Dietary sodium-to-potassium ratio as a risk factor for stroke, cardiovascular disease and all-cause mortality in Japan: the NIPPON DATA80 cohort study

OBJECTIVES

To evaluate the impact of dietary sodium and potassium (Na-K) ratio on mortality from total and subtypes of stroke, cardiovascular disease (CVD) and all causes, using 24-year follow-up data of a representative sample of the Japanese population.

SETTING

Prospective cohort study.

PARTICIPANTS

In the 1980 National Cardiovascular Survey, participants were followed for 24 years (NIPPON DATA80, National Integrated Project for Prospective Observation of Non-communicable Disease And its Trends in the Aged). Men and women aged 30-79 years without hypertensive treatment, history of stroke or acute myocardial infarction (n=8283) were divided into quintiles according to dietary Na-K ratio assessed by a 3-day weighing dietary record at baseline. Age-adjusted and multivariable-adjusted HRs were calculated using the Mantel-Haenszel method and Cox proportional hazards model.

PRIMARY OUTCOME MEASURES

Mortality from total and subtypes of stroke, CVD and all causes.

RESULTS

A total of 1938 deaths from all causes were observed over 176 926 person-years. Na-K ratio was significantly and non-linearly related to mortality from all stroke (p=0.002), CVD (p=0.005) and total mortality (p=0.001). For stroke subtypes, mortality from haemorrhagic stroke was positively related to Na-K ratio (p=0.024). Similar relationships were observed for men and women. The observed relationships remained significant after adjustment for other risk factors. Quadratic non-linear multivariable-adjusted HRs (95% CI) in the highest quintile versus the lowest quintile of Na-K ratio were 1.42 (1.07 to 1.90) for ischaemic stroke, 1.57 (1.05 to 2.34) for haemorrhagic stroke, 1.43 (1.17 to 1.76) for all stroke, 1.39 (1.20 to 1.61) for CVD and 1.16 (1.06 to 1.27) for all-cause mortality.

CONCLUSIONS

Dietary Na-K ratio assessed by a 3-day weighing dietary record was a significant risk factor for mortality from haemorrhagic stroke, all stroke, CVD and all causes among a Japanese population.

ABCA1 protein enhances Toll-like receptor 4 (TLR4)-stimulated interleukin-10 (IL-10) secretion through protein kinase A (PKA) activation

BACKGROUND

ABCA1 is known to suppress proinflammatory cytokines.

RESULTS

ABCA1 activates PKA and up-regulates anti-inflammatory cytokine IL-10. Elevated PKA transforms macrophages to M2-like phenotype. Disrupting lipid rafts by statins MCD, and filipin recuperates ABCA1 phenotype and likely functions downstream of ABCA1.

CONCLUSION

By modulating cholesterol, ABCA1 activates PKA. This generates M2-like macrophages.

SIGNIFICANCE

ABCA1 does not simply suppress inflammatory response. It promotes M2-like activation and facilitates resolution. Nonresolving inflammatory response from macrophages is a major characteristic of atherosclerosis. Macrophage ABCA1 has been previously shown to suppress the secretion of proinflammatory cytokine. In the present study, we demonstrate that ABCA1 also promotes the secretion of IL-10, an anti-inflammatory cytokine critical for inflammation resolution. ABCA1(+/+) bone marrow-derived macrophages secrete more IL-10 but less proinflammatory cytokines than ABCA1(-/-) bone marrow-derived macrophages, similar to alternatively activated (M2) macrophages. We present evidence that ABCA1 activates PKA and that this elevated PKA activity contributes to M2-like inflammatory response from ABCA1(+/+) bone marrow-derived macrophages. Furthermore, cholesterol lowering by statins, methyl-β-cyclodextrin, or filipin also activates PKA and, consequently, transforms macrophages toward M2-like phenotype. Conversely, cholesterol enrichment suppresses PKA activity and promotes M1-like inflammatory response. As the primary function of ABCA1 is cholesterol removal, our results suggest that ABCA1 activates PKA by regulating cholesterol. Indeed, forced cholesterol enrichment in ABCA1-expressing macrophages suppresses PKA activation and elicits M1-like response. Collectively, these findings reveal a novel protective process by ABCA1-activated PKA in macrophages. They also suggest cholesterol lowering in extra-hepatic tissues by statins as an anti-inflammation strategy.

Relationship of Insulin Resistance to Prevalence and Progression of Coronary Artery Calcification Beyond Metabolic Syndrome Components: Shiga Epidemiological Study of Subclinical Atherosclerosis

OBJECTIVE

The association between insulin resistance (IR) and coronary artery calcification (CAC) has been uncertain after adjustment for metabolic syndrome components. We aimed to evaluate whether IR is associated with CAC prevalence or progression independently of metabolic syndrome components.

APPROACH AND RESULTS

We conducted a population-based study in a random sample of Japanese men aged 40 to 79 years and determined IR using the homeostasis model assessment of insulin resistance (HOMA-IR). The associations of HOMA-IR and other diabetic parameters per 1-SD increase with CAC prevalence and progression were evaluated using multivariable logistic regression. Of 1006 total participants at baseline (mean age, 64±10 years), CAC prevalence was observed in 646 (64.2%), and of 789 participants at follow-up (mean duration, 4.9±1.3 years), CAC progression was observed in 365 (46.3%). After adjustment for covariates including metabolic syndrome components, higher HOMA-IR was independently associated with CAC prevalence (adjusted odds ratio 1.34, 95% confidence interval 1.10-1.63; P=0.003) and progression (odds ratio 1.32, 95% confidence interval 1.09-1.60; P=0.004). In participants without diabetes mellitus, positive associations were similarly observed (prevalence: odds ratio 1.29, 95% confidence interval 1.04-1.60; P=0.022; and progression: odds ratio 1.25, 95% confidence interval 1.01-1.55; P=0.042), whereas glucose and hemoglobin A1c were not associated with CAC prevalence and progression.

CONCLUSIONS

Higher IR was associated with CAC prevalence and progression independently of metabolic syndrome components in Japanese men and also in those without diabetes mellitus. Among diabetic measures, IR and fasting insulin, but not glucose and hemoglobin A1c, predicted CAC progression in men without diabetes mellitus.

Coronary Artery Calcium and Carotid Artery Intima Media Thickness and Plaque: Clinical Use in Need of Clarification

Atherosclerosis begins in early life and has a long latent period prior to onset of clinical disease. Measures of subclinical atherosclerosis, therefore, may have important implications for research and clinical practice of atherosclerotic cardiovascular disease (ASCVD). In this review, we focus on coronary artery calcium (CAC) and carotid artery intima-media thickness (cIMT) and plaque as many population-based studies have investigated these measures due to their non-invasive features and ease of administration. To date, a vast majority of studies have been conducted in the US and European countries, in which both CAC and cIMT/plaque have been shown to be associated with future risk of ASCVD, independent of conventional risk factors. Furthermore, these measures improve risk prediction when added to a global risk prediction model, such as the Framingham risk score. However, no clinical trial has assessed whether screening with CAC or cIMT/plaque will lead to improved clinical outcomes and healthcare costs. Interestingly, similar levels of CAC or cIMT/plaque among various regions and ethnic groups may in fact be associated with significantly different levels of absolute risk of ASCVD. Therefore, it remains to be determined whether measures of subclinical atherosclerosis improve risk prediction in non-US/European populations. Although CAC and cIMT/plaque are promising surrogates of ASCVD in research, we conclude that their use in clinical practice, especially as screening tools for primary prevention in asymptomatic adults, is premature due to many vagaries that remain to be clarified.

Cross-sectional comparison of coronary artery calcium scores between Caucasian men in the United States and Japanese men in Japan: the multi-ethnic study of atherosclerosis and the Shiga epidemiological study of subclinical atherosclerosis

The incidence of coronary heart disease in the United States has declined, and prevalences of several coronary disease risk factors have become comparable to those in Japan. Therefore, the burden of coronary atherosclerosis may be closer among younger persons in the 2 countries. We aimed to compare prevalences of coronary atherosclerosis, measured with coronary artery calcium scores, between men in the 2 countries by age group (45-54, 55-64, or 65-74 years). We used community-based samples of Caucasian men in the United States (2000-2002; n = 1,067) and Japanese men in Japan (2006-2008; n = 832) aged 45-74 years, stratifying them into groups with 0, 1, 2, or ≥3 of the following risk factors: current smoking, overweight, diabetes, dyslipidemia, and hypertension. We calculated adjusted odds ratios of US Caucasian men's having Agatston scores of ≥10, ≥100, and ≥400 with reference to Japanese men. Overall, the odds of Caucasian men having each Agatston cutoff point were greater. The ethnic difference, however, became smaller in younger age groups. For example, adjusted odds ratios for Caucasian men's having an Agatston score of ≥100 were 2.05, 2.43, and 3.86 among those aged 45-54, 55-64, and 65-74 years, respectively. Caucasian men in the United States had a higher burden of coronary atherosclerosis than Japanese men, but the ethnic difference was smaller in younger age groups.

Serum magnesium, phosphorus, and calcium levels and subclinical calcific aortic valve disease: A population-based study

BACKGROUND AND AIMS

Calcific aortic valve disease (CAVD) is the most common valve disease. Although micronutrients are known to contribute to cardiovascular disease, the relationship with CAVD remains poorly evaluated. We examined the association of serum levels of magnesium, phosphorus, and calcium with prevalence, incidence, and progression of aortic valve calcification (AVC).

METHODS

We conducted a prospective study in a population-based sample of Japanese men aged 40-79 years without known cardiovascular disease and chronic kidney disease at baseline, and quantified AVC from serial computed tomographic images with the Agatston method.

RESULTS

Of 938 participants at baseline (mean age, 63.7 ± 9.9 years), AVC prevalence was observed in 173 (18.4%). Of 596 participants without baseline AVC at follow-up (median duration, 5.1 years), AVC incidence was observed in 138 (23.2%). After adjustment for demographics, behaviors and cardiovascular risk factors, relative risks (95% confidence intervals) in the highest versus lowest categories of serum magnesium, phosphorus, and calcium were 0.62 (0.44-0.86), 1.45 (1.02-2.04), and 1.43 (0.95-2.15), respectively, for AVC prevalence and 0.62 (0.42-0.92), 1.93 (1.28-2.91), and 1.09 (0.77-1.55), respectively, for AVC incidence. Their linear trends of serum magnesium and phosphorus were also all statistically significant. Of 131 participants with baseline AVC, there was no association of any serum micronutrients with AVC progression.

CONCLUSIONS

Serum magnesium was inversely associated, while serum phosphorus was positively associated with AVC prevalence and incidence, suggesting that these serum micronutrients may be potential candidates for risk prediction or prevention of CAVD, and warranting further studies.

Relationship of serum irisin levels to prevalence and progression of coronary artery calcification: A prospective, population-based study

BACKGROUND

The mechanisms by which exercise reduces the risk of coronary heart disease remain poorly understood. Irisin, an exercise-induced polypeptide secreted from skeletal muscles, is proposed to potentially mediate beneficial effects of exercise, especially in metabolic regulation and development of atherosclerosis. We examined whether higher serum irisin levels are associated with lower prevalence and progression of coronary atherosclerosis.

METHODS AND RESULTS

We performed a prospective, population-based study of Japanese men aged 40-79 years without known coronary heart disease. We measured baseline serum irisin levels using an enzyme-linked immunosorbent assay and quantified coronary artery calcification (CAC) from serial computed tomography scans. Of 1038 participants (mean age, 63.9 years) at baseline, 670 (64.6%) had prevalent CAC. Of 810 participants at follow-up (median, 5.1 years), 407 (50.3%) experienced CAC progression. In Poisson regression with robust error variance adjusted for age and behavioral factors, serum irisin levels were inversely associated with CAC prevalence (relative risk [RR] of 4th versus 1st quartiles [95% confidence interval], 0.88 [0.78-0.99]; trend P = 0.016) and CAC progression (RR, 0.76 [0.63-0.91]; trend P = 0.002). After further adjustment for cardiometabolic risk factors, the inverse association with CAC prevalence disappeared (RR, 0.95 [0.84-1.08]; trend P = 0.319), but that with CAC progression persisted (RR, 0.77 [0.64-0.93]; trend P = 0.003). These associations were consistent when we applied ordinal logistic regression and across subgroups by cardiometabolic risk factor status.

CONCLUSIONS

Higher serum irisin levels were associated with less burden of coronary atherosclerosis. This association would be mediated through and beyond traditional cardiometabolic pathways.

Mendelian randomization analysis in three Japanese populations supports a causal role of alcohol consumption in lowering low-density lipid cholesterol levels and particle numbers

BACKGROUND AND AIMS

While alcohol consumption is known to increase plasma high-density lipoprotein (HDL) cholesterol levels, its relationship with low-density lipoprotein (LDL) cholesterol levels is unclear. Aldehyde dehydrogenase 2 (ALDH2) is a rate-controlling enzyme in alcohol metabolism, but a large number of Japanese people have the inactive allele. Here, we conducted a Mendelian randomization analysis using the ALDH2 genotype to clarify a causal role of alcohol on circulating cholesterol levels and lipoprotein particle numbers.

METHODS

This study was conducted in three independent general Japanese populations (men, n = 2289; women, n = 1940; mean age 63.3 ± 11.2 years). Alcohol consumption was assessed using a questionnaire. Lipoprotein particle numbers were determined by nuclear magnetic resonance spectroscopy.

RESULTS

Alcohol consumption increased linearly in proportion to the number of subjects carrying the enzymatically active *1 allele in men (p < 0.001). The *1 allele was also positively associated with HDL cholesterol level (adjusted mean ± standard error, *1*1: 60 ± 0.5, *1*2: 56 ± 0.6, *2*2: 55 ± 1.3 mg/dl, p < 0.001) and inversely associated with LDL cholesterol level (116 ± 0.9, 124 ± 1.1, 130 ± 2.6 mg/dl, p < 0.001). The *1 allele was also positively associated with HDL particle numbers (per-allele: 2.60 ± 0.32 μmol/l, p < 0.001) and inversely associated with LDL particle numbers (-67.8 ± 19.6 nmol/l, p = 0.001). Additional Mendelian randomization analysis failed to clarify the involvement of cholesteryl ester transfer protein in alcohol-related changes in lipoprotein cholesterol levels. No significant association was observed in women, presumably due to their small amount of alcohol intake.

CONCLUSIONS

Alcohol consumption has a causal role in not only increasing HDL cholesterol levels but also decreasing LDL cholesterol levels and particle numbers.

Associations of High-Density Lipoprotein Particle and High-Density Lipoprotein Cholesterol With Alcohol Intake, Smoking, and Body Mass Index - The INTERLIPID Study

BACKGROUND

Recently, high-density lipoprotein particles (HDL-P) have been found to be more strongly inversely associated with coronary artery disease (CAD) risk than their counterpart, HDL cholesterol (HDL-C). Given that lifestyle is among the first targets in CAD prevention, we compared the associations of HDL-P and HDL-C with selected lifestyle factors.

METHODS AND RESULTS

We examined 789 Japanese participants of the INTERLIPID Study: men (n=386) and women (n=403) aged 40-59 years in 1996-1998. Participants treated for dyslipidemias were excluded. Lifestyle factors included alcohol intake, smoking amount, and body mass index (BMI). Multivariable linear regression was used for cross-sectional analyses of these factors with HDL-P, HDL-C, HDL-P size subclasses (small, medium and large) and mean HDL-P size. In men, higher alcohol intake was associated with higher HDL-P and higher HDL-C. The associations of alcohol, however, were strongest with HDL-P. A higher smoking amount tended to be associated with lower HDL-P and HDL-C. In contrast, BMI was not associated with HDL-P, but was strongly inversely associated with HDL-C. While alcohol intake favored larger mean HDL-P size, smoking and BMI favored a lipid profile with smaller HDL-P subclasses and overall smaller mean HDL-P size. Similar, but generally weaker results were observed in women.

CONCLUSIONS

Although both HDL-P and HDL-C are parameters of HDL, they have different associations with alcohol, smoking and BMI.

Association between Pulse Wave Velocity and Coronary Artery Calcification in Japanese men

AIM

Pulse wave velocity (PWV) is a simple and valid clinical method for assessing arterial stiffness. Coronary artery calcification (CAC) is an intermediate stage in the process leading to overt cardiovascular disease (CVD) and an established determinant of coronary artery disease. This study aimed to examine the association between PWV and CAC in a population-based sample of Japanese men.

METHODS

This is a cross-sectional study of 986 randomly selected men aged 40-79 years from Shiga, Japan. CVD-free participants were examined from 2006 to 2008. Brachial-ankle PWV (baPWV) was measured using an automatic waveform analyzer. CAC was assessed using computed tomography. Agatston scores ≥ 10 were defined as the presence of CAC.

RESULTS

Prevalence of CAC progressively increased with rising levels of baPWV: 20.6%, 41.7%, 56.3%, and 66.7% across baPWV quartiles ＜ 1378, 1378-1563, 1564-1849, and ＞ 1849 cm/s (P ＜ 0.001 for trend). Associations remained significant after adjusting for age and other factors, including body mass index, systolic blood pressure, pulse rate, total and high-density lipoprotein cholesterol, hemoglobin A1c, drinking, smoking and exercise status, and the use of medication to treat hypertension, dyslipidemia and diabetes (P=0.042 for trend). The optimal cutoff level of baPWV to detect CAC was 1612 cm/s using receiver operating characteristic curve analysis.

CONCLUSIONS

Arterial stiffness as defined by an elevated baPWV is associated with an increased prevalence of CAC in a general population-based setting among Japanese men.

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.

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.

Plasma lipid abnormalities in Pakistani population: trends, associated factors, and clinical implications

Previous studies have reported increased prevalence of coronary heart disease (CHD) in Indians and South Asian settlers in North America. This increased burden of CHD among South Asians is mainly caused by dyslipidemia. To the best of our knowledge, none of the previous works has studied the patterns and prevalence of dyslipidemia in the Pakistani population. The present work aimed to study the plasma lipid trends and abnormalities in a population-based sample of urban and rural Pakistanis. The study included 238 participants (108 males,130 females). Plasma lipid profiles of the participants were determined using standard protocols. We observed that 63% of the study population displayed irregularities in at least one major lipid-fraction including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), or triglycerides (TG). The most common form of isolated-dyslipidemia was low HDL-C (17.3%) followed by high TG (11.2%). Several overlaps between high TC, LDL-C, TG and low HDL-C were also noted. Gender, urbanization, and occupational class were all observed to have an impact on lipid profiles. Briefly, male, urban, and blue-collar participants displayed higher prevalence of dyslipidemia compared to female, rural, and white-collar participants, respectively. In comparison to normal subjects, dyslipidemic subjects displayed significantly higher values for different anthropometric variables including body mass index (BMI), body fat percentage, and waist circumference. The present work provides a comprehensive estimation of the prevalence of dyslipidemia and CHD risk in the Pakistani population. This information will be helpful for better healthcare planning and resource allocation in Pakistan.

Relationship of sleep duration with incident cardiovascular outcomes: a prospective study of 33,883 adults in a general population

BACKGROUND

Studies on the effect of sleep duration on cardiovascular health have contradictory findings. Underlying health issues may have led to inconsistent results and warrant consideration. We aim to assess the relationship of night sleep duration with incident cardiovascular disease (CVD) in a general population, taking into consideration underlying chronic diseases.

METHODS

Data from Shanghai Suburban Adult Cohort and Biobank with a median follow-up of 5.1 years was used, including 33,883 adults aged 20-74 years old. Incident CVD cases were reported and recorded by the Center for Disease Prevention and Control in Songjiang, Shanghai. We used Cox proportional hazard regression models and restricted cubic spline (RCS) analysis to explore the relationship between different sleep groups and sleep duration with incident CVD outcomes, through stratification by gender and age, as well as different health conditions, with adjustments for potential confounders.

RESULTS

Long sleep duration (> 9 h) compared to > 7 to ≤ 8 h was associated with overall incident CVD in participants aged ≥ 50 years old: HR(95%CI) = 2.07 (1.15, 3.74) for 50-59y and 1.43 (1.04, 1.93) for 60-74y. RCS analysis showed a J-shaped relationship between sleep and CVD risk in those ≥ 50y, which was confirmed only in those with a chronic health condition. Non-linear relationships between sleep and CVD risk factors, such as BMI, blood glucose and glycated haemoglobin, were observed.

CONCLUSIONS

Long sleep duration is associated with increased risk of CVD in people ≥ 50y. However, CVD risk factors and underlying health conditions such as hypertension, and diabetes, may play a driving role in the relationship.

Association of triglyceride-glucose index with cardiovascular disease among a general population: a prospective cohort study

BACKGROUND

The impact of triglyceride-glucose (TyG) index, a surrogate marker for insulin resistance, on the risk of cardiovascular disease (CVD) in general populations remains controversial. We aimed to comprehensively study the relationship between TyG index with the risk of incident CVD events in the general population in Shanghai.

METHODS

A total of 42,651 participants without previous history of CVD events from Shanghai Suburban Adult Cohort and Biobank (SSACB) were included. SSACB was a community-based natural population cohort study using multistage cluster sampling method. TyG index was calculated as Ln [fasting serum triglyceride (mg/dL) * fasting blood glucose (mg/dL)/2]. Kaplan-Meier curves, log-rank test and cox proportional hazards model were used to calculate the association between TyG index and incident CVD, including stroke and coronary heart disease (CHD). Restricted cubic spline analyses were used to determine whether there was a non-linear relationship between TyG index and CVD events.

RESULTS

During a median follow-up of 4.7 years, 1,422 (3.3%) individuals developed CVD, including 674 (1.6%) cases of stroke and 732 (1.7%) cases of CHD. A one unit increment higher TyG index was associated with [HR(95%CI)] 1.16(1.04-1.29) in CVD and with 1.39(1.19-1.61) in stroke. Only linear relationships between TyG and CVD/stroke were observed, while no relationship was observed with CHD after adjustments for confounders. In subgroup analyses, younger (< 50y) and diabetic participants had higher risk of CVD than their counterpart groups, while hypertensive and dyslipidemic participants depicted lower risks than their counterparts.

CONCLUSION

Elevated TyG index was associated with a higher risk of incident CVD and stroke. TyG index may help in the early stage of identifying people at high risk of CVD.

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.

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.

Changes in epidemiological features of vaccine preventable infectious diseases among three eras of national vaccination strategies from 1953 to 2018 in Shanghai, China

Background

Recurring outbreaks of infectious diseases highlight the importance of population vaccination strategies. We aimed to assess the impact of national vaccination strategies on vaccine-preventable infectious diseases (VPDs) in Shanghai, China and to identify vulnerable groups that may benefit from future vaccination policies.

Methods

Infectious disease data from 1953 to 2018 was obtained from Xuhui District Center for Disease Control and Prevention, Shanghai China. We used joinpoint regression to show incidence, mortality and fatality trends and to determine annual percent change in incidence of 12 VPDs among three eras of national immunization strategies: (1)1953–1977, (2)1978–2007, and(3)2008–2018.

Findings

Incidence, mortality, and fatality from VPDs have decreased drastically over the three eras, despite the inclusion of more diseases over time. Strikingly, the overall yearly incidence of VPDs shows an increasing trend from 2000 to 2018 in Shanghai (annual percentage changes, APC:7.7, p = 0.025). In the third era (2008–2018), the three VPDs with the highest incidence were varicella (80.2 cases/100,000), hand, foot, and mouth disease (HFMD) (73.6 cases/100,000), and hepatitis (43.5 cases/100,000). A significant upward trend was also observed in hepatitis (APC:24.9, p<0.001), varicella (APC:5.9, p = 0.006), and HFMD (APC:11.8, p = 0.003) from 2008–2018. Hepatitis and tuberculosis are the only VPDs with fatality cases in this period.

Interpretation

Focus is needed in controlling adult hepatitis and tuberculosis, either by introducing adult booster vaccines or by research into more effective vaccines. Varicella and HFMD are on the rise, but vaccines for these are not included in national programs. Strategies funded by government agencies or encouraged by research incentives are needed for varicella and HFMD, such as two-dose and novel multi-valent vaccines, respectively.

Funding

Chinese Ministry of Education, Shanghai Municipal Government.

Association of Alcohol Consumption With Fat Deposition in a Community-Based Sample of Japanese Men: The Shiga Epidemiological Study of Subclinical Atherosclerosis (SESSA)

Background

Excessive alcohol intake has been shown to be associated with cardiovascular disease via metabolic pathways. However, the relationship between alcohol intake and obesity has not been fully elucidated. We aimed to examine the association of alcohol consumption with fat deposition and anthropometric measures.

Methods

From 2006–2008, we conducted a cross-sectional study in a population-based sample of Japanese men aged 40 through 79 years. Areas of abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were calculated using computed tomography imaging. Based on a questionnaire, we classified participants into five groups according to weekly alcohol consumption, excluding former drinkers: non-drinkers (0 g/week), 0.1–160.9, 161–321.9, 322–482.9, and ≥483 g/week. Multivariable linear regression was used to estimate adjusted means of obesity indices for each group.

Results

We analyzed 998 men (mean age and body mass index [BMI], 63.8 years and 23.6 kg/m², respectively). Higher weekly alcohol consumption was strongly and significantly associated with higher abdominal VAT area, percentage of VAT, and VAT-to-SAT ratio (all P for trend <0.001), and also with waist circumferences and waist-to-hip ratio (P for trend = 0.042 and 0.007, respectively). These associations remained significant after further adjustment for BMI, whereas alcohol consumption had no significant association with abdominal SAT area.

Conclusions

Higher alcohol consumption was associated with higher VAT area, VAT%, and VAT-to-SAT ratio, independent of confounders, including BMI, in general Japanese men. These results suggest that alcohol consumption may have a potential adverse effect on visceral fat deposition.

Smoking habits and progression of coronary and aortic artery calcification: A 5-year follow-up of community-dwelling Japanese men

BACKGROUND AND AIMS

To examine whether smoking habits, including smoking amount and cessation duration at baseline, are associated with atherosclerosis progression.

METHODS

At baseline (2006-08, Japan), we obtained smoking status, amount of smoking and time since cessation for quitters in a community-based random sample of Japanese men initially aged 40-79 years and free of cardiovascular disease. Coronary artery calcification (CAC) and aortic artery calcification (AAC) as biomarker of atherosclerosis was quantified using Agatston's method at baseline and after 5 years of follow-up. We defined progression of CAC and AAC (yes/no) using modified criteria by Berry.

RESULTS

A total of 781 participants was analyzed. Multivariable adjusted odds ratios (ORs) of CAC and AAC progression for current smokers were 1.73 (95% CI, 1.09-2.73) and 2.47 (1.38-4.44), respectively, as compared to never smokers. In dose-response analyses, we observed a graded positive relationship of smoking amount and CAC progression in current smokers (multivariable adjusted ORs: 1.23, 1.72, and 2.42 from the lowest to the highest tertile of pack-years). Among the former smokers, earlier quitters (≥10.7 years) had similar ORs of the progression of CAC and AAC to that of participants who had never smoked.

CONCLUSIONS

Compared with never smokers, current smokers especially those with greater pack-years at baseline had higher risk of atherosclerosis progression in community-dwelling Japanese men. Importantly, the residual adverse effect appears to be present for at least ten years after smoking cessation. The findings highlight the importance of early avoidance or minimizing smoking exposure for the prevention of atherosclerotic disease.

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 Coronary Artery Calcification with Estimated Coronary Heart Disease Risk from Prediction Models in a Community-Based Sample of Japanese Men: The Shiga Epidemiological Study of Subclinical Atherosclerosis (SESSA)

AIM

The clinical significance of coronary artery calcification (CAC) is not fully determined in general East Asian populations where background coronary heart disease (CHD) is less common than in USA/Western countries. We cross-sectionally assessed the association between CAC and estimated CHD risk as well as each major risk factor in general Japanese men.

METHODS

Participants were 996 randomly selected Japanese men aged 40-79 y, free of stroke, myocardial infarction, or revascularization. We examined an independent relationship between each risk factor used in prediction models and CAC score ≥100 by logistic regression. We then divided the participants into quintiles of estimated CHD risk per prediction model to calculate odds ratio of having CAC score ≥100. Receiver operating characteristic curve and c-index were used to examine discriminative ability of prevalent CAC for each prediction model.

RESULTS

Age, smoking status, and systolic blood pressure were significantly associated with CAC score ≥100 in the multivariable analysis. The odds of having CAC score ≥100 were higher for those in higher quintiles in all prediction models (p-values for trend across quintiles ＜0.0001 for all models). All prediction models showed fair and similar discriminative abilities to detect CAC score ≥100, with similar c-statistics (around 0.70).

CONCLUSIONS

In a community-based sample of Japanese men free of CHD and stroke, CAC score ≥100 was significantly associated with higher estimated CHD risk by prediction models. This finding supports the potential utility of CAC as a biomarker for CHD in a general Japanese male population.

A Comparison of Segment-Specific and Composite Measures of Carotid Intima-Media Thickness and their Relationships with Coronary Calcium

Aims: The utility of carotid intima-media thickness (cIMT) as a marker for coronary heart disease is under heavy debate. This is predominantly due to the lack of a standard definition of cIMT, leading to inconsistent results. We investigated and compared the relationships of five different measures of cIMT with coronary calcium.

Methods: Japanese men aged 40-79y ( n =869) from Shiga Epidemiological Study of Subclinical Atherosclerosis were examined. Mean cIMT was measured in three segments of the carotid arteries: common carotid artery (CCA _mean ), internal carotid artery (ICA _mean ) and bifurcation (Bif _mean ). Mean cIMT of average values (Mean cIMT) and mean cIMT of maximum values (Mean-Max cIMT) of all segments combined were assessed. Coronary calcium was assessed as coronary artery calcification (CAC). Ordinal logistic regression was used to determine the odds ratio (OR) of higher CAC per 1 standard deviation higher cIMT measure. Analyses were adjusted for cardiovascular covariates and stratified by age quartiles.

Results: All cIMT measures had positive associations with CAC ( p ＜0.001): [OR, 95% Confidence Interval]: ICA _mean [1.23, 1.07-1.42], CCA _mean [1.27, 1.08-1.49], Bif _mean [1.33, 1.15-1.53], Mean cIMT [1.42, 1.22-1.66], and Mean-Max [1.50, 1.28-1.75]. In age-stratified analyses, only Mean-Max cIMT maintained a significant relationship with CAC in every age quartile ( p ＜0.05), while CCA _mean had some of the weakest associations among age quartiles.

Conclusions: Mean-Max cIMT had consistently stronger associations with coronary calcium, independent of important confounders, such as age. The most oft-used measure, CCA _mean , was no longer associated with coronary calcium after age-adjustment and stratification.