, clear goals and targets with effective monitoring and evaluation mechanisms, addressing social aspects, adjustment to the local context, and foreseeing future demographic transition. Japan is committed to contributing to the world as a forerunner of the health challenges posed by unprecedented demographic change, by sharing its lessons in the global quest to create a world where all people can live longer and healthier lives.

Home blood pressure predicts stroke incidence among older adults with impaired physical function: the Ohasama study

OBJECTIVE

Several observational studies have found modifying effects of functional status on the association between conventional office blood pressure (BP) and adverse outcomes. We aimed to examine whether the association between higher BP and stroke was attenuated or inverted among older adults with impaired function using self-measured home BP measurements.

METHODS

We followed 501 Japanese community-dwelling adults aged at least 60 years (mean age, 68.6 years) with no history of stroke. Multivariate-adjusted hazard ratios for 1-SD increase in home BP and office BP measurements were calculated by the Cox proportional hazards model. Functional status was assessed by self-reported physical function.

RESULTS

During a median follow-up of 11.5 years, first strokes were observed in 47 participants. Higher home SBP, but not office SBP, was significantly associated with increased risk of stroke among both 349 participants with normal physical function and 152 participants with impaired physical function [hazard ratio (95% confidence interval) per 14.4-mmHg increase: 1.74 (1.12-2.69) and 1.77 (1.06-2.94), respectively], with no significant interaction for physical function (P = 0.56). Higher home DBP, but not office DBP, was also significantly associated with increased risk of stroke (P ≤ 0.029) irrespective of physical function (all P > 0.05 for interaction). Neither home BP nor office BP was significantly associated with all-cause mortality irrespective of physical function.

CONCLUSION

Higher home BP was associated with increased risk of stroke even among those with impaired physical function. Measurements of home BP would be useful for stroke prevention, even after physical function decline.

Atherosclerotic Cardiovascular Risk in Japan

Increased global mortality is associated with atherosclerosis, which appears to be independent of race. Cardiovascular disease is one of the leading causes of mortality and morbidity in Japan. Atherosclerosis, an inflammatory disease characterized by abnormal lipid accumulation and inflammation in the arterial wall, is the main underlying cause of cardiovascular disease. Numerous cardiovascular risk scores have been developed and are used to prioritize patients' treatment needs. The predictive performance of risk scores established in Western nations needs to be examined in Japanese populations. For secondary prevention, it is imperative to control hypertension, hyperlipidemia, diabetes mellitus, smoking, and local interventions. In this review, we present a historical overview of atherosclerotic risk research and the risk factors for atherosclerosis in Japan and compare the situation in Japan with that in Western nations. In addition, we discuss relevant cardiovascular risk assessment tools in the context of clinical practice in Japan.

Risk of stroke and heart failure attributable to atrial fibrillation in middle-aged and elderly people: Results from a five-year prospective cohort study of Japanese community dwellers

Background

The relative and absolute risks of stroke and heart failure attributable to atrial fibrillation (AF) have not been sufficiently examined.

Methods

A prospective study of 23,731 community-dwelling Japanese individuals was conducted. Participants were divided into two groups based on the presence or absence of prevalent AF (n = 338 and n = 23,393, respectively). Excess events (EE) due to AF and relative risks (RRs) determined using the non-AF group as the reference for incident stroke and heart failure were estimated using Poisson regression stratified by age groups (middle-aged: 40–69 years old; elderly: 70 years of age or older) after adjustment for sex and age.

Results

There were 611 cases of stroke and 98 cases of heart failure during the observation period (131,088 person-years). AF contributed to a higher risk of stroke both in middle-aged individuals (EE 10.4 per 1000 person-years; RR 4.88; 95% confidence interval [CI], 2.88–8.29) and elderly individuals (EE 18.3 per 1000 person-years; RR 3.05; 95% CI, 2.05–4.54). AF also contributed to a higher risk of heart failure in middle-aged individuals (EE 3.7 per 1000 person-years; RR 8.18; 95% CI, 2.41–27.8) and elderly individuals (EE 15.4 per 1000 person-years; RR 7.82; 95% CI, 4.11–14.9). Results obtained from multivariate-adjusted analysis were similar (stroke: EE 8.9 per 1000 person-years; RR 4.40; 95% CI, 2.57–7.55 in middle-aged and EE 17.4 per 1000 person-years; RR 2.97; 95% CI, 1.99–4.43 in elderly individuals; heart failure: EE 3.1 per 1000 person-years; RR 7.22; 95% CI, 2.06–25.3 in middle-aged and EE 14.1 per 1000 person-years; RR 7.41; 95% CI, 3.86–14.2 in elderly individuals).

Conclusions

AF increased the risk of stroke by the same magnitude as that reported previously in Western countries. AF increased the RR of heart failure more than that in Western populations.

•

Incidence rates for stroke and HF were estimated in Japanese community dwellers.

•

Subjects were divided into AF and non-AF groups separately by age (40–69 and ≥70).

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AF increased the risk of stroke by the same magnitude as in Western populations.

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AF increased the risk of HF more than that in Western populations.

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The absolute risk differences of outcomes were larger in the elderly individuals.

The long-term outcomes of hepatitis C virus core antigen-positive Japanese renal allograft recipients

BACKGROUND

The impact of hepatitis C virus (HCV) infections on patient long-term survival after renal transplants is unclear.

METHOD

To clarify the long-term outcomes of Japanese renal allograft recipients with HCV infections, we studied the cases of 187 patients (118 males and 69 females; 155 living donor cases, and 32 deceased donor cases; median follow-up period: 250 months) who underwent an initial renal transplant at Kanazawa Medical University from 1974 onwards.

RESULT

In this cohort, 35 patients (18.7%) were HCV core antigen (Ag)-positive, and 13 of them (37.1%) died (due to liver cirrhosis (4 cases), hepatocellular carcinoma (1 case), fibrosing cholestatic hepatitis due to HCV (1 case), and infections complicated with chronic hepatitis (6 cases)). However, only 14 of the 145 (9.7%) recipients died in the HCV-Ag/HCV antibody (Ab)-negative group. The Kaplan-Meier life table method indicated that the HCV-infected group exhibited significantly lower patient and death-censored allograft survival rates (log-rank test; patient survival: Chi-square: 11.2, p = 0.004; graft survival: Chi-square: 25.7, p < 0.001). The survival rate of the HCV-Ag-positive recipients decreased rapidly at 240 months after the renal transplant procedure. In addition, a Cox proportional hazards model indicated that positivity for the HCV-Ag was the most important independent risk factor for post-renal transplant survival and allograft function [survival: hazard ratio (HR) 3.93 (1.54-10.03), p = 0.004; graft function: HR 2.09 (1.14-3.81), p = 0.016].

CONCLUSION

HCV infection is a harmful risk factor for patient survival (especially at ≥20 years post-renal transplant) and renal allograft function in allograft recipients.

Similarities and differences between coronary heart disease and stroke in the associations with cardiovascular risk factors: The Japan Collaborative Cohort Study

BACKGROUND AND AIMS

Coronary heart disease (CHD) and stroke have common risk factors, but some of these differ in the magnitude or direction of associations between CHD and stroke. We assessed whether the impact of each risk factor differed between CHD and stroke mortality in Asians.

METHODS

In total, 104 910 subjects aged 40-79 years without histories of cancer, CHD and stroke at baseline were followed between 1988 and 2009. Competing-risks analysis was used to test for differences in the associations of each risk factor with two endpoints (CHD and stroke). Population attributable fractions (PAFs) were also calculated for these endpoints to estimate the population impact of each risk factor.

RESULTS

During a median 19.1-year follow-up, 1554 died from CHD and 3163 from stroke. The association of hypertension with CHD was similar to that with stroke in terms of the magnitude and direction (multivariable-adjusted hazard ratio for CHD: 1.63 vs. stroke: 1.73 in men and 1.70 vs. 1.66 in women). Conversely, the magnitude of these associations differed for smoking (CHD: 1.95 vs. stroke: 1.23 in men and 2.45 vs. 1.35 in women) and diabetes (1.49 vs. 1.09 in men and 2.08 vs. 1.39 in women). The highest PAF for CHD was caused by smoking in men and by hypertension in women; that for stroke was caused by hypertension in both sexes.

CONCLUSIONS

Hypertension associations and PAFs were consistent between CHD and stroke, but not for other risk factors. These findings may be useful to optimize public health intervention strategies.

Coronary Artery Calcium and Carotid Artery Intima Media Thickness and Plaque: Clinical Use in Need of Clarification

Atherosclerosis begins in early life and has a long latent period prior to onset of clinical disease. Measures of subclinical atherosclerosis, therefore, may have important implications for research and clinical practice of atherosclerotic cardiovascular disease (ASCVD). In this review, we focus on coronary artery calcium (CAC) and carotid artery intima-media thickness (cIMT) and plaque as many population-based studies have investigated these measures due to their non-invasive features and ease of administration. To date, a vast majority of studies have been conducted in the US and European countries, in which both CAC and cIMT/plaque have been shown to be associated with future risk of ASCVD, independent of conventional risk factors. Furthermore, these measures improve risk prediction when added to a global risk prediction model, such as the Framingham risk score. However, no clinical trial has assessed whether screening with CAC or cIMT/plaque will lead to improved clinical outcomes and healthcare costs. Interestingly, similar levels of CAC or cIMT/plaque among various regions and ethnic groups may in fact be associated with significantly different levels of absolute risk of ASCVD. Therefore, it remains to be determined whether measures of subclinical atherosclerosis improve risk prediction in non-US/European populations. Although CAC and cIMT/plaque are promising surrogates of ASCVD in research, we conclude that their use in clinical practice, especially as screening tools for primary prevention in asymptomatic adults, is premature due to many vagaries that remain to be clarified.

Radiation and circulatory disease

Exposure to therapeutic doses of ionizing radiation is associated with damage to the heart and coronary arteries. However, only recently have studies with high-quality individual dosimetry data allowed this risk to be quantified while also adjusting for concomitant chemotherapy, and medical and lifestyle risk factors. At lower levels of exposure the evidence is less clear. In this article I review radiation-associated risks of circulatory disease in groups treated with radiotherapy for malignant and non-malignant disease, and in occupationally- or environmentally-exposed groups receiving rather lower levels of radiation dose, also for medical diagnostic purposes. Results of a meta-analysis suggest that excess relative risks per unit dose for various types of heart disease do not exhibit statistically significant (p>0.2) heterogeneity between studies. Although there are no marked discrepancies between risks derived from the high-dose therapeutic and medical diagnostic studies and from the moderate/low dose occupational and environmental studies, at least for ischemic heart disease and stroke there are indications of larger risks per unit dose for lower dose rate and fractionated exposures. Risks for stroke and other types of circulatory disease are significantly more variable (p<0.0001), possibly resulting from confounding and effect-modification by well known (but unobserved) risk factors. Adjustment for any of mean dose, dose fractionation or age at exposure results in the residual heterogeneity for cerebrovascular disease becoming non-significant. The review provides strong evidence in support of a causal association between both low and high dose radiation exposure and most types of circulatory disease.

Traditional Risk Factors for Stroke in East Asia

Stroke is one of the leading causes of death and morbidity worldwide. The occurrence of stroke is strongly dependent on well-known vascular risk factors. After rapid modernization, urbanization, and mechanization, East Asian countries have experienced growth in their aged populations, as well as changes in lifestyle and diet. This phenomenon has increased the prevalence of vascular risk factors among Asian populations, which are susceptible to developing cardiovascular risk factors. However, differing patterns of stroke risk factor profiles have been noted in East Asian countries over the past decades. Even though the prevalence of vascular risk factors has changed, hypertension is still prevalent and the burden of diabetes and hypercholesterolemia will continue to increase. Asia remains a high tobacco-consuming area. Although indicators of awareness and management of vascular risk factors have increased in many East Asian countries, their rates still remain low. Here we review the burdens of traditional risk factors, such as hypertension, diabetes, hypercholesterolemia, and smoking in East Asia. We will also discuss the different associations between these vascular risk factors and stroke in Asian and non-Asian populations.

Validation of the european SCORE risk chart in the healthy middle-aged Japanese

BACKGROUND AND AIMS

The European Society of Cardiology developed prediction models (SCORE) for low- and high-risk populations in the European countries. However, whether or not these models are valid in different ethnicities is unknown. We aimed to evaluate the performance of the low-risk SCORE model in the general Japanese population.

METHODS

Healthy middle-aged Japanese participating in the NIPPON DATA80 cohort had been observed. The predicted 10-year cardiovascular death risk was calculated using the low-risk SCORE model for the overall population as well as for each gender individually. The model performance of the low-risk SCORE model was evaluated with the Harrel's c-statistics for discrimination and the Grønnesby and Borgan goodness-of-fit test for calibration.

RESULTS

A total of 4842 participants aged 40-64 years old and 47,606 person-years were evaluated in our study. 203 (4.19%) died within the ten-years of follow-up and 44 (0.91%) CV deaths were observed. The low-risk SCORE model in the overall population had reasonable discrimination (c statistics 0.72, 95% CI 0.71-0.73) but poor calibration (R(2), 0.67, Chi-square value 6.15, p = 0.01). Discrimination was reasonable in both men (c statistics 0.71, 95% CI 0.69-0.73) and women (c statistics 0.71, 95% CI 0.70-0.73). However, calibration was poor in men (R(2), 0.22, Chi-square value 0.749, p = 0.38) compared to women (R(2), 0.96, Chi-square value 1.39, p = 0.24).

CONCLUSIONS

Although the low-risk SCORE model performs reasonably well in women, the SCORE models generally overestimated the risk of cardiovascular death risk in the Japanese general population.

Radiation-related risks of non-cancer outcomes in the atomic bomb survivors

Risks of non-cancer outcomes after exposure to atomic bomb (A-bomb) radiation have been evaluated among the Life Span Study (LSS) cohort and its subcohort, the Adult Health Study (AHS). Information regarding non-cancer outcomes in the LSS is obtained from death certificates. In the AHS, members undergo clinical examinations biennially to determine their health status. Many AHS studies have been limited to participants attending the clinic over a limited period, and therefore have varying degrees of inferential utility; as such, care is required for comparison with the LSS results. Disease structure of non-cancer diseases in Japan has changed over the long follow-up period since the end of World War II. The health status of the A-bomb survivors may be associated with the hardships of living in a devastated city and impoverished country following the prolonged war effort, in addition to the direct effects of radiation exposure. Radiation-related risk of cardiovascular disease may have increased due to radiation-related increased risk of hypertension and other secondary associations, and the risk of atherosclerotic disorders has also been reported recently. These results should be interpreted with caution because of changes in disease definitions over the follow-up period. The radiation-related risk of non-cancer respiratory diseases also appears to have increased over the follow-up period, but the shapes of the dose-response curves have shown little consistency.

Relationship Between Serum High-Sensitivity C-Reactive Protein and Myocardial Infarction in a General Japanese Population

BACKGROUND

Due to ethic differences in its serum levels, clinical applicability of high-sensitivity C-reactive protein (hsCRP) to the primary prevention of atherosclerotic events has not completely been established in Japanese people whose hsCRP levels are lower than in Western people. This study investigated the relationship between hsCRP and myocardial infarction (MI) in general Japanese people.

METHODS

In relation to hsCRP, the incidence of MI was determined in a multiregional population-based prospective cohort study (n = 6,637; mean age 54.9 years; 2,513 men/4,124 women).

RESULTS

Fifty-six cases of MI were confirmed during a follow-up period of 10.7 years. The cut-off levels of hsCRP between the highest quartile (fourth quartile) and the other quartiles combined were 0.368 mg/l in men and 0.279 mg/l in women. The hazard ratio (HR) of the highest quartile for MI was significantly greater than that of the other quartiles combined (multivariate-adjusted HR: 2.07, 95% confidence interval: 1.03-4.15) in men, but not in women (1.03, 0.35-2.21).

CONCLUSIONS

In this population, serum hsCRP measurement predicted MI in men, but not in women. Under the low hsCRP level, a method of applicability of hsCRP to a risk assessment for preventing MI among Japanese people should be further explored.

Sex differences in clinical characteristics and long-term outcome in acute decompensated heart failure patients with preserved and reduced ejection fraction

In patients with acute decompensated heart failure (ADHF), sex differences considering clinical and pathophysiologic features are not fully understood. We investigated sex differences in left ventricular (LV) ejection fraction (LVEF), plasma B-type natriuretic peptide (BNP) levels, and prognostic factors in patients with ADHF in Japan. We studied 748 consecutive ADHF patients of 821 patients registered in the ADHF registry between January 2007 and December 2014. Patients were divided into four groups based on sex and LVEF [reduced (ejection fraction, or EF, <50%, heart failure with reduced EF, or HFrEF) or preserved (EF ≥50%, heart failure with preserved LVEF, or HFpEF)]. The primary endpoint was the combination of cardiovascular death and heart failure (HF) admission. The present study consisted of 311 female patients (50% HFrEF, 50% HFpEF) and 437 male patients (63% HFrEF, 37% HFpEF). There was significant difference between sexes in the LVEF distribution profile. The ratio of HFpEF patients was significantly higher in female patients than in male patients ( P = 0.0004). Although there were no significant sex differences in median plasma BNP levels, the prognostic value of BNP levels was different between sexes. Kaplan-Meier analysis revealed that the high BNP group had worse prognosis than the low BNP group in male but not in female patients. In multivariate analysis, log transformed BNP at discharge predicted cardiovascular events in male but not in female HF patients (female, hazard ratio: 1.169; 95% confidence interval: 0.981–1.399; P = 0.0806; male, hazard ratio: 1.289; 95% confidence interval: 1.120–1.481; P = 0.0004). In patients with ADHF, the distribution of LV function and the prognostic significance of plasma BNP levels for long-term outcome were different between the sexes.

Association of Dialysis Duration with Outcomes after Transplantation in a Japanese Cohort

BACKGROUND AND OBJECTIVES

Evidence regarding the differences in clinical outcomes after preemptive kidney transplantation (PKT) and non-PKT in Japan is lacking.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a retrospective cohort study at a single center in Japan. Consecutive patients ages >18 years old who had received a kidney transplant from a living donor between November of 2001 and December of 2013 at our institution (n=786) were enrolled. The primary study outcome was the occurrence of clinical events before the end of 2014. Clinical events were defined as any of the following: death with functioning graft (DWFG), graft loss, or post-transplant cardiovascular disease (CVD).

RESULTS

The median follow-up period was 61.0 (35.3-94.0) months. PKT was performed in 239 patients (30.4%). Clinical events occurred in 78 (9.9%). In the Cox proportional hazard model for univariate analysis, factors found to be associated with higher risk of clinical events included older age, men, ABO incompatibility, longer dialysis duration, diabetes, pretransplant CVD, and large ventricular mass index. PKT was associated with lower risk. Clinical event rate in patients who received a PKT was 3.3% compared with 10.8%, 11.1%, 10.4%, 10.2%, 16.7%, and 16.2% among patients who were on dialysis for <1, 1 to <2, 2 to <3, 3 to <4, 4 to <5, and ≥5 years before transplant, respectively (P=0.002). The multivariate analysis showed that ABO incompatibility (hazard ratio [HR], 2.98; 95% confidence interval [95% CI], 1.89 to 4.71), duration of dialysis per year (HR, 1.07; 95% CI, 1.03 to 1.11), and diabetes (HR, 3.54; 95% CI, 2.05 to 6.12) were only three independent risk factors for the incidence of clinical events.

CONCLUSIONS

Even in Japan, where the long-term outcomes of patients on hemodialysis are excellent, PKT could be beneficial to reduce DWFG, graft loss, and post-transplant CVD.