Prevalence of type 2 (non-insulin-dependent) diabetes mellitus and impaired glucose tolerance in the Japanese general population: the Hisayama Study

Association between corneal hysteresis and glaucoma in a Japanese population: the Hisayama Study

AIMS

To investigate the association between corneal hysteresis and the presence of glaucoma and its subtypes in a general Japanese population.

METHODS

We analysed the data of 2338 Japanese community-dwellers aged ≥40 years (1059 men, 1279 women) who underwent an eye examination in 2018 as part of the population-based, cross-sectional Hisayama Study. Participants were divided into quartile levels of corneal hysteresis, which had been measured with an ocular response analyzer. Glaucoma was defined based on the International Society of Geographical and Epidemiological Ophthalmology criteria. We conducted a logistic regression analysis to determine the ORs and their 95% CIs for the presence of outcomes according to the corneal hysteresis quartiles.

RESULTS

Glaucoma was diagnosed in 154 participants: primary open-angle glaucoma (POAG), n=115; primary angle-closure glaucoma, n=17; exfoliation glaucoma, n=21 and secondary glaucoma without exfoliation glaucoma, n=1. After adjustment for confounders, the OR for prevalent glaucoma was significantly increased in the participants in the first corneal-hysteresis quartile compared with those in the fourth quartile (OR: 1.80; 95% CI: 1.03 to 3.17). Regarding glaucoma subtypes, the first-quartile participants had significantly greater likelihoods of the presence of POAG (OR: 1.63; 95% CI: 1.02 to 2.61) and exfoliation glaucoma (OR: 6.49; 95% CI: 1.44 to 29.30) compared with those in the third and fourth quartiles after adjustment for potential confounders.

CONCLUSIONS

These results demonstrated a significant inverse association between corneal hysteresis and the likelihood of glaucoma, suggesting that the measurement of corneal hysteresis would provide useful information for elucidating the aetiology of glaucoma.

Inadequate care and excessive overprotection during childhood are associated with the presence of diabetes mellitus in adulthood in a general Japanese population: a cross-sectional analysis from the Hisayama Study

OBJECTIVE

To investigate associations between parenting styles during childhood and diabetes in adulthood in a Japanese community.

METHODS

In 2011, 710 community-dwelling Japanese residents aged ≥ 40 years were assessed for the presence of diabetes and for their perceptions of the parenting style of their parents, as measured using the "care" and "overprotection" scales of the Parental Bonding Instrument. Care and overprotection scores for each parent were dichotomized by age-specific median values. Diabetes mellitus was defined as a fasting plasma glucose level of ≥ 7.0 mmol/L, a 2-h post-loaded glucose level of ≥ 11.1 mmol/L, HbA1c ≥ 6.5%, and/or the current use of insulin or oral glucose-lowering agents. The odds ratios (ORs) for prevalent diabetes were calculated using a logistic regression model.

RESULTS

The prevalence of diabetes was 14.9%. Subjects with a high paternal overprotection score had a significantly greater likelihood of prevalent diabetes than those with a low paternal overprotection score after adjusting for confounders (OR 1.71, 95% confidence interval [CI] 1.06-2.77), while there was no significant association between paternal care and diabetes. Additionally, the multivariable-adjusted ORs for the presence of diabetes were significantly higher in subjects with a low maternal care score (OR 1.61, 95%CI 1.00-2.60) or in subjects with a high maternal overprotection score (OR 1.73, 95%CI 1.08-2.80). Moreover, the subjects with a low care score and high overprotection score for both their father and mother had a significantly higher multivariable-adjusted OR of diabetes than those with a high care score and low overprotection score for both parents (OR 2,12, 95%CI 1.14-3.95).

CONCLUSIONS

This study suggests that inadequate care and excessive overprotection during childhood may contribute to the development of diabetes in adulthood.

Prevalence of Glaucoma and Its Systemic Risk Factors in a General Japanese Population: The Hisayama Study

Purpose

To estimate the prevalence of glaucoma and its risk factors in a Japanese community.

Methods

This study included 3405 Japanese community dwellers who were ≥40 years of age and enrolled in the Hisayama Study. This population-based, cross-sectional study was conducted from 2017 to 2018. A glaucoma screening test was performed using stereo fundus images and swept-source optical coherence tomography. Glaucoma was defined based on the International Society of Geographical and Epidemiological Ophthalmology criteria.

Results

The prevalence of glaucoma was 7.6% (95% confidence interval [CI], 6.7–8.6) overall. The prevalence of primary open-angle glaucoma (POAG) was 5.8% (95% CI, 5.0–6.6); that of primary angle-closure glaucoma (PACG) was 0.7% (95% CI, 0.5–1.1); and that of exfoliation glaucoma was 1.1% (95% CI, 0.7–1.4). In addition to aging, lower estimated glomerular filtration rate (eGFR) (odds ratio [OR] = 1.15; 95% CI, 1.02–1.33), higher intraocular pressure (OR = 1.06; 95% CI, 1.01–1.12), longer axial length (OR = 1.44; 95% CI, 1.31–1.59), and thinner central corneal thickness (CCT) (OR = 1.09; 95% CI, 1.04–1.15) were significant risk factors for POAG. Diabetes (OR = 2.81; 95% CI, 1.19–6.62) was a significant risk factor for PACG, and diabetes (OR = 2.15; 95% CI, 1.03–4.47) and thinner CCT (OR = 1.14; 95% CI, 1.02–1.28) were significant risk factors for exfoliation glaucoma.

Conclusions

The prevalence of glaucoma was approximately 8%, probably due to the increase in the Japanese aging population. Not only ocular factors but also lower eGFR for POAG and diabetes for PACG and exfoliation glaucoma were risk factors in a general Japanese population.

Translational Relevance

Systemic factors such as eGFR and diabetes must also be considered when implementing preventive measures against glaucoma.

Risks of Mortality and Airflow Limitation in Japanese with Preserved Ratio Impaired Spirometry

RATIONALE

Several Western studies have reported that participants with preserved ratio impaired spirometry (PRISm) have higher risks of airflow limitation (AFL) and death. However, evidence in East Asian populations is limited.

OBJECTIVES

To investigate the relation between PRISm and the risks of death and incident AFL in a Japanese population.

METHODS

A total of 3,032 community-dwelling Japanese participants aged ≥40 years were followed up for a median of 5.3 years by annual spirometry examinations. Participants were classified into lung function categories at baseline as follows: normal spirometry (forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ≥0.70 and FEV1 ≥80% predicted), PRISm (≥0.70 and <80%), AFL Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1 (<0.70 and ≥80%), and AFL GOLD 2-4 (<0.70 and <80%). Hazard ratios (HRs) and their 95% confidence intervals (CIs) were computed using a Cox proportional hazard model.

MEASUREMENTS AND MAIN RESULTS

During the follow-up period, 131 participants died, 22 of whom died from cardiovascular disease, and 218 participants developed AFL. When examining the prognosis of each baseline pulmonary function category, participants with PRISm had higher risks of all-cause death (HR 2.20 [95%CI: 1.35 to 3.59]) and cardiovascular death (HR 4.07 [1.07 to 15.42]) than those with normal spirometry after adjusting for confounders. Moreover, the multivariable-adjusted risk of incident AFL was greater in participants with PRISm than in those with normal spirometry (HR 2.48 [1.83 to 3.36]).

CONCLUSIONS

PRISm was associated with higher risks of all-cause and cardiovascular death and a greater risk of the development of AFL in a Japanese community.

Pathologic Diabetic Nephropathy in Autopsied Diabetic Cases With Normoalbuminuria From a Japanese Community-Based Study

Introduction

Albuminuria is a clinical hallmark of diabetic nephropathy (DN). Nevertheless, it is controversial whether pathologic DN lesions exist in individuals with diabetes with normoalbuminuria. We investigated the association between albuminuria levels and the frequency of DN lesions in autopsied diabetic cases from a Japanese community.

Methods

A total of 106 autopsied cases with diabetes mellitus (mean age = 76 years, 43.4% male) who died within 6 years after their last health examination were included in the study. Urinary albumin-creatinine ratio (UACR) levels were divided into the following 3 groups: <30.0, 30.0 to 299.9, and ≥300.0 mg/g. The kidney specimens were evaluated with light microscopy. Glomerular DN lesions were categorized into class 0 to I, IIa, IIb, and III glomerular DN lesions according to the criteria of the Renal Pathology Society. A Cochran-Armitage test was used to evaluate the association between the UACR levels and the presence of class IIa or higher glomerular DN lesions.

Results

The frequency of class IIa or higher glomerular DN lesions was 63.2% (IIa, 36.8%; IIb, 3.8%; and III, 22.6%) among overall cases. The frequencies increased significantly with higher UACR levels (P for trend = 0.02). The frequency of class IIa or higher glomerular DN lesions was 51.2%, even in individuals with UACR < 30 mg/g.

Conclusion

This study revealed a positive association of the UACR levels with the presence of class IIa or higher glomerular DN lesions, which were also frequently found even in the normal range of UACR levels, among autopsied diabetic cases from a Japanese community.

Risk Prediction Model for Incident Atrial Fibrillation in a General Japanese Population - The Hisayama Study

BACKGROUND

The risk prediction of incident atrial fibrillation (AF) is useful to prevent AF and its complications. The aim of this study is to develop a new risk prediction model for incident AF using the prospective longitudinal data from a general Japanese population.Methods and Results:A total of 2,442 community-dwelling AF-free residents aged ≥40 years were followed up from 1988 to 2012 (46,422 person-years). The development of AF was confirmed by a standard 12-lead electrocardiogram at repeated health examinations and by medical records at clinics or hospitals. The risk prediction model for incident AF was developed using a Cox proportional hazards model. During the follow up, 230 AF events were confirmed. Age, sex, systolic blood pressure, waist circumference, estimated glomerular filtration rate, abnormal cardiac murmur, high R-wave amplitude, and arrhythmia other than AF were selected for inclusion in the model. This model showed good discrimination (Harrell's c statistics: 0.785) and calibration (Greenwood-Nam-D'Agostino test: P=0.87) for AF risk at 10 years.

CONCLUSIONS

The new risk prediction model showed good performance on the individual risk assessment of the future onset of AF in a general Japanese population. As this model included commonly used clinical parameters, it may be useful for determining the requirements for the careful evaluation of AF, such as frequent electrocardiogram examinations in clinical settings, and subsequent reductions in the risk of AF-related complications.

Serum NT-proBNP levels and histopathological myocardial fibrosis in autopsied cases from a Japanese community: The Hisayama Study

BACKGROUND

natriuretic peptide is associated with myocardial fibrosis in animal models and among patients with heart disease. However, it remains unclear whether serum N-terminal pro-B-type peptide (NT-proBNP) levels are associated with histopathologically proven myocardial fibrosis among individuals without apparent heart disease. This study aimed to evaluate the association between serum NT-proBNP levels and the histopathologically estimated myocardial fibrotic area in autopsied samples from a community.

METHODS

we selected 63 cases without apparent heart disease with available data of serum NT-proBNP concentrations within six years before death (average age: 82 years; male: 52%) from autopsied cases in a community, and evaluated the percentage areas of myocardial fibrosis in four cardiac segments from each case (i.e. 252 cardiac segments in total). The association between serum NT-proBNP levels and the percentage area of myocardial fibrosis was estimated using a linear mixed model for repeated measures.

RESULTS

serum NT-proBNP levels were positively correlated with myocardial fibrotic area [Pearson's correlation coefficient: r = 0.49 (95% confidence interval: 0.28-0.66), p <0.001]. Serum NT-proBNP levels were significantly associated with the percentage areas of myocardial fibrosis after adjusting for potential confounding factors. There was no evidence of heterogeneity in the association between the subgroups with and without reduced estimated glomerular filtration rate (<60 mL/min/1.73 m²).

CONCLUSIONS

the present study demonstrated that elevated serum NT-proBNP levels were associated with the histopathologically measured myocardial fibrotic area in autopsied cases from a community. These findings may help clarify the association between elevated serum NT-proBNP levels and myocardial fibrosis and their influence on prognosis.

Serum High-Sensitivity C-Reactive Protein Levels and the Development of Atrial Fibrillation in a General Japanese Population - The Hisayama Study

BACKGROUND

Atrial fibrillation (AF) is a common arrhythmia in the elderly, and causes complications such as cardioembolic stroke. Serum high-sensitivity C-reactive protein (hs-CRP), a marker of systemic inflammation, has been reported to be a risk factor for developing AF in Western countries. However, few community-based studies have examined this issue in general Asian populations.Methods and Results:A total of 2,510 community-dwelling Japanese participants aged ≥40 years without a history of AF were divided into 4 groups according to the sex-specific quartiles of serum hs-CRP concentrations (Q1, lowest and Q4, highest) and followed up for 24 years. The hazard ratios and their 95% confidence intervals for the development of AF were estimated using a Cox proportional hazards model. During the follow up, 234 subjects developed AF. The risk of AF increased significantly with elevating serum hs-CRP levels after adjustment for potential confounding factors (hazard ratio [95% confidence interval], Q1, 1.00 [reference]; Q2, 1.26 [0.83-1.92]; Q3, 1.77 [1.18-2.66]; and Q4, 1.89 [1.24-2.86]; P for trend <0.001).

CONCLUSIONS

The study findings suggest that elevated serum hs-CRP levels are an independent risk factor for the development of AF in a general Japanese population.

Cohort Profile: The Ganka-Ekigaku Network (GEN), a Network of Japanese Ophthalmological Epidemiology Studies

PURPOSE

Japan has been known as a super-aged society, and ageing is a well-known risk factor for blinding eye diseases. However, epidemiological studies in ophthalmology are still scarce in Japan, and the sizes of the cohorts are relatively small. "Ganka-Ekigaku Network" (GEN, an acronym for the epidemiological network in ophthalmology in Japanese) is established to develop a capacity to boost each epidemiological study and enrich a potential inter-study collaboration to identify risk factors of visual impairment in aged society.

METHODS

We reviewed cohort studies in Japan with the inclusion criteria as: (1) at least n = 1000 at baseline, (2) multiple modalities of ophthalmic data, and (3) diagnosis reviewed by ophthalmologist(s), and (4) ophthalmologists are involved in the investigators group. As of January 2020, GEN includes 4 individual Japanese epidemiological studies namely, Hisayama study, Yamagata Study (Funagata), Tsuruoka Metabolomics Cohort study, and the Nagahama Prospective Genome Cohort for Comprehensive Human Bioscience.

RESULTS

GEN includes approximately 25,000 Japanese participants. The baseline surveys started from 1998 to 2012, and since then the data has been prospectively collected approximately every 5 years. A variety of ophthalmic measurements and other factors have been collected in each study in GEN: ophthalmic measurements (fundus photography, optical coherence tomography, etc.), systemic conditions (laboratory data, etc.), and others (DNA, etc.).

CONCLUSION

GEN is an open platform for observational ophthalmic epidemiological studies to share standardized methodologies. While each study in GEN pursues specific and original research questions, standardization of the methods will enable us to conduct reliable meta-analysis/pooled data analyses.

Lifetime cumulative incidence of dementia in a community-dwelling elderly population in Japan

OBJECTIVE

To estimate the lifetime cumulative incidence of dementia and its subtypes from a community-dwelling elderly population in Japan.

METHODS

A total of 1,193 community-dwelling Japanese individuals without dementia, aged 60 years or older, were followed up prospectively for 17 years. The cumulative incidence of dementia was estimated based on a death- and dementia-free survival function and the hazard functions of dementia at each year, which were computed by using a Weibull proportional hazards model. The lifetime risk of dementia was defined as the cumulative incidence of dementia at the point in time when the survival probability of the population was estimated to be less than 0.5%.

RESULTS

During the follow-up, 350 participants experienced some type of dementia; among them, 191 participants developed Alzheimer disease (AD) and 117 developed vascular dementia (VaD). The lifetime risk of dementia was 55% (95% confidence interval, 49%-60%). Women had an approximately 1.5 times greater lifetime risk of dementia than men (65% [57%-72%] vs 41% [33%-49%]). The lifetime risks of developing AD and VaD were 42% (35%-50%) and 16% (12%-21%) in women vs 20% (7%-34%) and 18% (13%-23%) in men, respectively.

CONCLUSION

Lifetime risk of all dementia for Japanese elderly was substantial at approximately 50% or higher. This study suggests that the lifetime burden attributable to dementia in contemporary Japanese communities is immense.

Glucose Tolerance Levels and Circumpapillary Retinal Nerve Fiber Layer Thickness in a General Japanese Population: The Hisayama Study

PURPOSE

To investigate the relationship between glucose tolerance levels and the circumpapillary retinal nerve fiber layer thickness (cpRNFLT) in a general Japanese population.

DESIGN

Population-based, cross-sectional study.

METHODS

In 2012 and 2013, a total of 2809 Japanese community dwellers aged 40-79 years in the Hisayama Study underwent eye examinations including cpRNFLT measurement with spectral domain optical coherence tomography. Of these, 1324 subjects (578 men and 746 women) were enrolled. Glucose tolerance levels were determined by a 75-g oral glucose tolerance test. We conducted an analysis of covariance to estimate the mean values of cpRNFLT according to the subjects' glucose intolerance status.

RESULTS

The subjects with prediabetes or with diabetes mellitus had significantly lower age- and sex-adjusted mean cpRNFLT values than those with normal glucose tolerance (P = .04 and P = .0004, respectively). The age- and sex-adjusted mean values of cpRNFLT decreased significantly with elevating fasting plasma glucose and 2-hour postload glucose levels (all P for trend < .05). These associations were substantially unchanged after adjustment for potential confounding factors. The coexistence of poorer glucose tolerance and higher intraocular pressure levels was additively associated with thinner cpRNFLT.

CONCLUSIONS

Our analyses revealed that poorer glucose tolerance was significantly associated with the reduction of cpRNFLT in a Japanese general population, suggesting that the loss of neural tissue in the eye begins at the prediabetic stage, and that hyperglycemia may play a role in the reduction of cpRNFLT.

Long-term regular exercise and intraocular pressure: the Hisayama Study

PURPOSE

To investigate the association between long-term regular exercise (exercise frequency and exercise time) and 5-year changes in intraocular pressure in a general Japanese population.

METHODS

This population-based, cohort study was conducted in 2007. A total of 3119 Japanese community dwellers aged ≥ 40 years underwent eye examinations including intraocular pressure measurement with a noncontact tonometer. Of these, 1871 subjects (801 men and 1070 women) who underwent intraocular pressure measurement in 2012 participated. We assessed the associations of exercise frequency and exercise time with intraocular pressure using a linear regression model, adjusted for age and possible risk factors that can affect intraocular pressure.

RESULTS

The mean 5-year intraocular pressure change ± standard deviation was - 0.84 ± 1.9 mmHg. After adjustment for age, sex, systolic blood pressure, diabetes, total cholesterol, high-density lipoprotein cholesterol, body mass index, waist circumference, smoking habit, alcohol intake, work intensity levels, and intraocular pressure at baseline, we observed that increased exercise frequency (times/week) and increased exercise time (min/week) were both significantly associated with reduced intraocular pressure (p < 0.05 each). In the subgroup analyses based on the presence/absence of possible confounding risk factors, there was no evidence of heterogeneity among all subgroups (p for heterogeneity > 0.2).

CONCLUSIONS

Increased exercise frequency levels and increased exercise time are both independently associated with reduced intraocular pressure levels after adjustment for confounding factors.

Reduced Estimated GFR and Cardiac Remodeling: A Population-Based Autopsy Study

RATIONALE & OBJECTIVE

Evidence suggests that cardiac remodeling, including left ventricular hypertrophy and myocardial fibrosis, develops with progression of kidney disease. Few studies have examined cardiac pathology across a range of estimated glomerular filtration rates (eGFRs), which was the objective of this investigation.

STUDY DESIGN

Population-based cross-sectional study of deceased patients undergoing autopsy.

SETTING & PARTICIPANTS

334 of 694 consecutive deceased patients undergoing autopsy with available cardiac tissue, with a prior health examination within 6 years and without a prior diagnosis of heart disease.

EXPOSURE

eGFR.

OUTCOMES

The thickness of the left ventricular wall, sizes of cardiac cells, and percentages of fibrosis, estimated from pathology examination of autopsy samples.

ANALYTICAL APPROACH

Generalized estimating equations.

RESULTS

Lower eGFRs were associated with greater left ventricular wall thickness. Deceased patients with eGFRs≥60, 45 to 59, 30 to 44, and <30mL/min/1.73m² had left ventricular wall thicknesses of 9.1, 9.5, 9.8, and 10.3mm, respectively (P for trend<0.05). Lower eGFRs were also significantly associated with greater mean values of cardiac cell size in the left ventricular wall after adjusting for confounders: 15.3, 16.1, 16.4, and 17.4μm for eGFRs≥60, 45 to 59, 30 to 44, and <30mL/min/1.73m² (P for trend<0.01). Patients with lower eGFRs had significantly higher multivariable-adjusted geometric mean values for fibrosis percentage in the left ventricular wall: 3.22%, 4.33%, 3.83%, and 6.14% for eGFRs≥60, 45 to 59, 30 to 44, and <30mL/min/1.73m² (P for trend<0.001). The negative association of eGFR with multivariable-adjusted mean values of cardiac cell width was stronger among patients with than those without anemia.

LIMITATIONS

Cross-sectional study with a high proportion of elderly patients, no available information for severity or duration of hypertension and other cardiovascular risk factors, no information for medication use.

CONCLUSIONS

These findings suggest that reduced eGFR is associated with cardiac hypertrophy and fibrosis of the left ventricle, cardiac cell enlargement, and cardiac fibrosis.

Japanese Legacy Cohort Studies: The Hisayama Study

The Hisayama Study is a population-based prospective cohort study designed to evaluate the risk factors for lifestyle-related diseases, such as stroke, coronary heart disease, hypertension, diabetes, and dementia, in a general Japanese population. The prospective follow-up surveys have been conducted in subjects aged 40 or older since 1961. Notable characteristics of this study include its high participation rate (70-80% of all residents aged 40 or older), high follow-up rate (99% or over), and high autopsy rate (approximately 75% of deceased cases). The Hisayama Study has provided valuable evidence of secular change in the prevalence and incidence of several lifestyle-related disease and their risk factors. The study has thereby contributed to elucidation of the preventive strategies for lifestyle-related disease. Research efforts in this cohort are ongoing and will provide additional data for the improvement of human health and longevity.

Development and validation of a risk assessment tool for gastric cancer in a general Japanese population

BACKGROUND

There have been very few reports of risk score models for the development of gastric cancer. The aim of this study was to develop and validate a risk assessment tool for discerning future gastric cancer risk in Japanese.

METHODS

A total of 2444 subjects aged 40 years or over were followed up for 14 years from 1988 (derivation cohort), and 3204 subjects of the same age group were followed up for 5 years from 2002 (validation cohort). The weighting (risk score) of each risk factor for predicting future gastric cancer in the risk assessment tool was determined based on the coefficients of a Cox proportional hazards model in the derivation cohort. The goodness of fit of the established risk assessment tool was assessed using the c-statistic and the Hosmer-Lemeshow test in the validation cohort.

RESULTS

During the follow-up, gastric cancer developed in 90 subjects in the derivation cohort and 35 subjects in the validation cohort. In the derivation cohort, the risk prediction model for gastric cancer was established using significant risk factors: age, sex, the combination of Helicobacter pylori antibody and pepsinogen status, hemoglobin A1c level, and smoking status. The incidence of gastric cancer increased significantly as the sum of risk scores increased (P trend < 0.001). The risk assessment tool was validated internally and showed good discrimination (c-statistic = 0.76) and calibration (Hosmer-Lemeshow test P = 0.43) in the validation cohort.

CONCLUSIONS

We developed a risk assessment tool for gastric cancer that provides a useful guide for stratifying an individual's risk of future gastric cancer.

Dietary Protein Intake and Stroke Risk in a General Japanese Population: The Hisayama Study

BACKGROUND AND PURPOSE

The influence of dietary protein intake on stroke risk is an area of interest. We investigated the association between dietary protein intake and stroke risk in Japanese, considering sources of protein.

METHODS

A total of 2400 subjects aged 40 to 79 years were followed up for 19 years. Dietary protein intake was estimated using a 70-item semiquantitative food frequency questionnaire. The risk estimates for incident stroke and its subtypes were calculated using a Cox proportional hazards model.

RESULTS

During the follow-up, 254 participants experienced stroke events; of these, 172 had ischemic stroke, and 58 had intracerebral hemorrhage. Higher total protein intake was significantly associated with lower risks of stroke and intracerebral hemorrhage (both P for trend <0.05). With regard to sources of protein, the risks of total stroke and ischemic stroke significantly decreased by 40% (95% confidence interval, 12%-59%) and 40% (5%-62%), respectively, in subjects with the highest quartile of vegetable protein intake compared with those with the lowest one. In contrast, subjects with the highest quartile of animal protein intake had a 53% (4%-77%) lower risk of intracerebral hemorrhage. Vegetable protein intake was positively correlated with intakes of soybean products, vegetable, and algae, whereas animal protein intake was positively correlated with intakes of fish, meat, eggs, and milk/dairy products. Both types of protein intakes were negatively correlated with intakes of rice and alcohol.

CONCLUSIONS

Our findings suggest that higher dietary protein intake is associated with a reduced risk of stroke in the general Japanese population.

Age-specific impact of diabetes mellitus on the risk of cardiovascular mortality: An overview from the evidence for Cardiovascular Prevention from Observational Cohorts in the Japan Research Group (EPOCH-JAPAN)

Background

Diabetes mellitus is a strong risk factor for cardiovascular disease. However, the age-specific association of diabetes with cardiovascular risk, especially in the elderly, remains unclear in non-Western populations.

Methods

A pooled analysis was conducted using 8 cohort studies (mean follow-up period, 10.3 years) in Japan, combining the data from 38,854 individual participants without history of cardiovascular disease. In all, 1867 of the participants had diabetes, defined based on the 1998 World Health Organization criteria. The association between diabetes and the risk of death from cardiovascular disease, coronary heart disease (CHD), and stroke was estimated using a stratified Cox model, accounting for variability of baseline hazard functions among cohorts.

Results

During the follow-up, 1376 subjects died of cardiovascular disease (including 268 of coronary heart disease and 621 of stroke). Diabetes was associated with an increased risk of cardiovascular death after multivariable adjustment (hazard ratio [HR] 1.62; 95% confidence interval [CI], 1.35–1.94). Similarly, diabetes was a risk factor for CHD (HR 2.13; 95% CI, 1.47–3.09) and stroke (HR 1.40; 95% CI, 1.05–1.85). In the age-stratified analysis of the risk of cardiovascular death, the relative effects of diabetes were consistent across age groups (p for heterogeneity = 0.18), whereas the excess absolute risks of diabetes were greater in participants in their 70s and 80s than in younger subjects.

Conclusions

The management of diabetes is important to reduce the risk of death from cardiovascular disease, not only in midlife but also in late life, in the Japanese population.

•

We conducted meta-analysis of individual data from 8 Japanese cohorts (n = 38,854).

•

Diabetes raised cardiovascular mortality in Japan.

•

Impact of diabetes on cardiovascular death was similar across 10-year age groups.

Combination of Helicobacter pylori Antibody and Serum Pepsinogen as a Good Predictive Tool of Gastric Cancer Incidence: 20-Year Prospective Data From the Hisayama Study

BACKGROUND

There is little information regarding whether the combination of Helicobacter pylori (H. pylori) antibody and serum pepsinogen (sPG), which is a marker of the degree of atrophic gastritis, has a discriminatory ability for detecting incident gastric cancer. We examined this issue in a long-term prospective cohort study of a Japanese population.

METHODS

A total of 2446 Japanese community-dwelling individuals aged ≥40 years were stratified into four groups according to baseline H. pylori serological status and sPG: Group A (H. pylori[-], sPG[-]), Group B (H. pylori[+], sPG[-]), Group C (H. pylori[+], sPG[+]), and Group D (H. pylori[-], sPG[+]), and participants were followed up prospectively for 20 years.

RESULTS

During the follow-up, 123 subjects developed gastric cancer. Compared with that in Group A, the cumulative incidence of gastric cancer was significantly increased in Groups B, C, and D, whereas no significant difference was found between Groups C and D. The multivariable-adjusted risk of gastric cancer was significantly increased in Group B (hazard ratio [HR], 4.08; 95% confidence interval [CI], 1.62-10.28) and in Groups C and D combined (HR 11.1; 95% CI, 4.45-27.46). When the multivariable model with H. pylori antibody was changed into that with the combination of H. pylori antibody and sPG, the C statistics for developing gastric cancer increased significantly (0.773 vs 0.732, P = 0.005), and the continuous net reclassification improvement value was 0.591 (P < 0.001).

CONCLUSIONS

Our findings suggest that the combination of H. pylori antibody and sPG is a useful tool for predicting the development of gastric cancer.

Perceived inadequate care and excessive overprotection during childhood are associated with greater risk of sleep disturbance in adulthood: the Hisayama Study

BACKGROUND

Sleep disturbance and poor sleep quality are major health problems worldwide. One potential risk factor for the development and maintenance of sleep disturbance is the parenting style experienced during childhood. However, its role in sleep disturbance in adulthood has not yet been estimated. This Japanese population study was done to clarify the relation between the parenting styles "care" and "overprotection" during childhood and sleep disturbance in adulthood.

METHODS

A total of 702 community-dwelling Japanese residents aged ≥ 40 years were assessed in 2011 for their perceptions of the parenting style of their parents by use of the Parental Bonding Instrument (PBI) and for sleep disturbance by use of the Pittsburgh Sleep Quality Index (PSQI). The odds ratio (OR) for sleep disturbance (a global PSQI score > 5) was calculated using a logistic regression model.

RESULTS

The prevalence of sleep disturbance was 29 %. After adjusting for sociodemographic, lifestyle, and physical factors in a comparison with the optimal parenting styles (high care and low overprotection), the ORs for sleep disturbance by men were significantly higher for low paternal care, by 2.49 times (95 % confidence interval [CI]: 1.21-5.09), and for high overprotection, by 2.40 times (95 % CI: 1.19-4.85), while the ORs were not significant for low maternal care and high overprotection. For women the only significant factor was high maternal overprotection, by 1.62 times (95 % CI: 1.05-2.52), while the ORs were not significant for low maternal care, low paternal care and high paternal overprotection. The association remained significant for high paternal overprotection for men after additionally controlling for depression.

CONCLUSIONS

This study suggests that parenting style, especially inadequate care and excessive overprotection during childhood, is related to sleep disturbance in adulthood and that the association is much more significant for parents of the same sex as the child.

Insulin Resistance Is a Risk Factor for Increased Intraocular Pressure: The Hisayama Study

PURPOSE

To investigate association of the homeostasis model assessment of insulin resistance (HOMA-IR), a surrogate index of insulin resistance, with IOP in a general Japanese population.

METHODS

In 2007, a total of 3119 Japanese community-dwellers, aged 40 years or older, underwent eye examinations, including IOP measurement with a noncontact tonometer. Of these, 2254 residents participated in this study. Fasting serum glucose and plasma insulin were measured to determine the HOMA-IR. The association of HOMA-IR with IOP was assessed using a linear regression model, adjusted for age and possible risk factors that can elevate IOP.

RESULTS

The mean IOP ± SD was 13.7 ± 2.7 mm Hg in the right eye and 13.6 ± 2.7 mm Hg in the left eye. After adjusting for age, sex, systolic blood pressure, diabetes, total cholesterol, high-density lipoprotein cholesterol, body mass index, waist circumference, smoking habits, alcohol intake, and regular exercise, increased HOMA-IR levels were significantly associated with increasing IOP (P < 0.05). In the subgroup analyses based on the presence or absence of possible confounding risk factors, there was no evidence of heterogeneity between all subgroups (P for heterogeneity > 0.08).

CONCLUSIONS

The HOMA-IR is independently associated with elevated IOP levels after adjustment for confounding factors.

Increasing Number of People with Diabetes in Japan: Is This Trend Real?

Diabetes mellitus, especially type 2 diabetes, has been a major concern among health issues for Japanese policy requiring serious address. In this regard, the increasing number of people with diabetes in Japan over the past few decades has been regarded as a fundamental and evident problem. We herein clarify that the crude diabetes prevalence is likely to have increased mainly as a result of changes in the population distribution, namely, aging of the general population in Japan. We also predict the future trend for the number of people with diabetes according to available concrete evidence in this review.

Impact of population aging on trends in diabetes prevalence: A meta-regression analysis of 160,000 Japanese adults

AIMS/INTRODUCTION

To provide age- and sex-specific trends, age-standardized trends, and projections of diabetes prevalence through the year 2030 in the Japanese adult population.

MATERIALS AND METHODS

In the present meta-regression analysis, we included 161,087 adults from six studies and nine national health surveys carried out between 1988 and 2011 in Japan. We assessed the prevalence of diabetes using a recorded history of diabetes or, for the population of individuals without known diabetes, either a glycated hemoglobin level of ≥6.5% (48 mmol/mol) or the 1999 World Health Organization criteria (i.e., a fasting plasma glucose level of ≥126 mg/dL and/or 2-h glucose level of ≥200 mg/dL in the 75-g oral glucose tolerance test).

RESULTS

For both sexes, prevalence appeared to remain unchanged over the years in all age categories except for men aged 70 years or older, in whom a significant increase in prevalence with time was observed. Age-standardized diabetes prevalence estimates based on the Japanese population of the corresponding year showed marked increasing trends: diabetes prevalence was 6.1% among women (95% confidence interval [CI] 5.5-6.7), 9.9% (95% CI 9.2-10.6) among men, and 7.9% (95% CI 7.5-8.4) among the total population in 2010, and was expected to rise by 2030 to 6.7% (95% CI 5.2-9.2), 13.1% (95% CI 10.9-16.7) and 9.8% (95% CI 8.5-12.0), respectively. In contrast, the age-standardized diabetes prevalence using a fixed population appeared to remain unchanged.

CONCLUSIONS

This large-scale meta-regression analysis shows that a substantial increase in diabetes prevalence is expected in Japan during the next few decades, mainly as a result of the aging of the adult population.

Paternal and maternal bonding styles in childhood are associated with the prevalence of chronic pain in a general adult population: the Hisayama Study

BACKGROUND

Previous research has suggested that extraordinary adverse experiences during childhood, such as abuse, are possible risk factors for the development of chronic pain. However, the relationship between the perceived parental bonding style during childhood and chronic pain has been much less studied.

METHODS

In this cross-sectional study, 760 community-dwelling Japanese adults were asked if they had pain that had been present for six months or more. They completed the Parental Bonding Instrument (PBI), a self-administrated questionnaire designed to assess perceived parental bonding, and the Patient Health Questionnaire-9 to assess current depressive symptoms. The PBI consists of care and overprotection subscales that are analyzed by assigning the parental bonding style to one of four quadrants: Optimal bonding (high care/low overprotection), neglectful parenting (low care/low overprotection), affectionate constraint (high care/high overprotection), and affectionless control (low care/high overprotection). Logistic regression analysis was done to estimate the contribution of the parental bonding style to the risk of chronic pain, controlling for demographic variables.

RESULTS

Compared to the optimal bonding group, the odds ratios (ORs) for having chronic pain were significantly higher in the affectionless control group for paternal bonding (OR: 2.21, 95% CI: 1.50-3.27) and for maternal bonding (OR: 1.60, 95% CI: 1.09-2.36). After adjusting for depression, significance remained only for paternal bonding.

CONCLUSION

The results demonstrate that the parental bonding style during childhood is associated with the prevalence of chronic pain in adults in the general population and that the association is more robust for paternal bonding than for maternal bonding.

Impact of impaired glucose tolerance on clopidogrel response in patients with coronary artery disease

Although patients with impaired glucose tolerance (IGT) are at increased atherothrombotic risk, it is unclear how antiplatelet drugs act in patients with IGT. The aim of this study was to investigate the pharmacodynamic response to clopidogrel in patients with IGT and insulin resistance (IR). A 75 g oral glucose tolerance test was performed in 65 coronary artery disease (CAD) patients on aspirin and clopidogrel therapy. Platelet function tests were assessed at 3 time-points by light transmittance aggregometry using ADP (5 and 20 μmol/L) stimuli. 30 patients had IGT and 35 normal glucose tolerance (NGT). Among them, 13 patients showed IR. Following ADP stimuli, patients with IGT showed significantly higher maximal platelet aggregation at each time point than those with NGT patients. This resulted in greater high on-treatment platelet reactivity (HPR) rates at each time point in IGT patients (53.3-36.7 vs. 14.3-11.4 %, p < 0.05). A multivariable logistic regression analysis showed that IGT status was the strongest predictor of HPR (odds ratio 7.54, 95 % CI 1.95-29.1, p = 0.003). Following a glucose load, profiles of platelet reactivity varied according to IR status, with minimal changes over time in patients with IR, while there was a significant reduction in the non-IR patients. In aspirin and clopidogrel-treated patients with CAD, IGT is associated with enhanced platelet reactivity and increased rates of HPR compared with NGT patients. These findings suggest the presence of platelet dysfunction in patients with IGT, which may be attributed to the presence of IR.

The construction of risk prediction models using GWAS data and its application to a type 2 diabetes prospective cohort

Recent genome-wide association studies (GWAS) have identified several novel single nucleotide polymorphisms (SNPs) associated with type 2 diabetes (T2D). Various models using clinical and/or genetic risk factors have been developed for T2D risk prediction. However, analysis considering algorithms for genetic risk factor detection and regression methods for model construction in combination with interactions of risk factors has not been investigated. Here, using genotype data of 7,360 Japanese individuals, we investigated risk prediction models, considering the algorithms, regression methods and interactions. The best model identified was based on a Bayes factor approach and the lasso method. Using nine SNPs and clinical factors, this method achieved an area under a receiver operating characteristic curve (AUC) of 0.8057 on an independent test set. With the addition of a pair of interaction factors, the model was further improved (p-value 0.0011, AUC 0.8085). Application of our model to prospective cohort data showed significantly better outcome in disease-free survival, according to the log-rank trend test comparing Kaplan-Meier survival curves (p--value 2:09 x 10(-11)). While the major contribution was from clinical factors rather than the genetic factors, consideration of genetic risk factors contributed to an observable, though small, increase in predictive ability. This is the first report to apply risk prediction models constructed from GWAS data to a T2D prospective cohort. Our study shows our model to be effective in prospective prediction and has the potential to contribute to practical clinical use in T2D.

Alexithymia is associated with greater risk of chronic pain and negative affect and with lower life satisfaction in a general population: the Hisayama Study

INTRODUCTION

Chronic pain is a significant health problem worldwide, with a prevalence in the general population of approximately 40%. Alexithymia -- the personality trait of having difficulties with emotional awareness and self-regulation -- has been reported to contribute to an increased risk of several chronic diseases and health conditions, and limited research indicates a potential role for alexithymia in the development and maintenance of chronic pain. However, no study has yet examined the associations between alexithymia and chronic pain in the general population.

METHODS

We administered measures assessing alexithymia, pain, disability, anxiety, depression, and life satisfaction to 927 adults in Hisayama, Japan. We classified the participants into four groups (low-normal alexithymia, middle-normal alexithymia, high-normal alexithymia, and alexithymic) based on their responses to the alexithymia measure. We calculated the risk estimates for the criterion measures by a logistic regression analysis.

RESULTS

Controlling for demographic variables, the odds ratio (OR) for having chronic pain was significantly higher in the high-normal (OR: 1.49, 95% CI: 1.07-2.09) and alexithymic groups (OR: 2.56, 95% CI: 1.47-4.45) compared to the low-normal group. Approximately 40% of the participants belonged to these two high-risk groups. In the subanalyses of the 439 participants with chronic pain, the levels of pain intensity, disability, depression, and anxiety were significantly increased and the degree of life satisfaction was decreased with elevating alexithymia categories.

CONCLUSIONS

The findings demonstrate that, in the general population, higher levels of alexithymia are associated with a higher risk of having chronic pain. The early identification and treatment of alexithymia and negative affect may be beneficial in preventing chronic pain and reducing the clinical and economic burdens of chronic pain. Further research is needed to determine if this association is due to a causal effect of alexithymia on the prevalence and severity of chronic pain.

Serum 1,25-dihydroxyvitamin d and the development of kidney dysfunction in a Japanese community

BACKGROUND

 Recent evidence indicates that vitamin D deficiency is associated with an increased risk of renal impairment, but studies addressing the influence of vitamin D deficiency on the development of chronic kidney disease (CKD) in the general Asian population have been few.

METHODS AND RESULTS

 A total of 2,417 community-dwelling individuals without CKD stage 3-5 aged ≥40 years were followed for 5 years (mean age, 60 years; women, 59.1%). The cumulative incidence of CKD stage 3-5, defined as estimated glomerular filtration rate (eGFR) <60ml·min(-1)·1.73m(-2), and the rate of decline in eGFR according to quartile of serum 1,25-dihydroxyvitamin D (1,25(OH)2D), were estimated. During follow-up, 378 subjects experienced CKD stage 3-5. The age- and sex-adjusted incidence of CKD stage 3-5 increased significantly with decreasing serum 1,25(OH)2D (P for trend <0.001). Compared with the highest quartile, the multivariate-adjusted odds ratio for the development of CKD stage 3-5 was 1.90 in the lowest quartile and 1.74 in the second lowest quartile, after adjusting for confounding factors. Additionally, lower serum 1,25(OH)2D was significantly associated with a greater change in eGFR (-0.10ml·min(-1)·1.73m(-2)·year(-1) per 10-pg/ml decrement in serum 1,25(OH)2D).

CONCLUSIONS

 Lower serum 1,25(OH)2D is a significant risk factor for the development of CKD stage 3-5 in the general Asian population. 

Haemoglobin A1c even within non-diabetic level is a predictor of cardiovascular disease in a general Japanese population: the Hisayama Study

Background

There is little information about predictive ability of haemoglobin A1c (HbA1c) for cardiovascular disease (CVD) in Asians. To investigate the discriminatory ability of HbA1c to identify subjects who are at greater risk of developing CVD in a prospective study of a defined community-dwelling Japanese population.

Methods

A total of 2,851 subjects aged 40–79 years were stratified into five groups (HbA1c levels with ≤ 5.0, 5.1–5.4, 5.5–6.4, and ≥ 6.5% and a group with antidiabetic medication) and followed up prospectively for 7 years (2002–2009).

Results

During the follow-up, 119 subjects developed CVD. The multivariable-adjusted risk of CVD was significantly increased in subjects with HbA1c levels of 5.5–6.4 and ≥ 6.5% and diabetic medication compared to HbA1c level with ≤ 5.0% (hazard ratio, 2.26 [95% confidence interval, 1.29–3.95] for the 5.5–6.4%; 4.43 [2.09–9.37] for the ≥ 6.5%; and 5.15 [2.65–10.0] for the antidiabetic medication group). With regard to CVD subtype, the positive associations between HbA1c levels and the risk of coronary heart disease (CHD) and ischaemic stroke were also significant, but no such associations were seen for haemorrhagic stroke. The C statistic for developing CVD was significantly increased by adding HbA1c values to the model including other risk factors (0.789 vs. 0762, p = 0.006), and the net reclassification improvement was 0.105 (p = 0.004).

Conclusions

Our findings suggest that elevated HbA1c levels are an independent risk factor for CVD, especially CHD and ischaemic stroke, and that the addition of HbA1c to the model with traditional risk factors significantly improves the predictive ability of CVD.

Systemic risk factors associated with polypoidal choroidal vasculopathy and neovascular age-related macular degeneration

PURPOSE

To compare the association of systemic risk factors between neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV).

METHODS

Seven hundred and three patients (235 with nAMD and 468 with PCV) were included. Associated systemic conditions, including hypertension, cardiovascular disease, stroke, diabetes mellitus, and end-stage renal disease, were investigated through an interview and questionnaire.

RESULTS

The prevalence of diabetes mellitus and end-stage renal disease in nAMD was significantly higher than that in PCV (P < 0.001 and P = 0.021, respectively, multivariate logistic regression analysis). Moreover, in diabetic patients with nAMD or PCV, the more severe form of diabetic retinopathy was more prevalent in nAMD cases than in PCV cases (P = 0.006, multivariate logistic regression analysis).

CONCLUSION

Diabetes mellitus and end-stage renal disease are more prevalent in patients with nAMD than in those with PCV. Specific systemic conditions might be associated with the development of nAMD.

Trends in the prevalence of type 2 diabetes and prediabetes in community-dwelling Japanese subjects: The Hisayama Study

Aims/Introduction

We examined secular trends in the prevalence of type 2 diabetes and prediabetes in community‐dwelling Japanese subjects.

Materials and Methods

A total of 2,490 subjects in 1988 and 2,852 subjects in 2002 aged 40–79 years underwent a 75‐g oral glucose tolerance test, and their glucose tolerance status was defined by the 1998 World Health Organization criteria.

Results

The age‐adjusted prevalence of type 2 diabetes increased significantly from 1988 to 2002 in men (14.6% in 1988 to 20.8% in 2002, P < 0.001) and women (9.1% in 1988 to 11.2% in 2002, P = 0.002). A significant rise in the age‐adjusted prevalence of prediabetes was also observed in both sexes (26.2% in 1988 to 35.3% in 2002, P < 0.001 for men; 22.5% in 1988 to 25.1% in 2002, P = 0.04 for women). In age‐stratified analysis, the prevalence of type 2 diabetes increased markedly over time in men aged 60–69 and 70–79 years (both P < 0.001) and women aged 70–79 years (P = 0.02). The prevalence of overall and central obesity increased significantly in men aged 60–69 and 70–79 years, and women aged 70–79 years from 1988 to 2002, whereas the frequency of regular exercise decreased significantly in men aged 70–79 years between the surveys.

Conclusions

Our findings suggest that the prevalence of type 2 diabetes and prediabetes increased significantly in both sexes from the 1980s to the 2000s in a general Japanese population, and that the increasing prevalence of obesity and the decline in physical activity exerted an influence on this rising trend.

Elevated depressive symptoms in metabolic syndrome in a general population of Japanese men: a cross-sectional study

BACKGROUND

Uncertainty still surrounds the association between metabolic syndrome (MetS) and depression. We aimed to evaluate the association between MetS and elevated depressive symptoms in a general Japanese population.

METHODS

This is a cross-sectional survey of 3,113 community-dwelling individuals aged 40 years or over. MetS was defined according to the joint interim statement. MetS was diagnosed when a subject had three or more of the following components: 1) central obesity (waist circumference ≥ 90 cm for men, ≥ 80 cm in for women); 2) elevated blood pressure (≥ 130/85 mmHg or current use of antihypertensive medication); 3) hypertriglyceridemia (≥ 1.7 mmol/L); 4) low HDL cholesterol (< 1.0 mmol/L for men, < 1.3 mmol/L for women); and 5) elevated fasting plasma glucose (≥ 5.55 mmol/L or current use of antidiabetic medication). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). The age- and multivariable-adjusted odds ratio (OR) and 95% confidence interval (CI) were estimated using a logistic regression model.

RESULTS

Elevated depressive symptoms were observed in 4.3% of male and 6.3% of female participants. In men, the age-adjusted prevalence of elevated depressive symptoms was significantly higher in subjects with MetS than in those without (7.1% versus 3.6%, p = 0.04). The prevalence of elevated depressive symptoms rose progressively as the number of MetS components increased (3.5%, 3.6%, 5.8%, and 9.2% in male subjects with 0-1, 2, 3, and ≥ 4 components, respectively; p = 0.02 for trend). This association remained significant even after adjustment for age, marital status, history of cardiovascular disease, smoking habit, alcohol intake, and regular exercise. In women, on the other hand, there was no clear association between MetS and depressive symptoms.

CONCLUSIONS

MetS was associated with elevated depressive symptoms in a general population of Japanese men.

Brachial-ankle pulse wave velocity predicts the development of cardiovascular disease in a general Japanese population: the Hisayama Study

OBJECTIVE

We examined the relationship between brachial-ankle pulse wave velocity and the development of cardiovascular disease in a general Japanese population.

METHODS

A total of 2916 community-dwelling Japanese individuals without history of cardiovascular disease aged at least 40 years were followed up for an average of 7.1 years, and the relationship between brachial-ankle pulse wave velocity and the cardiovascular risk was estimated using the Cox proportional hazards model. To compare the accuracy of the risk assessment for cardiovascular events between the models adjusted for known cardiovascular risk factors with and without brachial-ankle pulse wave velocity, the area under the receiver-operating characteristic curve and net reclassification improvement were computed.

RESULTS

During the follow-up period, 126 patients experienced cardiovascular events. Age and sex-adjusted incidence rates of cardiovascular disease increased linearly with elevating brachial-ankle pulse wave velocity levels (P for trend <0.001). After adjusting for confounding factors, every 20% increment in brachial-ankle pulse wave velocity was associated with a 1.30-fold [95% confidential interval (CI) 1.10-1.53] greater cardiovascular risk. When brachial-ankle pulse wave velocity was incorporated into a model with known cardiovascular risk factors, the area under the receiver-operating characteristic curve was significantly increased (0.776 vs. 0.760; P = 0.01), and the net reclassification improvement was 0.085 (P = 0.008).

CONCLUSIONS

Our findings suggest that brachial-ankle pulse wave velocity is a significant predictive factor for cardiovascular disease in the general Japanese population and that information on brachial-ankle pulse wave velocity substantially improves cardiovascular risk assessment beyond that achieved by a model based on potential risk factors in general practice.

White-coat and masked hypertension are associated with carotid atherosclerosis in a general population: the Hisayama study

BACKGROUND AND PURPOSE

On the basis of combined measurements of clinic blood pressure (CBP) and home blood pressure (HBP), blood pressure status can be divided into normotension, white-coat hypertension (WCHT), masked hypertension (MHT), and sustained hypertension (SHT). Despite the clear impact of MHT and SHT on clinical and subclinical arterial disease, uncertainty about the influence of WCHT remains. The objective of this study was to investigate the associations of WCHT, MHT, and SHT with carotid atherosclerosis in a general population.

METHODS

This is a cross-sectional survey of 2915 community-dwelling Japanese aged ≥ 40 years. Normotension was defined as CBP<140/90 and HBP<135/85 mm Hg; WCHT, CBP ≥ 140/90 and HBP<135/85 mm Hg; MHT, CBP<140/90 and HBP ≥ 135/85 mm Hg; and SHT, CBP ≥ 140/90 and HBP ≥ 135/85 mm Hg. Mean intima-media thickness of carotid arteries was measured using a computer-automated system, and carotid stenosis was defined as diameter stenosis ≥ 30%.

RESULTS

There were 1374 subjects (47.1%) with normotension, 200 (6.9%) with WCHT, 639 (21.9%) with MHT, and 702 (24.1%) with SHT. The geometric average of mean intima-media thickness was significantly higher among subjects with WCHT (0.73 mm), MHT (0.77 mm), and SHT (0.77 mm) than those with normotension (0.67 mm; all P<0.001 versus normotension). Compared with normotension, all types of hypertension were also associated with increased likelihood of carotid stenosis (age- and sex-adjusted odds ratio, 2.36 [95% confidence interval, 1.27-4.37] for WCHT, 1.95 [1.25-3.03] for MHT, and 3.02 [2.01-4.54] for SHT). These associations remained significant even after adjustment for other cardiovascular risk factors.

CONCLUSIONS

WCHT, as well as MHT, and SHT were associated with carotid atherosclerosis in a general Japanese population.

Dietary patterns and risk of dementia in an elderly Japanese population: the Hisayama Study

BACKGROUND

To our knowledge, there are no previous reports that assessed the association between dietary patterns and risk of dementia in Asian populations.

OBJECTIVE

We investigated dietary patterns and their potential association with risk of incident dementia in a general Japanese population.

DESIGN

A total of 1006 community-dwelling Japanese subjects without dementia, aged 60-79 y, were followed up for a median of 15 y. The reduced rank regression procedure was used to efficiently determine their dietary patterns. Estimated risk conferred by a particular dietary pattern on the development of dementia was computed by using a Cox proportional hazards model.

RESULTS

Seven dietary patterns were extracted; of these, dietary pattern 1 was correlated with high intakes of soybeans and soybean products, vegetables, algae, and milk and dairy products and a low intake of rice. During the follow-up, 271 subjects developed all-cause dementia. Of these individuals, 144 subjects had Alzheimer disease (AD), and 88 subjects had vascular dementia (VaD). After adjustment for potential confounders, risks of development of all-cause dementia, AD, and VaD were reduced by 0.66 (95% CI: 0.46, 0.95), 0.65 (95% CI: 0.40, 1.06), and 0.45 (95% CI: 0.22, 0.91), respectively, in subjects in the highest quartile of score for dietary pattern 1 compared with subjects in the lowest quartile.

CONCLUSION

Our findings suggest that a higher adherence to a dietary pattern characterized by a high intake of soybeans and soybean products, vegetables, algae, and milk and dairy products and a low intake of rice is associated with reduced risk of dementia in the general Japanese population.

Impact of eating rate on obesity and cardiovascular risk factors according to glucose tolerance status: the Fukuoka Diabetes Registry and the Hisayama Study

AIMS/HYPOTHESIS

Medical nutrition therapy plays a critical role in the prevention and treatment of type 2 diabetes. However, appropriate measures of eating behaviours, such as eating rate, have not yet been clearly established. The aim of the present study was to examine the associations among eating rate, obesity and cardiovascular risk factors.

METHODS

A total of 7,275 Japanese individuals aged ≥40 years who had normal fasting glucose levels, impaired fasting glucose or diabetes were divided into four groups according to self-reported eating rate: slow, medium, relatively fast and very fast. The associations between eating rate and various cardiovascular risk factors were investigated cross-sectionally.

RESULTS

The proportions of participants who were obese or who had elevated waist circumference levels increased progressively with increases in eating rate (p for trend <0.001), regardless of glucose tolerance status. These associations remained significant after adjustment for potential confounders, namely, age, sex, total energy intake, dietary fibre intake, current smoking, current drinking and regular exercise (p for trend <0.001). Blood pressure and lipid levels also tended to increase in association with eating rate. HbA(1c) rose significantly as eating rate increased, even after multivariate adjustment, including BMI, in diabetic patients on insulin therapy (p = 0.02), whereas fasting plasma glucose did not increase significantly.

CONCLUSIONS/INTERPRETATION

Our findings suggest that eating rate is associated with obesity and other cardiovascular risk factors and therefore may be a modifiable risk factor in the management of cardiovascular risk factors and diabetes.

Coffee consumption, serum γ-glutamyltransferase, and glucose tolerance status in middle-aged Japanese men

Recently, coffee consumption has been related to decreased risk of type 2 diabetes mellitus (DM) among those with high levels of serum γ-glutamyltransferase (GGT). We examined the association between coffee and glucose tolerance, determined by a 75 g oral glucose tolerance test, and the effect modification of serum GGT on the association.

The study subjects were 5320 men aged 46–60 years who received a health examination at two Self-Defense Forces hospitals from January 1997 to March 2004. Those medicated for DM were excluded. Coffee consumption was classified into <1, 1–2, 3–4, and ≥5 cups/day. Statistical adjustment was made for age, body mass index, smoking, alcohol use, leisure-time physical activity, green tea consumption, parental diabetes, hospital, and rank in the Self-Defense Forces.

Men with normal glucose tolerance, isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT), combined IFG/IGT, and type 2 DM numbered 3384, 398, 790, 348, and 400, respectively. The prevalence odds of isolated IGT, combined IFG/IGT, and type 2 DM, but not of isolated IFG, decreased with increasing consumption of coffee. An inverse association with coffee was observed for isolated IGT in both low (≤40 IU/L) and high (>40 IU/L) GGT groups, and for combined IFG/IGT and type 2 DM in the latter group.

Coffee drinking is protective against glucose intolerance. A possible effect modification of GGT on the coffee-DM association warrants further studies.

Association between glucose tolerance level and cancer death in a general Japanese population: the Hisayama Study

The authors examined the associations of glucose tolerance status and fasting and 2-hour postload glucose levels with the risk of cancer death in a 19-year follow-up study of 2,438 Japanese subjects aged 40-79 years who underwent a 75-g oral glucose tolerance test (1988-2007). During follow-up, 229 subjects died of cancer. The risk of cancer death was significantly higher in subjects with fasting plasma glucose levels of ≥5.6 mmol/L or 2-hour postload glucose levels of ≥11.1 mmol/L than in those with the lowest fasting or 2-hour postload glucose levels, after adjustment for potentially confounding factors. According to glucose tolerance status, not only diabetes but also impaired fasting glycemia and impaired glucose tolerance were significant risk factors for cancer death (for impaired fasting glycemia, multivariable-adjusted hazard ratio (HR) = 1.49 (95% confidence interval (CI): 1.05, 2.11); for impaired glucose tolerance, HR = 1.52 (95% CI: 1.05, 2.22); and for diabetes, HR = 2.10 (95% CI: 1.41, 3.12)). With regard to site-specific cancers, elevated fasting or 2-hour postload glucose levels were associated with the risks of death from stomach, liver, and lung cancer. These findings suggest that both prediabetic hyperglycemia and diabetes are significant risk factors for cancer death in the general Japanese population.

Impact of lower range of prehypertension on cardiovascular events in a general population: the Hisayama Study

OBJECTIVES

The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7) defined blood pressure (BP) levels of 120-139/80-89  mmHg as prehypertension. The objective of the present analysis was to examine the impact of prehypertension and its population-attributable fraction for development of cardiovascular events in a general Japanese population.

METHODS

Two thousand, six hundred and thirty-four residents of the town of Hisayama aged at least 40 years without cardiovascular disease were followed up for 19 years. BP categories were defined using JNC7, and prehypertension was divided into the lower (120-129/80-84  mmHg) and higher ranges (130-139/85-89  mmHg). During the follow-up period, 449 participants developed cardiovascular disease (305 strokes and 187 coronary heart diseases).

RESULTS

The frequencies of normal BP, prehypertension, and stages 1 and 2 hypertension were 24.9, 37.7, 23.8, and 13.6%, respectively. The age and sex-adjusted incidence of cardiovascular disease rose progressively with elevation of BP levels (P < 0.001 for trend). The risks of cardiovascular disease in lower and higher ranges of prehypertension were 58% [95% confidence interval (CI) 11-126%] and 70% (95% CI 18-144%) higher than normal BP even after controlling for other cardiovascular risk factors. The population-attributable fraction of prehypertension was 13.2%, which was similar to those of stages 1 and 2 hypertension.

CONCLUSIONS

The risks of cardiovascular disease increased significantly from the lower range of prehypertension in a general Japanese population. Approximately one-third of excess cardiovascular events attributable to elevated BP levels were estimated to occur among individuals with prehypertension.

Prospective study on waist circumference and risk of all-cause and cardiovascular mortality: pooled analysis of Japanese community-based studies

BACKGROUND

The aim of the present study was to clarify the association between waist circumference and all-cause and cardiovascular disease (CVD) mortality risk in relatively lean Japanese subjects.

METHODS AND RESULTS

A total of 3,554 men and 4,472 women who had no history of CVD were examined and their waist circumference measured at baseline. The subjects were aged ≥40 years and were obtained from 3 prospective cohort studies during 1988-1996. Hazard ratios for all-cause and CVD mortality were analyzed over a follow-up period of 14.7 years using a Cox proportional hazards model and penalized spline method, after adjustment for study cohort, age, smoking, alcohol drinking, hypertension, dyslipidemia, and diabetes. Compared with the lowest quintile, the highest quintile of waist circumference in men was associated with a linear reduction in all-cause mortality risk (multivariate-adjusted hazard ratio, 0.73; 95% confidence interval: 0.60-0.89; P for trend=0.001). CVD mortality risk was increased in men aged ≤65 years with a higher waist circumference. This relationship was U-shaped. Waist circumference was not associated with all-cause or CVD mortality risk in women.

CONCLUSIONS

Waist circumference was associated inversely with increased risk of all-cause death in men, but not in women. Middle-aged men with a greater waist circumference potentially have an increased risk of CVD mortality.

Self-reported dietary intake of potassium, calcium, and magnesium and risk of dementia in the Japanese: the Hisayama Study

OBJECTIVES

To investigate whether higher intake of potassium, calcium, and magnesium reduces the risk of incident dementia.

DESIGN

Prospective cohort study.

SETTING

The Hisayama Study, in Japan.

PARTICIPANTS

One thousand eighty-one community-dwelling Japanese individuals without dementia aged 60 and older.

MEASUREMENTS

A 70-item semiquantitative food frequency questionnaire was used to assess potassium, calcium, and magnesium intakes. Hazard ratios (HRs) for the development of all-cause dementia and its subtypes were estimated using Cox proportional hazards model.

RESULTS

During a 17-year follow-up, 303 participants experienced all-cause dementia; of these, 98 had vascular dementia (VaD), and 166 had Alzheimer's disease (AD). The multivariable-adjusted HRs for the development of all-cause dementia were 0.52 (95% confidence interval [CI] = 0.30-0.91), 0.64 (95% CI = 0.41-1.00), and 0.63 (95% CI = 0.40-1.01) for the highest quartiles of potassium, calcium, and magnesium intake, respectively, compared with the corresponding lowest quartiles. Similarly, the HRs for the development of VaD were 0.20 (95% CI = 0.07-0.56), 0.24 (95% CI = 0.11-0.53), and 0.26 (95% CI = 0.11-0.61) for the highest quartiles of potassium, calcium, and magnesium intake, respectively. There was no evidence of a linear association between these mineral intakes and the risk of AD.

CONCLUSION

Higher self-reported dietary intakes of potassium, calcium, and magnesium reduce the risk of all-cause dementia, especially VaD, in the general Japanese population.

Optimal cutoff value of the serum pepsinogen level for prediction of gastric cancer incidence: the Hisayama Study

BACKGROUND

Serum pepsinogen (sPG) levels have been established as a good marker of chronic atrophic gastritis and the sequential occurrence of gastric cancer. However, there have been few prospective investigations which investigated the predictive performance of sPG for future gastric cancer incidence.

SUBJECTS AND METHODS

We prospectively followed-up a total of 2446 community-dwelling Japanese aged ≥ 40 years for 10 years and used the Youden's index to determine the cutoff values of the pepsinogen I level and pepsinogen I/II ratio to accurately discriminate gastric cancer events. Predictive performance of sPG was assessed by ROC curve.

RESULTS

During the follow-up, 69 subjects developed gastric cancer. The most predictive sPG test criteria were determined to be a pepsinogen I level ≤ 59 ng/ml and pepsinogen I/II ratio ≤ 3.9. The sensitivity and specificity of these criteria to discriminate the actual occurrence of gastric cancer were 71.0% and 69.2%, respectively. The area under the ROC curve for gastric cancer occurrence increased significantly by adding the sPG test to the model that included the status of Helicobater pylori infection and other potential risk factors (from 0.742 to 0.809; p for difference in the area < 0.001).

CONCLUSIONS

This study determined the optimal sPG test criteria for predicting gastric cancer occurrence over 10 years in a general Japanese population. These criteria would be effective to screen for individuals at high risk of this disease.

Dietary vitamin A intake and incidence of gastric cancer in a general Japanese population: the Hisayama Study

BACKGROUND

The results of prospective studies examining the association between dietary vitamin A intake and the risk of gastric cancer have often been conflicting. The objective of this study was to investigate this issue in a general Japanese population.

METHODS

A total of 2,467 community-dwelling Japanese subjects aged 40 years or older were followed up prospectively for 14 years. Dietary vitamin A intake was estimated using a semiquantitative food frequency method.

RESULTS

During the follow-up period, gastric cancer developed in 93 subjects. The age- and sex-adjusted incidence of gastric cancer rose progressively with increasing levels of dietary vitamin A intake: at 2.2, 3.0, 3.8, and 4.5 per 1,000 person-years for quartile groups defined by dietary vitamin A intake levels of <639, 639-837, 838-1,061, and >1,061 μg retinol equivalents (RE)/day, respectively (P for trend <0.01). The risk of gastric cancer was significantly higher in the fourth quartile than in the first one even after multivariate adjustment [hazard ratio (HR) = 1.47, 95% confidence interval (CI) = 0.70-3.09, P = 0.30 for the second quartile; HR = 1.85, 95% CI = 0.82-4.18, P = 0.14 for the third quartile; HR = 2.96, 95% CI = 1.12-7.80, P = 0.03 for the fourth quartile]. Comparable effects of vitamin A intake were observed irrespective of the location or histological type of gastric cancer. The HR for gastric cancer increased significantly only in subjects with a combination of high vitamin A intake (>1,061 μg RE/day) and Helicobacter pylori infection.

CONCLUSIONS

Our findings suggest that dietary vitamin A intake is clearly associated with the risk of gastric cancer in the general Japanese population.

White blood cell count and risk of gastric cancer incidence in a general Japanese population: the Hisayama study

The authors examined the association between white blood cell (WBC) count and the development of gastric cancer in a 19-year follow-up study of 2,558 Japanese subjects aged ≥40 years (1988-2007). The subjects were stratified into 4 groups according to baseline WBC quartile (≤4.4, 4.5-5.2, 5.3-6.3, or ≥6.4 × 10(3) cells/μL). During follow-up, 128 subjects developed gastric cancer. The age- and sex-adjusted incidence of gastric cancer increased linearly with higher WBC level: 1.7, 2.6, 3.9, and 5.4 per 1,000 person-years, respectively, for the 4 quartile groups (P for trend < 0.01). The risk of gastric cancer was 2.22-fold (95% confidence interval: 1.19, 4.14) higher in the highest WBC quartile group than in the lowest group after adjustment for confounding factors. With respect to Helicobacter pylori infection status, H. pylori-seropositive subjects in the highest WBC quartile group showed a significantly greater risk of gastric cancer than those in the lower 3 quartile groups, whereas such an association was not observed in H. pylori-seronegative subjects. There was no evidence of heterogeneity in the association (P for heterogeneity = 0.65). The study findings suggest that higher WBC levels are a risk factor for gastric cancer, especially in subjects with H. pylori infection.

Two risk score models for predicting incident Type 2 diabetes in Japan

AIMS

Risk scoring methods are effective for identifying persons at high risk of Type 2 diabetes mellitus, but such approaches have not yet been established in Japan.

METHODS

A total of 1935 subjects of a derivation cohort were followed up for 14 years from 1988 and 1147 subjects of a validation cohort independent of the derivation cohort were followed up for 5 years from 2002. Risk scores were estimated based on the coefficients (β) of Cox proportional hazards model in the derivation cohort and were verified in the validation cohort.

RESULTS

In the derivation cohort, the non-invasive risk model was established using significant risk factors; namely, age, sex, family history of diabetes, abdominal circumference, body mass index, hypertension, regular exercise and current smoking. We also created another scoring risk model by adding fasting plasma glucose levels to the non-invasive model (plus-fasting plasma glucose model). The area under the curve of the non-invasive model was 0.700 and it increased significantly to 0.772 (P < 0.001) in the plus-fasting plasma glucose model. The ability of the non-invasive model to predict Type 2 diabetes was comparable with that of impaired glucose tolerance, and the plus-fasting plasma glucose model was superior to it. The cumulative incidence of Type 2 diabetes was significantly increased with elevating quintiles of the sum scores of both models in the validation cohort (P for trend < 0.001).

CONCLUSIONS

We developed two practical risk score models for easily identifying individuals at high risk of incident Type 2 diabetes without an oral glucose tolerance test in the Japanese population.