Improvement in Japanese Clinical Laboratory Measurements of Total Cholesterol and HDL-cholesterol by the US Cholesterol Reference Method Laboratory Network

Risk factors for intracerebral hemorrhage by five specific bleeding sites: Japan Public Health Center-based Prospective Study

BACKGROUND

Evaluating the risk factors for intracerebral hemorrhage is indispensable for primary prevention. However, the pathogenesis varies depending on the bleeding site, and few prospective studies have explored risk factors in detail for each site.

PARTICIPANTS AND METHODS

The Japan Public Health Center-based Prospective Study is a prospective study comprising a population-based sample of Japanese adults in 1990 (Cohort I) and in 1993 (Cohort II). A total of 34,137 participants (11,907 men and 22,230 women) were enrolled in this study and followed up until 2009 for Cohort I and until 2012 for Cohort II. The association between risk factors (age, sex, blood pressure, serum cholesterol, triglycerides, blood glucose, body mass index, smoking, and drinking status) and intracerebral hemorrhage by its bleeding site (lobes, putamen, thalamus, cerebellum, and brainstem) was assessed using Cox proportional hazards analysis.

RESULTS

During a median 20-year follow-up, 571 intracerebral hemorrhage events occurred. Hypertension was associated with an increased risk of total intracerebral hemorrhage, but not lobar hemorrhage. The multivariable hazard ratio (95% confidence intervals) was 2.09 (1.75-2.50) for total intracerebral hemorrhage. In contrast, a low serum total cholesterol level was associated only with lobar hemorrhage (1.73 (1.01-2.96)). Heavy drinking was associated with the risk of total and putamen hemorrhage, and obesity was associated with the risk of putamen hemorrhage.

DISCUSSION AND CONCLUSION

The present study identified different risk factors depending on the bleeding site of intracerebral hemorrhage.

Relationship between Ikigai and longitudinal changes in serum HDL cholesterol levels: the Circulatory Risk in Communities Study (CIRCS)

BACKGROUND

Having positive psychological well-being has been associated with serum high-density lipoprotein cholesterol (HDLC), but no longitudinal study to date has examined the association between Ikigai and serum HDLC. Therefore, we examined the association between Ikigai and change in serum HDLC over time using a cohort dataset spanning 2010-2018.

METHODS

The study included 471 men and 776 women aged 40-74 years who underwent a cardiovascular examination in 2010 and were asked their levels of Ikigai. We combined "definitely yes" and "yes" as "with Ikigai" and recorded "a little" as "with a little Ikigai" and "no" as "without Ikigai". We measured serum HDLC using direct methods. The association between Ikigai and serum HDLC levels at baseline, and changes in this relationship during an eight-year period, were analyzed using linear mixed-effect models.

RESULTS

At the baseline, relative to those without Ikigai, women with Ikigai had higher serum HDLC (baseline difference in those with a little Ikigai = 7.52 mg/dl, 95% confidence interval [CI]: 1.12 to 13.9 and in those with Ikigai = 8.11 mg/dl, 95% CI: 1.54 to 14.7). The difference in serum HDLC between women with and without Ikigai remained over the eight-year follow-up period. There were no similar Ikigai-associated differences in the serum HDLC of men.

CONCLUSIONS

Women with Ikigai showed differences in serum HDLC that were observed at baseline and persisted over time.

Association of Pro-Inflammatory Diet with Long-Term Risk of All-Cause and Cardiovascular Disease Mortality: NIPPON DATA80

AIM

A pro-inflammatory diet may increase the risk of cardiovascular disease (CVD) and all-cause mortality. However, this remains inconclusive as there is yet no study using a dietary record method that has been conducted in a large general population. Furthermore, an underestimation of the pro-inflammatory diet may exist due to the unmeasured effect of salt intake. Thus, in this study, we aimed to examine how pro-inflammatory diet is associated with the long-term risk of all-cause and CVD mortality in a representative Japanese population.

METHODS

A national nutrition survey was conducted throughout Japan in 1980. After considering the exclusion criteria, 9284 individuals (56% women aged 30-92 years) were included in this study. In total, 20 dietary parameters derived from 3-day weighed dietary records were used to calculate the dietary inflammatory index (DII). The causes of death were monitored until 2009. The Cox proportional hazards model was used to determine multivariable-adjusted hazard ratios (HRs). Stratified analysis according to salt intake level was also performed.

RESULTS

Compared with the lowest quartile of DII, multivariable-adjusted HRs (95% confidence intervals) in the highest quartile were 1.28 (1.15, 1.41), 1.35 (1.14, 1.60), 1.48 (1.15, 1.92), 1.62 (1.11, 2.38), and 1.34 (1.03, 1.75) for all-cause mortality, CVD mortality, atherosclerotic CVD mortality, coronary heart disease mortality, and stroke mortality, respectively. Stratified analysis revealed stronger associations among individuals with higher salt intake.

CONCLUSIONS

As per our findings, a pro-inflammatory diet was determined to be positively associated with the long-term risk of all-cause and CVD mortality in a representative Japanese population. Thus, considering both salt intake and pro-inflammatory diet is deemed crucial for a comprehensive assessment of CVD risk.

Changes in cardiovascular disease risk factors during menopausal transition in Japanese women: the Circulatory Risk in Communities Study (CIRCS)

OBJECTIVE

We aimed to longitudinally clarify the changes in cardiovascular disease risk factors associated with menopause in Japanese women in the 2000s.

METHODS

Of the 4,596 women who underwent health examinations between 2007 and 2012 in three communities of the Circulatory Risk in Communities Study, 263 women who reported going through menopause during that period were included in the study. We randomly selected 1,665 men as control subjects who participated in a health examination at least once between 2001 and 2009 and at least once between 2010 and 2018 by 1:1 pair-matching for age, community, and examination year. The health examination data from 3 to 6 years before (2001-2009) and after menopause age (2010-2018) were compared in terms of body mass index, systolic and diastolic blood pressure levels, serum total cholesterol, high-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol, triglycerides, uric acid, hemoglobin A 1c , hemoglobin, aspartate aminotransferase, alanine aminotransferase, and current smoker status.

RESULTS

Compared with the men, the women showed a greater increase in serum total cholesterol (+16.7 vs -3.1 mg/dL, P < 0.001), non-high-density lipoprotein cholesterol (+15.9 vs -6.3 mg/dL, P < 0.001), fasting triglycerides (+1.2 vs +1.0 mg/dL, P = 0.027), triglycerides regardless of fasting status (+1.2 vs -0.9 mg/dL, P < 0.001), uric acid (+0.5 vs +0.2 mg/dL, P = 0.008), hemoglobin (+0.9 vs -0.3 g/dL, P < 0.001), aspartate aminotransferase (+2.9 vs -2.7 IU/L, P < 0.001), and alanine aminotransferase (+2.9 vs -2.6 IU/L, P < 0.001). No differences were found in the changes in body mass index, systolic and diastolic blood pressures, and hemoglobin A 1c between the women and the matched men.

CONCLUSIONS

Menopause may be a crucial factor related to changes in serum total cholesterol, non-high-density lipoprotein cholesterol, triglycerides, uric acid, hemoglobin, and liver enzymes.

Risk Factors That Most Accurately Predict Coronary Artery Disease Based on the Duration of Follow-up - NIPPON DATA80

BACKGROUND

This study assessed sex-specific time-associated changes in the impact of risk factors on coronary artery disease (CAD) mortality in a general population over long-term follow-up.

METHODS AND RESULTS

A prospective longitudinal cohort study was conducted on representative Japanese populations followed up for 29 years. Data from 8,396 participants (3,745 men, 4,651 women) were analyzed. The sex-specific multivariable adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of 4 risk factors (smoking, diabetes, serum total cholesterol [TC], and systolic blood pressure [SBP]) for CAD mortality were calculated at baseline and at 10, 15, 20, 25, and 29 years of follow-up. In men, smoking (HR 3.23; 95% CI 1.16-9.02) and a 1-SD increase in TC (HR 1.82; 95% CI 1.29-2.57) were strongly associated with a higher risk of CAD in the first 10 years, but this association decreased over time. Diabetes (HR 2.30; 95% CI 1.37-3.85) and a 1-SD increase in SBP (HR 1.23; 95% CI 1.00-1.50) were strongly correlated with a higher risk of CAD after 29 years). In women, diabetes was correlated with CAD after 20 years (HR 2.53; 95% CI 1.19-5.36) and this correlation persisted until after 29 years (HR 2.47; 95% CI 1.40-4.35).

CONCLUSIONS

The duration of follow-up needed for the accurate assessment of risk factors for CAD mortality varies according to risk factor and sex.

Relationship between non-fasting triglycerides and cardiovascular disease mortality in a 20-year follow-up study of a Japanese general population: NIPPON DATA90

Background

Non-fasting triglycerides (TG) are considered a better predictor of cardiovascular disease (CVD) than fasting TG. However, the effect of non-fasting TG on fatal CVD events remains unclear. In the present study, we aimed to explore the relationship between non-fasting TG and CVD mortality in a Japanese general population.

Methods

A total of 6,831 participants without a history of CVD, in which those who had a blood sampling over 8 hours or more after a meal were excluded, were followed for 18.0 years. We divided participants into seven groups according to non-fasting TG levels: ≤59 mg/dL, 60–89 mg/dL, 90–119 mg/dL, 120–149 mg/dL, 150–179 mg/dL, 180–209 mg/dL, and ≥210 mg/dL, and estimated the multivariable-adjusted hazard ratios (HRs) of each TG group for CVD mortality after adjusting for potential confounders, including high density lipoprotein cholesterol. Additionally, we performed analysis stratified by age <65 and ≥65 years.

Results

During the follow-up period, 433 deaths due to CVD were detected. Compared with a non-fasting TG of 150–179 mg/dL, non-fasting TG ≥210 mg/dL was significantly associated with increased risk for CVD mortality (HR 1.56: 95% CI, 1.01–2.41). Additionally, lower levels of non-fasting TG were also significantly associated with increased risk for fatal CVD. In participants aged ≥65 years, lower levels of non-fasting TG had a stronger impact on increased risk for CVD mortality, while higher levels of non-fasting TG had a stronger impact in those aged <65 years.

Conclusion

In a general Japanese population, we observed a U-shaped association between non-fasting TG and fatal CVD events.

Seven-Day Pedometer-Assessed Step Counts and Brain Volume: A Population-Based Observational Study

BACKGROUND

To investigate the association between step counts and brain volumes (BVs)-global and 6 a priori selected cognition-related regions of interest-in Japanese men aged 40-79 years.

METHODS

The authors analyzed data from 680 cognitively intact participants of the Shiga Epidemiological Study of Subclinical Atherosclerosis-a population-based observational study. Using multivariable linear regression, the authors assessed cross-sectional associations between 7-day step counts at baseline (2006-2008) and BVs at follow-up (2012-2015) for age-stratified groups (<60 y and ≥60 y).

RESULTS

In the older adults ≥60 years, step counts at baseline (per 1000 steps) were associated with total BV at follow-up (β = 1.42, P = .022) while adjusted for potential covariates. Regions of interest-based analyses yielded an association of step counts with both prefrontal cortexes (P < .05) in older adults, while the left entorhinal cortex showed marginally significant association (P = .05). No association was observed with hippocampus, parahippocampal, cingulum, and cerebellum. No association was observed in younger adults (<60 y).

CONCLUSIONS

The authors found a positive association between 7-day step counts and BVs, including prefrontal cortexes, and left entorhinal cortex in apparently healthy Japanese men.

Relationship Between Step Counts and Cerebral Small Vessel Disease in Japanese Men

BACKGROUND AND PURPOSE

Cerebral small vessel disease (CSVD) is a common subclinical feature of the aging brain. Steps per day may contribute to its prevention. We herein investigated the association between step counts and CSVD in a healthy Japanese male population.

METHODS

We analyzed data from 680 men who were free of stroke and participated in this observational study. Seven-day step counts were assessed at baseline (2006-2008) using a pedometer. CSVD was assessed at follow-ups (2012-2015) based on deep and subcortical white matter hyperintensities (WMHs), periventricular hyperintensities, lacunar infarcts, and cerebral microbleeds on magnetic resonance imaging. Using a logistic regression analysis, we computed the adjusted odds ratios, with 95% CIs, of prevalent CSVD according to quartiles of step counts (reference: Q1). We also investigated the association between step counts and WMH volumes using a quantile regression.

RESULTS

Steps per day were significantly associated with lower odds ratios, with the lowest at Q3 (8175-10 614 steps/day), of higher (versus low or no burden) deep and subcortical WMHs (odds ratio, 0.52 [95% CI, 0.30-0.89]), periventricular hyperintensities (0.50 [95% CI, 0.29-0.86]), and lacunar infarcts (0.52 [95% CI, 0.30-0.91]) compared with Q1 (≤6060 steps/day) but not cerebral microbleeds. An inverse linear association was observed between step counts and WMH volumes. These associations were independent of age and smoking and drinking status and remained consistent when adjusted for vascular risk factors.

CONCLUSIONS

We found a J-shaped relationship between step counts and prevalent CSVD in healthy Japanese men, with the lowest risk being observed among participants with ≈8000 to 10 000 steps/day. Higher steps were also associated with lower WMH volumes.

The relationship between serum levels of LOX-1 ligand containing ApoAI as a novel marker of dysfunctional HDL and coronary artery calcification in middle-aged Japanese men

BACKGROUND AND AIMS

Dysfunctional high-density lipoprotein (HDL) is a risk factor for cardiovascular disease (CVD) beyond HDL concentrations. Recently, a novel method has been introduced to measure LOX-1 ligand containing apolipoprotein AI (LAA), which is an indicator of various types of modified HDL with binding capacity to LOX-1 and related to impaired anti-atherogenic functions of HDL. This study aimed to examine the relationship between LAA as a novel marker of dysfunctional HDL and coronary artery calcification (CAC).

METHODS

We selected 910 community-dwelling Japanese men aged 40-79 years without a history of CVD. The odds ratios per 1SD of LAA for the presence of CAC (Agatston score >10) were estimated using logistic regression model adjusted for confounders, including HDL-C or HDL particle (HDL-P) concentration. In addition, we performed further analysis stratified by age (<65 and ≥ 65 years).

RESULTS

The mean age of the participants was 63.6 years, and the median LAA was 187.0 ng/mL. The prevalent CAC was 46.2%. The multivariable adjusted odds ratio (95% confidence interval) per 1SD of LAA for CAC was 1.14 (0.96-1.36) for all participants. After stratification by age, multivariable adjusted odds ratios per 1SD of LAA were 1.34 (1.02-1.76) and 0.97 (0.77-1.23) in men aged <65 and ≥ 65 years, respectively.

CONCLUSIONS

The present study showed that LAA was associated with CAC independent of HDL-C or HDL-P in middle-aged Japanese men. This finding suggests that LAA might be an early marker for CVD events. Future longitudinal studies are warranted.

Proteinuria and Reduced Estimated Glomerular Filtration Rate are Independently Associated With Lower Cognitive Abilities in Apparently Healthy Community-Dwelling Elderly Men in Japan: A Cross-sectional Study

BACKGROUND

The association of proteinuria and reduced estimated glomerular filtration rate (eGFR) with cognition needs more clarification. We cross-sectionally examined whether proteinuria and reduced eGFR, even in moderate stages, were independently associated with lower cognition in a community-based sample of elderly men.

METHODS

Our cohort initially comprised 1,094 men aged 40-79 years from a random sample from Shiga, Japan in 2006-2008. Of 853 men who returned for the follow-up examination (2009-2014), we analyzed 561 who were ≥65 years, free of stroke, and completed the Cognitive Abilities Screening Instrument (CASI) at follow-up (higher CASI scores [range 0 to 100] indicate better cognition). Proteinuria was assessed via dipstick. eGFR was calculated according to the Chronic Kidney Disease Epidemiology Collaboration Equation. Participants were divided into three groups either by eGFR (≥60, 59-40, and <40 mL/min/1.73 m2) or by proteinuria (no, trace, and positive), considered normal, moderate, and advanced, respectively. Using linear regression, we computed mean CASI score, with simultaneous adjustment for proteinuria and eGFR in addition to other potential confounders.

RESULTS

Significant trends of lower cognition were observed across the groups of worse proteinuria and lower eGFR independently: multivariable-adjusted mean CASI scores were 90.1, 89.3, and 88.4 for proteinuria (Ptrend = 0.029), and 90.0, 88.5, and 88.5 for eGFR (Ptrend = 0.015) in mutual-adjustment model.

CONCLUSIONS

Proteinuria and reduced eGFR, even in their moderate stages, were independently associated with lower cognition in a community-based sample of elderly men. The results suggest the importance of proteinuria and low eGFR for early detection and prevention of cognitive decline.

Metabolic Syndrome, Physical Activity, and Inflammation: A Cross-Sectional Analysis of 110 Circulating Biomarkers in Japanese Adults

BACKGROUND

Metabolic syndrome (MetS) is a systemic inflammatory state. Low physical activity (PA) could modify this patho-physiology or act as an independent contributor to inflammation. Previous studies of both conditions have identified altered levels of inflammation- and immune-related proteins based on limited sets of candidate markers.

METHODS

We investigated associations of MetS and low PA with circulating inflammation markers in a stratified random sample of Japanese adults (N = 774, mean age 60.7 years) within the Japan Public Health Center-based Prospective Study (JPHC) Cohort II. AHA/NHLBI criteria were used to define MetS (19%) and the bottom quartile of PA was considered low. 110 circulating biomarkers, including cytokines, chemokines, and soluble receptors were measured by multiplex bead-based and proximity-extension assays. Associations of MetS and low PA with marker quantiles were adjusted for each other and for age, sex, study site, cigarette smoking, alcohol consumption, and blood sample fasting state by ordinal logistic regression. P values were corrected for FDR.

RESULTS

MetS was significantly associated with levels of six markers: IL18R1 [odds ratio 2.37; 95% confidence interval (CI), 1.45-3.87], CRP (2.07; 95% CI, 1.48-2.90), SAP (2.08; 95% CI, 1.47-2.95), CCL19/MIP3β (2.06; 95% CI, 1.48-2.88), CXCL12/SDF1α+β (0.48; 95% CI, 0.32-0.65), and CCL28 (0.44; 95% CI, 0.27-0.71). Low PA had no significant marker associations.

CONCLUSIONS

Positively associated markers with MetS are mostly Th1 immune response-related and acute phase proteins, whereas negatively associated markers are generally Th2-related.

IMPACT

MetS is associated with a broad range of alterations in immune and inflammatory biomarkers that may contribute to risks of various chronic diseases, independent of low PA.

Elevated Fasting Blood Glucose Levels Are Associated With Lower Cognitive Function, With a Threshold in Non-Diabetic Individuals: A Population-Based Study

Background

Cognitive dysfunction has been recognized as a diabetes-related complication. Whether hyperglycemia or elevated fasting glucose are associated with cognitive decline remains controversial. We aimed to investigate the relationship between fasting glucose levels and cognitive function in diabetic and non-diabetic individuals.

Methods

Participants were Japanese diabetic (n = 191) and non-diabetic (n = 616) men, aged 46–81 years, from 2010–2014. Blood samples were taken after a 12 h fast. The Cognitive Ability Screening Instrument (CASI), with a maximum score of 100, was used for cognitive assessment. Cognitive domains of CASI were also investigated. Fractional logit regression with covariate adjustment for potential confounders was used to model cross-sectional relationships between fasting blood glucose and CASI score.

Results

For diabetic individuals, CASI score was 0.38 (95% confidence interval: 0.66–0.12) lower per 1 mmol/L higher fasting glucose level. Short-term memory domain also exhibited an inverse association. For non-diabetic individuals, a reverse U-shaped relationship was observed between fasting glucose and cognitive function, identifying a threshold for highest cognitive performance of 91.8 CASI score at 3.97–6.20 mmol/L (71.5–111.6 mg/dL) fasting glucose. Language ability domain displayed a similar relationship with fasting glucose.

Conclusions

Elevated fasting glucose levels in diabetic men were associated with lower cognitive function, in which short-term memory was the main associated domain. Interestingly, in non-diabetic men, we identified a threshold for the inverse relationship of elevated fasting glucose with cognitive function. Contrastingly to diabetic men, language ability was the main associated cognitive domain among non-diabetic men.

Liver fat accumulation assessed by computed tomography is an independent risk factor for diabetes mellitus in a population-based study: SESSA (Shiga Epidemiological Study of Subclinical Atherosclerosis)

AIMS

Ectopic fat accumulation is related to insulin resistance and diabetes mellitus (DM). However, the effect of fatty liver on DM in non-obese individuals has not been clarified. We investigated whether liver fat accumulation assessed by computed tomography (CT) is associated with the incidence of DM.

METHODS

In a prospective population-based study, 640 Japanese men were followed up for 5 years. The liver to spleen (L/S) ratio of the CT attenuation value was used as the liver fat accumulation index. We calculated the odds ratio (OR) and 95% confidence interval (CI) for the DM incidence of per 1 standard deviation (SD) lower L/S and those of L/S < 1.0 compared with L/S ≥ 1.0, using logistic regression models.

RESULTS

Both per 1 SD lower L/S and L/S < 1.0 were significantly associated with a risk for DM incidence (1 SD lower L/S: OR = 1.57, 95%CI = 1.14-2.16; L/S < 1.0: OR = 2.27, 95%CI = 1.00-5.14). The relationship between L/S and incidence of DM was consistent in the obese and non-obese groups, with thresholds of BMI 25 kg/m², waist circumference 85 cm, or visceral adipose tissue 100 cm².

CONCLUSIONS

Liver fat accumulation assessed by CT was associated with the incidence of DM.

The Association Between Coronary Artery Calcification and Subclinical Cerebrovascular Diseases in Men: An Observational Study

Aim: Coronary artery calcification (CAC) is an independent predictor of stroke and dementia, in which subclinical cerebrovascular diseases (SCVDs) play a vital pathogenetic role. However, few studies have described the association between CAC and SCVDs. Therefore, the aim of this study was to assess the clinical relationship between CAC and SCVDs in a healthy Japanese male population.

Methods: In this observational study, 709 men, free of stroke, were sampled from a city in Japan from 2010 to 2014. CAC was scored using the Agatston method. The following SCVDs were assessed using magnetic resonance imaging: intracranial arterial stenosis (ICAS), lacunar infarction, deep and subcortical white matter hyperintensity (DSWMH), periventricular hyperintensity (PVH), and microbleeds. The participants were categorized according to CAC scores as follows: no CAC (0), mild CAC (1–100), and moderate-to-severe CAC (> 100). The adjusted odds ratios of prevalent SCVDs were computed in reference to the no-CAC group using logistic regression.

Results: The mean (standard deviation) age of the participants was 68 (8.4) years. Participants in the moderate-to-severe CAC category showed significantly higher odds of prevalent lacunar infarction, DSWMH, and ICAS in age-adjusted and risk-factor-adjusted models. Microbleeds and PVH, in contrast, did not show any significant associations. The trends for CAC with lacunar infarction, DSWMH, and ICAS were also significant (all P-values for trend ≤ 0.02).

Conclusions: Higher CAC scores were associated with higher odds of lacunar infarction, DSWMH, and ICAS. The presence and degree of CAC may be a useful indicator for SCVDs involving small and large vessels.

Non-High-Density Lipoprotein Cholesterol and Risk of Stroke Subtypes and Coronary Heart Disease: The Japan Public Health Center-Based Prospective (JPHC) Study

Aim: A positive association between non-high-density lipoprotein cholesterol (non-HDL-C) and coronary heart disease (CHD) has been established; however, associations between non-HDL-C and stroke subtypes have not been determined.

Methods: We conducted a prospective study of 30,554 individuals aged 40–69 yrs with no history of cardiovascular disease (CVD) in Japan. Sex-specific hazard ratios (HRs) and 95% confidence intervals (CIs) for the incidence of stroke subtypes and CHD were estimated according to quintiles of non-HDL-C, using Cox proportional hazard models adjusted for other established risk factors.

Results: We identified 1,705 stroke and 296 CHD events over a median 15 yrs of follow-up. The fractional polynomials analysis revealed a U-shaped association between non-HDL-C and stroke risk in men. When analyzed for stroke subtypes, the data revealed an inverse relationship between non-HDL-C and intracerebral hemorrhage (ICH), primarily with lobar ICH, and a positive association between non-HDL-C and large-artery occlusive infarction in men [adjusted HR 0.55 (95% CI, 0.35–0.87) and 2.05 (95% CI, 1.07–3.93) for the highest and lowest quintile of non-HDL-C, respectively]. The lowest risk of ICH in women was observed in the fourth quintile, and the lowest risk of embolic infarction was observed in the third quintile. In contrast, non-HDL-C was positively associated with CHD in both sexes.

Conclusions: In Japanese men, lower non-HDL-C levels were associated with a decreased risk of large-artery occlusive infarction and an increased risk of ICH, particularly lobar ICH.

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

BACKGROUND

Many studies show that dietary factors such as vegetables, fruit, and salt are associated with cardiovascular disease (CVD) risk. However, a risk assessment chart for CVD mortality according to combinations of dietary factors has not been established.

METHODS AND RESULTS

Participants were 9,115 men and women aged 30-79 years enrolled in the National Nutritional Survey of Japan in 1980 with a 29-year follow-up. Dietary intake was assessed using a 3-day weighed dietary record at baseline. Cox regression models were used to estimate the hazard ratio (HR) of CVD mortality stratified by vegetables, fruit, fish, and salt consumption. HRs of CVD mortality according to combinations of dietary factors were color coded on an assessment chart. Higher intakes of vegetables, fruit, and fish, and lower salt intake were associated with lower CVD mortality risk. HRs calculated from combinations of dietary factors were displayed using 5 colors corresponding to the magnitude of the HR. People with the lowest intake of vegetables, fruit, and fish, and higher salt intake had a HR of 2.87 compared with those with the highest intake of vegetables, fruit, and fish, and lower salt intake.

CONCLUSIONS

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

Anthropometric Obesity Indices were Stronger than CT-Based Indices in Associations with Carotid Intima-Media Thickness in Japanese Men

AIM

Computed tomography (CT) can directly provide information on body compositions and distributions, compared to anthropometric indices. It has been shown that various obesity indices are associated with carotid intima-media thickness (IMT). However, whether CT-based obesity indices are stronger than anthropometric indices in association with atherosclerosis remains to be determined in a general population.

METHODS

We cross-sectionally assessed carotid IMT using ultrasound in 944 community-dwelling Japanese men free of stroke and myocardial infarction. CT image at the L4-L5 level was obtained to compute areas of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Anthropometric measures assessed included body mass index (BMI), waist circumference, and waist-to-hip ratio. Using multivariable linear regression, slopes of IMT per 20^th to 80^th percentile of each index were compared. We also compared the slope of index with simultaneous adjustment for BMI in the same model.

RESULTS

Areas of VAT and SAT were positively associated with IMT, but not stronger than those of anthropometric indices in point estimates. Among all obesity indices, BMI was strongest in association with IMT after adjusting for age and lifestyle factors or further adjusting for metabolic factors. In simultaneous adjustment models, BMI, but not CT-based indices, remained significant and showed the strongest association.

CONCLUSIONS

In community-dwelling Japanese men, anthropometric obesity indices, BMI in particular, were more strongly associated with carotid atherosclerosis than CT-based obesity indices. The association of general obesity with carotid atherosclerosis was strong and adding CT-based obesity measure did not considerably influence in the association.

Eshak E, Kinuta M, Nagao M, Cui R, Imano H, Ohira T, Iso H. Association between vitamin B group supplementation with changes in % flow-mediated dilatation and plasma homocysteine levels: a randomized controlled trial

There is limited evidence examining the association between B vitamin supplementation and improved endothelial function via lowering plasma homocysteine levels. This study investigated whether low-dose B vitamin supplementation improves endothelial dysfunction in Japanese adults with one or more components of metabolic syndrome. A randomized, controlled, crossover trial, without a washout period or blinding of subjects, was conducted from May-September, 2010. The subjects were 127 Japanese men and women aged 40-65 years who had at least one component of metabolic syndrome without medication. Participants took a supplement drink for two months but were divided into early intervention or later intervention groups. The flow-mediated dilatation, plasma homocysteine level, serum B-vitamins, and vitamin C levels were measured. A significant increase in serum B vitamins and vitamin C levels, and a reduction in plasma homocysteine levels were observed. The mean serum homocysteine level pre- and post-intervention was 9.8 and 8.2 µmol/L in the early intervention group and 10.8 and 7.4 µmol/L in the later intervention group (p<0.01). However, no significant changes in flow-mediated dilatation was found. Low-dose multivitamin supplementation including B vitamins is associated with a significant reduction in plasma homocysteine levels among patients with one or more components of metabolic syndrome. This study was registered at the University Hospital Medical Information Network (UMIN) centre, and has the identifier UMIN000004436.

The Prospective Association Between Plasma Concentrations of Cellular Growth Factors and Risk of Heart Failure Mortality in Japanese Population

Background

Limited evidence is available on the association of insulin-like growth factors (IGFs) and risk of heart failure in population-based samples. We investigated whether serum IGFs concentrations can predict mortality from heart failure.

Methods

We conducted a nested case-control study of 39,242 subjects aged 40–79 years who participated in the JACC study, a large Japanese prospective cohort study; participants provided serum samples and were followed up for 9 years. In heart failure cases and age-, sex-, community-, and year of blood withdrawal-matched controls, we measured serum concentrations of IGF-I, IGF-II, and IGF binding protein 3 (IGFBP3) and transforming growth factor (TGF-β1).

Results

During the follow-up, there were 88 heart failure deaths (44 men and 44 women). Each increment of 1 standard deviation [SD] of IGF-II (120.0 ng/mL in women and 143.7 ng/mL in men) was associated with a 47% reduced risk of mortality from heart failure; multivariable odds ratio was 0.53 (95% confidence interval [CI], 0.30–0.94, P-trend = 0.03). The multivariable odds ratio in the highest quartile of IGFBP3 serum concentrations (≥3.29 µg/mL in women and ≥3.31 µg/mL in men) compared with the lowest (<2.11 µg/mL in women and <2.56 µg/mL in men) was 0.24 (95% CI, 0.05–1.11; P-trend = 0.12). No association was found between serum concentrations of IGF-I or TGF-β1 and risk of heart failure.

Conclusions

Higher serum concentrations of IGF-II were associated with lower mortality from heart failure, which might suggest a possible role of IGF-II in the occurrence or prognosis of heart failure.

One-year weight loss maintenance outcomes following a worksite-based weight reduction program among Japanese men with cardiovascular risk factors

Objectives

Worksite‐based programs present a simple and effective approach to facilitate weight reduction in employees. Despite the importance of 1‐year weight loss maintenance, studies have generally focused on the short‐term effects of weight reduction programs. In addition, little is known about the long‐term weight maintenance outcomes in Asian populations. We examined the long‐term maintenance effects of a worksite‐based weight reduction program among Japanese men with cardiovascular risk factors.

Methods

The study sample comprised 58 overweight men with cardiovascular risk factors who had voluntarily participated in a randomized crossover trial involving a 3‐month weight reduction program. Participants were followed up for 1 year after the trial concluded, and both groups were merged for the analysis. We compared the changes in body weight before the post‐trial follow‐up and after 12 months to examine the long‐term maintenance effects of the program. Changes in other cardiovascular risk factors (eg, waist circumference, blood pressure, lipid measures, and diabetes‐related measures) were also examined.

Results

Both groups of study participants achieved weight loss during the weight reduction program. Total 53 participants (91.4%) completed the 12‐month post‐trial follow‐up. There were no significant changes in mean body weight (mean: −0.11, 95% confidence interval: −0.7‐0.49 kg) and other cardiovascular risk factors between the beginning and end of the follow‐up period.

Conclusions

This study showed that the worksite‐based weight reduction program not only enabled short‐term weight loss, but that the participants were able to successfully maintain their weight for 1 year after the program without any supplementary interventions.

Time-Related Changes in Relationships Between the Keys Score, Dietary Lipids, and Serum Total Cholesterol in Japan - NIPPON DATA80/90/2010

BACKGROUND

In recent years, individuals with high serum total cholesterol (TC) have been more likely to modify their diet by reducing their intake of dietary lipids. The aim of this study was to investigate time-related changes in the relationships between the Keys score, dietary lipids, and TC between 1980 and 2010 in representative Japanese populations.

METHODS AND RESULTS

We used 3 cross-sectional cohort studies conducted among Japanese representative populations in 1980, 1990, and 2010 (NIPPON DATA80/90/2010) for the analyses. We analyzed data for 10,365, 7,714, and 2,657 participants, respectively, in each dataset. The relationships between TC and the Keys score (calculated by dietary lipids, cholesterol, and energy intake)/dietary lipids were examined. In men, a 1-unit higher Keys score correlated with 0.92 mg/dL and 0.64 mg/dL TC in 1980 and 1990, respectively, but not in 2010. In women, a 1-unit higher Keys score correlated with 0.70 mg/dL and 0.74 mg/dL TC in 1980 and 1990, respectively, but with 0.33 mg/dL in 2010. In men and women, dietary cholesterol, saturated fatty acid (SFA), and trans fatty acid (TFA) levels were positively associated with TC concentrations in 1980 and 1990, but not in 2010.

CONCLUSIONS

In these representative Japanese populations, a higher Keys score as well as dietary cholesterol, SFA, and TFA levels correlated with higher TC concentrations in 1980/1990, but the relationships were weaker or not observed in 2010.

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.

Differences Between Coronary Artery Calcification and Aortic Artery Calcification in Relation to Cardiovascular Disease Risk Factors in Japanese Men

AIMS

Calcification in the coronary and aortic arteries has been linked to cardiovascular morbidity and mortality. The pathophysiological influence of aortic artery calcification (AAC) differs from that of coronary artery calcification (CAC). We aimed to compare the relationships between CAC and AAC and cardiovascular disease (CVD) risk factors.

METHODS

We examined a random sample of 1035 Japanese men aged 40-79 years. CAC and AAC were measured by computed tomography and scored according to the Agatston method. Using a logistic regression, we calculated the odds ratio (OR) as being in the highest quintile (Q5) of the calcification score compared to the lower quintiles (Q1-Q4) per 1 standard deviation higher CVD risk factor. Models were simultaneously adjusted for age, body mass index (BMI), systolic blood pressure, smoking (pack-year), alcohol intake, hemoglobin A1c, uric acid, estimated glomerular filtration rate (eGFR), serum lipids, and C-reactive protein. Differences in ORs were investigated using a generalized estimating equation. We performed a multiple linear regression using log-transformed CAC and AAC values as dependent variables.

RESULTS

CAC and AAC were independently associated with age (OR, 95% CI: 2.30 [1.77-2.98] for CAC and 3.48 [2.57-4.73] for AAC), p for difference ＜0.001), systolic blood pressure (1.29 [1.08-1.53] and 1.28 [1.07-1.54], p for difference=0.270), and smoking (1.22, [1.04-1.43] and 1.34 [1.13-1.58]) p for difference=0.071). Alcohol correlated with AAC only (1.17 [0.97-1.41] for CAC and 1.42 [1.16-1.73] for AAC, p for difference= 0.020).

CONCLUSIONS

CAC and AAC were associated with similar CVD risk factors. The strength of association slightly differed between CAC and AAC.

Self-reported Sleep Duration and Subclinical Atherosclerosis in a General Population of Japanese Men

Aim: There are few data regarding associations between sleep duration and subclinical atherosclerosis in Japan. The aim of this study was to evaluate associations of self-reported sleep duration with calcification in the coronary arteries (CAC) and carotid intima media thickness (IMT) in Japanese men.

Methods: This was a cross-sectional survey of 1093 randomly selected men from Kusatsu City, Japan. Average sleep duration on weekdays was estimated through questionnaire; CAC by computed tomography; and carotid IMT by ultrasonography.

Results: The prevalence of CAC was 50.0% for participants with sleep duration < 5.5 h, 43.9% with 5.5–6.4 h, 50.0% with 6.5–7.4 h, 49.3% with 7.5–8.4 h, and 62.5% with ≥ 8.5 h. In univariate analysis, participants with sleep duration ≥ 8.5 h had significantly higher prevalence of CAC than those with 6.5–7.4 h (p = 0.043). After adjustment for age and other risk factors, however, the association was not significant (p = 0.776). The average IMT was 0.85 mm for participants with sleep duration < 5.5 h, 0.83 mm with 5.5–6.4 h, 0.85 mm with 6.5–7.4 h, 0.88 mm with 7.5–8.4 h, and 0.90 mm with ≥ 8.5 h. None of the differences in IMT observed in crude or multivariable-adjusted analyses was significant (all p > 0.1).

Conclusion: Self-reported sleep duration was not associated with increased CAC or carotid IMT in a general population of Japanese men.

Association of high-density lipoprotein cholesterol concentration with different types of stroke and coronary heart disease: The Japan Public Health Center-based prospective (JPHC) study

BACKGROUND AND AIMS

Although low high-density lipoprotein (HDL) cholesterol concentration is an established risk factor for coronary heart disease (CHD), information regarding subtypes of stroke is very limited, especially in Asian populations.

METHODS

A prospective study was conducted among 30,736 individuals aged 40-69 years, who lived in nine communities in Japan and did not have a history of cardiovascular disease (CVD). CHD and stroke, including its subtypes, were assessed, and sex-specific hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes were estimated according to quintiles of HDL cholesterol using Cox proportional models adjusted for other CVD risk factors.

RESULTS

We identified 296 CHD and 1712 stroke events over a median 15 yr of follow-up. HDL cholesterol concentration showed an inverse association with CHD in men and women. A low HDL cholesterol concentration slightly raised the risk for total strokes in men, but not in women. When analyzed by subtypes, we observed an inverse relationship between HDL cholesterol concentration and the incidence of lacunar infarction, with an adjusted HR for the lowest quintile of HDL cholesterol concentration compared with the highest quintile of 1.63 (95% CI, 1.00-2.66) in men and 1.97 (95% CI, 1.19-3.26) in women. HDL cholesterol concentration was positively associated with the risk of intracerebral hemorrhage (ICH) in a linear manner in women (p for trend = 0.028), but not in men.

CONCLUSIONS

The associations of HDL cholesterol concentration with lacunar infarction and ICH may be related to different functional properties of HDL rather than to its protective function against lipid-rich atherosclerosis.

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.

Changes in ischaemic ECG abnormalities and subsequent risk of cardiovascular disease

Objective

The prognostic importance of changes in ischaemic ECG abnormalities over time (especially ST-T abnormalities) among Asians has not been fully investigated. We examined the associations between changes in ischaemic abnormalities upon serial ECG (improvement, persistence, deterioration) and cardiovascular disease (CVD) risk.

Methods

A prospective study cohort was conducted with 9374 men and women aged 40–69 years in four communities. Participants had multiple ECGs at study entry and during the next 10 years, and were followed up for a median period of 23.0 years. Total CVD (stroke and coronary heart disease) was ascertained under systematic surveillance. ECG abnormalities were defined by the Minnesota Code, ST depression (Code4), abnormal T wave (Code5) and categorised into nine groups (no–no, no–minor, no–major, minor–no, minor–minor, minor–major, major–no, major–minor, major–major) by comparison with the point of entrance and maximum change.

Results

We documented 1196 CVD events. Compared with no–no abnormality, no–minor, minor–major and major–major in Code4, HRs (95% CI) adjusted for cardiovascular risk factors were 1.19 (1.00–1.42), 1.57 (1.15–2.12) and 1.87 (1.42–2.47). Similar results were observed in Code5.

Conclusions

Changes in ischaemic ECG abnormalities from none to minor, and minor to major, as well as persistent major abnormalities, were associated with an increased risk of CVD.

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 non-high-density lipoprotein cholesterol and the long-term mortality of cardiovascular diseases: NIPPON DATA 90

BACKGROUND

Non-high-density lipoprotein (HDL) cholesterol level, generally less affected by fasting status or serum triglyceride levels, may be useful for predicting future cardiovascular events in daily clinical practice. This study aimed to investigate the role of non-HDL cholesterol in the development of fatal coronary events and stroke in the general Japanese population.

METHODS AND RESULTS

From the NIPPON DATA 90 prospective cohort study, 8383 participants were followed up for 20years since 1990. After exclusion of 666 cases without lipid or covariates data, 561 cases who were 75years old or older, 274 cases with history of cardiovascular disease, and 181 cases with lipid-lowering treatment, 6701 participants were included in this analysis. Non-HDL cholesterol was defined as total cholesterol minus HDL cholesterol. Outcomes were death from coronary heart disease and stroke. During the period, 69 participants died from coronary heart disease and 112 from stroke. Compared with participants with non-HDL cholesterol level <3.9mmol/L, age- and sex-adjusted hazard ratios for mortality by coronary heart disease in those with non-HDL cholesterol levels of 3.9-4.3mmol/L, 4.4-4.8mmol/L and ≥4.9mmol/L were 1.27 (95% confidence interval [CI] 0.65-2.49), 1.81 (95% CI 0.92-3.55) and 2.40 (95% CI 1.30-4.43), respectively (P trend=0.010). This association remained significant even after adjusting for other cardiovascular risk factors (P trend=0.010). There was no clear association between non-HDL cholesterol levels and mortality by stroke (P trend=0.052).

CONCLUSIONS

Among the general Japanese population, non-HDL cholesterol levels were clearly associated with future mortality by coronary heart disease, but not by stroke.

Lipoprotein-associated phospholipase A2 is related to risk of subclinical atherosclerosis but is not supported by Mendelian randomization analysis in a general Japanese population

OBJECTIVE

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an enzyme predominantly bound to low-density lipoprotein (LDL). Lp-PLA2 is recognized as playing a key role in inflammatory processes and the development of atherosclerosis. This study aimed to investigate whether Lp-PLA2 is related to subclinical atherosclerosis, independently from traditional risk factors, in a general Japanese population by analyses of both the observational study and Mendelian randomization using V279F polymorphism.

METHODS AND RESULTS

We cross-sectionally examined community-based sample of 929 Japanese men aged 40-79 years, without statin treatment, who were randomly selected from the resident registration. Multiple regression analyses of Lp-PLA2 activity and concentration were undertaken separately for men aged 40-49 years and 50-79 years, to clarify interactions of age and Lp-PLA2. Lp-PLA2 activity for men aged 50-79 years was significantly and positively related to intima-media thickness (IMT) (P = 0.013) and plaque index (P = 0.008) independent of traditional risk factors including small LDL particles, but not to coronary artery calcification (CAC) score. Associations with Lp-PLA2 concentration were qualitatively similar to those of activity. Corresponding relationships were not observed in men aged 40-49 years. Mendelian randomization analyses based on V279F genotype did not show any significant associations with subclinical atherosclerosis, although the homozygote and heterozygote of V279F showed low Lp-PLA2 activity and concentration.

CONCLUSIONS

Lp-PLA2 activity in Japanese men aged 50-79 years was associated significantly and positively with IMT and plaque in the carotid artery but Mendelian randomization did not support that Lp-PLA2 is a causative factor for subclinical atherosclerosis.

The Relationship between Very High Levels of Serum High-Density Lipoprotein Cholesterol and Cause-Specific Mortality in a 20-Year Follow-Up Study of Japanese General Population

AIMS

There is no community-based cohort study to examine the effect of very high level of high-density lipoprotein cholesterol (HDL-C) on coronary heart disease (CHD) and other cause-specific mortality. Therefore, we investigated the relationship between HDL-C including very high level and cause-specific mortality in a 20-year cohort study of the representative sample of Japanese.

METHODS

We followed 7,019 individuals from the Japanese general population (2,946 men and 4,073 women). We defined HDL-C levels as follow: low (HDL-C ＜1.04 mmol/L), reference (1.04-1.55 mmol/L), high (1.56-2.06 mmol/L), very high (≥2.07 mmol/L). The multivariate adjusted hazard ratio (HR) for all-cause or cause-specific mortality was calculated using a Cox proportional hazards model adjusted for other traditional risk factors.

RESULTS

During follow-up, we observed 1,598 deaths. No significant association was observed between HDL-C and all-cause mortality. Serum HDL-C also showed no association with stroke. In contrast, the risk for CHD among high HDL-C was lower than reference, HRs were 0.51 [95% confidence interval (CI): 0.21-1.23] in men, 0.33 (95% CI: 0.11-0.95) in women, and 0.41 (95% CI: 0.21-0.81) when men and women were combined. However, very high HDL-C did not show significant association with CHD and other cause-specific mortality.

CONCLUSIONS

HDL-C was not associated with all-cause and stroke mortality. In contrast, high serum HDL-C levels, at least up to 2.06 mmol/L, were protective against CHD, although further high levels were not. However, sample size of cause-specific death in very high HDL-C group was not enough even in this 20-year follow-up of 7,019 Japanese; larger cohort studies should be warranted.

Associations of serum LDL particle concentration with carotid intima-media thickness and coronary artery calcification

BACKGROUND

Low-density lipoprotein particle (LDL-P) has recently been found to be a stronger predictor of cardiovascular disease (CVD) than LDL-cholesterol (LDL-C).

OBJECTIVES

Whether LDL-P is associated with subclinical atherosclerosis, independent of LDL-C, as well as other lipid measures has not been fully examined. We aimed to analyze LDL-P associations with measures of subclinical atherosclerosis.

METHODS

We examined 870 Japanese men randomly selected from Kusatsu City, Shiga, Japan, aged 40-79 years from 2006-2008, free of clinical CVD and not using lipid-lowering medication. Cross-sectional associations of lipid measures with carotid intima-media thickness (cIMT) and coronary artery calcification (CAC; >0 Agatston score) were examined.

RESULTS

LDL-P was significantly positively associated with cIMT and maintained this association after adjustments for LDL-C and other lipid measures. Although these lipid measures were positively associated with cIMT, model adjustment for LDL-P removed any significant relationships. Higher LDL-P was associated with a significantly higher odds ratio of CAC and further adjustment for LDL-C did not affect this relationship. In contrast, the LDL-C association with CAC was no longer significant after adjustment for LDL-P. Other lipid measures attenuated associations of LDL-P with CAC. Likewise, associations of these measures with CAC were attenuated when model adjustments for LDL-P were made.

CONCLUSIONS

In a community-based sample of Japanese men, free of clinical CVD, LDL-P was a robust marker for subclinical atherosclerosis, independent of LDL-C and other lipid measures. Associations of LDL-C and other lipid measures with either cIMT or CAC were generally not independent of LDL-P.

Relationship between the ankle-brachial index and the risk of coronary heart disease and stroke: the circulatory risk in communities study

AIM

Patients with peripheral artery disease (PAD) are at a high risk of cardiovascular disease (CVD) among Western populations. However, evidence for an elevated risk in Asian populations is limited.

METHODS

This prospective cohort study examined 939 Japanese men 60-74 years of age at the time of the baseline survey. A total of 115 cases of CVD were detected during a median 9.3 years of follow-up, and the ankle brachial blood pressure index (ABI) functioned as a surrogate measurement of PAD.

RESULTS

The age-adjusted risks of coronary heart disease, ischemic stroke and ischemic CVD (coronary heart disease and ischemic stroke) were higher among men in the lowest ABI tertile compared with that observed in the men in the highest tertile (<1.08 vs. >1.17). These associations did not change substantially after adjusting for cardiovascular risk factors. The respective multivariable hazard ratios (HRs, 95% CI) for the three conditions were as follows: 2.48 (1.08-5.71), p for trend=0.03; 1.95 (0.94-4.02), p for trend=0.04; and 2.16 (1.25-3.72), p for trend=0.004. These results did not vary based on a comparison of the three ABI categories: ≤0.90, 0.91-1.10 and >1.10. The multivariable HRs (95% CI) for an ABI ≤0.90 versus >1.10 were as follows: 2.04 (0.67-6.20), p for trend=0.14 for coronary heart disease; 3.39 (1.10-10.5), p for trend=0.006 for ischemic stroke; and 2.61 (1.19-5.76), p for trend=0.003 for ischemic CVD. There were no associations between the ABI and the risk of hemorrhagic stroke.

CONCLUSIONS

A low ABI is associated with the risk of coronary heart disease, ischemic stroke and ischemic CVD in elderly Japanese men.

Total cholesterol performance of Abell-Levy-Brodie-Kendall reference measurement procedure: Certification of Japanese in-vitro diagnostic assay manufacturers through CDC's Cholesterol Reference Method Laboratory Network

BACKGROUND

Accurate measurement of total cholesterol (TC) is important for cardiovascular disease risk management. The US Centers for Disease Control and Prevention (CDC) and Cholesterol Reference Method Laboratory Network (CRMLN) perform Abell-Levy-Brodie-Kendall (AK) reference measurement procedure (RMP) for TC as a secondary reference method, and implement Certification Protocol for Manufacturers. Japanese CRMLN laboratory at Osaka performed the AK RMP for 22 years, and conducted TC certification for reagent/calibrator/instrument systems of six Japanese manufacturers every 2 years for 16 years. Osaka TC performance was examined and compared to CDC's reference values.

METHODS

AK RMP involved sample hydrolysis, cholesterol extraction, and determination of cholesterol levels by spectrophotometry. The Certification Protocol for Manufacturers includes comparison with AK RMP using at least 40 fresh specimens. Demonstration of average bias ≤3% and total coefficient of variation ≤3% qualified an analytical system for certification.

RESULTS

In the AK RMP used in the Osaka CRMLN laboratory, the regression equation for measuring TC was y (Osaka)=1.000x (CDC)+0.032 (n=619, R(2)=1.000). Six Japanese manufacturers had allowable performance for certification.

CONCLUSIONS

The AK RMP for TC measurement was accurate, precise, and stable for 22 years. Six Japanese manufacturers were certified for 16 years.

High-density lipoprotein particle concentration and subclinical atherosclerosis of the carotid arteries in Japanese men

OBJECTIVE

The association of high-density lipoprotein particle (HDL-P) with atherosclerosis may be stronger than that of HDL-cholesterol (HDL-C) and independent of conventional cardiovascular risk factors. Whether associations persist in populations at low risk of coronary heart disease (CHD) remains unclear. This study examines the associations of HDL-P and HDL-C with carotid intima-media thickness (cIMT) and plaque counts among Japanese men, who characteristically have higher HDL-C levels and a lower CHD burden than those in men of Western populations.

METHODS

We cross-sectionally examined a community-based sample of 870 Japanese men aged 40-79 years, free of known clinical cardiovascular disease (CVD) and not on lipid-lowering medication. Participants were randomly selected among Japanese living in Kusatsu City in Shiga, Japan.

RESULTS

Both HDL-P and HDL-C were inversely and independently associated with cIMT in models adjusted for conventional CHD risk factors, including low-density lipoprotein cholesterol (LDL-C) and diabetes. HDL-P maintained an association with cIMT after further adjustment for HDL-C (P < 0.01), whereas the association of HDL-C with cIMT was noticeably absent after inclusion of HDL-P in the model. In plaque counts of the carotid arteries, HDL-P was significantly associated with a reduction in plaque count, whereas HDL-C was not.

CONCLUSION

HDL-P, in comparison to HDL-C, is more strongly associated with measures of carotid atherosclerosis in a cross-sectional study of Japanese men. Findings demonstrate that, HDL-P is a strong correlate of subclinical atherosclerosis even in a population at low risk for CHD.

Lipoprotein particle profiles compared with standard lipids in association with coronary artery calcification in the general Japanese population

OBJECTIVE

The utility of lipoprotein particle profiles measured by nuclear magnetic resonance (NMR) spectroscopy beyond standard serum lipids remains inconclusive. Furthermore, few studies have compared NMR measurements with standard lipids in association with coronary artery calcification (CAC) in Japanese, where the coronary atherosclerotic burden is low. We examined whether NMR-based lipoprotein particle profiles are associated with CAC, and compared them with standard lipid and lipid ratios in the Japanese general population.

METHODS AND RESULTS

We conducted a cross-sectional study in 851 men aged 40-79 years without cardiovascular diseases and lipid-lowering therapies. Adjusted odds ratios (ORs) (95% confidence intervals) for the top versus the bottom quartile of NMR-measured particle concentrations were 2.01 (1.24-3.23) for low-density lipoprotein (LDL-P), 1.04 (0.62-1.75) for high-density lipoprotein (HDL-P), 1.82 (1.13-2.95) for very-low-density lipoprotein (VLDL-P), and 1.92 (1.18-3.17) for LDL-P/HDL-P ratio. Similarly adjusted ORs of NMR-measured particle sizes were 0.59 (0.36-0.97) for LDL-P, 0.66 (0.40-1.10) for HDL-P, and 0.67 (0.40-1.12) for VLDL-P. The corresponding ORs were 1.82 (1.14-2.90) for total cholesterol (TC), 2.06 (1.28-3.30) for low-density lipoprotein cholesterol (LDL-C), 0.56 (0.34-0.91) for high-density lipoprotein cholesterol (HDL-C), 2.02 (1.24-3.29) for triglycerides, 2.08 (1.29-3.36) for non-high-density lipoprotein cholesterol (non-HDL-C), 2.27 (1.37-3.78) for TC/HDL-C ratio, and 1.73 (1.06-2.85) for LDL-C/HDL-C ratio. After mutual adjustment for total LDL-P concentration and TC/HDL-C ratio or non-HDL-C, LDL-P was no longer associated, whereas TC/HDL-C ratio remained significantly associated with CAC.

CONCLUSIONS

In community-based Japanese men, the overall association of CAC with NMR-measured lipoprotein indices is comparable, but not superior, to that with standard lipids.

The dose-response relationship between body mass index and the risk of incident stage ≥3 chronic kidney disease in a general japanese population: the Ibaraki prefectural health study (IPHS)

Purpose

To examine the relationship between body mass index (BMI) and the risk of stage ≥3 chronic kidney disease (CKD) in a general Japanese population.

Methods

A total of 105 611 participants aged 40–79 years who completed health checkups in Ibaraki Prefecture, Japan, and were free of CKD in 1993 were followed-up through 2006. Stage ≥3 CKD was defined by an estimated glomerular filtration rate <60 mL/min/1.73 m² reported during at least 2 successive annual surveys or as treatment for kidney disease. Hazard ratios (HRs) for the development of stage ≥3 CKD relative to the BMI categories were calculated using the Cox proportional hazards regression model, which was adjusted for possible confounders and mediators.

Results

During a mean follow-up of 5 years, 19 384 participants (18.4%) developed stage ≥3 CKD. Compared to a BMI of 21.0–22.9 kg/m², elevated multivariable-adjusted HRs were observed among men with a BMI ≥23.0 kg/m² and women with a BMI ≥27.0 kg/m². Significant dose-response relationships between BMI and the incidence of stage ≥3 CKD were observed in both sexes (P for trend <0.001).

Conclusions

Obesity was associated with the risk of developing stage ≥3 CKD among men and women.

Association of short sleep duration with impaired glucose tolerance or diabetes mellitus

Aims/Introduction:  To examine the cross‐sectional relationship between sleep duration and impaired glucose tolerance (IGT), including diabetes mellitus (DM), we analyzed a large‐scale healthy workers database in Japan.

Materials and Methods:  We examined the baseline database of 4143 participants (3415 men and 728 women) aged 19–69 years. Sleep duration of participants was categorized into four groups: <6, 6 to <7, 7 to <8 and ≥8 h. The physical activity of each participant was classified according to the International Physical Activity Questionnaire (IPAQ). We defined IGT including DM (IGT/DM) in the present study according to previous studies as follows: fasting blood sugar level ≥110 mg/dL, or if <8 h after meals ≥140 mg/dL, or on medication for diabetes mellitus, or those diagnosed as having DM. Logistic regression was applied to estimate the odds ratio (OR) to examine the relationship between IGT/DM, sleep duration and other related factors.

Results:  The number of participants with IGT/DM was 402 (9.7%). The factors that significantly associated with IGT/DM were age (OR 1.08, 95% confidence interval [CI] 1.07–1.10, P < 0.001), high blood pressure (OR 1.94, CI 1.52–2.47, P < 0.001), and <6 h of sleep duration in comparison with 6 to <7 h sleep (OR 2.32, CI 1.18–4.55, P = 0.015). The associations of difficulty in sleep initiation, IPAQ classification, current smoking and alcohol intake with IGT/DM were not statistically significant.

Conclusions:  Our results showed that shorter sleep duration (<6 h of sleep duration per night) was associated with a risk of IGT/DM independent of other lifestyle habits and metabolic risk factors. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00114.x, 2011)

Relationship between shift work and clustering of the metabolic syndrome diagnostic components

AIM

To examine the relationship between the type of work and the number of metabolic syndrome diagnostic components(MetS-DC), as well as the risk of MetS, with adjustment for lifestyle habits in Japanese workers.

METHODS

We examined the baseline data from 4,427 participants(81.4% male) aged 19 to 69 years old. The physical activity of each participant was classified according to the International Physical Activity Questionnaire(IPAQ). We defined the four MetS-DC in this study as follows: 1) high blood pressure(BP): systolic BP ≥130 mmHg, or diastolic BP ≥85 mmHg, or the use of antihypertensive drugs; 2) dyslipidemia: high-density lipoprotein-cholesterol concentration ＜40 mg/dl or triglyceride concentration ≥150 mg/dl, or on medication for dyslipidemia; 3) dysglycemia: fasting blood sugar level ≥110 mg/dl, or if less than eight hours after meals ≥140mg/dl, or on medication for diabetes mellitus; 4) overweight: a body mass index ≥25kg/m(2). We defined MetS as overweight plus two or more of the MetS-DC.

RESULTS

There were 3,094 subjects in the daytime work group, 73 in the fixed nighttime work group, 1,017 in the shift work group and 243 in the day-to-night work group. The Poisson regression analysis revealed that fixed nighttime (regression coefficient [b]=-0.233, P=0.028) and shift work (b=0.098, P=0.034) independently contributed to the number of MetS-DC, compared to daytime work. The multivariate logistic analysis not including sleep hours in the model showed that shift work was positively related to MetS (odd ratio=1.47, P＜0.01).

CONCLUSION

Shift work were significantly associated with the number of MetS-DC, and was related to risk of MetS compared to daytime work.