Yoko M. Nakao

Hypertension and lifetime risk of stroke

Background: The lifetime risk (LTR) articulates the probability of disease in the residual lifetime for an index age. These estimates can be useful for general audience-targeted knowledge translation activities against hypertension. There are only a few reports on lifetime of impact of hypertension on stroke events in Asians in whom stroke incidence is higher than Westerners. Methods: The Suita Study, a cohort study of cardiovascular diseases in Japan, was established in 1989. We included all participants who were stroke free at baseline. Age (in years) was used as the time scale. Age-specific incidence rates were calculated with person-year method within 10-year bands. We estimated the sex and index-age specific LTR of first-ever stroke with taking the competing risk of death into account. Results: We followed 5783 men and women during 1989–2007 for 74u200a933 person-years. During the follow-up period, 276 (149 men and 127 women) participants had incident stroke. Of them, majority were cerebral infarction; 166 (102 men and 64 women). The LTR of stroke, accounted for competing risk of death, at 45 years of age for men without hypertension was 17.21% and it was 32.79% for hypertensive men. Among the hypertensive patients, participants with stage 2 or greater hypertension had higher LTR of stroke than the participants with stage 1 hypertension. This increased LTR of stroke for hypertensive patients were also observed among women and across all index ages for stroke. Conclusion: In this urban community-based population, we observed that hypertension has significant effect on the residual LTR of stroke among both men and women of middle age, specifically for ischemic stroke.

Interaction of Blood Pressure and Body Mass Index With Risk of Incident Atrial Fibrillation in a Japanese Urban Cohort: The Suita Study

BACKGROUND AND PURPOSEnTo prevent stroke, strategies for atrial fibrillation (AF) prevention and an early detection of AF by electrocardiogram are essential. However, only a limited prospective studies have examined the risk factors for AF, even in blood pressure (BP) and body mass index (BMI), which are not clear among general populations. We investigated the impacts of BP and BMI on the risk of incident AF in a general population.nnnMETHODSnA total of 6,906 participants (30-84 years) in the Suita Study were prospectively followed up for incident AF. Participants were diagnosed with AF if AF or atrial flutter was present on an electrocardiogram from a routine health examination (every 2 years) or if AF was indicated as a present illness from health examinations and/or medical records during follow-up. Adjusted Cox proportional hazard ratios (HRs) were calculated.nnnRESULTSnDuring the 12.8-year follow-up, 253 incident AF events occurred. Compared with the systolic BP (SBP) < 120 mm Hg and normal-weight, the adjusted HRs (95% confidence intervals; CIs) of incident AF in the systolic hypertension and the overweight (BMI ≥ 25kg/m(2)) groups were 1.74 (1.22-2.49) and 1.35 (1.01-1.80), respectively. Compared with SBP < 120 mm Hg and normal weight, the adjusted HRs (95% CIs) of incident AF in the SBP = 120-139 mm Hg with overweight and the systolic hypertension with normal or overweight were 1.72 (1.01-2.91), 1.66 (1.10-2.50), and 2.31 (1.47-3.65), respectively (P for interaction = 0.04).nnnCONCLUSIONSnSystolic prehypertension and overweight are associated with incident AF in Japanese population. The association between SBP and AF may be evident by overweight.

Development of a Basic Risk Score for Incident Atrial Fibrillation in a Japanese General Population ― The Suita Study ―

BACKGROUNDnAn atrial fibrillation (AF) risk score for a non-Western general population has not been established.Methodsu2004andu2004Results:A total of 6,898 participants (30-79 years old) initially free of AF have been prospectively followed for incident AF since 1989. AF was diagnosed when AF or atrial flutter was present on ECG at a biannual health examination; was indicated as a current illness; or was in the medical records during follow-up. Cox proportional hazard ratios were analyzed after adjusting for cardiovascular risk factors at baseline. During the 95,180 person-years of follow-up, 311 incident AF events occurred. We developed a scoring system for each risk factor as follows: 0/-5, 3/0, 7/5, and 9/9 points for men/women in their 30 s-40 s, 50 s, 60 s, and 70 s, respectively; 2 points for systolic hypertension, overweight, excessive drinking, or coronary artery disease; 1 point for current smoking; -1 point for moderate non-high-density lipoprotein-cholesterol; 4 points for arrhythmia; and 8, 6, and 2 points for subjects with cardiac murmur in their 30 s-40 s, 50 s, and 60 s, respectively (C-statistic 0.749; 95% confidence interval, 0.724-0.774). Individuals with score ≤2, 10-11, or ≥16 points had, respectively, ≤1%, 9%, and 27% observed probability of developing AF in 10 years.nnnCONCLUSIONSnWe developed a 10-year risk score for incident AF using traditional risk factors that are easily obtained in routine outpatient clinics/health examinations without ECG.

Changes in Waist Circumference and the Incidence of Type 2 Diabetes in Community-Dwelling Men and Women: The Suita Study

BACKGROUNDSnThe association between weight gain and the incidence of type 2 diabetes is well known. The aim of our study was to investigate the relationship between change in waist circumference (WC) and type 2 diabetes incidence.nnnMETHODSnThe participants in the Suita Study, a population-based cohort study in an urban area of Japan, underwent a baseline survey between 1989 and 1994 (Exam 1) and were examined at follow-up every 2 years. We performed a 9.3-year cohort study of 946 men and 1327 women with no history of diabetes who underwent Exam 1 and Exam 2 (between 1997 and 1999). Participants were stratified by sex and median WC at Exam 1, and, in each stratum, participants were further classified into three categories by tertile of WC change per year between Exam 1 and Exam 2. Hazard ratios (HRs) and 95% confidence intervals (CIs) for type 2 diabetes incidence were calculated by Cox proportional hazard models. The endpoints were first diagnosis of type 2 diabetes or March 2011.nnnRESULTSnDuring follow-up, 287 participants developed type 2 diabetes. In both sexes with median WC or higher, participants in the highest tertile of WC change had a significantly higher risk of developing type 2 diabetes. Multivariable adjusted HRs were 1.84 (95% CI, 1.10-3.08) in men and 2.30 (95% CI, 1.31-4.04) in women. No significant association was observed among participants with WC below median.nnnCONCLUSIONSnPreventing WC gain is important in preventing type 2 diabetes in the Japanese population, especially among individuals with a relatively high WC.

Risk for metabolic diseases in normal weight individuals with visceral fat accumulation: a cross-sectional study in Japan

Objective To investigate the association between visceral fat area (VFA) and metabolic syndrome (Mets) among normal weight Japanese. Design A cross-sectional study. Setting The health check-up centre of the Takeda Hospital group in Kyoto, Japan. Methods This study involved 1674 men and 1448 women aged 30–74u2005years who underwent medical check-ups in 2012 in the health check-up centre. They were stratified by Body Mass Index (BMI cut-off for obesity is set at 23.0u2005kg/m2 for Asians): normal weight 18.5–22.9u2005kg/m2 or higher weight ≥23.0u2005kg/m2. The age-adjusted ORs of the 2nd to 4th groups of sex-specific VFA quartiles compared with the 1st quartile for a Mets component clustering were estimated. The clustering was having two or more of the following factors: high blood pressure, high fasting blood glucose (FBG), low high-density lipoprotein cholesterol (HDL-C) and high triglycerides. Statistical analyses were conducted in 2016. Results Participants in the 2nd to 4th VFA quartiles had significantly higher clustering risks; ORs were 3.4 (1.5 to 8.0), 6.3 (2.8 to 14.2) and 9.3 (4.2 to 20.7) for normal weight participants, and 1.7 (1.2 to 2.6), 2.6 (1.8 to 3.9) and 6.0 (4.1 to 8.8) for higher weight participants, respectively. The ORs of the 4th VFA quartile for Mets components were significantly higher; ORs for normal weight participants were 2.1 (1.5 to 3.0) (high blood pressure), 2.4 (1.4 to 4.2) (high FBG), 5.2 (2.1 to 12.9) (low HDL-C) and 12.0 (5.7 to 25.3) (high triglycerides), and higher weight participants were 3.9 (2.8 to 5.5), 4.1 (2.8 to 6.2), 3.9 (2.2 to 6.9) and 5.0 (3.4 to 7.4), respectively. Conclusions Among participants with normal weight, as well as those of higher weight, dose-dependent responses were observed between VFA and risk for Mets components and the clustering among Japanese adults. VFA may be useful information for interventions to improve metabolic risk factors in people with normal weight.

J Wave Is Better Left Alone

electrical heart disease has been excluded and are affected by reflex syncope have an excellent prognosis.13 Many poor outcomes seem to be related to the severity of the “underlying condition” rather than to syncope per se.14 Recent studies suggest that the J wave is a marker of increased dispersion of repolarization,15 suggesting the J wave could be an “underlying condition” in subjects with syncope. Considering early repolarization syndrome and Brugada syndrome can be a common clinical entity under the term of J-wave syndromes,16 the association between the J wave and reflex syncope has now become even more important. Chiba et al show that a J-wave pattern in the inferior or lateral leads was associated with reflex syncope. However, Löbe et al reported a completely different result that J waves in the inferior leads are less frequently found in subjects with vasovagal syncope than in those with unexplained syncope.17 To date, J waves in the inferolateral leads can be an important diagnostic sign of a high-risk person with a history of syncope.10 Until we have further evidence from syncope subjects, we are left with the observation that in subjects with J waves in the inferolateral leads and any type of syncope, arrhythmic events may occur.

Impact of hypertension on the lifetime risk of coronary heart disease

The lifetime risk estimate conveys the probability of disease in the remaining lifetime for an index age. These estimates may be useful for general audience-targeted knowledge translation activities against hypertension. There are only a few reports on the impact of hypertension on the lifetime risk of cardiovascular events. The Suita Study, a cohort study of urban residents, was established in 1989. We included all participants who were coronary heart disease (CHD) free at baseline. Age (in years) was used as the timescale. Age-specific incidence rates were calculated with the person-year method within 5-year bands. We estimated the sex- and index-age-specific lifetime risk of first-ever CHD, taking the competing risk of death into account. We followed 5834 participants from 1989 to 2007 for a total of 75u2009387.5 person-years. At age 45 years, the competing risk of death-adjusted lifetime risk for all CHD for men was 14.12% for normotensive men and 26.95% for hypertensive men. The competing risk of death-adjusted lifetime risk for all CHD at 45 years of age for women was 6.21% for normotensive women and 14.85% for hypertensive women. This increased lifetime risk of CHD for hypertensive patients was observed among both men and women across all index ages. Although the overall lifetime risk of CHD was lower than in the Western population, hypertension showed a significant effect on the residual lifetime risk of CHD among Japanese middle-aged men and women. This easy-to-understand knowledge may be used as an important index to assist public health education and planning.

Effectiveness of nationwide screening and lifestyle intervention for abdominal obesity and cardiometabolic risks in Japan: The metabolic syndrome and comprehensive lifestyle intervention study on nationwide database in Japan (MetS ACTION-J study)

Background Lifestyle interventions can substantially improve obesity and cardiometabolic risks. However, evidence of long-term benefits of national intervention is sparse. We aimed to evaluate the long-term effectiveness of a nationwide program for abdominal obesity. Methods A retrospective cohort study was performed using a longitudinal nationwide individual data in subjects aged 40–74 years who underwent checkups in fiscal year (FY) 2008. Lifestyle interventions were provided via interview in subjects with abdominal obesity and at least one cardiometabolic risk factor. Subjects who attended the lifestyle intervention (participants) were compared to those who did not attend (non-participants). Outcomes were waist circumferences (WC) and body mass index (BMI) reduction, reversal of metabolic syndrome (MetS), and changes in cardiometabolic risks. We used a three-step process with robust analytic approaches to account for selection bias that included traditional multivariate analysis, propensity-score matching and instrumental variable (IV) analyses. Results Of 19,969,722 subjects, 4,370,042 were eligible for analyses; 111,779 participants and 907,909 non-participants. A higher percentage of participants had ≥5% reductions in obesity profiles at year 3, compared to non-participants (WC, 21.4% vs 16.1%; BMI, 17.6% vs 13.6%; p<0.001 each). Participants also had higher reversal for MetS (adjusted odds ratio 1.31; 95% confidence interval: 1.29–1.33; p<0.001). Greater reductions in cardiometabolic risks were observed in participants. Those results were confirmed in analyses using a propensity score-matched cohort (n = 75,777, each) and IV analyses. Limitations of this work include the use of non-randomized national data in Japan to assess the effectiveness of the nationwide preventive program. Conclusions In the nationwide lifestyle intervention for abdominal obesity, the at-risk population achieved significant reductions in WC, BMI, and cardiometabolic risks in 3 years. This study provides evidence that the nationwide program effectively achieved long-term improvement in abdominal obesity and cardiometabolic risks.

Impact of Intima–Media Thickness Progression in the Common Carotid Arteries on the Risk of Incident Cardiovascular Disease in the Suita Study

Background No prospective study of the relationship between intima–media thickness (IMT) progression and incident cardiovascular disease (CVD) has been performed. Methods and Results We studied 4724 participants (mean age: 59.7±11.9 years; without CVD at the baseline) who had carotid ultrasonographic measurement of IMT on both sides of the entire carotid artery area (ie, the entire scanned common carotid artery [CCA], carotid artery bulb, internal carotid artery, and external carotid artery areas for both sides) between April 1994 and August 2001. Carotid ultrasonographic follow‐up was performed every 2 years between April 1994 and March 2005 in 2722 of these participants, newly revealing 193 CCA plaques (maximum IMT in the CCA >1.1 mm). We followed up for incident CVD until December 2013. Statistical analyses were performed using a Cox proportional hazards regression model, evaluated using C statistics, and net reclassification improvement. During the 59 909 person‐years of follow‐up, we observed 221 strokes and 154 coronary heart disease events. CCA plaque and maximum IMT in the whole carotid artery area >1.7 mm were risk factors for CVD. CCA plaque presented an increased risk of CVD based on C statistics and the reclassification improvement of the current risk prediction model. After adding the new incident CCA plaques, during the 23 702 person‐years of follow‐up, 69 strokes and 43 coronary heart disease events occurred. The adjusted hazard ratios for incident CCA plaque were 1.95 (95% confidence interval, 1.14–3.30) in CVD and 2.01 (95% confidence interval, 1.01–3.99) in stroke. Conclusions Maximum IMT in the CCA contributed significantly but modestly to the predictive power of incident CVD used in calculating traditional risk factors. This study provides the first demonstration that new progression of incident CCA plaque is a CVD risk.

HIGH SYSTOLIC BLOOD PRESSURE IS ASSOCIATED WITH INCIDENT LATENT HEART FAILURE: THE SUITA STUDY

Objective: Preventing organ dysfunction is essential for the extension of the healthy life expectancy among the high prevalence of longevity populations, but there are few epidemiological studies on heart failure (HF) for residents other than Westerners. We hypothesized that high systolic blood pressure (BP) affects the risk of subsequent latent HF in a general Japanese population. Design and method: We prospectively followed-up 2,760 participants (average age 66.7u200a±u200a10.4 years) initially free of latent HF for incident latent HF in the Suita Study. B-type natriuretic peptide (BNP) was measured by the CLEIA method. Latent HF was defined as BNP >u200a=u200a100u200apg/mL or HF medication from medical records. Each subjects health status and BNP were checked in biannual medical examinations, and annual questionnaires were also completed by all subjects. BP was measured twice in the sitting position after resting for >u200a=u200a5u200amin. The values’ mean was used for the analysis. The endpoint of the follow-up period for incident latent HF was whichever of the following occurred first: the date of the first diagnosis of latent HF, BNP>u200a=u200a100u200apg/mL, or HF medication. We analyzed Cox proportional hazard ratios (HRs) and 95% confidence intervals (CIs) for incident latent HF after adjusting for cardiovascular risk factors. Results: In 16,856 person-years of follow-up, 270 incident latent HF events occurred. The age- and sex-adjusted HRs (95% CI) for incident latent HF were 1.92 (1.24–2.99) in grade II or III systolic hypertension (>u200a=u200a160 mmHg) and 1.99 (1.30–3.06) in high pulse pressure >u200a=u200a60 mmHg, compared with optimal systolic BP (<120 mmHg) and low pulse pressure <40 mmHg, respectively. The multivariable-adjusted HR (95%CIs) for incident latent HF was 2.17 (1.37–3.44), compared with optimal systolic BP. The age- and sex- and multivariable-adjusted HRs (95%CIs) for incident latent HF were 1.34 (1.05–1.72) and 1.09 (0.83–1.43) in antihypertensive drug use, respectively. No association between diastolic BP and incident latent HF was observed. Conclusions: Our findings are the first to show that grade II or III systolic hypertension is a robust predictive marker of incident latent HF in a general Japanese population.