Fatty Liver Index as a proxy for non-alcoholic fatty liver disease and the risk of stroke and coronary heart disease: The Suita Study.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in developed countries, but its role in predicting cardiovascular disease (CVD) needs further investigation. Herein, we studied the association between NAFLD and the risk of CVD, stroke, and coronary heart disease (CHD) among Japanese people. METHODS: This prospective cohort study analyzed data from 2,517 men and 3,958 women, aged 30-84 years, who were registered in the Suita Study. NAFLD was defined as Fatty Liver Index (FLI) ≥ 60. Cox proportional hazard models were applied to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of incident CVD, stroke, and CHD events by baseline FLI. The results were adjusted for age, smoking, alcohol consumption, hypertension, diabetes, lipid profile, chronic kidney disease, and cardiac murmur or valvular diseases. RESULTS: Within 16.6 years of median follow-up, 590 participants developed CVD (346 stroke events and 244 CHD events). Women with NAFLD (FLI ≥ 60) showed a higher risk of CVD and stroke: HRs (95% CIs) = 1.69 (1.16, 2.46) and 2.06 (1.31, 3.24), respectively. Besides, women in the fourth and fifth (highest) FLI quintiles showed a higher risk of CVD and stroke than those in the third (middle) quintile: HRs (95% CIs) = 1.60 (1.08, 2.36) and 1.67 (1.13, 2.45) for CVD and 1.73 (1.07, 2.79) and 1.90 (1.18, 3.05) for stroke, respectively. No corresponding associations were detected in men. NAFLD was not associated with CHD risk in either sex. CONCLUSIONS: NAFLD, diagnosed by FLI, was associated with a higher risk of CVD and stroke in Japanese women. From a preventive perspective, women with NAFLD should be targeted for CVD screenings and interventions.

The effect of age on the relationship between body mass index and risks of incident stroke subtypes: The JPHC study.

OBJECTIVE: The associations between body mass index (BMI) and stroke subtypes, particularly intracerebral hemorrhage, have not been consistent. Such inconsistencies may be due to differences in the age at which BMI was obtained. We examined the possible age modifications in the association between BMI and stroke risk. MATERIALS AND METHODS: We followed 88,754 participants, aged 40-69 years at baseline (1990-1994), of the Japan Public Health Center-based prospective (JPHC) study for stroke incidence. BMI was obtained using self-reported body weight and height, which were categorized using the following cut-off points: 18.5, 21, 23, 25, 27.5, and 30 kg/m2. Time-dependent Cox proportional hazards models that updated BMI and covariates using 5- and 10-year questionnaire responses were used to estimate hazard ratios and 95 % confidence intervals. The analyses were stratified by age group (40-59 and ≥60 years) and the age of the individuals was updated. RESULTS: During the median follow-up period of 19 years, we documented 4,690 strokes, including 2,781 ischemic strokes and 1,358 intracerebral hemorrhages. After adjusting for sex, age, smoking, alcohol consumption, leisure-time physical activity, history of hypertension, dyslipidemia, and diabetes mellitus, we observed a positive linear association between BMI and ischemic stroke (linear trend, p < 0.001) in both age groups (interaction p>0.05). In contrast, a curvilinear association between BMI and intracerebral hemorrhage was observed in both the middle (curvilinear trend, p=0.017) and the older group (curvilinear trend, p=0.098) (interaction p>0.05). CONCLUSION: BMI and stroke associations did not vary significantly with age, although the association may differ according to subtype.

The association between stair climbing and modifiable cardiovascular disease risk factors: the Suita Study.

BACKGROUND: Stair climbing is a readily available form of physical activity with potential cardiovascular benefits. This study aimed to investigate the association between stair climbing and numerous modifiable cardiovascular disease (CVD) risk factors. METHODS: In this cross-sectional study, we used data from 7282 Japanese people (30-84 years) residing in Suita City, Osaka. CVD risk factors and stair climbing frequency were assessed during the Suita Study health examination. Logistic regressions were used to calculate the odds ratios (ORs) and 95% confidence intervals (95% CIs) for CVD risk factors across stair climbing frequencies. RESULTS: After adjustment for age, sex, lifestyle, and medical conditions, stair climbing >60% of the time, compared to <20% of the time, was inversely associated with obesity, smoking, physical inactivity, and stress: ORs (95% CIs) = 0.63 (0.53, 0.75), 0.81 (0.69, 0.96), 0.48 (0.41, 0.55), and 0.67 (0.58, 0.78), respectively (p-trends < 0.05). CONCLUSION: Stair climbing was inversely associated with obesity, smoking, physical inactivity, and stress; suggesting a potential role for cardiovascular disease prevention.

Liver enzymes and the risk of stroke among the general Japanese population: a prospective cohort study.

BACKGROUND: Stroke is a major cause of morbidity and mortality. Liver enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transpeptidase (GGT), are markers of liver diseases with potential cardiovascular implications. OBJECTIVE: This study aimed to investigate the prospective association between liver enzymes and stroke risk. METHODS: We analyzed data from 3,379 men and 4,007 women without cardiovascular disease and registered in the Suita Study; a Japanese population-based prospective cohort study. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) of stroke risk were estimated per quintiles of ALT, AST, and GGT in men and women. RESULTS: Within a median follow-up period of 16.7 years, 438 incident stroke events were diagnosed. In men, compared to the second quintiles, the fifth (highest) quintiles of liver enzymes showed increased stroke risks: HRs (95% CIs) = 2.07 (1.35, 3.18) in ALT, 1.66 (1.10, 2.53) in AST, and 1.76 (1.11, 2.81) in GGT. The associations did not change with cerebral infarction risk: HRs (95% CIs) = 2.09 (1.24, 3.50) in ALT, 1.84 (1.11, 3.06) in AST, and 1.74 (1.00, 3.04) in GGT, respectively. The lowest ALT, AST, and GGT quintiles tended to show increased stroke and cerebral infarction risks, yet these associations were statistically insignificant. No such associations were shown in women. CONCLUSION: Elevated ALT, AST, and GGT levels were associated with increased stroke and cerebral infarction risks among Japanese men.

Fatty Liver Index and the Risk of Atrial Fibrillation in a General Japanese Population　- The Suita Study.

BACKGROUND: Atrial fibrillation (AF) is the most diagnosed arrhythmia in clinical settings. The fatty liver index (FLI) is a marker of liver steatosis with potential cardiovascular implications. This study investigated whether FLI could predict the risk of AF.Methods and Results: We used data from the Suita Study, a Japanese population-based prospective cohort study. A total of 2,346 men and 3,543 women, aged 30-84 years, without prevalent AF were included and followed up. The diagnosis of AF was established during follow-up using electrocardiograms, hospital records, and death certificates. FLI was assessed during a baseline health checkup. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for incident AF per FLI quintile and log-transformed FLI. Within a median 14.5 years of follow-up, 142 men and 105 women developed AF. Compared with women in the third (middle) FLI quintile, women in the first (lowest), fourth, and fifth (highest) quintiles showed a higher risk of AF, with multivariable-adjusted HRs of 2.37 (95% CI 1.06-5.31), 2.60 (95% CI 1.30-5.17), and 2.04 (95% CI 1.00-4.18), respectively. No corresponding associations were observed in men. The change in log-transformed FLI was not associated with the risk of AF in either sex. CONCLUSIONS: A U-shaped association between FLI and AF risk was detected in Japanese women. FLI could be a screening tool to detect women at high risk of developing AF.

Impact of Cardiovascular Disease on the Death Certificate Diagnosis of Heart Failure, Ischemic Heart Disease, and Cerebrovascular Disease　- The Japan Public Health Center-Based Prospective Study.

BACKGROUND: There is considerable interest in the trending discrepancy between ischemic heart disease (IHD) and heart failure (HF) in vital statistics. Clinically, acute myocardial infarction (AMI) and stroke are closely associated with HF, but their contribution to HF as the underlying cause of death (UCD) is unclear.Methods and Results: In 1990 and 1992-1993, we enrolled a total of 140,420 residents of Japanese nationality (aged 40-69 years) from 11 public health center areas. We prospectively examined the occurrence of cardiovascular disease (CVD), including AMI, sudden cardiac death within 1 h (SCD), and stroke, and analyzed the 14,375 participants without a history of CVD at baseline who died during the 20-year follow-up. A time-dependent Cox proportional hazards model was used to estimate hazard ratios and the population attributable fraction (PAF) of AMI, AMI+SCD, stroke, and CVD for deaths due to HF, IHD, and cerebrovascular disease as the UCD, adjusted for individuals' lifestyles and comorbid conditions. The PAF of AMI for HF deaths was 2.4% (95% confidence interval [CI] 1.7-2.9%), which increased to 12.0% (95% CI 11.6-12.2%) for AMI+SCD. The PAF of CVD-attributed HF deaths was estimated to be 17.6% (95% CI 15.9-18.9%). CONCLUSIONS: HF as the UCD was partly explained by CVD. The data imply that most HF deaths reported in vital statistics may be associated with underlying causes other than CVD.

Risk and population attributable fraction of stroke subtypes in Japan.

BACKGROUND: Associations of major risk factors for stroke with total and each type of stroke as well as subtypes of ischemic stroke and their population attributable fractions had not been examined comprehensively. METHODS: Participants of the Japan Public Health Center-based prospective (JPHC) Study Cohort II without histories of cardiovascular disease and cancer (n=14,797) were followed from 1993 through 2012. Associations of current smoking, hypertension, diabetes, overweight (body mass index ≥ 25 kg/m2), non-high-density lipoprotein cholesterol (non-HDLC) categories, low HDLC (< 40 mg/dL), urine protein, and history of arrhythmia were examined in a mutually-adjusted Cox regression model that included age and sex. Population attributable fraction (PAF) was estimated using the hazard ratios and the prevalence of risk factors among cases. RESULTS: Subjects with hypertension were 1.63 to 1.84 times more likely to develop any type of stroke. Diabetes, low HDLC, current smoking, overweight, urine protein, and arrhythmia were associated with risk of overall and ischemic stroke. Hypertension and urine protein were associated with risk of intracerebral hemorrhage while current smoking, hypertension, and low non-HDLC were associated with subarachnoid hemorrhage. Hypertension alone accounted for more than a quarter of stroke incidence, followed by current smoking and diabetes. High non-HDLC, current smoking, low HDLC, and overweight contributed mostly to large-artery occlusive stroke. Arrhythmia explained 13.2% of embolic stroke. Combined PAFs of all the modifiable risk factors for total, ischemic and large-artery occlusive strokes were 36.7 and 44.5% and 61.5%, respectively. CONCLUSION: Although there are differences according to the subtypes, hypertension could be regarded as the most crucial target for preventing strokes in Japan.

Relationship between carotid intima-media thickness and periodontal disease in a Japanese urban population with and without hypertension: The Suita Study.

AIM: To investigate the association between periodontal disease and atherosclerosis and to examine whether the association is modified by hypertension status. MATERIALS AND METHODS: In this cross-sectional study, 1472 Japanese individuals aged 50-79 years who underwent a medical check-up, dental examination, and carotid ultrasonography were studied. Carotid atherosclerosis was expressed as the maximum and mean carotid intima-media thickness (max-IMT, mean-IMT) and the presence of stenosis (≥75%). Periodontal status was examined by the Community Periodontal Index (CPI, codes 0-4). The participants were divided into three groups according to the periodontal status (CPI0-2, CPI3, CPI4). RESULTS: A positive correlation was found between mean-IMT and periodontal disease after adjustment for cardiovascular risk factors in the entire cohort (mean-IMT in hypertensives: CPI0-2: 0.848 mm, CPI3: 0.857 mm, CPI4: 0.877 mm; normotensives: 0.782, 0.802, 0.826). In the entire cohort, the multivariable-adjusted odds ratio of stenosis based on mean-IMT significantly increased according to periodontal status in normotensives (odds ratio; CPI0-2: 1, CPI3: 1.39, CPI4: 2.53; p-value for trend = .004) but showed only marginal significant increase in hypertensives (1, 1.15, 1.55; p-value for trend = .063). No significant relationships were observed for max-IMT in all analyses. CONCLUSION: We observed an association between periodontal disease and atherosclerosis in normotensive and hypertensive participants.

Stair climbing and the incidence of atherosclerotic cardiovascular disease: a population-based prospective cohort study.

BACKGROUND: Stair climbing is a readily available form of physical activity with potential cardioprotective merits. Herein, we investigated the association between stair climbing and atherosclerotic cardiovascular disease (ASCVD) incidence among Japanese people. METHODS: This prospective cohort study used data from 7,282 participants, aged 30-84 years, registered in the Suita Study and free from stroke and ischemic heart disease (IHD). Standard approaches were used to detect incident ASCVD events, including cerebral infarction and IHD, during follow-up. Stair climbing was assessed using a baseline questionnaire. We applied the Cox regression to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of incident ASCVD for climbing stairs in 20-39%, 40-59%, and ≥60% compared to <20% of the time. We adjusted the regression models for age, sex, body mass index, smoking, alcohol consumption, physical activity, hypertension, diabetes, atrial fibrillation, lipid profile, chronic kidney disease, and history of cardiac murmur or valvular diseases. RESULTS: A total of 536 new ASCVD events were detected within a median follow-up period of 16.6 years. In the age- and sex-adjusted model, stair climbing 20-39%, 40-59%, and ≥60% of the time was associated with lower ASCVD incidence: HRs (95% CIs) = 0.72 (0.56, 0.92), 0.86 (0.68, 1.08), and 0.78 (0.61, 0.99), respectively (p-trend = 0.020). The corresponding associations were attenuated after adjusting for lifestyle and clinical factors: HRs (95% CIs) = 0.74 (0.58, 0.95), 0.90 (0.71, 1.13), and 0.89 (0.69, 1.13), respectively (p-trend = 0.152). CONCLUSION: Frequent stair climbing was associated with lower ASCVD incidence; however, this association was partly explained by lifestyle and clinical factors of participants.

Life satisfaction and the risk of atherosclerotic cardiovascular disease in the general Japanese population: the Suita Study.

BACKGROUND: Atherosclerotic cardiovascular disease (ASCVD) is a major cause of morbidity and mortality. Life satisfaction is a measure of mental health with a potential cardioprotective role. This study aimed to investigate the association between life satisfaction and ASCVD risk in the general Japanese population. METHOD: We used data from 6,877 people (30-84 years) registered in the Suita Study, a Japanese population-based prospective cohort study. All participants were free from stroke and coronary heart disease (CHD) at baseline. Then, participants were followed up for incident ASCVD, including cerebral infarction and CHD. Cox proportional hazards models were used to calculate the hazard ratio (HR) and 95% confidence interval (95% CI) of incident ASCVD according to life satisfaction. RESULTS: Within 102,545 person-years (median follow-up = 16.6 years), 482 incident ASCVD events were identified. In the age- and sex-adjusted model, being very satisfied, rather satisfied, or not sure, compared to being dissatisfied with life, showed a lower risk of ASCVD: HR (95% CI) = 0.55 (0.41, 0.74), 0.67 (0.50, 0.89), and 0.57 (0.36, 0.88), respectively (p-trend < 0.001). The associations remained consistent after adjusting for stress and unfortunate events: HR (95% CI) = 0.57 (0.42, 0.77), 0.68 (0.50, 0.91), and 0.54 (0.35, 0.84), respectively (p-trend < 0.001). The results did not vary between cerebral infarction and CHD: HR (95% CI) for being very satisfied with life = 0.58 (0.37, 0.91) and 0.55 (0.36, 0.84), respectively. CONCLUSION: Life satisfaction was inversely associated with the risk of ASCVD in the investigated general Japanese population.

Alcohol consumption and the risk of heart failure: the Suita Study and meta-analysis of prospective cohort studies.

BACKGROUND: Alcohol consumption is a modifiable lifestyle, but its role in heart failure (HF) development is controversial. Herein, we investigated the prospective association between alcohol consumption and HF risk. METHODS: A total of 2,712 participants (1,149 men and 1,563 women) from the Suita Study were followed up every two years. Cox regression was applied to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of HF risk for heavy drinking (≥46 g/day in men or ≥23 g/day in women) and never drinking compared to light drinking (<23 g/day in men or <11.5 g/day in women). Then, we combined the results of the Suita Study with those from other eligible prospective cohort studies in a meta-analysis using the random-effects model. RESULTS: In the Suita Study, within a median follow-up period of 8 years, 319 HF cases (162 in men and 157 in women) were detected. In men, but not women, never and heavy drinking carried a higher risk of HF than light drinking: HRs (95% CIs) = 1.65 (1.00, 2.73) and 2.14 (1.26, 3.66), respectively. Alike, the meta-analysis showed a higher risk of HF among heavy drinkers: HR (95% CI) = 1.37 (1.15, 1.62) and abstainers: HR (95% CI) = 1.18 (1.02, 1.37). CONCLUSION: We indicated a J-shaped association between alcohol consumption and HF risk among Japanese men. The results of the meta-analysis came in line with the Suita Study. Heavy-drinking men should be targeted for lifestyle modification interventions.

Development of new scores for atherosclerotic cardiovascular disease using specific medical examination items: the Suita Study.

BACKGROUND: We previously developed risk models predicting stroke, coronary heart disease (CHD), and cardiovascular disease (CVD) among Japanese people from the Suita Study. Yet, applying these models at the national level was challenging because some of the included risk factors differed from those collected in the Japanese governmental health check-ups, such as Tokutei-Kenshin. We, therefore, conducted this study to develop new risk models for stroke, CHD, and atherosclerotic CVD (ASCVD), based on data from the Suita Study. The new models used traditional cardiovascular risk factors similar to those in the Japanese governmental health check-ups. METHODS: We included 7,413 participants, aged 30-84 years, initially free from stroke and CHD. All participants received baseline health examinations, including a questionnaire assessing their lifestyle and medical history, medical examination, and blood and urine analysis. The risk factors of stroke, CHD, and ASCVD (cerebral infarction or CHD) were determined using the multivariable-adjusted Cox regression. The models' performance was assessed using the C-statistics for discrimination and the Hosmer-Lemeshow for calibration. We also developed three simple scores (zero to 100) that could predict the 10-year incidence of stroke, CHD, and ASCVD. RESULTS: Within 110,428 person-years (median follow-up = 16.6 years), 410 stroke events, 288 CHD events, and 527 ASCVD events were diagnosed. Age, smoking, hypertension, and diabetes were associated with stroke, CHD, and ASCVD risk. Men and those with decreased high-density lipoproteins or increased low-density lipoproteins showed a higher risk of CHD and ASCVD. Urinary proteins were associated with an increased risk of stroke and ASCVD. The C-statistic values of the risk models were >0.750 and the p-values of goodness-of-fit were >0.30. The 10-year incidence of stroke, CVD, and ASCVD events was 3.8%, 3.5%, and 5.7% for scores 45-54, 10.3%, 11.8%, and 19.6% for scores 65-74, and 27.7%, 23.5%, and 60.5% for scores ≥85, respectively. CONCLUSIONS: We developed new Suita risk models for stroke, CHD, and ASCVD using variables similar to those in the Japanese governmental health check-ups. We also developed new risk scores to predict incident stroke, CHD, and ASCVD within 10 years.

Arterial hypertension.

Arterial hypertension is the most important contributor to the global burden of disease; however, disease control remains poor. Although the diagnosis of hypertension is still based on office blood pressure, confirmation with out-of-office blood pressure measurements (ie, ambulatory or home monitoring) is strongly recommended. The definition of hypertension differs throughout various guidelines, but the indications for antihypertensive therapy are relatively similar. Lifestyle adaptation is absolutely key in non-pharmacological treatment. Pharmacologically, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, calcium channel blockers, and diuretics are the first-line agents, with advice for the use of single-pill combination therapy by most guidelines. As a fourth-line agent, spironolactone should be considered. The rapidly evolving field of device-based therapy, especially renal denervation, will further broaden therapeutic options. Despite being a largely controllable condition, the actual rates of awareness, treatment, and control of hypertension are disappointingly low. Further improvements throughout the process of patient screening, diagnosis, treatment, and follow-up need to be urgently addressed.

Developing a Stroke Risk Prediction Model Using Cardiovascular Risk Factors: The Suita Study.

INTRODUCTION: Stroke remains a major cause of death and disability in Japan and worldwide. Detecting individuals at high risk for stroke to apply preventive approaches is recommended. This study aimed to develop a stroke risk prediction model among urban Japanese using cardiovascular risk factors. METHODS: We followed 6,641 participants aged 30-79 years with neither a history of stroke nor coronary heart disease. The Cox proportional hazard model estimated the risk of stroke incidence adjusted for potential confounders at the baseline survey. The model's performance was assessed using the receiver operating characteristic curve and the Hosmer-Lemeshow statistics. The internal validity of the risk model was tested using derivation and validation samples. Regression coefficients were used for score calculation. RESULTS: During a median follow-up duration of 17.1 years, 372 participants developed stroke. A risk model including older age, current smoking, increased blood pressure, impaired fasting blood glucose and diabetes, chronic kidney disease, and atrial fibrillation predicted stroke incidence with an area under the curve = 0.76 and p value of the goodness of fit = 0.21. This risk model was shown to be internally valid (p value of the goodness of fit in the validation sample = 0.64). On a risk score from 0 to 26, the incidence of stroke for the categories 0-5, 6-7, 8-9, 10-11, 12-13, 14-15, and 16-26 was 1.1%, 2.1%, 5.4%, 8.2%, 9.0%, 13.5%, and 18.6%, respectively. CONCLUSION: We developed a new stroke risk model for the urban general population in Japan. Further research to determine the clinical practicality of this model is required.

Secondhand smoke and the risk of incident cardiovascular disease among never-smoking women.

The prospective association between secondhand smoke (SHS) and the risk of incident cardiovascular disease (CVD) remains unclear. This study was the first to examine the association between SHS and risks of ischemic heart disease (IHD), stroke, and total CVD in a large cohort in Asia. The study followed 24,232 never-smoking women aged 40-59 from around Japan (Akita, Iwate, Nagano, Niigata, Ibaraki, Kochi, Nagasaki, and Okinawa prefectures). Their husbands were classified into never, former, and current smokers. After adjustment for age, body mass index, alcohol consumption, histories of hypertension and diabetes mellitus, medication use for hyperlipidemia, menopausal status, and public health center areas, the hazard ratios (HRs) of CVD according to husbands' smoking status were estimated by Cox proportional hazards models. During the 440,360 person-years follow-up, 846 women had total CVDs (103 IHDs, 744 strokes). The proportional hazard assumption was not assured during the total follow-up from 1990 to 2012, but so was then the follow-up of < and ≥ 10 person-years were examined separately. The multivariable HRs (95% confidence intervals) associated with husbands' current versus non-current smoking was 2.02 (1.19-3.45) for IHD, 1.18 (0.98-1.42) for stroke, and 1.25 (1.05-1.49) for total CVD in the follow-up of ≥10 person-years. The SHS from husbands may raise the risk of IHD among middle-aged never-smoking women.

Playing a musical instrument and the risk of dementia among older adults: a systematic review and meta-analysis of prospective cohort studies.

BACKGROUND: Engaging in leisure activities was suggested to protect older adults from dementia. However, the association between playing a musical instrument and the risk of dementia is not well-established. This study aimed to investigate this association in older adults using a systematic review and meta-analysis of prospective cohort studies. METHODS: Pooled hazard ratio (HR) and 95% confidence interval (CI) of having dementia for older adults playing a musical instrument were calculated using the random-effects model. We performed the I2 statistic to detect heterogeneity across studies and the test for funnel plot asymmetry to assess publication bias. The risk of bias assessment was conducted using the modified Newcastle-Ottawa Scale. RESULTS: A total of three prospective cohort studies were found eligible: two from the U.S. and one from Japan. Playing a musical instrument, in the meta-analysis, was significantly associated with a decreased risk of dementia (HR = 0.64; 95% CI: 0.41, 0.98) among older adults. No signs of significant heterogeneity across studies (I2 = 23.3% and p-heterogeneity = 0.27) or publication bias (z= -1.3 and p-publication bias = 0.18) were identified. CONCLUSION: Playing a musical instrument was associated with a decreased risk of dementia among older adults. Older adults should be encouraged to engage in leisure activities, especially playing musical instruments.

Association Between White Blood Cell Count and Atrial Fibrillation Risk　- A Population-Based Prospective Cohort Study.

BACKGROUND: The incidence and prevalence of atrial fibrillation (AF) are increasing. The white blood cell (WBC) count is an indicator of systemic inflammation and is related to increased cardiovascular disease risk. Using data from the Suita Study, we investigated the association between WBC count and AF risk in the general Japanese population.Methods and Results: This prospective cohort study included 6,884 people, aged 30-84 years, with no baseline AF. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for AF incidence by WBC count quintile. Within a median follow-up period of 14.6 years, 312 AF cases were diagnosed. Compared with the lowest WBC count quintile, the highest quintile was associated with an increased AF risk (HR 1.57; 95% CI 1.07-2.29). The association was more pronounced among women than men (HR 2.16 [95% CI 1.10-4.26] and 1.55 [95% CI 0.99-2.44], respectively; P interaction=0.07), and among current than non-smokers (HR 4.66 [95% CI 1.89-11.50] and 1.61 [95% CI 1.01-2.57], respectively; P interaction=0.20). For each 1.0×109-cells/L increment in WBC count, AF risk increased by 9% in men (9% in non-smokers, 10% in current smokers) and 20% in women (13% in non-smokers, 32% in current smokers). CONCLUSIONS: A higher WBC count was positively associated with an elevated AF risk in the general Japanese population, especially in women who smoked.

QRS transitional zone rotations and the risk of atrial fibrillation: the Suita Study.

ECG screening can detect people at risk of developing atrial fibrillation (AF). Recent literature indicated that QRS transitional zone rotations could predict several cardiovascular events. Herein, we investigated the association between QRS transitional zone rotations and the future risk of AF. This prospective cohort study included 6794 participants (3178 men and 3616 women), aged 30-84 years, from the urban Japanese city of Suita. QRS transitional zone rotations were diagnosed by ECG during baseline, while AF was diagnosed by ECG, hospital records, and checkups during follow-up. The Cox regression was used to compute the sex-specified hazard ratios (HRs) and 95% confidence intervals (CIs) of incident AF for participants with counterclockwise and clockwise QRS transitional zone rotations compared to those with normal rotation. Within a median follow-up period of 14.6 years, 311 participants (206 men and 105 women) developed AF. Counterclockwise rotation was associated with the reduced risk of AF among men, but not women, in the age-adjusted model: HR (95% CI) = 0.66 (0.44, 0.98) and the multivariable-adjusted model: HR (95% CI) = 0.65 (0.43, 0.97). Clockwise rotation was not associated with AF risk in either sex. To the best of our knowledge, this is the first study to indicate that counterclockwise rotation could be associated with the reduced risk of AF in men. More studies are needed to confirm our findings and elucidate possible mechanisms.

The Lifelong Health Support 10: a Japanese prescription for a long and healthy life.

BACKGROUND: Although the age-adjusted incidence and mortality of cancer and cardiovascular disease (CVD) have been decreasing steadily in Japan, both diseases remain major contributors to morbidity and mortality along with the aging society. Herein, we aim to provide a prescription of 10 health tips for long and healthy life named the "Lifelong Health Support 10 (LHS10)." METHOD: The LHS10 was developed by the preventive medicine specialists at the National Cerebral and Cardiovascular Center in Suita, where it has been used for health guidance to prevent CVD, cancer, and cognitive decline in addition to their major risk factors such as hypertension, diabetes, and obesity. It consisted of the lifestyle modification recommendations of the 2014 Japanese Society of Hypertension guidelines and the 2017 Japan Atherosclerosis Society Guidelines for preventing atherosclerotic CVD. Further, it came in line with other international lifestyle modification guidelines. In this narrative review, we summarized the results of several Japanese epidemiological studies investigating the association between the LHS10 items and the risk of cancer, CVD, and other chronic diseases including dementia, diabetes, and chronic kidney disease. RESULTS: The LHS10 included avoiding smoking and secondhand smoke exposure, engaging in physical activity, refraining from excessive alcohol drinking, reducing fried foods and sugary soft drinks, cutting salt in food, consuming more vegetables, fruits, fish, soy foods, and fibers, and maintaining proper body weight. All items of the LHS10 were shown to reduce the risk of cancer, CVD, and other chronic diseases. CONCLUSIONS: The LHS10 can be a helpful tool for health guidance.

Stair climbing and incident atrial fibrillation: a prospective cohort study.

BACKGROUND: A protective role for physical activity against the development of atrial fibrillation (AF) has been suggested. Stair climbing is a readily available form of physical activity that many people practice. Herein, we investigated the association between stair climbing and the risk of AF in a Japanese population. METHODS: In this prospective cohort study, we used data of 6,575 people registered in the Suita Study, aged 30-84 years, and had no history of AF. The frequency of stair climbing was assessed by a baseline questionnaire, while AF was diagnosed during the follow-up using a 12-lead ECG, health records, check-ups, and death certificates. We used the Cox regression to calculate the hazard ratios and 95% confidence intervals of AF incidence for climbing stairs in 20-39%, 40-59%, and ≥60% compared with <20% of the time. RESULTS: Within 91,389 person-years of follow-up, 295 participants developed AF. The incidence of AF was distributed across the stair climbing groups <20%, 20-39%, 40-59%, and ≥60% as follows: 3.57, 3.27, 3.46, and 2.63/1,000 person-years, respectively. Stair climbing ≥60% of the time was associated with a reduced risk of AF after adjustment for age and sex 0.69 (0.49, 0.96). Further adjustment for lifestyle and medical history did not affect the results 0.69 (0.49, 0.98). CONCLUSION: Frequent stair climbing could protect from AF. From a preventive point of view, stair climbing could be a simple way to reduce AF risk at the population level.