Trends for blood pressure and its contribution to stroke incidence in the middle-aged Japanese population: the Circulatory Risk in Communities Study (CIRCS)

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 fractions (PAFs) were 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%, 44.5%, and 61.5%, respectively.

CONCLUSION

Although there are differences according to subtypes, hypertension could be regarded as the most crucial target for preventing strokes in Japan.

Serum folate and risk of disabling dementia: a community-based nested case-control study

PURPOSE

The aim of this study was to examine associations between serum folate levels and risk of disabling dementia that required care under the national insurance (disabling dementia).

METHODS

We performed a nested case-control study in a community-based cohort, the Circulatory Risk in Communities Study, involving 13,934 Japanese individuals aged 40-84 years at the baseline period of 1984-2005. Serum folate was measured in 578 cases of incident disabling dementia, and in 1,156 controls whose age (±1 years), sex, area of residence, and baseline year were matched with the cases. The diagnosis of disabling dementia was performed by attending physicians under the National Long-Term Care Insurance System in Japan. Conditional odds ratios of disabling dementia according to quintiles of serum folate were calculated using conditional logistic regression models.

RESULTS

After a 20.8-year follow-up, serum folate was inversely associated with risk of disabling dementia. The respective multivariable odds ratios (95% CIs) were 0.71 (0.51-0.99), 0.76 (0.54-1.06), 0.70 (0.49-1.00), and 0.62 (0.43-0.90) for persons with the second, third, fourth, and highest quintiles of serum folate as compared with the lowest quintile (P for trend = 0.03). A similar association was observed for dementia with or without stroke.

CONCLUSION

In this nested case-control study with a long follow-up, low serum folate levels were associated with an increased risk of disabling dementia among Japanese individuals.

Systemic hemodynamic atherothrombotic syndrome: from hypothesis to evidence

Hypertension is a risk factor for cardiovascular disease (CVD). However, the association between blood pressure (BP) and CVD events has been based on mean BP alone. BP variability (BPV) is associated with increased organ damage and CVD events independently or beyond average home BP. To explain this association, we propose the systemic hemodynamic atherothrombotic syndrome (SHATS) hypothesis. The SHATS hypothesis indicates that hemodynamic stress increases vascular disease and vice versa, leading to a vicious cycle of the association between hemodynamic stress and a vascular disease; this association provides not only the risk but also the trigger for CVD events. The evidences of SHATS were gradually accumulating. We showed arterial stiffness synergistically amplified the association between hemodynamic stress and cardiac overload / CVD events in patients with at least one CVD risk factor.

Serum High-Sensitivity Cardiac Troponin T as an Independent Predictor for Incident Coronary Heart Disease in the Japanese General Population: The Circulatory Risk in Communities Study (CIRCS)

AIMS

Epidemiological evidence is extremely limited about high-sensitivity cardiac troponin T (hs-cTnT) and future coronary heart disease (CHD) events for the general population in countries with low mortality from CHD. Therefore, we investigated the association between hs-cTnT levels and the risk of incident CHD using a nested case-control study in a large Japanese cohort study.

METHODS

The participants were residents of four Japanese communities in the Circulatory Risk in Communities Study (CIRCS). We obtained 120 cases (81 men and 39 women, aged 38-86 years at baseline) of first incident CHD and 240 controls matched by age, sex, communities, and blood sampling term. Serum hs-cTnT levels were measured using an electrochemiluminescence immunoassay with stored sera collected between 2001 and 2011. The median period between sampling at survey and CHD incidence was 2.0 (interquartile range, 0.9-3.7) years. After adjusting for conventional risk factors, the multivariable odds ratios (ORs) of CHD were calculated using conditional logistic regression analyses.

RESULTS

hs-cTnT ranged from ≤ 3 (assay detection limit) to 155 ng/L. Compared with the lowest quartile of hs-cTnT, multivariable ORs (95% confidence intervals) of CHD for the second, third, and highest quartiles were 1.30 (0.57-2.95), 2.48 (1.09-5.64), and 3.01 (1.27-7.12), respectively. Similar associations were observed after adjusting for estimated glomerular filtration, or after excluding matched groups, including people with chronic kidney disease.

CONCLUSION

Serum hs-cTnT could predict CHD in the Japanese general population. These findings implicate a benefit from monitoring hs-cTnT to predict CHD even among populations in countries with low mortality from CHD.

Dietary fiber intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study

OBJECTIVES

It has been hypothesized that dietary fiber intake has a beneficial impact on prevention of dementia, but the epidemiological evidence is scant. We sought to examine whether dietary fiber intake is inversely associated with risk of dementia requiring care under the national insurance (disabling dementia).

METHODS

The study setting was the Circulatory Risk in Communities Study, involving 3739 Japanese individuals aged 40-64 years at the dietary surveys (1985-99). Dietary fiber intake was estimated using the 24-hour dietary recall method. Incident disabling dementia was followed up from 1999 through 2020. Disabling dementia was further classified into that with or without a history of stroke. Hazard ratios of disabling dementia according to quartiles of total, soluble, and insoluble fiber intake were calculated using the Cox proportional hazards model.

RESULTS

During a median 19.7-year follow-up, a total of 670 cases of disabling dementia developed. Dietary fiber intake was inversely associated with risk of dementia: the multivariate hazards ratios (95% confidence intervals) were 0.83 (0.67-1.04), 0.81 (0.65-1.02), and 0.74 (0.57-0.96) for individuals with the second, third, and highest quartiles of dietary fiber intake, respectively, as compared with the lowest quartile (P for trend = 0.03). The inverse association was more evident for soluble fiber intake and was confined to dementia without a history of stroke. As for fiber-containing foods, potatoes, but not vegetables or fruits, showed a similar association.

CONCLUSIONS

Dietary fiber intake, especially soluble fiber, was inversely associated with risk of disabling dementia in a general Japanese population.

Total protein intake and subsequent risk of chronic kidney disease: the Circulatory Risk in Communities Study

BACKGROUND

Whether dietary protein intake worsens renal function in the general population has been discussed but not yet determined. We aimed to examine the longitudinal association between dietary protein intake and risk of incident chronic kidney disease (CKD).

METHODS

We conducted a 12-year follow-up study with 3,277 Japanese adults (1,150 men and 2,127 women) aged 40-74 years, initially free from CKD, who participated in cardiovascular risk surveys from two Japanese communities under the Circulatory Risk in Communities Study. The development of CKD was defined by the estimated glomerular filtration rate (eGFR) during the follow-up period. Protein intake was measured at baseline by using the brief-type self-administered diet history questionnaire. We estimated sex-, age-, community- and multivariate-adjusted hazard ratios (HR) for incident CKD were calculated using the Cox proportional hazards regression models according to quartiles of percentage of energy (%energy) from protein intake.

RESULTS

During 26,422 person-years of follow-up, 300 participants developed CKD (137 men and 163 women). The sex-, age-, and community-adjusted HR (95% confidence interval, CI) for the highest (≥16.9%energy) versus lowest (≤13.4%energy) quartiles of total protein intake was 0.66 (0.48-0.90), p for trend = 0.007. The multivariable HR (95%CI) was 0.72 (0.52-0.99), p for trend = 0.016 after further adjustment for body mass index, smoking status, alcohol drinking status, diastolic blood pressure, antihypertensive medication use, diabetes mellitus, serum total cholesterol levels, cholesterol-lowering medication use, total energy intake, and baseline eGFR. The association did not vary by sex, age, and baseline eGFR. When examining animal and vegetable protein intake separately, the respective multivariable HRs (95%CIs) were 0.77 (0.56-1.08), p for trend = 0.036, and 1.24 (0.89-1.75), p for trend = 0.270.

CONCLUSIONS

Higher protein intake, more specifically animal protein intake was associated with a lower risk of CKD.

Association between Serum Uric Acid and Impaired Endothelial Function: The Circulatory Risk in Communities Study

AIMS

Higher serum uric acid (UA) may impair endothelial function. However, population-based evidence examining the association between serum UA levels and endothelial function remains to be limited. Thus, in this study, we aimed to investigate this in the general population.

METHODS

In this cross-sectional study, 1000 participants (496 males and 504 females), aged 30-79 years, free from a history of gout, have undergone both serum UA and brachial artery flow-mediated dilation (FMD) measurements. Participants were divided into four groups based on serum UA quartiles. Logistic regression models were used to calculate odds ratios (ORs) for low FMD according to the serum UA levels.

RESULTS

In total, 203 participants (138 males and 65 females) with %FMD ≤ 5.0% were identified to have endothelial dysfunction. The multivariable OR of low FMD for highest quartiles vs. lowest quartiles was 2.39 (95% confidence interval [CI]: 1.32-4.34), while OR per 1-standard deviation (SD) increment was 1.28 (95% CI: 1.04-1.56). The positive association was noted to be more evident in females (OR per 1-SD increment: 1.46; 95% CI: 1.08-1.96) than in males and confined to individuals not using antihypertensive medications. The ORs per 1-SD increment were 1.01 (95% CI: 0.68-1.50) among individuals using antihypertensive medications and 1.43 (95% CI: 1.12-1.81) among individuals not using antihypertensive medications.

CONCLUSION

Higher serum UA was positively associated with the prevalence of endothelial dysfunction in samples of the general Japanese population and that positive association was confined to individuals not using antihypertensive medications.

Lower urinary potassium excretion was associated with higher risk of cerebro-cardiovascular- and renal events in patients with hypertension under treatment with anti-hypertensive drugs

BACKGROUND

Hypertension is one of the risk factors for cerebro-cardiovascular and renal (CCR) diseases. High blood pressure is affected by the amount of salt (NaCl) and potassium (K) intake. There are many studies reporting the relationship between urinary sodium or potassium excretion and CCR events or all-cause mortality in general populations. Thus, it is necessary to investigate the relationship between urinary NaCl or K excretion and CCR events or all-cause mortality in hypertensive patients under control with anti-hypertensive drugs.

METHODS

A prospective, multi-center cohort study was performed in 3210 hypertensives under treatment with anti-hypertensive drugs for 5 years. The primary outcome was the CCR events, and the secondary outcome was all-cause mortality. A time-dependent Cox proportional hazards regression analysis was performed to assess the association between outcomes and urinary NaCl and K excretion, blood pressure, or heart rate.

RESULTS

During the follow-up period, 61 CCR events and 110 all-cause deaths occurred. There was no association between urinary NaCl excretion and CCR events or all-cause mortality. Lower urinary K excretion and higher Na/K ratio were associated with higher risk of CCR events or all-cause mortality. The CCR events were not associated with systolic, diastolic blood pressure, or heart rate.

CONCLUSION

Lower urinary K excretion was associated with higher risk of CCR events or all-cause mortality in hypertensive patients under treatment with anti-hypertensive drugs.

Cardiovascular risk in patients receiving antihypertensive drug treatment from the perspective of endothelial function

Blood-pressure-lowering therapy with antihypertensive drugs can reduce the risk of cardiovascular morbidity and mortality in patients with hypertension. However, patients treated with antihypertensive drugs generally have a worse prognosis than untreated individuals. Consistent with the results obtained from epidemiological studies, a clinical study showed that endothelial function was impaired more in treated patients with hypertension than in untreated individuals with the same blood pressure level, suggesting that blood-pressure-lowering therapy with currently available antihypertensive drugs cannot restore endothelial function to the level of that in untreated individuals. Several mechanisms of endothelial dysfunction in treated patients are postulated: irreversible damage to the endothelium caused by higher cumulative elevated blood pressure exposure over time; the persistence of the primary causes of hypertension even after the initiation of antihypertensive drug treatment, including an activated renin-angiotensin-aldosterone system, oxidative stress, and inflammation; and higher global cardiovascular risk related not only to conventional cardiovascular risk factors but also to undetectable nonconventional risk factors. Lifestyle modifications/nonpharmacological interventions should be strongly recommended for both untreated and treated individuals with hypertension. Lifestyle modifications/nonpharmacological interventions may directly correct the primary causes of hypertension, which can improve endothelial function and consequently reduce cardiovascular risk regardless of the use or nonuse of antihypertensive drugs.

Age-period-cohort analysis of stroke mortality attributable to high systolic blood pressure in China and Japan

Stroke is a principal cause of mortality in China and Japan. High systolic blood pressure (SBP) was considered a chief risk factor for stroke mortality. Herein, we evaluated temporal trends of high SBP-attributable stroke mortality in China and Japan between 1990 and 2017. Data on stroke mortality were retrieved from the Global Burden of Disease Study 2017 (GBD 2017). Using the age-period-cohort method, we computed overall net drifts, local drifts, longitudinal age curves, and cohort/period rate ratios (RRs) for high SBP-attributable stroke mortality. The age-standardized mortality rates (ASMRs) displayed decreasing trends for high SBP-attributable stroke mortality. The annual net drift values were - 1.4% and - 3.5% in Chinese men and women versus - 3.1% and - 4.9% in Japanese men and women. The local drift values in both countries were < 0 among all age groups but were lower in women than in men. The longitudinal age curves showed a greater high SBP-attributable stroke mortality in men than in women across all age groups. Similar decreasing patterns were shown in the period and cohort RRs in both sexes with women having a quicker decline than men. In China and Japan, the ASMRs, as well as the period and cohort RRs of high SBP-attributable stroke mortality, decreased between 1990 and 2017 in both sexes and across all age groups. Yet, the prevalence of high SBP remained worrisome in both countries. Thus, SBP control should be encouraged to prevent stroke mortality.

Dietary intake of tocopherols and risk of incident disabling dementia

Tocopherols, strong antioxidants, may be useful in preventing dementia, but the epidemiological evidence is insufficient. We performed a community-based follow-up study of Japanese, the Circulatory Risk in Community Study, involving 3739 people aged 40-64 years at baseline (1985-1999). Incident disabling dementia was followed up from 1999 through 2020. For subtype analysis, we classified disabling dementia into that with and that without a history of stroke. Dietary intake of tocopherols (total, α, β, γ, and δ) were estimated using 24-h recall surveys. During a median follow-up of 19.7 years, 670 cases of disabling dementia developed. Total tocopherol intake was inversely associated with risk of disabling dementia with multivariable hazard ratios (95% confidence intervals) of 0.79 (0.63-1.00) for the highest versus lowest quartiles of total tocopherol intake (P for trend = 0.05). However, the association was strengthened when further adjusted for α-linolenic acid intake (Spearman correlation with total tocopherol intake = 0.93), with multivariable hazard ratios of 0.50 (0.34-0.74) (P for trend = 0.001) but was weakened and nonsignificant when further adjusted for linoleic acid intake (Spearman correlation with total tocopherol intake = 0.92), with multivariable hazard ratios of 0.69 (0.47-1.01) (P for trend = 0.05). Similar but nonsignificant inverse associations were observed for α-, γ-, and δ-tocopherols but not for β-tocopherol. These results were similar regardless of the presence of a history of stroke. Dietary tocopherol intake was inversely associated with risk of disabling dementia, but its independent effect was uncertain owing to a high intercorrelation of α-linolenic linoleic acids with total tocopherol intake. Even with such confounding, a diet high in tocopherols may help prevent the onset of dementia.

Impact of Perceived Social Support on the Association Between Anger Expression and the Risk of Stroke: The Circulatory Risk in Communities Study (CIRCS)

BACKGROUND

Anger has been suggested as a risk factor for stroke. Perceived social support (PSS) may relieve anger, thus reducing the risk of stroke; however, evidence supporting this is limited. We aimed to examine whether PSS modifies the risk of stroke associated with anger expression.

METHODS

A cohort study was conducted among 1,806 community residents aged 40-74 years who received a cardiovascular risk survey including anger expression in 1997. A Cox proportional hazards model was applied to the participants with low and high PSS to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) of the risks of total stroke and its subtypes based on total anger expression after adjusting for known stroke risk factors.

RESULTS

The median follow-up duration was 18.8 years, with 51 incident strokes. Among the participants with low PSS, anger expression had a positive association with the total stroke risk: The multivariable HR per SD increment of total anger expression was 1.43 (95% CI, 1.13-1.82). In contrast, no association was identified among those with high PSS. The corresponding HR was 0.83 (95% CI, 0.49-1.40), with a significant interaction between low and high PSS (p = 0.037). Similar associations regarding the risk of ischemic stroke were found.

CONCLUSIONS

We found an increased risk of stroke associated with anger expression among the participants with low PSS, but not among those with high PSS. Our results suggest that PSS might mitigate the risk of stroke associated with anger.

Relationship between Endothelial Dysfunction and Prevalence of Chronic Kidney Disease: The Circulatory Risk in Communities Study (CIRCS)

AIMS

Patients with chronic kidney disease (CKD) have a higher burden of cardiovascular morbidity and mortality than the general population. Endothelial dysfunction has been suggested to play a role in both glomerular filtration rate loss and cardiovascular damage. Thus, the present study aimed to evaluate the relationship between endothelial dysfunction and the prevalence of CKD in the general Japanese population.

METHODS

We conducted a cross-sectional study of 1042 men and women aged 30-81 years in two communities under the Circulatory Risk in Communities Study between 2013 and 2017. Endothelial function was evaluated by percent change of brachial artery flow-mediated dilation (%FMD) before and after the cuff inflation.

RESULTS

Among the total 1042 participants, there were 62 cases of CKD (~6%). The multivariable odds ratios (ORs) (95% confidence intervals [CIs]) of CKD according to quartiles of %FMD were 2.02 (0.68-5.99), 3.56 (1.27-9.94), and 3.14 (1.10-8.93) for the third to lowest quartile compared with the highest %FMD quartile; p for trend=0.02. The respective multivariable ORs (95% CIs) of CKD in subjects without antihypertensive medication use (39 cases among 886 subjects) were 1.83 (0.46-7.33), 3.41 (0.92-12.61), and 4.60 (1.22-17.31); p for trend=0.01, and that for one-point decrement in %FMD was 1.16 (1.00-1.35); p for interaction with the status of antihypertensive medication use was 0.12.

CONCLUSIONS

Our cross-sectional study suggested the relationship between endothelial dysfunction and the higher prevalence of CKD in the general Japanese population.

Serum Albumin and Risks of Stroke and Its Subtypes - The Circulatory Risk in Communities Study (CIRCS)

BACKGROUND

Few studies have investigated the association between serum albumin levels and the risk of stroke subtypes among the general Japanese population.Methods and Results:In this study, 5,071 men and 7,969 women aged 40-74 years, initially free from stroke, coronary artery disease, and kidney and hepatic failure, and residing in 4 Japanese communities completed a baseline risk factor survey between 1985 and 1994. During the 24-year follow-up, 528 men and 553 women experienced stroke. In the entire study cohort, multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) of total stroke, ischemic stroke, and intracerebral hemorrhage for the lowest vs. highest quartiles of serum albumin were 1.45 (1.18-1.77), 1.52 (1.17-1.97), and 1.57 (1.04-2.37), respectively. In men, multivariable HRs (95% CIs) for total stroke, ischemic stroke, and intracerebral hemorrhage in the lowest vs. highest serum albumin quartile were 1.44 (1.07-1.92), 1.48 (1.03-2.11) and 1.71 (0.92-3.18), respectively, whereas in women they were 1.50 (1.13-1.99), 1.63 (1.11-2.39), and 1.56 (0.89-2.74), respectively. Similar inverse associations were observed for each of the ischemic stroke subtypes, but not for subarachnoid hemorrhage.

CONCLUSIONS

Low serum albumin levels were associated with an increased risk of total stroke, ischemic stroke, ischemic stroke subtypes, and intracerebral hemorrhage.

Leukocyte Count and Risks of Stroke and Coronary Heart Disease: The Circulatory Risk in Communities Study (CIRCS)

Aim: This study aimed to investigate the associations of leukocyte count with the risks of stroke and coronary heart disease among the general Japanese population.

Methods: A total of 5,242 residents aged 40–69 years living in two Japanese communities underwent leukocyte count measurements between 1991 and 2000, and the data were updated using 5- or 10-year follow-ups or both. Participants who had histories of stroke, coronary heart disease, or high values of leukocyte count (＞130×10 ² cells/mm ³ ) were excluded. Hazard ratios with 95% confidence intervals (CIs) were calculated according to quartiles of cumulative average leukocyte count.

Results: During follow-up of 21 years, 327 stroke and 130 coronary heart disease cases were determined. After adjustments for age, sex, community, and updated cardiovascular risk factors, the multivariable hazard ratio (95% CI) for the highest versus lowest quartile of leukocyte count was 1.50 (1.08–2.08) for ischemic stroke, 1.59 (1.00–2.51) for lacunar infarction, 1.42 (0.90–2.26) for non-lacunar infarction, 2.17 (1.33–3.55) for coronary heart disease, and 1.40 (1.11–1.76) for total cardiovascular disease. In smoking status-stratified analyses, the corresponding multivariable hazard ratio (95% CI) was 2.45 (1.11–5.38) for ischemic stroke, 2.73 (1.37–5.44) for coronary heart disease in current smokers, 2.42 (1.07–5.46), 1.55 (0.58–4.15) in former smokers, and 1.17 (0.75–1.82), 1.78 (0.83–3.82) in never smokers.

Conclusion: Leukocyte count was positively associated with the risks of ischemic stroke and coronary heart disease among the general Japanese population, especially in current smokers.

Salt taste perception and blood pressure levels in population-based samples: the Circulatory Risk in Communities Study (CIRCS)

To examine the associations of salt perception with salt intake and blood pressure levels in general populations, we performed a cross-sectional study in two communities where salt intake level is different, Akita and Osaka in Japan. Taste perception (detection for certain taste and recognition for salt taste) was determined using a Na-impregnated test strip for 1024 Akita and 1199 Osaka adults aged 30-74 years. The proportions of detection for 0·1 % salt were 61, 62, 79, and 79 % in Akita men, Osaka men, Akita women and Osaka women, respectively. The corresponding proportions of not recognising of 1·6 % salt taste (>1·6 %) were 34, 30, 16 and 21 %. Detection threshold was higher in Akita than in Osaka for women aged 60-74 years, and recognition threshold was lower in Akita than in Osaka for women aged 30-59 and 60-74 years. The high detection (≥0·4 %) and recognition (>1·6 %) thresholds of salt taste were associated with higher salt intake scores for Akita men aged 30-59 years, whose detection and recognition thresholds tended be positively associated with systolic and diastolic blood pressures (SBP and DBP) after adjustment for potential confounders. Among Akita elderly men, detection threshold tended to be positively associated with SBP and DBP, while among Akita middle-aged women, recognition threshold was associated with SBP. In conclusion, the high thresholds of salt perception were inversely associated with salt intake for Akita middle-aged men and with blood pressure levels for Akita middle-aged and elderly men and middle-aged women.

The relationship between home blood pressure measurement and room temperature in a Japanese general population

Blood pressure (BP) is influenced by various factors, and it is known that temperature and BP have a negative relationship. However, few reports have examined the relationship between BP and temperature throughout the day in the same participant over time. Therefore, this study aimed to investigate the relationship between BP and temperature in the morning and evening in the same participants during a time period of ~1 year. In total, 401 participants, who participated in a community-based health checkup survey in Tarumizu, Japan, were enrolled. Five participants were excluded due to missing data. All participants measured their BP and the room temperature at home using a blood pressure monitor (HEM-9700T, OMRON Healthcare, Kyoto, Japan). The mean systolic BP (SBP) and diastolic BP (DBP) in the morning were significantly higher than the mean of the measurements taken in the evening (SBP: morning vs. evening 128 ± 15 mmHg vs. 122 ± 14 mmHg, P < 0.0001; DBP: morning vs. evening 77 ± 10 mmHg vs. 72 ± 8 mmHg, P < 0.0001). Using a linear mixed model with participants as a random effect, SBP and DBP were significantly associated with temperature in both the morning and evening. In the morning, in almost every month except July, a significant association between SBP and temperature was observed. However, there was a significant relationship between evening BP and temperature in all months. In conclusion, BP was significantly related to temperature in both the morning and evening during the year-long study. Furthermore, BP and temperature were significantly associated in all months except morning measurements in July.

Association between the uric acid and hypertension in community-based Chinese population: stratified analysis based on body mass index and age

Many studies have shown that uric acid was related to hypertension. However, the association dependence on body mass index (BMI) or age was unclear. This study was performed with a group of 4012 Chinese population aged 30 to 92 years old. Subjects were divided into four groups according to the quartiles of uric acid (UA) concentration [First group: ≤ 231 μmol/L (reference), Second group: 231-289 μmol/L, Third group: 289-362 μmol/L, Fourth group: > 362 μmol/L]. Hypertension was defined as newly measured blood pressure ≥ 140/90 mmHg or taking antihypertensive drugs. Stratified analysis based on BMI (< 28 kg/m² vs ≥ 28 kg/m²) and age (< 60 years old vs ≥ 60 years old) to analyze the association between UA and hypertension. Subjects were 54.50 (45.00, 63.00) years old, and 40.98% were male, 38.33% were hypertension. Adjusted odds ratios (95% confidence intervals) for the association of UA and hypertension were 2.226 (1.662, 2.980), 4.340 (3.253, 5.790), 5.898 (4.434, 7.845) and 6.557 (4.927, 8.727) in the four groups among ≥ 60 years old respectively comparing with first group among < 60 years old. Adjusted odds ratios (95% confidence intervals) for the association between UA and hypertension were 2.170 (1.236, 3.808), 5.260 (3.267, 8.468), 9.056 (5.509, 14.888) and 3.730 (2.529, 5.550) in the four groups among BMI ≥ 28 kg/m² respectively comparing with first group among BMI < 28 kg/m². Uric acid was significantly associated with the hypertension. The association was stronger among subjects ≥ 60 years old or BMI ≥ 28 kg/m².

Epidemiology of hypertension in Japan: beyond the new 2019 Japanese guidelines

From the national surveys of Japan over a 55-year period (1961-2016), a steady decrease was observed in systolic blood pressure (BP) levels among all age groups of men and women, but not in diastolic BP levels-particularly among men. Hypertension prevalence remains high: over 60% of men aged ≥50 years and women aged ≥60 years had hypertension in 2016. However, the control rates of hypertension have continuously improved over a 36-year period, and were ~40% in 2016. Nonetheless, the over 50% prevalence of uncontrolled hypertension is a major risk factor for future cardiovascular diseases. Of the estimated 43 million hypertensives in Japan, most (31 million, 72%) were under poor control. According to new Japanese hypertension guidelines (JSH 2019), there will be only a small increase (2.2 million, 2.1 percentage points) in adults who are recommended for antihypertensive medication compared with 2014 guidelines. However, an additional 5.3 million (22.1 percentage points) adults taking antihypertensive medication would have a BP above the target defined by JSH 2019. The number of hypertensives with poor control was targeted to decrease by 7 million-from 31 million in 2017 to 24 million in 2028-when the followings are achieved: (1) the prevalence of hypertension decreases by 5 percentage points; (2) the treatment rate of hypertension among hypertensives increases by 10 percentage points; and (3) the control rate of hypertension, defined as BP <140/90 mmHg, among individuals taking antihypertensive medication increases by 10 percentage points. Both high-risk and population strategies to manage and prevent hypertension deserve greater priority.

Serum High-Sensitivity C-Reactive Protein Levels and the Risk of Atrial Fibrillation in Japanese Population: the Circulatory Risk in Communities Study

AIM

This study aimed to investigate the association between the serum high-sensitivity C-reactive protein (hs-CRP) levels and incident atrial fibrillation risk in the general Japanese population, who have lower hs-CRP levels than the Western population, and assess whether the association is modified by sex, overweight, hypertension, and smoking status.

METHODS

We conducted a prospective study in 6517 Japanese men and women aged 40-79 years without atrial fibrillation at baseline and enrolled in the Circulatory Risk in Communities Study (2002-2008). The hs-CRP levels were measured using the latex particle-enhanced immunonephelometric assay. Atrial fibrillation was identified using standard 12-lead electrocardiograms and information on physician-diagnosed atrial fibrillation history from the follow-up surveys. We used a Cox proportional hazard regression stratified by community.

RESULTS

During a median follow-up of 11 years, 127 new cases of atrial fibrillation (74 and 53 cases among men and women, respectively) were found. Compared to the lowest quintile of hs-CRP levels, the multivariable hazard ratios (95% confidence intervals) were 2.54 (1.17-5.50), 2.28 (1.06-4.93), 2.92 (1.37-6.23), and 2.77 (1.30-5.91) for the second, third, fourth, and fifth (highest) quintiles, respectively. There was no significant effect modification by sex, overweight, hypertension, and smoking status (P for interaction ＞0.05).

CONCLUSIONS

Elevated hs-CRP levels were significantly associated with increased risk of atrial fibrillation in the Japanese population. The association of hs-CRP levels with incident atrial fibrillation did not vary according to sex, overweight, hypertension status, or smoking status.

A Combination of Blood Pressure and Total Cholesterol Increases the Lifetime Risk of Coronary Heart Disease Mortality: EPOCH-JAPAN

AIM

Lifetime risk (LTR) indicates the absolute risk of disease during the remainder of an individual's lifetime. We aimed to assess the LTRs for coronary heart disease (CHD) mortality associated with blood pressure (BP) and total cholesterol levels in an Asian population using a meta-analysis of individual participant data because no previous studies have assessed this risk.

METHODS

We analyzed data from 105,432 Japanese participants in 13 cohorts. Apart from grade 1 and 2-3 hypertension groups, we defined "normal BP" as systolic/diastolic BP ＜130/＜80 mmHg and "high BP" as 130-139/80-89 mmHg. The sex-specific LTR was estimated while considering the competing risk of death.

RESULTS

During the mean follow-up period of 15 years (1,553,735 person-years), 889 CHD deaths were recorded. The 10-year risk of CHD mortality at index age 35 years was ≤ 0.11%, but the corresponding LTR was ≥ 1.84%. The LTR of CHD at index age 35 years steeply increased with an increase in BP of participants with high total cholesterol levels [≥ 5.7 mmol/L (220 mg/dL)]. This risk was 7.73%/5.77% (95% confidence interval: 3.53%-10.28%/3.83%-7.25%) in men/women with grade 2-3 hypertension and high total cholesterol levels. In normal and high BP groups, the absolute differences in LTRs between the low and high total cholesterol groups were ≤ 0.25% in men and ≤ 0.40% in women.

CONCLUSIONS

High total cholesterol levels contributed to an elevated LTR of CHD mortality in hypertensive individuals. These findings could help guide high-risk young individuals toward initiating lifestyle changes or treatments.

Longitudinal Trends in Blood Pressure Associated With the Frequency of Laughter: The Circulatory Risk in Communities Study (CIRCS), a Longitudinal Study of the Japanese General Population

Background

The frequency of laughter has been associated with cardiovascular disease and related biomarkers, but no previous studies have examined association between laughter and changes in blood pressure levels. We sought to identify temporal relationships between frequency of laughter in daily life and systolic and diastolic blood pressure changes in participants from 2010 through 2014.

Methods

Participants were 554 men and 887 women aged 40–74 years who answered self-administered questionnaire quantifying frequency of laughter at baseline. We measured participant blood pressure levels twice using automated sphygmomanometers for each year from 2010 to 2014. The associations between laughter and changes in blood pressure over time were analyzed using linear mixed-effect models.

Results

There was no significant difference in blood pressure according to frequency of laughter at baseline in either sex. Men with frequency of laughter 1 to 3 per month or almost never had significantly increased systolic and diastolic blood pressure levels over the 4-year period (time-dependent difference: 0.96 mm Hg (95% confidence interval [CI], −0.2 to 1.8; P = 0.05). Changes in blood pressure associated with infrequent laughter (ie, 1 to 3 per month or almost never) were evident in men without antihypertensive medication use over 4 years (0.94 mm Hg; 95% CI, −0.2 to 2.0; P = 0.09) and men who were current drinkers at baseline (1.29 mm Hg; 95% CI, −0.1 to 2.3; P = 0.04). No significant difference was found between frequency of laughter and systolic (0.23 mm Hg; 95% CI, −1.0 to 1.5; P = 0.72) and diastolic (−0.07 mm Hg; 95% CI, −0.8 to 0.7; P = 0.86) blood pressure changes in women.

Conclusions

Infrequent laughter was associated with long-term blood pressure increment among middle-aged men.

Overweight and Hypertension in Relation to Chronic Musculoskeletal Pain Among Community-Dwelling Adults: The Circulatory Risk in Communities Study (CIRCS)

Background

The association between overweight and chronic musculoskeletal pain may vary by anatomical site and be modified by hypertension status. This study examined the associations between overweight and low back and knee pains and their effect modification by hypertension status.

Methods

We conducted a community-based cross-sectional study involving 2,845 adults (1,080 men and 1,765 women) aged 40–89 years. Chronic knee pain (CKP) and low back pain (CLBP) lasting more than 3 months were categorized into more or less severe pain. Odds ratios (ORs) and 95% confidence intervals (CIs) of the association between overweight and more or less severe CKP and CLBP were determined using logistic regression and stratified by hypertension status. Adjustment variables were age, sex, area, hypertension, smoking and drinking status, inactivity, job category, mental stress, depression, and overall CKP or CLBP.

Results

Overall, 288 (10.1%) and 631 (22.2%) adults had more and less severe CKP, respectively, and 284 (10.0%) and 830 (29.2%) had more and less severe CLBP, respectively. Overweight was associated with overall CKP and more or less severe CKP, regardless of hypertension status. Overweight was not associated with overall CLBP; its association was more pronounced for more severe CLBP. The association between overweight and more severe CLBP was evident among non-hypertensives (multivariable OR 1.72; 95% CI, 1.09–2.71); however, that between overweight and less severe CLBP was not evident (multivariable OR 1.07; 95% CI, 0.73–1.56).

Conclusions

As hypertension may attenuate the association between overweight and CLBP, we should consider hypertension status for proper management of CLBP among overweight individuals.

Intracranial Atherosclerosis and Stage 1 Hypertension Defined by the 2017 ACC/AHA Guideline

BACKGROUND

In 2017, the American College of Cardiology (ACC)/American Heart Association (AHA) released a new, stricter definition of stage 1 hypertension which was previously considered prehypertension. However, impacts of the novel stage 1 hypertension on deleterious target-organ outcomes are still controversial. In this study, we evaluated the relationship between this newly defined stage 1 hypertension and the presence of intracranial atherosclerosis (ICAS) lesions in neurologically healthy participants.

METHODS

We assessed consecutive participants in routine health checkups between January 2006 and December 2013. Blood pressure (BP) was classified according to the 2017 ACC/AHA hypertension guideline, and ICAS was defined as occlusion or ≥50% stenosis of intracranial vessels on flight magnetic resonance angiography.

RESULTS

Among 3,111 healthy participants (mean age: 56 years, sex: 54% men), 85 (3%) had ICAS lesions. In multivariate analysis, stage 1 hypertension (adjusted odds ratio: 2.46, 95% confidence interval: 1.10-5.51, P = 0.029) remained an independent predictor of ICAS after adjustment for confounders. Stage 2 hypertension showed a higher odds ratio and a lower P value, indicating a dose-response effect. Age and HbA1c level were also significantly associated with ICAS, independent of the BP categories. The ICAS lesion burden showed a dose-response effect across the BP categories (P for trend <0.001), whereas ICAS lesion location did not (P for trend = 0.699).

CONCLUSIONS

We demonstrated that stage 1 hypertension, defined according to the 2017 ACC/AHA guideline, was associated with a higher prevalence and burden of ICAS lesions in a neurologically healthy population.

Rise of blood pressure value in young patients at first visit at a dental university hospital in Japan

Background/purpose

Hypertension is a risk factor for stroke and heart disease. Psycho-social reasons are thought to influence blood pressure fluctuation in the dental clinic, but no previous studies have investigated these relationships. In this study, we analyzed a correlation between patients' blood pressure values and their backgrounds.

Materials and methods

We measured blood pressure in 4990 outpatients at our hospital. After determining the age groups in which blood pressure deviated from national averages, patients were classified into the Hypertension group and Normal group. Differences between these groups with regard to the prevalence of systemic disease, dental history and reasons for dental consultation were analyzed.

Results

Average systolic blood pressure of males in their 20's, 30's, 40's and females in their 20's, 30's, 40's, 50's was significantly higher than national averages. In these age groups, disease prevalence was significantly higher in the Hypertension group than in the Normal group. Furthermore, the Hypertension group expressed psycho-social reasons for dental consultation more frequently than the Normal group.

Conclusion

Relatively younger patients tended to show higher systolic blood pressure. It was suggested that psycho-social backgrounds as well as medical causes influenced the blood pressure increase.

Prevalence of sleep disturbances: Sleep disordered breathing, short sleep duration, and non-restorative sleep

Recently, interest in sleep disturbances, such as sleep disordered breathing (SDB), short sleep duration, and non-restorative sleep (NRS), has been increasing. The potentially large public health implications of sleep disturbances indicate a need to determine their prevalence in a general population. This review describes the characteristics of population-based sleep cohorts from past to present. Unavoidable methodological and baseline characteristic heterogeneity was found between studies. The prevalence of SDB (apnea hypopnea index (AHI), respiratory disturbance index (RDI), or oxygen desaturation index (ODI) ≥5/h) was 24.0-83.8% in men and 9.0-76.6% in women, and that of moderate-to-severe SDB (AHI, RDI, or ODI ≥15/h) was 7.2-67.2% in men and 4.0-50.9% in women. Additionally, the prevalence of SDB in post-menopausal women was 3-6 times higher than in pre-menopausal women. The prevalence of subjective short sleep duration (<6 h) was 7.5-9.6%, while that of objective short sleep duration (<6 h) was 22.1-53.3%. The prevalence of NRS was 19.2-31.0% in men and 26.3-42.1% in women, as determined from studies using a yes-no questionnaire, while a multi-national survey using a telephone-based expert system showed a wide range of prevalence between countries, from 2.4% to 16.1%. An association between SDB, short sleep duration, and NRS has recently been suggested. To gain a better understanding of the burden of sleep disturbances, a consensus on the definition of several sleep disturbances is needed, as methodological heterogeneity exists, including SDB scoring rules, subjective versus objective data collection for short sleep duration, and the definition of NRS itself.

Trends in cerebrovascular diseases mortality in Serbia, 1997-2016: a nationwide descriptive study

OBJECTIVES

Over the last decades, mortality from cerebrovascular diseases (CVDs) has decreased in many countries. The aim of this study was to assess the trends of CVDs mortality in Serbia.

METHODS

Descriptive epidemiological study. Age-standardised rates (ASRs) for CVDs mortality were assessed by joinpoint regression analysis to identify significant changes in trends and estimate annual per cent changes with 95% CI. The age-period-cohort analysis has been used to describe variations in mortality.

RESULTS

Over this 20-year period, there were 312 847 deaths from CVDs, with the overall average annual ASR of 148.4 per 100 000. The trend of ASRs from CVDs mortality in males in Serbia showed a significant joinpoint: rates insignificantly decreased from 1997 to 2005 by -0.8% per year (95% CI -1.7% to 0.2%) and thereafter rapidly decreased by -5.0% per year (95% CI -5.6% to -4.5%). A joinpoint for females was found in 2006: the mortality trend was first significantly decreasing by -1.0% per year (95% CI -1.9% to -0.0%) and then sharply falling down by -6.0% per year (95% CI -6.8% to -5.3%). Results of age-period-cohort analysis indicated that the relative risk for CVDs mortality showed statistically significant (p<0.05) cohort and period effects, as well as the net drift and local drifts in Serbian population. The trends in mortality for all subtypes of CVDs were similar in both sexes: trends significantly decreased for most subtypes, with the exception of a significant increase for cerebral infarction.

CONCLUSIONS

After a decade of increase, CVDs mortality rates are declining in last decade in Serbia. However, mortality rates from CVDs remain exceedingly high in Serbia. Differences in mortality trends of the stroke subtypes should be taken into account in the creation of both prevention and treatment guidelines.

Dietary Intake of Energy and Nutrients from Breakfast and Risk of Stroke in The Japanese Population: The Circulatory Risk in Communities Study (CIRCS)

Aims: The frequency of breakfast intake has been reported to be inversely associated with the risk of cardiovascular events; however, it is uncertain what the impact of the energy and nutrient intakes from breakfast are. We assessed the association between these intakes from breakfast and the risk of stroke prospectively.

Methods: In a baseline survey of four Japanese communities between 1981 and 1990, we enrolled 3 248 residents (1 662 men and 1 586 women) aged 40–59 years who were free from stroke and heart disease and who responded to the 24-hour dietary recall survey. We assessed the dietary intake at breakfast, lunch, dinner, and other times separately.

Results: During the median 25-year follow-up, 230 individuals (147 men and 83 women) developed stroke. After adjustment for age, community, other dietary intakes, and lifestyle and physiological factors, the multivariable-adjusted hazard ratios (95% confidence intervals) of intracerebral hemorrhage for the highest versus lowest quartiles of energy intake from breakfast were 0.38 (0.15–0.99) in men and 1.36 (0.36–5.10) in women. For the major nutrients, a higher saturated or monounsaturated fat intake at breakfast was associated with a reduced risk of intracerebral hemorrhage in men, and remained statistically significant after further adjustment for intake of other major nutrients from breakfast.

Conclusions: A higher intake of energy from breakfast, primarily saturated or monounsaturated fat, was associated with a reduced risk of intracerebral hemorrhage in Japanese men.

Lifetime Risk of Stroke and Coronary Heart Disease Deaths According to Blood Pressure Level

Lifetime risk (LTR) provides an absolute risk assessment during the remainder of one’s life. Few studies have focused on the LTRs of stroke and coronary heart disease (CHD), categorized by fine blood pressure in Asian populations. We aimed to assess it using a large database of a meta-analysis with the individual participant data. The present meta-analysis included 107 737 Japanese (42.4% men; mean age, 55.1 years) from 13 cohorts. During the mean follow-up of 15.2±5.3 years (1 559 136 person-years), 1922 died from stroke and 913 from CHD. We estimated risks after adjusting for competing risk of death other than the outcome of interest. The 10-year risk of stroke and CHD deaths at index age of 35 years was ≤1.9% and ≤0.3%, respectively. The LTRs of stroke death at the index age of 35 years (men/women) were 6.1%/4.8% for optimal, 5.7%/6.3% for normal, and 6.6%/6.0% for high-normal blood pressure groups, and 9.1%/7.9% for grade 1, 14.5%/10.3% for grade 2, and 14.6%/14.3% for grade 3 hypertension groups. The LTRs of CHD death similarly elevated with an increase in blood pressure but were lower (≤7.2%) than those of stroke death. In conclusion, blood pressure was clearly associated with an elevated LTR of stroke or CHD death, although the LTR of CHD death was one-half of that of stroke death in an Asian population. These results would help young people with hypertension to adopt a healthy lifestyle or start antihypertensive therapy early.

The Circulatory Risk in Communities Study (CIRCS): A Long-Term Epidemiological Study for Lifestyle-Related Disease Among Japanese Men and Women Living in Communities

The Circulatory Risk in Communities Study (CIRCS) is an ongoing community-based epidemiological study of lifestyle-related disease involving dynamic prospective cohorts of approximately 12,000 adults from five communities of Japan: Ikawa, Ishizawa and Kita-Utetsu (Akita Prefecture), Minami-Takayasu (Osaka Prefecture), Noichi (Kochi Prefecture), and Kyowa (Ibaraki Prefecture). One of the most notable features of CIRCS is that it is not only an observational cohort study to identify risk factors for cardiovascular diseases (CVD), such as stroke, coronary heart disease, and sudden cardiac death, but it also involves prevention programs for CVD. Using basic, clinical, epidemiological, and statistical techniques, CIRCS has clarified characteristics of CVD and the related risk factors to develop specific methodologies towards CVD prevention in Japanese middle-aged or older adults for more than half a century.

Serum Fatty Acid and Risk of Coronary Artery Disease - Circulatory Risk in Communities Study (CIRCS)

BACKGROUND

Few prospective studies have explored the association between fatty acids (FA) and risk of CAD. Understanding of the role of each individual serum FA as a coronary risk or protective factor is still limited. The aim was to investigate which serum FA are associated with the incidence of CAD in Japanese subjects. Methods and Results: A prospective nested case-control study of 40-85-year-old Japanese subjects was undertaken using frozen serum samples collected from 12,840 participants who participated in cardiovascular risk surveys from 1984 to 1998 for 1 community and 1989-1997 for 2 other communities. Three control subjects per case were matched by sex, age, community, year of serum storage and fasting status. By 2005 we had identified 152 incident cases of CAD. Mean n-3-polyunsaturated and saturated FA did not differ between cases and controls, while mean n-6-polyunsaturated FA was higher in controls compared with cases. The multivariable OR of CAD for the highest vs. lowest quartiles of miristic acid (14:0), palmitic acid (16:0), palmitoleic acid (16:1), and linoleic acid (18:2) were 2.8 (95% CI: 1.5-5.2), 2.7 (95% CI: 1.4-5.5), 3.2 (95% CI: 1.7-6.1) and 0.4 (95% CI: 0.2-0.7), respectively.

CONCLUSIONS

High serum miristic acid, palmitic acid and palmitoleic acid have an adverse effect, and high serum linoleic acid had a protective effect, on the risk of CAD.

Cerebral small vessel disease and risk of incident stroke, dementia and depression, and all-cause mortality: A systematic review and meta-analysis

MRI features of cerebral small vessel disease (CSVD), i.e. white matter hyperintensities, lacunes, microbleeds, perivascular spaces, and cerebral atrophy, may be associated with clinical events, but the strength of these associations remains unclear. We conducted a systematic review and meta-analysis on the association between these features and incident ischaemic and haemorrhagic stroke, all-cause dementia and depression, and all-cause mortality. For the association with stroke, 36 studies were identified (number of individuals/events [n] = 38,432/4,136), for dementia 28 (n = 16,458/1,709), for depression nine (n = 9,538/1,746), and for mortality 28 (n = 23,031/2,558). Only two studies evaluated perivascular spaces; these results were not pooled. Pooled analyses showed that all other features were associated with all outcomes (hazard ratios ranged 1.22–2.72). Combinations of two features were more strongly associated with stroke than any individual feature. Individual features and combinations of CSVD features are strongly associated with incident ischaemic and haemorrhagic stroke, all-cause dementia and depression, and all-cause mortality. If these associations are causal, the strength of these associations suggests that a substantial burden of disease is attributable to CSVD.

Nonfasting Glucose and Incident Stroke and Its Types - The Circulatory Risk in Communities Study (CIRCS)

BACKGROUND

The effect of postprandial glucose on the risk of cardiovascular disease has been emphasized, but it is controversial whether nonfasting glucose is related to incident stroke and its types.Methods and Results:We investigated the associations of nonfasting glucose with incident stroke and its types among 7,198 participants aged 40-74 years from the Circulatory Risk in Communities Study, enrolled in 1995-2000. We estimated multivariable hazard ratios (HR) using Cox proportional hazard models. Over a median follow-up of 14.1 years, 291 cases of total stroke (ischemic strokes: 191 including 109 lacunar infarctions) were identified. Nonfasting glucose concentration was associated with greater risk of incident total stroke, ischemic stroke and lacunar infarction when modeled categorically (for prediabetic type: 7.8-11.0 mmol/L vs. normal type: <7.8 mmol/L among all subjects, HR for lacunar infarction was 2.02, 95% confidence interval (CI): 1.19, 3.43) or continuously (per one standard deviation increment among all subjects, HR for lacunar infarction was 1.29, 95% CI: 1.15, 1.45). Diabetic type showed similar results. Population attributable fractions of nonfasting hyperglycemia were 13.2% for ischemic stroke and 17.4% for lacunar infarction.

CONCLUSIONS

Nonfasting glucose concentration, either as a diagnosis of prediabetic and diabetic types or as a continuous variable, proved to be an independent predictor significantly attributed to incident total stroke, especially ischemic stroke and lacunar infarction, in the general population.

Associations of Tobacco Smoking with Impaired Endothelial Function: The Circulatory Risk in Communities Study (CIRCS)

Aims: Smoking impairs endothelial function as an acute effect. However, few population-based studies have examined the association between smoking status and endothelial function or the dose-response and duration- response association of smoking with endothelial function. We examined whether smoking habits were associated with impaired endothelial function depending on smoking dose and duration.

Methods: We conducted a cross-sectional study of 910 men and women aged 30–79 years from 2013 to 2016. Statistical analyses of the data were conducted between 2016 and 2017. Endothelial function was assessed by brachial artery flow-mediated dilation (FMD) measurement. Low FMD was defined in two ways as the cutoff point based on the lowest quartile of %FMD (< 5.1%) and median of %FMD (< 6.8%), regarding as impaired endothelial function. We investigated the smoking status in terms of cigarettes consumed per day and the duration of smoking.

Results: Heavy and chronic smokers were associated with a high prevalence of impaired endothelial function. Those associations did not change substantially after adjustment for other cardiovascular risk factors. Among all participants, the multivariable-adjusted ORs (95% CIs) of low FMD (< 5.1%) with reference to never smokers were 2.23 (1.00–5.14) for current heavy smokers of ≥ 30 cigarettes per day, 1.83 (1.04–3.20) for heavy smokers of ≥ 40 pack-years, and 2.16 (1.15–4.06) for chronic smokers of ≥ 40 years. For low FMD (< 6.8%) those values was 2.17 (1.01–5.05), 1.70 (1.01–2.86), and 1.98 (1.07–3.69), respectively.

Conclusions: Similar associations were observed among only men. Heavy or long-term tobacco smoking may induce impaired endothelial function.

Impact of obstructive sleep apnea on blood pressure and cardiovascular risk factors in Japanese men: A cross-sectional study in work-site group

It has been shown that obstructive sleep apnea (OSA) is related to hypertension and cardiovascular disease; however, the prevalence of OSA in general population and the impact of it on blood pressure especially in Japan has not been well determined. We have conducted a screening test for OSA from 2003 to 2011. In addition, a cross-sectional analysis was performed in 2012 to determine the association of OSA and cardiovascular risk factors in Japanese men (18-69 years of age; mean age, 44.4 ± 0.2). The study group consisted of 2208 male employees, and OSA was evaluated by using the 4% oxygen desaturation index and apnea-hypopnea index (AHI). The prevalence of mild-to-moderate (5≤AHI<30) and severe (AHI≥30) OSA in the studied subjects were 7.1%, and 6.1%, respectively. Among the 135 severe OSA subjects, 105 (77.8%) had been treated with continuous positive airway pressure. Both systolic and diastolic blood pressures (DBP) were significantly increased in the subjects with severe OSA compared with those without OSA. These associations in DBP remained observed after adjustment for age, body mass index (BMI), estimated glomerular filtration rate, HbA_1c, current alcohol intake, current smoking habits, and OSA treatment. DBP in severe OSA subjects were significantly increased in 1807 subjects who were not treated for hypertension or OSA. However, the levels of blood pressures were not decreased by OSA treatment. These results suggest that the prevalence of OSA is relatively high in middle-aged Japanese men and that blood pressures were elevated in the subjects with severe OSA.

Exploring risk patterns for incident ischemic stroke during more than a decade of follow-up: A survival tree analysis

BACKGROUND AND PURPOSE

The burden of stroke is increasing in low to middle income countries. Identifying risk patterns for ischemic stroke (IS) can help develop individualized preventive measures for at risk populations.

METHODS

The study population included 3088 Iranian subjects (1426 men) aged ≥50 years, free of cardiovascular diseases at baseline. The risk factors for ischemic stroke were identified by multivariate Cox analysis. A survival tree model was used to explore interactions between risk factors.

RESULTS

During 12years of follow-up, 106 cases of IS occurred. Age (hazard ratio (HR): 1.08), male gender (HR: 1.69), diastolic blood pressure (DBP) (HR: 1.04), fasting plasma glucose (HR: 1.10), waist circumference (WC) (HR: 1.03) and smoking (HR: 1.96), were associated with increased risk and estimated glomerular filtration rate (eGFR) (HR: 0.97) and wrist circumference (HR: 0.68) decreased the risk of IS (all P-values <0.05). The survival tree identified six risk patterns. The highest and lowest risks were related to subjects ≥60.5years with DBP ≥100mmHg and subjects <60.5years with DBP<97mmHg, respectively. In subjects ≥60.5years with DBP <100mmHg, risk of ischemic stroke was determined by WC ≥96.5cm or (eGFR) <60.87ml/min/1.73m².

CONCLUSION

By applying survival tree as a complementary method to the conventional Cox-analysis, for the first time, we identified risk patterns of ischemic stroke and explored the interactions between risk factors of the disease. DBP was the most important predictor of ischemic stroke in middle-aged and old subjects. In elderly subjects with DBP <100mmHg, abdominal obesity was associated with high risk; however, among non-obese subjects, kidney dysfunction increased the risk of ischemic stroke. Wrist circumference was reported as a novel predictor.

Impact of Hypertension and Subclinical Organ Damage on the Incidence of Cardiovascular Disease Among Japanese Residents at the Population and Individual Levels - The Circulatory Risk in Communities Study (CIRCS)

BACKGROUND

In Japan, a community-based screening program for cardiovascular disease (CVD) has been effective in preventing stroke and coronary artery disease (CAD). The present study aimed to clarify which risk factors assessed at the screening examinations affect the incidence of CVD and the magnitude of the association after the late 1990 s.Methods and Results:We conducted a 12.5-year prospective study of 10,612 Japanese residents aged 40-74 years between 1995 and 2000, initially free of CVD and who underwent the screening examinations. During the follow-up, 364 cases of stroke and 137 cases of CAD were identified. The population attributable fraction of stroke was the largest for hypertension (HT; 46%), while the relative risk of stroke was the highest for atrial fibrillation (multivariable hazard ratio, 4.9; 95% confidence interval, 2.9-8.3). The population attributable fraction of CAD was relatively large for HT, current smoking, and high non-high-density lipoprotein cholesterol (20-29%). A dose-response relationship was found between the incidence of these cardiovascular events and the number of comorbid hypertensive subclinical organ damage markers: funduscopic changes, ST-T changes on ECG at rest, proteinuria and low estimated glomerular filtration rate.

CONCLUSIONS

HT and hypertensive subclinical organ damage are significantly associated with incident stroke and CAD at the population level, suggesting that management of HT and assessment of subclinical organ damage in hypertensive subjects at a screening program are still beneficial for community-based CVD prevention.

Associations of central aortic pressure and brachial blood pressure with flow mediated dilatation in apparently healthy Japanese men: The Circulatory Risk in Communities Study (CIRCS)

BACKGROUND AND AIMS

Endothelial dysfunction is considered the first stage in the development of atherosclerosis and cardiovascular disease, and brachial flow-mediated dilation (FMD) is a measure of endothelial function. It is uncertain which of central systolic aortic pressure (CAP) or brachial systolic blood pressure (SBP) is more strongly associated with FMD. Therefore, we examined the correlations of CAP and SBP with FMD in Japanese men.

METHODS

The study subjects comprised 507 male volunteers aged 30-79 years that were residents in two communities under the Circulatory Risk in Communities Study (CIRCS) between 2013 and 2015. The low percent change of FMD (%FMD) ≤5.0%, after 5 min of reactive hyperemia evaluated by the brachial artery diameter, was used to assess endothelial dysfunction. Values of CAP and SBP were divided into tertiles, with the lowest tertile used as a reference.

RESULTS

After adjustment for cardiovascular risk factors, the multivariable odds ratio (95% CI) of low FMD for the highest versus lowest tertile of CAP was 1.5 (0.9-2.6) for total subjects and 1.4 (0.5-3.8) for those with, and 2.4 (1.2-4.8) for those without antihypertensive medication use. The corresponding odd ratios for the highest versus lowest tertile of SBP were 0.9 (0.5-1.5), 0.8 (0.3-2.2), and 1.3 (0.7-2.5), respectively.

CONCLUSIONS

Higher CAP levels were associated with low FMD for men without antihypertensive medication, but such an association was not found for SBP levels.

Retinal Vascular Changes and Prospective Risk of Disabling Dementia: the Circulatory Risk in Communities Study (CIRCS)

AIM

To investigate the association of retinal vascular changes with a risk of dementia in longitudinal population-based study.

METHODS

We performed a nested case-control study of 3,718 persons, aged 40-89 years, enrolled between 1983 and 2004. Retinal vascular changes were observed in 351 cases with disabling dementia (average period before the onset, 11.2 years) and in 702 controls matched for sex, age, and baseline year. Incidence of disabling dementia was defined as individuals who received cares for disabilities including dementia-related symptoms and/or behavioral disturbance. Conditional logistic regression analysis was used to calculate odds ratio (OR) and multivariable adjusted OR (Models 1 and 2) for incidence of disabling dementia according to each retinal vascular change. Regarding confounding variables, Model 1 included overweight status, hypertension, hyperglycemia, dyslipidemia, and smoking status, whereas Model 2 also included incidence of stroke prior to disabling dementia for further analysis.

RESULTS

The proportion of cases (controls) with retinal vascular changes was 23.1 (15.7)% for generalized arteriolar narrowing, 7.7 (7.5)% for focal arteriolar narrowing, 15.7 (11.8)% for arteriovenous nicking, 10.5 (9.3)% for increased arteriolar wall reflex, and 11.4 (9.8)% for any other retinopathy. Generalized arteriolar narrowing was associated with an increased risk of disabling dementia: crude OR, 1.66 (95% confidence interval, 1.19-2.31); Model 1: OR, 1.58 (1.12-2.23); Model 2: OR, 1.48 (1.04-2.10). The number of retinal abnormalities was associated in a dose-response manner with the risk.

CONCLUSION

Generalized arteriolar narrowing and total number of retinal abnormalities may be useful markers for identifying persons at higher risks of disabling dementia.

Serum uric acid as a predictor of future hypertension: Stratified analysis based on body mass index and age

BACKGROUND

Serum uric acid level is a predictor of future hypertension. However, its dependence on body mass index or age is unclear.

METHODS

We examined 26,442 Japanese males aged 18-60years free from hypertension or diagnosed cardiovascular disease at baseline followed up between 2000 and 2010. Participants were categorized into three groups according to the tertile of serum uric acid levels [mg/dL; 1st (reference): 0.1-5.3; 2nd: 5.4-6.2; 3rd: 6.3-11.6]. Incident hypertension was defined as newly detected blood pressure≥140/90mmHg and/or antihypertensive drugs initiation. Body mass index (<25kg/m(2) vs. ≥25kg/m(2)) and age (<40years vs. ≥40years) were stratified into two groups.

RESULTS

During a mean follow-up of 7.2years, there were 11,361 (43%) hypertension cases. Mean serum uric acid levels (mg/dL) at baseline in each group were 1st tertile, 4.6; 2nd tertile, 5.8; and 3rd tertile, 7.0. The cumulative incident hypertension rate was significantly higher in the 3rd tertile (50.8%) than in the 1st (37.4%). Multiple-adjusted hazard ratios (95% confidence interval) for incident hypertension compared with 1st tertile were 1.01 (0.96-1.05) and 1.15 (1.10-1.21) in the 2nd and 3rd tertile, respectively. There was a significant interaction between age and serum uric acid level (p for interaction=0.035). In subjects aged ≥40years, the 3rd serum uric acid group showed higher hazard ratios [1.48 (1.38-1.59)].

CONCLUSION

High serum uric acid level was associated with future hypertension in young and middle-aged Japanese males. This association was stronger among subjects ≥40years old.

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.

Relationship between HbA1c and risk of retinal hemorrhage in the Japanese general population: The Circulatory Risk in Communities Study (CIRCS)

AIMS

Retinal hemorrhage is an important finding on fundus photography. Diabetes mellitus is a cause of retinal hemorrhage, although other causes exist. We sought to better characterize the association between retinal hemorrhage and HbA1c in the Japanese population.

METHODS

We conducted a prospective study of 11,644 Japanese men and women aged 30-78years between 2001 and 2011. Fundus photography was performed as part of an annual cardiovascular disease risk survey. HbA1c was determined by the latex coagulation method throughout the study. We used logistic regression models to examine the association between HbA1c and the risk of retinal hemorrhage and diabetic retinal hemorrhage.

RESULTS

During a median follow-up period of 4.6years, 509 retinal hemorrhages, including 96 diabetic retinal hemorrhages, were diagnosed. HbA1c was positively associated with the risk of retinal hemorrhage and diabetic retinal hemorrhage among subjects not taking medication for diabetes mellitus at baseline, but not among subjects who were taking medication at baseline.

CONCLUSIONS

HbA1c was positively associated with the risk of retinal hemorrhage and the subcategory of diabetic retinal hemorrhage among subjects not taking medication for diabetes mellitus at baseline. The association was evident for diabetic retinal hemorrhage, compared with retinal hemorrhage.

Use of Electrocardiography to Predict Future Development of Hypertension in the General Population

Cardiac muscle responds to increased afterload by developing hypertrophy. During the early stages of hypertension, the heart can be transiently, but frequently, exposed to increased afterload. This study was designed to test the hypothesis that left ventricular hypertrophy (LVH) assessed by electrocardiography (ECG) can be used to predict future development of hypertension.Sokolow-Lyon voltage and Cornell product were calculated using ECG in 5770 normotensive participants who visited our hospital for a physical checkup (age 52.7 ± 11.3 years). LVH was defined as a Sokolow-Lyon voltage of >3.8 mV or a Cornell product of >2440 mm × ms. After baseline examination, participants were followed up with the endpoint being the development of hypertension.During the median follow-up period of 1089 days (15,789 person-years), hypertension developed in 1029 participants (65.2/1000 person-years). A Kaplan-Meier analysis demonstrated a significantly higher incidence of hypertension in participants with LVH than in those without LVH as assessed by Sokolow-Lyon voltage or Cornell product (P < 0.0001 for both). The hazard ratios for incident hypertension in participants with LVH defined by Sokolow-Lyon voltage and Cornell product were 1.49 (95% confidence interval [CI] 1.16-1.90, P < 0.01) and 1.34 (95% CI 1.09-1.65, P < 0.01), respectively, after adjustment for possible risk factors. Furthermore, in multivariable Cox hazard analysis, where Sokolow-Lyon voltage and Cornell product were taken as continuous variables, both indices were independent predictors of future hypertension (P < 0.0001).Both Sokolow-Lyon voltage and Cornell product are novel predictors of future development of hypertension in the general population.

Heavy Alcohol Consumption is Associated with Impaired Endothelial Function

Aim: Previous studies have reported that moderate alcohol consumption is protective against cardiovascular disease, but heavy alcohol consumption increases its risk. Endothelial dysfunction is hypothesized to contribute to the development of atherosclerosis and cardiovascular disease. However, few population-based studies have examined a potential effect of alcohol consumption on endothelial function.

Methods: This study included 404 men aged 30–79 years who were recruited from residents in 2 communities under the Circulatory Risk in Communities Study in 2013 and 2014. We asked the individuals about the frequency and volume of alcohol beverages and converted the data into grams of ethanol per day. Endothelial function was assessed by brachial artery flow-mediated dilation (FMD) measurements during reactive hyperemia. We performed cross-sectional analysis of alcohol consumption and %FMD by logistic regression analysis, adjusting for age, baseline brachial artery diameter, body mass index, systolic blood pressure, low-density lipoprotein cholesterol, HbA1c, smoking, antihypertensive medication use, and community.

Results: Individuals who drank ≥ 46 g/day ethanol had a lower age-adjusted mean %FMD than non-drinkers (p<0.01). Compared with non-drinkers, the age-adjusted odds ratios (ORs) (95% confidence interval) of low %FMD (<5.3%) for former, light (<23.0 g/day ethanol), moderate (23.0–45.9 g/day ethanol), and heavy (≥ 46.0 g/day ethanol) drinkers were 1.61 (0.67–3.89), 0.84 (0.43–1.66), 1.09 (0.52–2.25), and 2.99 (1.56–5.70), respectively. The corresponding multivariable-adjusted ORs were 1.76 (0.69–4.50), 0.86 (0.42–1.76), 0.98 (0.45–2.12), and 2.39 (1.15–4.95), respectively.

Conclusions: Heavy alcohol consumption may be an independent risk factor of endothelial dysfunction in Japanese men.

The relationship between sodium concentrations in spot urine and blood pressure increases: a prospective study of Japanese general population: the Circulatory Risk in Communities Study (CIRCS)

Background

Although several cross-sectional and intervention studies showed that sodium intake or excretion was associated with blood pressure levels, no prospective study has examined the long-term association between sodium excretion in spot urine and blood pressure changes.

Methods

We conducted a prospective study of 889 normotensive subjects (295 men and 594 women, mean age 57.3 years) who underwent the baseline survey including spot urine test in 2005 and the follow-up survey in 2009 to 2011 (mean follow-up period: 5.8 years). We examined the association between sodium concentration in spot urine, a validated index of sodium excretion occurring over 24-h, and blood pressure changes between baseline and follow-up survey in all, non-overweight (body mass index(BMI) ≤ 25 kg/m²) and overweight normotensives.

Results

For all subjects, sodium concentrations in spot urine were not associated with either systolic or diastolic blood pressure changes. When stratified by BMI at baseline survey, sodium concentrations were positively associated with systolic blood pressure changes in non-overweight subjects, but not in overweight subjects. After adjustment for age, sex, BMI, alcohol intake status, current smoking and estimated glomerular filtration rate, the multivariable-adjusted mean values of the systolic blood pressure change among non-overweight subjects was +7.3 mmHg in the highest quartiles of sodium concentrations, while it was +3.9 mmHg in the lowest quartile (P for difference = 0.021, P for trend = 0.040). After further adjustment of baseline blood pressure levels, the association was slightly weakened; the multivariable-adjusted mean values of the systolic blood pressure changes were +7.0 mmHg and +4.2 mmHg (P for difference = 0.047, P for trend = 0.071).

Conclusions

High sodium concentrations in spot urine were associated with subsequent systolic blood pressure increases among non-overweight normotensive individuals. (272 words)

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0219-1) contains supplementary material, which is available to authorized users.