Occupational status, educational level, and the prevalence of carotid atherosclerosis in a general population sample of middle-aged Swedish men and women: results from the Malmö Diet and Cancer Study

Defined shapes of carotid artery calcifications on panoramic radiographs correlate with specific signs of cardiovascular disease on ultrasound examination

OBJECTIVE

The aim was to optimize diagnostics for carotid artery calcifications (CACs) on panoramic radiographs (PRs) to identify cardiovascular disease (CVD) by investigating how 4 defined CAC shapes are associated with ultrasound (US) findings indicating CVD.

STUDY DESIGN

The study included 414 participants (802 neck sides) from the Malmö Offspring Dental Study, examined with PRs. The PRs were assessed for CAC shapes stratified into 4 categories: single, scattered, vessel-width defining, and vessel-outlining. The carotid arteries were examined with US for signs of CVD: the presence of plaques, largest individual area of a plaque, number of plaques, and percentage reduction of the lumen. Associations between the different CAC categories and US characteristics were analyzed.

RESULTS

All categories of CAC were significantly associated with a higher degree of US findings indicating CVD compared with no CAC (P < .001). The most significant differences were found for vessel-outlining CAC, with the mean of the largest individual plaque area of 17.9 vs 2.3 mm2, mean number of plaques 1.6 vs 0.2, and mean percentage reduction of the lumen 24.1% vs 3.5% (all P < .001).

CONCLUSIONS

Independent of shape, CACs detected on PRs were associated with a higher degree of US findings of CVD. This was most pronounced for vessel-outlining CAC. With refined differential diagnostics of CACs in PRs, dentists may contribute to improved identification of patients in need of cardiovascular prevention.

Elevated soluble LOX-1 predicts risk of first-time myocardial infarction

BACKGROUND

There is an unmet clinical need for novel therapies addressing the residual risk in patients receiving guideline preventive therapy for coronary heart disease. Experimental studies have identified a pro-atherogenic role of the oxidized LDL receptor LOX-1. We investigated the association between circulating soluble LOX-1 (sLOX-1) and the risk for development of myocardial infarction.

METHODS

The study subjects (n = 4658) were part of the Malmö Diet and Cancer study. The baseline investigation was carried out 1991-1994 and the incidence of cardiovascular events monitored through national registers during a of 19.5 ± 4.9 years follow-up. sLOX-1 and other biomarkers were analyzed by proximity extension assay and ELISA in baseline plasma.

RESULTS

Subjects in the highest tertile of sLOX-1 had an increased risk of myocardial infarction (hazard ratio (95% CI) 1.76 (1.40-2.21) as compared with those in the lowest tertile. The presence of cardiovascular risk factors was related to elevated sLOX-1, but the association between sLOX-1 and risk of myocardial infarction remained significant when adjusting for risk factors.

CONCLUSIONS

In this prospective population study we found an association between elevated sLOX-1, the presence of carotid disease and the risk for first-time myocardial infarction. Taken together with previous experimental findings of a pro-atherogenic role of LOX-1, this observation supports LOX-1 inhibition as a possible target for prevention of myocardial infarction.

The Long-Term Mortality Effects Associated with Exposure to Particles and NOx in the Malmö Diet and Cancer Cohort

In this study, the long-term mortality effects associated with exposure to PM10 (particles with an aerodynamic diameter smaller than or equal to 10 µm), PM2.5 (particles with an aerodynamic diameter smaller than or equal to 2.5 µm), BC (black carbon), and NOx (nitrogen oxides) were analyzed in a cohort in southern Sweden during the period from 1991 to 2016. Participants (those residing in Malmö, Sweden, born between 1923 and 1950) were randomly recruited from 1991 to 1996. At enrollment, 30,438 participants underwent a health screening, which consisted of questionnaires about lifestyle and diet, a clinical examination, and blood sampling. Mortality data were retrieved from the Swedish National Cause of Death Register. The modeled concentrations of PM10, PM2.5, BC, and NOx at the cohort participants' home addresses were used to assess air pollution exposure. Cox proportional hazard models were used to estimate the associations between long-term exposure to PM10, PM2.5, BC, and NOx and the time until death among the participants during the period from 1991 to 2016. The hazard ratios (HRs) associated with an interquartile range (IQR) increase in each air pollutant were calculated based on the exposure lag windows of the same year (lag0), 1-5 years (lag1-5), and 6-10 years (lag6-10). Three models were used with varying adjustments for possible confounders including both single-pollutant estimates and two-pollutant estimates. With adjustments for all covariates, the HRs for PM10, PM2.5, BC, and NOx in the single-pollutant models at lag1-5 were 1.06 (95% CI: 1.02-1.11), 1.01 (95% CI: 0.95-1.08), 1.07 (95% CI: 1.04-1.11), and 1.11 (95% CI: 1.07-1.16) per IQR increase, respectively. The HRs, in most cases, decreased with the inclusion of a larger number of covariates in the models. The most robust associations were shown for NOx, with statistically significant positive HRs in all the models. An overall conclusion is that road traffic-related pollutants had a significant association with mortality in the cohort.

Longitudinal Lipidomic Profile of Hypertension in American Indians: Findings From the Strong Heart Family Study

BACKGROUND

Dyslipidemia is an important risk factor for hypertension and cardiovascular disease. Standard lipid panel cannot reflect the complexity of blood lipidome. The associations of individual lipid species with hypertension remain to be determined in large-scale epidemiological studies, especially in a longitudinal setting.

METHODS

Using liquid chromatography-mass spectrometry, we repeatedly measured 1542 lipid species in 3699 fasting plasma samples at 2 visits (1905 at baseline, 1794 at follow-up, ~5.5 years apart) from 1905 unique American Indians in the Strong Heart Family Study. We first identified baseline lipids associated with prevalent and incident hypertension, followed by replication of top hits in Europeans. We then conducted repeated measurement analysis to examine the associations of changes in lipid species with changes in systolic blood pressure, diastolic blood pressure, and mean arterial pressure. Network analysis was performed to identify lipid networks associated with the risk of hypertension.

RESULTS

Baseline levels of multiple lipid species, for example, glycerophospholipids, cholesterol esters, sphingomyelins, glycerolipids, and fatty acids, were significantly associated with both prevalent and incident hypertension in American Indians. Some lipids were confirmed in Europeans. Longitudinal changes in multiple lipid species, for example, acylcarnitines, phosphatidylcholines, fatty acids, and triacylglycerols, were significantly associated with changes in blood pressure measurements. Network analysis identified distinct lipidomic patterns associated with the risk of hypertension.

CONCLUSIONS

Baseline plasma lipid species and their longitudinal changes are significantly associated with hypertension development in American Indians. Our findings shed light on the role of dyslipidemia in hypertension and may offer potential opportunities for risk stratification and early prediction of hypertension.

Longitudinal lipidomic signatures of all-cause and CVD mortality in American Indians: findings from the Strong Heart Study

Dyslipidemia is an independent and modifiable risk factor for aging and age-related disorders. Routine lipid panel cannot capture all individual lipid species in blood (i.e., blood lipidome). To date, a comprehensive assessment of the blood lipidome associated with mortality is lacking in large-scale community-dwelling individuals, especially in a longitudinal setting. Using liquid chromatograph-mass spectrometry, we repeatedly measured individual lipid species in 3,821 plasma samples collected at two visits (~ 5.5 years apart) from 1,930 unique American Indians in the Strong Heart Family Study. We first identified baseline lipids associated with risks for all-cause mortality and CVD mortality (mean follow-up period: 17.8 years) in American Indians, followed by replication of top hits in European Caucasians in the Malmö Diet and Cancer-Cardiovascular Cohort (n = 3,943, mean follow-up period: 23.7 years). The model adjusted age, sex, BMI, smoking, hypertension, diabetes, and LDL-c at baseline. We then examined the associations between changes in lipid species and risk of mortality. Multiple testing was controlled by false discovery rate (FDR). We found that baseline levels and longitudinal changes of multiple lipid species, e.g., cholesterol esters, glycerophospholipids, sphingomyelins, and triacylglycerols, were significantly associated with risks of all-cause or CVD mortality. Many lipids identified in American Indians could be replicated in European Caucasians. Network analysis identified differential lipid networks associated with risk of mortality. Our findings provide novel insight into the role of dyslipidemia in disease mortality and offer potential biomarkers for early prediction and risk reduction in American Indians and other ethnic groups.

Sex-Specific Risk Factors for Deep Venous Thrombosis and Pulmonary Embolism in a Population-Based Historical Cohort Study of Middle-Aged and Older Individuals

Background Whether sex-specific differences exist for risk factors for pulmonary embolism (PE) and deep venous thrombosis (DVT), with the exception of pregnancy and estrogen therapy, has been sparsely studied. We aimed to study whether sex-specific differences of risk factors exist for noncancer-related DVT and PE in middle-aged and older individuals without cardiovascular history or previous diagnosis in a population-based historical (retrospective) cohort. Methods and Results Potential venous thromboembolism (VTE) risk factors were registered at baseline in 15 807 women and 9996 men aged 44 to 74 years, who participated in the Malmö Diet and Cancer study (1991-1996). We excluded subjects with a previous history of VTE, cancer, a diagnosis of cardiovascular disease, or a diagnosis of cancer-associated VTE during follow-up. Patients were followed up from baseline until the first event of PE or DVT, death, or December 31, 2018. During the follow-up period, 365 (2.3%) women and 168 (1.7%) men were affected by first DVT, and 309 (2.0%) women and 154 (1.5%) men were affected by first PE. In the multivariable Cox regression models, the anthropometric obesity markers of weight, body mass index, waist and hip circumference, fat percentage, and muscle weight were in a dose-dependent way associated with DVT and PE among women but not men. In an analysis that included patients with cardiovascular disease and cancer-related VTE, the results were similar for women. For men, several obesity measures became significantly associated with PE or DVT but were weaker than in women, especially for DVT. Conclusions Anthropometric obesity measures are more important risk factors for both DVT and PE among women than men, especially for individuals without cardiovascular history or previous diagnosis or cancer-related VTE.

Cadmium contributes to atherosclerosis by affecting macrophage polarization

Chronic cadmium (Cd) exposure contributes to the progression of atherosclerosis, but the direct role of Cd and its mechanisms in atherosclerosis remains incompletely understood. Atherosclerosis is a chronic inflammatory disease promoting macrophage polarization to M1 phenotype and producing pro-inflammations that are vital in regulating the inflammatory response. Herein, through a case-control study, we found that Cd exposure may promote the occurrence of carotid plaque via inflammation, where interleukin-6 (IL-6) may play an important role. We also combined in vivo and in vitro experiments to explore the underlying mechanism of Cd-promoted plaque formation and the production of IL-6. With or without cadmium chloride (CdCl₂) fed ApoE^-/- mouse and treated RAW264.7 cells, we found Cd accumulated in the aortas which significantly increased the plaque area in atherosclerotic mice, macrophage accumulation, and lipid accumulation, and Cd promoted M1 phenotype macrophage polarization reflected by the increased expression of CD86 which produced tumor necrosis factor-α (TNF-α) and IL-6. However, the influences on M2 phenotype and anti-inflammatory cytokines interleukin-4 (IL-4) and interferon-γ (IFN-γ) were non-significant. Moreover, we found that JAK2/STAT3 pathway was greatly activated in the plaques and CdCl₂-treated macrophages. The inhibition of JAK2/STAT3 substantially reversed the Cd-stimulated macrophage M1 phenotype macrophage polarization and the expression of pro-inflammatory cytokines including TNF-α and IL-6. Altogether, Cd intensifies atherosclerosis by modulating macrophage polarization via JAK2/STAT3 to up-regulated the expression of IL-6.

Clinical and Imaging Phenotypes and Outcomes in a Costa Rican Cohort of Acute Ischemic Stroke Survivors: A Retrospective Study

BACKGROUND

We characterized clinical and imaging phenotypes and their association with clinical outcomes in acute ischemic stroke (AIS) survivors in the understudied region of Costa Rica.

METHODS

We conducted a retrospective cohort study in AIS patients treated at a tertiary stroke center in Costa Rica from 2011-2015. Participants underwent detailed phenotyping for cardiovascular risk factors and stroke etiology. We assessed the association of ischemic brain lesion features and clinical outcomes using the Oxfordshire Community Stroke Project (OCSP) classification.

RESULTS

We included 684 AIS survivors (60.2% males, aged 68.1 ± 13.6 years, mean ± SD). While the cardiovascular risk profiles and mortality rates of our patients were similar to populations in European and North American countries, only 20.2% of patients with atrial fibrillation (AF) received anticoagulation. On multivariable analysis, patients with total anterior circulation infarct (TACI) displayed an increased risk of complications (OR: 4.2; 95% CI: 2.2-7.8; p < 0.001), higher mortality (OR: 6.9; 95% CI: 2.9-16.1; p < 0.001) and lower chance of functional independence at discharge (OR: 8.9; 95% CI: 4.1-19; p < 0.001) compared to non-TACI. The comorbidity of bronchopneumonia increased the probability of death by 14.5 times.

CONCLUSIONS

Our observations in a Costa Rican cohort of AIS survivors might help improve local measures for preventing and managing AIS.

Causal analysis of plasma IL-8 on carotid intima media thickness, a measure of subclinical atherosclerosis

BACKGROUND

We investigated the causality of IL-8 on carotid intima-media thickness (c-IMT), a measure of sub-clinical atherosclerosis.

METHODS

The IMPROVE is a multicenter European study (n = 3,711). The association of plasma IL-8 with c-IMT (mm) was estimated by quantile regression. Genotyping was performed using the Illumina CardioMetabo and Immuno chips. Replication was attempted in three independent studies and a meta-analysis was performed using a random model.

RESULTS

In IMPROVE, each unit increase in plasma IL-8 was associated with an increase in median c-IMT measures (all p<0·03) in multivariable analyses. Linear regression identified rs117518778 and rs8057084 as associated with IL-8 levels and with measures of c-IMT. The two SNPs were combined in an IL-8-increasing genetic risk that showed causality of IL-8 on c-IMT in IMPROVE and in the UK Biobank (n = 22,179). The effect of IL-8 on c-IMT measures was confirmed in PIVUS (n = 1,016) and MDCCC (n = 6,103). The association of rs8057084 with c-IMT was confirmed in PIVUS and UK Biobank with a pooled estimate effect (β) of -0·006 with 95%CI (-0·008- -0·003).

CONCLUSION

Our results indicate that genetic variants associated with plasma IL-8 also associate with c-IMT. However, we cannot infer causality of this association, as these variants lie outside of the IL8 locus.

Prevalence and Ascertainment of Dementia Cases in the Malmö Diet and Cancer Study

Background:

Register diagnoses, both hospital-based and from open clinic care, are often used in research studies in Sweden. The validity of such diagnoses has been debated and a validation assessment can improve the diagnostic accuracy for use in research studies.

Objective:

The aim of this study was to investigate the quality of register-derived dementia diagnoses in the Malmö Diet and Cancer population study (MDCS) and to validate these diagnoses using systematic criteria.

Methods:

MDCS is a population-based prospective study comprising 30,446 participants. Register diagnoses of dementia for the MDCS population were derived from the Swedish National Patient Register (NPR) and validated through re-evaluation of available medical records by physicians.

Results:

In the MDCS cohort, 2,206 participants were diagnosed with dementia according to the NPR during a mean follow-up of 18.1 years. The general dementia diagnosis was valid in 96% of the cases, but 40% of the specific dementia diagnoses were changed during the process of reevaluation. The diagnostic validity varied between 25.2% and 82.9% for the different diagnoses. The results from the validity assessment per diagnostic category revealed that the validity of the NPR diagnoses was higher for the more specific diagnoses and lower for unspecified dementia. The major diagnostic shift during the re-evaluation was from unspecified dementia to more specific diagnoses.

Conclusion:

Validation of dementia diagnoses using medical records results in more precise diagnoses. Dementia diagnoses derived from registers should be validated in order to study associations between influential factors and different dementia diagnoses.

Gender dimension in cardio-pulmonary continuum

Cardio-pulmonary diseases, which were once regarded as a man's illness, have been one of the leading causes of morbidity and mortality for both men and women in many countries in recent years. Both gender and sex influence the functional and structural changes in the human body and therefore play an important role in disease clinical manifestation, treatment choice, and/or response to treatment and prognosis of health outcomes. The gender dimension integrates sex and gender analysis in health sciences and medical research, however, it is still relatively overlooked suggesting the need for empowerment in the medical research community. Latest advances in the field of cardiovascular research have provided supportive evidence that the application of biological variables of sex has led to the understanding that heart disease in females may have different pathophysiology compared to males, particularly in younger adults. It has also resulted in new diagnostic techniques and a better understanding of symptomatology, while gender analysis has informed more appropriate risk stratification and prevention strategies. The existing knowledge in the pulmonary field shows the higher prevalence of pulmonary disorders among females, however, the role of gender as a socio-cultural construct has yet to be explored for the implementation of targeted interventions. The purpose of this review is to introduce the concept of gender dimension and its importance for the cardiopulmonary continuum with a focus on shared pathophysiology and disease presentation in addition to interrelation with chronic kidney disease. The review presents basic knowledge of what gender dimension means, and the application of sex and gender aspects in cardiovascular medicine with a specific focus on early pulmonary development, pulmonary hypertension, and chronic obstructive pulmonary disease (COPD). Early vascular aging and inflammation have been presented as a potential pathophysiological link, with further interactions between the cardiopulmonary continuum and chronic kidney disease. Finally, implications for potential future research have been provided to increase the impact of gender dimension on research excellence that would add value to everybody, foster toward precision medicine and ultimately improve human health.

Racial and Ethnic Differences in the Association Between Classical Cardiovascular Risk Factors and Common Carotid Intima-Media Thickness: An Individual Participant Data Meta-Analysis

Background The major risk factors for atherosclerotic cardiovascular disease differ by race or ethnicity but have largely been defined using populations of European ancestry. Despite the rising prevalence of cardiovascular disease in Africa there are few related data from African populations. Therefore, we compared the association of established cardiovascular risk factors with carotid-intima media thickness (CIMT), a subclinical marker of atherosclerosis, between African, African American, Asian, European, and Hispanic populations. Methods and Results Cross-sectional analyses of 34 025 men and women drawn from 15 cohorts in Africa, Asia, Europe, and North America were undertaken. Classical cardiovascular risk factors were assessed and CIMT measured using B-mode ultrasound. Ethnic differences in the association of established cardiovascular risk factors with CIMT were determined using a 2-stage individual participant data meta-analysis with beta coefficients expressed as a percentage using the White population as the reference group. CIMT adjusted for risk factors was the greatest among African American populations followed by Asian, European, and Hispanic populations with African populations having the lowest mean CIMT. In all racial or ethnic groups, men had higher CIMT levels compared with women. Age, sex, body mass index, and systolic blood pressure had a significant positive association with CIMT in all races and ethnicities at varying magnitudes. When compared with European populations, the association of age, sex, and systolic blood pressure with CIMT was weaker in all races and ethnicities. Smoking (beta coefficient, 0.39; 95% CI, 0.09-0.70), body mass index (beta coefficient, 0.05; 95% CI, 0.01-0.08) and glucose (beta coefficient, 0.13; 95% CI, 0.06-0.19) had the strongest positive association with CIMT in the Asian population when compared with all other racial and ethnic groups. High-density lipoprotein-cholesterol had significant protective effects in African American (beta coefficient, -0.31; 95% CI, -0.42 to -0.21) and African (beta coefficient, -0.26; 95% CI, -0.31 to -0.19) populations only. Conclusions The strength of association between established cardiovascular risk factors and CIMT differed across the racial or ethnic groups and may be due to lifestyle risk factors and genetics. These differences have implications for race- ethnicity-specific primary prevention strategies and also give insights into the differential contribution of risk factors to the pathogenesis of cardiovascular disease. The greatest burden of subclinical atherosclerosis in African American individuals warrants further investigations.

Incident cardiovascular disease and long-term exposure to source-specific air pollutants in a Swedish cohort

BACKGROUND

Air pollution is associated with cardiovascular morbidity and mortality, but its role in the development of congestive heart failure (CHF) and the role of different pollution sources in cardiovascular disease remain uncertain.

METHODS

Participants were enrolled in the Malmö Diet and Cancer cohort in 1991-1996 with information on lifestyle and clinical indicators of cardiovascular disease. The cohort participants were followed through registers until 2016. Annual total and local source-specific concentrations of particulate matter less than 10 μm and 2.5 μm (PM₁₀ and PM_2.5), black carbon (BC), and nitrogen oxides (NO_x) from traffic, residential heating, and industry were assigned to each participant's address throughout the study period. Cox proportional hazards models adjusted for possible confounders was used to estimate associations between air pollution 1-5 years prior to outcomes of incident CHF, fatal myocardial infarction (MI), major adverse coronary events (MACE), and ischemic stroke.

RESULTS

Air pollution exposure levels (mean annual exposures to PM_2.5 of 11 μg/m³ and NO_x of 26 μg/m³) within the cohort were moderate in terms of environmental standards. After adjusting for confounders, we observed statistically significant associations between NO_x and CHF (hazard ratio [HR] 1.11, 95% confidence interval [CI] 1.01-1.22) and NO_x and fatal MI (HR 1.10, 95%CI 1.01-1.20) per interquartile range (IQR) of 9.6 μg/m³. In fully adjusted models, the estimates were similar, but the precision worse. In stratified analyses, the associations were stronger in males, ever-smokers, older participants, and those with baseline carotid artery plaques. Locally emitted and traffic-related air pollutants generally showed positive associations with CHF and fatal MI. There were no associations between air pollution and MACE or stroke.

DISCUSSION/CONCLUSION

In an area with low to moderate air pollution exposure, we observed significant associations of long-term residential NO_x with increased risk of incident CHF and fatal MI, but not with coronary events and stroke.

A longitudinal linkage study of occupation and ischaemic heart disease in the general and Māori populations of New Zealand

Objectives

Occupation is a poorly characterised risk factor for cardiovascular disease (CVD) with females and indigenous populations under-represented in most research. This study assessed associations between occupation and ischaemic heart disease (IHD) in males and females of the general and Māori (indigenous people of NZ) populations of New Zealand (NZ).

Methods

Two surveys of the NZ adult population (NZ Workforce Survey (NZWS); 2004–2006; n = 3003) and of the Māori population (NZWS Māori; 2009–2010; n = 2107) with detailed occupational histories were linked with routinely collected health data and followed-up until December 2018. Cox regression was used to calculate hazard ratios (HR) for IHD and “ever-worked” in any of the nine major occupational groups or 17 industries. Analyses were controlled for age, deprivation and smoking, and stratified by sex and survey.

Results

‘Plant/machine operators and assemblers’ and ‘elementary occupations’ were positively associated with IHD in female Māori (HR 2.2, 95%CI 1.2–4.1 and HR 2.0, 1.1–3.8, respectively) and among NZWS males who had been employed as ‘plant/machine operators and assemblers’ for 10+ years (HR 1.7, 1.2–2.8). Working in the ‘manufacturing’ industry was also associated with IHD in NZWS females (HR 1.9, 1.1–3.7), whilst inverse associations were observed for ‘technicians and associate professionals’ (HR 0.5, 0.3–0.8) in NZWS males. For ‘clerks’, a positive association was found for NZWS males (HR 1.8, 1.2–2.7), whilst an inverse association was observed for Māori females (HR 0.4, 0.2–0.8).

Conclusion

Associations with IHD differed significantly across occupational groups and were not consistent across males and females or for Māori and the general population, even within the same occupational groups, suggesting that current knowledge regarding the association between occupation and IHD may not be generalisable across different population groups.

Education and household income and carotid intima-media thickness in Japan: baseline data from the Aidai Cohort Study in Yawatahama, Uchiko, Seiyo, and Ainan

Background

Epidemiological evidence for the relationship between education and income and carotid intima-media thickness (CIMT) has been limited and inconsistent. The present cross-sectional study investigated this issue using baseline data from the Aidai Cohort Study.

Methods

Study subjects were 2012 Japanese men and women aged 34−88 years. Right and left CIMT were measured at the common carotid artery using an automated carotid ultrasonography device. Maximum CIMT was defined as the largest CIMT value in either the left or right common carotid artery. Carotid wall thickening was defined as a maximum CIMT value > 1.0 mm.

Results

The prevalence of carotid wall thickening was 13.0%. In participants under 60 years of age (n = 703) and in those aged 60 to 69 years (n = 837), neither education nor household income was associated with carotid wall thickening or with maximum CIMT. Among those aged 70 years or older (n = 472), however, higher educational level, but not household income, was independently related to a lower prevalence of carotid wall thickening: the multivariate-adjusted odds ratio for high vs. low educational level was 0.43 (95% confidence interval 0.21−0.83, p for trend = 0.01). A significant inverse association was observed between education, but not household income, and maximum CIMT (p for trend = 0.006).

Conclusions

Higher educational level may be associated with a lower prevalence of carotid wall thickening and a decrease in maximum CIMT only in participants aged 70 years or older.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12199-021-01011-6.

Association Between a Body Shape Index and Subclinical Carotid Atherosclerosis in Population Free of Cardiovascular and Cerebrovascular Diseases

AIM

We used a dataset from a cross-sectional survey conducted in China to determine which of the anthropometric indices of obesity are important in terms of carotid atherosclerosis free of cardiovascular and cerebrovascular diseases.

METHODS

A total of 5,245 participants who were volunteering for carotid ultrasound unit in this cross-sectional survey were included in the present analysis. All subjects were free of angina, myocardial infarction, heart failure and stroke, and cancer. A low-risk subgroup was defined as people free of hypertension, diabetes, and hyperlipidemia. All analyses based on logistic regression were gender-specific.

RESULTS

The present study consisted of 2,501 males and 2,744 females, with 776 (31.03%) diagnosed as carotid artery plaque in males and 550 (20.04%) in females. Univariable analyses in unadjusted logistic model showed significant associations between disease presence and all central obesity indices. After adjusting for more variables, only a body shape index (ABSI) was associated with the presence of disease in both males and females. Moreover, stepwise regression approaches revealed that ABSI was always an independent determinant of the presence of subclinical carotid plaque. Multiple regression shows a linear and significant increase in the prevalence of atherosclerosis in males and females as ABSI decile levels increased. Similar results were obtained when the association between ABSI and carotid plaque was studied in this low-risk subgroup.

CONCLUSIONS

ABSI, as a novel anthropometric indicator compared with traditional indices, was found to have a closer relationship with subclinical carotid atherosclerosis, even in populations free of hypertension, diabetes, and hyperlipidemia.

Aortic Stiffness, Inflammation, and Incidence of Cardiovascular Events in Elderly Participants From the General Population

Low-grade inflammation and arterial stiffness are key factors in the development of vascular aging. However, the interplay between arterial stiffness and inflammation for cardiovascular (CV) disease is unclear. Aortic pulse wave velocity (aPWV) and the inflammatory markers, high-sensitivity C-reactive protein (CRP) and orosomucoid, were measured in 2710 participants (median age: 72 years). These participants were followed up for a mean of 7.6 years for a composite CV disease end point. Per 1 interquartile range increment of CRP and orosomucoid, respectively, aPWV increased by 0.19 m/s (95% CI: 0.07-0.32) and 0.19 m/s (0.11-0.27), after multifactorial adjustment. Mediation analysis showed that aPWV, after multifactorial adjustment, mediated 8% (-4, 20) of the CV disease risk associated with CRP and 8% (-4, 18) of orosomucoid risk. The associated risk increased with combinations of high aPWV and high CRP or orosomucoid. We found no evidence that arterial PWV acted as an important mediator of the relationship between systemic inflammation and CV disease risk in this elderly population. The results instead indicate an additive effect. Our study supports the view that arterial stiffness and chronic inflammation affects CV risk mainly through separate causal pathways.

Long-term exposure to air pollution and atherosclerosis in the carotid arteries in the Malmö diet and cancer cohort

BACKGROUND

Long-term exposure to air pollution increases the risk of cardiovascular morbidity and mortality, but the mechanisms are not fully known. Current evidence suggests that air pollution exposure contributes to the development of atherosclerosis. There are few studies investigating associations between air pollution and carotid plaques, a well-known precursor of cardiovascular disease.

METHODS

A Swedish population-based cohort (aged 45-64 years at recruitment) was randomly selected from the Malmö Diet and Cancer study between 1991 and 1994, of which 6103 participants underwent ultrasound examination of the right carotid artery to determine carotid plaque presence and carotid intima media thickness (CIMT). Participants were assigned individual residential air pollution exposure (source-specific PM_2.5, PM₁₀, NO_x, BC) at recruitment from Gaussian dispersion models. Logistic and linear regression models, adjusted for potential confounders and cardiovascular risk factors, were used to investigate associations between air pollutants and prevalence of carotid plaques, and CIMT, respectively.

RESULTS

The prevalence of carotid plaques was 35%. The mean levels of PM_2.5 and PM₁₀ at recruitment were 11 and 14 μg/m³, most of which was due to long range transport. The exposure contrast within the cohort was relatively low. PM_2.5 exposure was associated with carotid plaques in a model including age and sex only (OR 1.10 (95% CI 1.01-1.20) per 1 μg/m³), but after adjustment for cardiovascular risk factors and socioeconomic status (SES) the association was weak and not significant (OR 1.05 (95% CI 0.96-1.16) per 1 μg/m³). The pattern was similar for PM₁₀ and NO_x exposure. Associations between air pollutants and plaques were slightly stronger for long-term residents and in younger participants with hypertension. There was no clear linear trend between air pollution exposure and plaque prevalence. Non-significant slightly positive associations were seen between air pollution exposures and CIMT.

CONCLUSIONS

In this large, well-controlled cross-sectional study at low exposure levels we found no significant associations between air pollution exposures and subclinical atherosclerosis in the carotid arteries, after adjusting for cardiovascular risk factors and SES. Further epidemiological studies of air pollution and intermediate outcomes are needed to explain the link between air pollution and cardiovascular events.

Exploring and comparing definitions of healthy vascular ageing in the population: characteristics and prospective cardiovascular risk

Different methods can be used to define healthy vascular ageing (HVA). In this prospective cohort study, we explored three different definitions in order to provide guidance for which to use. 2718 subjects were included from the Cardiovascular (CV) arm of the Malmö Diet Cancer Study (MDCS; median age 71.9 years, 62.2% females). Three different definitions of HVA were used: HVA-1 (<15th percentile of aortic pulse wave velocity (aPWV) distribution from age-quintiles); HVA-2 (<35th percentile of aPWV+ <35th percentile of carotid Intima-Media Thickness. cIMT); and HVA-3 (aPWV < 7.6 m/s + no hypertension). The HVA-1 and HVA-2 groups were compared with the HVA-3, and to the corresponding groups without HVA (non-HVA), in cross-sectional analyses for baseline characteristics and using Cox regressions for prospective risk, yielding hazard ratios (HRs) adjusted for conventional risk factors. A composite CVD endpoint was used, consisting of myocardial infarctions, ischemic heart disease mortality, and coronary artery procedures. The baseline characteristics were, with minor exceptions, similar across HVA groups. In the fully adjusted model, the HRs (95%CI) were 0.62 (0.41-0.93), 0.45 (0.26-0.76), and 0.56 (0.34-0.91) for HVA-1, HVA-2, and HVA-3, respectively. In summary, this observational study of elderly subjects provides examples of integrating hypertension and cIMT in the definition of HVA, as compared with only using aPWV. As aPWV itself is such a robust marker of HVA, it is demanding to find additional markers which improve the definition. There is a need to create a generally accepted definition of HVA.

High water intake and low urine osmolality are associated with favorable metabolic profile at a population level: low vasopressin secretion as a possible explanation

Purpose

Elevated plasma concentration of the vasopressin marker copeptin and low water intake are associated with elevated blood glucose and diabetes risk at a population level. Moreover, in individuals with low urine volume and high urine osmolality (u-Osm), water supplementation reduced fasting plasma (fp) copeptin and fp-glucose. In this observational study, we investigated if low total water intake or high u-Osm correlated with high fp-copeptin and components of the metabolic syndrome at the population level.

Methods

In the population-based Malmö Offspring Study (MOS, n = 2599), fp-copeptin and u-Osm from morning urine samples were measured, and diet and total water intake (from beverages and food moisture) was assessed by a 4-day web-based record.

Results

Increasing water intake by tertile was after adjustment for age and sex associated with low fp-triglycerides (p = 0.002) and high fp-HDL (p = 0.004), whereas there was no association with the other investigated metabolic traits (HbA1c, fp-glucose, BMI or waist circumference). Increasing u-Osm by tertile was, after adjustment for age and sex, associated with high fp-glucose (p = 0.007), and borderline significantly associated with high HbA1c (p = 0.053), but no association was observed with fp-HDL, fp-triglycerides, BMI or waist circumference. Fp-copeptin concentration correlated significantly with water intake (r = − 0.13, p < 0.001) and u-Osm (r = 0.27, p < 0.001). High copeptin was associated with all investigated metabolic traits (p < 0.001 for all).

Conclusion

Low concentrations of the vasopressin marker copeptin is linked to high water intake, low u-Osm, and a favorable metabolic profile, suggesting that vasopressin lowering lifestyle interventions, such as increased water intake, may promote metabolic health.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02202-7) contains supplementary material, which is available to authorized users.

Low Levels of CD4 + CD28 null T Cells at Baseline Are Associated With First-Time Coronary Events in a Prospective Population-Based Case-Control Cohort

Objective:

CD4 + CD28 null T cells have been shown to be associated with recurrent coronary events and suggested as potential biomarker and therapeutic target. It is unknown whether CD4 + CD28 null T cells associate with first-time cardiovascular events. We examined CD4 + CD28 null T cells in a prospective population-based cohort and in patients with advanced atherosclerosis.

Approach and Results:

CD4 + CD28 null T cells were quantified in 272 individuals experiencing a first-time coronary event during up to 17 years of follow-up and 272 age- and sex-matched controls in a case-control study, nested within the population-based Malmö Diet and Cancer study. The highest tertile of CD4 + CD28 null T cells was associated with a lower incidence of first-time coronary events compared with the lowest tertile (odds ratio, 0.48 [95% CI, 0.29–0.79], P =0.004) when adjusting for Framingham risk factors. This association remained significant for events recorded after >9 years of follow-up, when most coronary events occurred, but not during the first 9 years of follow-up, despite similar odds ratio. Additionally, we analyzed CD4 + CD28 null T cells in 201 patients with advanced atherosclerosis undergoing carotid endarterectomy. The adjusted hazard ratio for cardiovascular events in patients with advanced atherosclerosis was 2.11 (95% CI, 1.10–4.05, P =0.024), comparing the highest with the lowest CD4 + CD28 null T-cell tertile.

Conclusions:

Our findings reveal complex associations between CD4 + CD28 null T cells and cardiovascular disease. Although we confirm the reported positive associations with an adverse prognosis in patients with already established disease, the opposite associations with first-time coronary events in the population-based cohort may limit the clinical use of CD4 + CD28 null T cells.

Blood Lead Levels and Risk of Atherosclerosis in the Carotid Artery: Results from a Swedish Cohort

BACKGROUND

Lead exposure has been associated with increased incidence of adverse clinical cardiovascular outcomes. Atherosclerosis has been suggested as one of the underlying mechanisms, and findings from experimental studies support this, but human data are scarce.

OBJECTIVES

Our objective was to determine the association between environmental lead exposure based on blood lead (B-Pb) concentrations and the prevalence of atherosclerotic plaque in the carotid artery.

METHODS

We used cross-sectional data from the Malmö Diet and Cancer Study cardiovascular cohort (MDCS-CC; recruitment in 1991-1994) covering 4,172 middle-aged men and women. B-Pb at baseline, measured by inductively coupled plasma mass spectrometry, was used as the exposure biomarker. The presence of atherosclerotic plaque in the carotid artery was determined by B-mode ultrasonography. We used logistic regression to estimate odds ratios (ORs) for prevalence of plaque in the carotid artery according to B-Pb quartiles.

RESULTS

The median B-Pb was 25μg/L (range: 1.5-258), and 36% of the cohort had any atherosclerotic plaque. After controlling for confounders and known cardiovascular risk factors, the OR for prevalence of plaque in the highest quartile (Q4) of B-Pb compared with the lowest quartile (Q1) was 1.35 (95% CI: 1.09, 1.66) in the total group, 1.58 (95% CI: 1.20, 2.08) among women, and 1.18 (95% CI: 0.83, 1.69) among men. Among women, associations were limited to those who were postmenopausal [OR for Q4 vs. Q1=1.72 (95% CI: 1.26, 2.34) vs. OR=0.96 (95% CI: 0.49, 1.89 in premenopausal women)]. Associations were weak and nonsignificant in never-smokers [OR for Q4 vs. Q1=1.14 (95% CI: 0.81, 1.61)].

DISCUSSION

Our study shows an association between B-Pb concentrations and occurrence of atherosclerotic plaque in the carotid artery, adding evidence for an underlying pro-atherogenic role of lead in cardiovascular disease. Associations appeared to be limited to postmenopausal (vs. premenopausal) women. https://doi.org/10.1289/EHP5057.

Midlife Atherosclerosis and Development of Alzheimer or Vascular Dementia

Objective

To investigate whether midlife atherosclerosis is associated with different dementia subtypes and related underlying pathologies.

Methods

Participants comprised the cardiovascular cohort of the Swedish prospective population‐based Malmö Diet and Cancer Study (N = 6,103). Carotid plaques and intima media thickness (IMT) were measured at baseline (1991–1994). Dementia incidence until 2014 was obtained from national registers. Diagnoses were reviewed and validated in medical records. In a cognitively unimpaired subcohort (n = 330), β‐amyloid₄₂ and tau were quantified in cerebrospinal fluid (CSF), and white matter hyperintensity volume, lacunar infarcts, and cerebral microbleeds were estimated on magnetic resonance imaging (2009–2015).

Results

During 20 years of follow‐up, 462 individuals developed dementia (mean age at baseline = 57.5 ± 5.9 years, 58% women). Higher IMT in midlife was associated with an increased hazard ratio (HR) of all‐cause dementia (adjusted HR = 1.14 [95% confidence interval (CI) = 1.03–1.26]) and vascular dementia (adjusted HR = 1.32 [95% CI = 1.10–1.57]) but not Alzheimer disease (AD) dementia (adjusted HR = 0.95 [95% CI = 0.77–1.17]). Carotid plaques were associated with vascular dementia when assessed as a 3‐graded score (adjusted HR = 1.90 [95% CI = 1.07–3.38]). In the cognitively unimpaired subcohort (53.8 ± 4.6 years at baseline, 60% women), higher IMT in midlife was associated with development of small vessel disease (adjusted odds ratio [OR] = 1.47 [95% CI = 1.05–2.06]) but not significantly with abnormal CSF AD biomarkers (adjusted OR = 1.28 [95% CI = 0.87–1.90] for Aβ₄₂ and 1.35 [95% CI = 0.86–2.13] for Aβ₄₂/p‐tau). Carotid plaques revealed no significant association with any of the underlying brain pathologies.

Interpretation

Our findings support an association between midlife atherosclerosis and development of vascular dementia and cerebral small vessel disease but not between atherosclerosis and subsequent AD dementia or AD pathology. ANN NEUROL 2020;87:52–62

The relationship between red cell distribution width and all-cause and cause-specific mortality in a general population

Red Cell Distribution Width (RDW) could be a risk factor for developing various chronic diseases, and seems to be a prognostic marker in patients with cardiovascular disease (CVD) or cancer. Our aim was to explore the association between RDW and all-cause and cause-specific mortality in a general population. RDW was measured in 27,063 participants (aged 45–73 years) from the population-based Malmö Diet and Cancer cohort. After a follow-up of 19.8 ± 5.5 years, Cox proportional hazards regression analysis was used to study the relationship between RDW and all-cause and cause-specific mortality, with adjustment for confounding factors. A total of 9388 individuals (4715 men and 4673 women) died during the follow up. High RDW was significantly associated with all-cause mortality (HR, 4^th vs. 1^st quartile: 1.34, 95%CI: 1.24–1.45), cancer mortality (HR: 1.27, 95%CI: 1.12–1.44), CVD mortality (HR: 1.39, 95%CI: 1.21–1.59), and respiratory disease mortality (HR: 1.47, 95%CI: 1.06–2.03). The C-statistic increased significantly from 0.732 to 0.737 when adding RDW to a model adjusted for age and sex. There was a significant interaction between RDW and BMI with respect to all-cause mortality. We concluded that RDW is associated with mortality and propose that high RDW is a significant, but non-specific marker of mortality risk in the general population.

Association between blood pressure components and the presence of carotid plaque among adults aged 45 years and older: a population-based cross-sectional study in rural China

OBJECTIVE

Pulse pressure is strongly associated with the early development of large-vessel atherosclerotic disease. However, the relationship between pulse pressure and carotid plaque in China is unknown. Thus, we investigated the associations of pulse pressure and mean arterial pressure with the presence of carotid plaques in a low-income population in rural China.

PARTICIPANTS AND METHODS

Residents, aged ≥45 years, without histories of stroke or cardiovascular disease were enrolled. Participant demographics, previous medical histories, and lifestyle information were collected; anthropometric measures, serum profiles, and B-mode ultrasonographic investigations were also performed.

RESULTS

The mean age of participants (n = 3789) was 59.9 years overall (men 61.1 years; women, 59.1 years). The mean SBP (146.42 mmHg) and DBP (86.81 mmHg), pulse pressures (59.61 mmHg), and mean arterial pressures (106.68 mmHg) were high in this population. The odds ratio (95% confidence interval) for the association of pulse pressure with the presence of carotid plaques was 1.028 (1.023-1.033), in the univariate analysis. After gradual adjustment for demographic features, risk factors, and serum profile measurements, this positive association remained statistically significant (all, P < 0.001). However, there was no significant relationship between mean arterial pressure and the presence of carotid plaques.

CONCLUSION

These findings suggest that an elevated pulse pressure is an independent risk factor for the presence of carotid plaque. These results suggest that enhanced monitoring of blood pressure components, among low-income residents, is crucial for decreasing the risk of stroke and other cardiovascular disease in China.

A Vascular Aging Index as Independent Predictor of Cardiovascular Events and Total Mortality in an Elderly Urban Population

The morphology and function of the arteries can be directly measured using different established methods. This prospective cohort study aimed to translate 2 of these, aortic pulse wave velocity (aPWV) and carotid intima-media thickness (cIMT), into a combined Vascular Aging Index (VAI) and then evaluate the predictive power of aPWV, cIMT, and VAI. Patients (n = 2718) were included from the cardiovascular arm of the Malmö Diet and Cancer Study (median age 71.9 years, 62.2% females). Total follow-up time was 16 448 person-years and a composite cardiovascular disease (CVD) end point was used. Cox regressions yielded adjusted hazard ratios (95% confidence interval) per 1 standard deviation increment of log_e aPWV, log_e cIMT, and log_e VAI of 1.25 (1.08-1.45, P = .003), 1.27 (1.13-1.44, P < .001), and 1.45 (1.26-1.68, P < .001), respectively. The C-statistics increased from 0.714 to 0.734 when adding aPWV and cIMT to a model of conventional risk factors. Net Reclassification Index also showed a significant (P < .001) improvement for the classification of event-free patients and no change for patients with events. A VAI based on aPWV and cIMT had a good predictive performance. Used together, aPWV and cIMT incrementally and significantly improve the prediction of CVD events by correctly down-adjusting the predicted risk for noncases.

Education, sex and risk of stroke: a prospective cohort study in New South Wales, Australia

OBJECTIVE

To determine whether the association between highest educational attainment and stroke differed by sex and age; and whether potential mediators of observed associations differ by sex.

DESIGN

Prospective cohort study.

SETTING

Population based, New South Wales, Australia.

PARTICIPANTS

253 657 stroke-free participants from the New South Wales 45 and Up Study.

OUTCOME MEASURES

First-ever stroke events, identified through linkage to hospital and mortality records.

RESULTS

During mean follow-up of 4.7 years, 2031 and 1528 strokes occurred among men and women, respectively. Age-standardised stroke rate was inversely associated with education level, with the absolute risk difference between the lowest and highest education group greater among women than men. In relative terms, stroke risk was slightly more pronounced in women than men when comparing low versus high education (age-adjusted HRs: 1.41, 95% CI 1.16 to 1.71 and 1.25, 95% CI 1.07 to 1.46, respectively), but there was no clear evidence of statistical interaction. This association persisted into older age, but attenuated. Much of the increased stroke risk was explained by modifiable lifestyle factors, in both men and women.

CONCLUSION

Low education is associated with increased stroke risk in men and women, and may be marginally steeper in women than men. This disadvantage attenuates but persists into older age, particularly for women. Modifiable risk factors account for much of the excess risk from low education level. Public health policy and governmental decision-making should reflect the importance of education, for both men and women, for positive health throughout the life course.

Blood Lead Levels and Decreased Kidney Function in a Population-Based Cohort

BACKGROUND

Environmental lead exposure has been associated with decreased kidney function, but evidence from large prospective cohort studies examining low exposure levels is scarce. We assessed the association of low levels of lead exposure with kidney function and kidney disease.

STUDY DESIGN

Prospective population-based cohort.

SETTING & PARTICIPANTS

4,341 individuals aged 46 to 67 years enrolled into the Malmö Diet and Cancer Study-Cardiovascular Cohort (1991-1994) and 2,567 individuals subsequently followed up (2007-2012).

PREDICTOR

Blood lead concentrations in quartiles (Q1-Q4) at baseline.

OUTCOMES

Change in estimated glomerular filtration rate (eGFR) between the baseline and follow-up visit based on serum creatinine level alone or in combination with cystatin C level. Chronic kidney disease (CKD) incidence (185 cases) through 2013 detected using a national registry.

MEASUREMENTS

Multivariable-adjusted linear regression models to assess associations between lead levels and eGFRs at baseline and follow-up and change in eGFRs over time. Cox regression was used to examine associations between lead levels and CKD incidence. Validation of 100 randomly selected CKD cases showed very good agreement between registry data and medical records and laboratory data.

RESULTS

At baseline, 60% of study participants were women, mean age was 57 years, and median lead level was 25 (range, 1.5-258) μg/L. After a mean of 16 years of follow-up, eGFR decreased on average by 6mL/min/1.73m² (based on creatinine) and 24mL/min/1.73m² (based on a combined creatinine and cystatin C equation). eGFR change was higher in Q3 and Q4 of blood lead levels compared with Q1 (P for trend = 0.001). The HR for incident CKD in Q4 was 1.49 (95% CI, 1.07-2.08) compared with Q1 to Q3 combined.

LIMITATIONS

Lead level measured only at baseline, moderate number of CKD cases, potential unmeasured confounding.

CONCLUSIONS

Low-level lead exposure was associated with decreased kidney function and incident CKD. Our findings suggest lead nephrotoxicity even at low levels of exposure.

Is Radiation a Risk Factor for Atherosclerosis? An Echo-Color Doppler Study on Hodgkin and Non-Hodgkin Patients

Aims and background

The aim of the present paper was to study the role of irradiation in the atherosclerotic process in patients affected by Hodgkin and non-Hodgkin lymphoma.

Methods

We studied 84 subjects, 42 with Hodgkin or non-Hodgkin disease and 42 controls. All 42 cases had been irradiated and were comparable in terms of risk factors for atherosclerosis. All 84 subjects underwent echo-color Doppler of the arterial axis (carotids, abdominal aorta, and femoral arteries), and the intima-media thickness was measured.

Results

The irradiated cases had a greater intima-media thickness in the carotid district, even after dividing them according to age and sex; males were affected more than females. The irradiated patients were at greater risk of developing cardiovascular events than the controls.

Conclusions

An echo-color Doppler of the carotid district is advisable in all patients who have been submitted to radiotherapy, and the patients with a significantly greater than normal intima-media thickness need a strict follow-up, and antioxidant or antiaggregant therapy should be considered.

Partial Mediation by Cadmium Exposure of the Association Between Tobacco Smoking and Atherosclerotic Plaques in the Carotid Artery

Exposure to cadmium confers increased cardiovascular risk. Tobacco smoke contains cadmium, which, hypothetically, may mediate parts of the tobacco-associated risk of developing atherosclerotic plaques. Baseline data from the Swedish Malmö Diet and Cancer cohort (1991-1996) were used to test this hypothesis. Mediation analysis was used to examine associations between smoking and blood cadmium levels and the prevalence of ultrasound-assessed carotid atherosclerotic plaques. The total association with smoking status (never smokers, 2 categories of former smokers, and current smokers) was split into direct and indirect association, and the proportion mediated was estimated. The adjusted estimated plaque prevalence was approximately 27% among never smokers. We identified both a direct and an indirect pathway between smoking and carotid plaques; the indirect association, through cadmium, was observed among current smokers and former smokers who had quit smoking less than 15 years before. For current smokers, the prevalence ratio for plaque was 1.5, with 60%-65% of the association with smoking being mediated through cadmium. Recent former smokers had a prevalence ratio of 1.3, and 40%-45% was mediated through cadmium. Long-time former smokers had a prevalence ratio of 1.2, but none of the association was mediated through cadmium. In conclusion, about two-thirds of the proatherosclerotic association with smoking was mediated by cadmium.

Carotid Intima-Media Thickness as Surrogate for and Predictor of CVD

Carotid artery intima-media thickness (IMT) is a noninvasive measurement of the artery wall thickness, inclusive of atherosclerotic plaque, obtained using ultrasound imaging. In the MESA (Multi-Ethnic Study of Atherosclerosis) study, IMT measurements are used as a surrogate for subclinical cardiovascular disease and as a variable predictive of cardiovascular events. IMT measurements of the common carotid artery are available in more than 99% of the MESA population and are predictive of cardiovascular events. More importantly, IMT and plaque thickness measurements made in the internal carotid artery and carotid bulb are also available in more than 98% of the population and are also strongly predictive of cardiovascular events. This article reviews the techniques used to obtain the MESA IMT values, compares them to those made in other epidemiological studies, and summarizes how they have been used in the MESA study as both surrogates for and predictors of cardiovascular disease.

Cadmium, Carotid Atherosclerosis, and Incidence of Ischemic Stroke

Background

Exposure to cadmium has been associated with carotid plaques, inflammation in carotid plaques, and increased risk of ischemic stroke. This study examined the separate and interacting effects of blood cadmium levels and carotid plaques on the risk of incident ischemic stroke.

Methods and Results

Cadmium levels were measured in 4156 subjects (39.2% men; mean±SD age 57.3±5.9 years) without history of stroke, from the Malmö Diet and Cancer cohort. The right carotid artery was examined using B‐mode ultrasound examination at baseline. Incidence of ischemic stroke was monitored over a mean follow‐up of 16.7 years. Carotid plaque was present in 34.5% of participants. Cadmium was significantly higher in subjects with plaque (mean±SD: 0.53±0.58 μg/L versus 0.42±0.49 μg/L; P<0.001). A total of 221 subjects had ischemic stroke during the follow‐up. Incidence of ischemic stroke was associated both with carotid plaque (hazard ratio 1.44, 95% confidence interval, 1.09–1.90, P=0.009) and cadmium (hazard ratio for quartile [Q] 4 versus Q1–3: 1.95, confidence interval, 1.33–2.85, P=0.001), after adjustment for risk factors. There was a significant interaction between cadmium and plaque with respect to risk of ischemic stroke (P=0.011). Adjusted for risk factors, subjects with plaque and cadmium in Q4 had a hazard ratio of 2.88 (confidence interval, 1.79–4.63) for ischemic stroke, compared with those without plaque and cadmium in Q1 to Q3.

Conclusions

Cadmium was associated with incidence of ischemic stroke, both independently and in synergistic interaction with carotid plaques. This supports the hypothesis that cadmium promotes vulnerability of carotid plaques, thereby increasing the risk of rupture and ischemic stroke.

The association between socioeconomic status and subclinical atherosclerosis in a rural Bangladesh population

BACKGROUND

In Bangladesh, CVD accounts for the majority of non-communicable mortality. The purpose of this study was to determine the role of socioeconomic status (SES) on subclinical atherosclerosis measured as carotid intima-media thickness (IMT) in a rural Bangladesh population.

METHODS

Carotid IMT was measured between 2010 and 2011 in 1022 participants (average age 46, 40% male) randomly selected from the Health Effects of Arsenic Longitudinal Study (HEALS), a population-based prospective cohort study based in rural Bangladesh. SES was measured as occupation type, land ownership, educational attainment, and television ownership.

RESULTS

Half of the participants received formal education (53%) and under half owned land (48%) and a television (44%). Women were primarily homemakers (95%) and men worked as factory workers (24%), laborers (18%), or in business (55%). In univariate analysis, those owning greater than one acre of land (p=0.03), owning a television (p=0.02), or laborers and business owners compared to factory workers had higher levels of carotid IMT (p<0.01). In multivariate analysis after adjustment for confounders, only men employed in the business sector had elevated carotid IMT compared to factory workers. The association was strongest in older men (58.7μm, 95% CI 17.2-100.0, ≥50years old) compared to younger men (13.7μm, 95% CI -7.8-35.2, <50years old).

CONCLUSION

Business sector employment was positively associated with subclinical atherosclerosis after adjustment for confounders. This finding is consistent with evidence from other developing nations suggesting that certain SES factors are independent predictors of CVD.

Fasting levels of growth hormone are associated with carotid intima media thickness but are not affected by fluvastatin treatment

Background

Growth hormone (GH) has been linked to cardiovascular disease but the exact mechanism of this association is still unclear. We here test if the fasting levels of GH are cross-sectionally associated with carotid intima media thickness (IMT) and whether treatment with fluvastatin affects the fasting level of GH.

Methods

We examined the association between GH and IMT in 4425 individuals (aged 46–68 years) included in the baseline examination (1991–1994) of the Malmö Diet and Cancer cardiovascular cohort (MDC-CC). From that cohort we then studied 472 individuals (aged 50-70 years) who also participated (1994–1999) in the β-Blocker Cholesterol-Lowering Asymptomatic Plaque Study (BCAPS), a randomized, double blind, placebo-controlled, single-center clinical trial. Using multivariate linear regression models we related the change in GH-levels at 12 months compared with baseline to treatment with 40 mg fluvastatin once daily.

Results

In MDC-CC fasting values of GH exhibited a positive cross-sectional relation to the IMT at the carotid bulb independent of traditional cardiovascular risk factors (p = 0.002). In a gender-stratified analysis the correlation were significant for males (p = 0.005), but not for females (p = 0.09). Treatment with fluvastatin was associated with a minor reduction in the fasting levels of hs-GH in males (p = 0.05) and a minor rise in the same levels among females (p = 0.05).

Conclusions

We here demonstrate that higher fasting levels of GH are associated with thicker IMT in the carotid bulb in males. Treatment with fluvastatin for 12 months only had a minor, and probably not clinically relevant, effect on the fasting levels of hs-GH.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0563-9) contains supplementary material, which is available to authorized users.

Clustering of cardiovascular risk factors and carotid intima-media thickness: The USE-IMT study

Background

The relation of a single risk factor with atherosclerosis is established. Clinically we know of risk factor clustering within individuals. Yet, studies into the magnitude of the relation of risk factor clusters with atherosclerosis are limited. Here, we assessed that relation.

Methods

Individual participant data from 14 cohorts, involving 59,025 individuals were used in this cross-sectional analysis. We made 15 clusters of four risk factors (current smoking, overweight, elevated blood pressure, elevated total cholesterol). Multilevel age and sex adjusted linear regression models were applied to estimate mean differences in common carotid intima-media thickness (CIMT) between clusters using those without any of the four risk factors as reference group.

Results

Compared to the reference, those with 1, 2, 3 or 4 risk factors had a significantly higher common CIMT: mean difference of 0.026 mm, 0.052 mm, 0.074 mm and 0.114 mm, respectively. These findings were the same in men and in women, and across ethnic groups. Within each risk factor cluster (1, 2, 3 risk factors), groups with elevated blood pressure had the largest CIMT and those with elevated cholesterol the lowest CIMT, a pattern similar for men and women.

Conclusion

Clusters of risk factors relate to increased common CIMT in a graded manner, similar in men, women and across race-ethnic groups. Some clusters seemed more atherogenic than others. Our findings support the notion that cardiovascular prevention should focus on sets of risk factors rather than individual levels alone, but may prioritize within clusters.

Cadmium exposure is associated with soluble urokinase plasminogen activator receptor, a circulating marker of inflammation and future cardiovascular disease

BACKGROUND

Diet and smoking are the main sources of cadmium exposure in the general population. Cadmium increases the risk of cardiovascular diseases, and experimental studies show that it induces inflammation. Blood cadmium levels are associated with macrophages in human atherosclerotic plaques. Soluble urokinase-type plasminogen activator receptor (suPAR) is an emerging biomarker for cardiovascular events related to inflammation and atherosclerotic plaques. The aim was to examine whether blood cadmium levels are associated with circulating suPAR and other markers of inflammation.

METHODS

A population sample of 4648 Swedish middle-aged women and men was examined cross-sectionally in 1991-1994. Plasma suPAR was assessed by ELISA, leukocytes were measured by standard methods, and blood cadmium was analysed by inductively coupled plasma mass spectrometry. Prevalent cardiovascular disease, ultrasound-assessed carotid plaque occurrence, and several possible confounding factors were recorded.

RESULTS

After full adjustment for risk factors and confounding variables, a 3-fold increase in blood cadmium was associated with an 10.9% increase in suPAR concentration (p<0.001). In never-smokers, a 3-fold increase in blood cadmium was associated with a 3.7% increase in suPAR concentration (p<0.01) after full adjustment. Blood cadmium was not associated with C-reactive protein, white blood cell count and Lp-PLA2 but with neutrophil/lymphocyte ratio in one of two statistical models.

CONCLUSIONS

Exposure to cadmium was associated with increased plasma suPAR in the general population, independently of smoking and cardiovascular disease. These results imply that cadmium is a possible cause for raised levels of this inflammatory marker.

Growth of Carotid Intima-Media Thickness in Black and White Young Adults

Background

There are few longitudinal studies that have comprehensively examined the intima‐media thickness (IMT) growth pattern and its determinants among racial population groups.

Methods and Results

Mean and maximum IMT were measured by B‐mode ultrasonography up to 3 times in 253 white and 268 black participants, aged 13 to 36 years (mean age±standard deviation 24±3.2 years old). The development of IMT was assessed using individual growth curve modeling. A total of 521 participants with 1015 IMT measurements were eligible for this study. We found higher IMT in both left and right sides in blacks compared to whites (P<0.001) in young adulthood. Both whites and blacks showed a strong linear increase in mean IMT with age. Body mass index and father's education level were associated with mean IMT, and only body mass index was associated with maximum IMT (P<0.05). We did not observe an interaction between age and race/ethnicity on the growth of IMT, suggesting that blacks and whites developed IMT in similar patterns. Interestingly, we found a faster increase in mean left‐side IMT than mean right‐side IMT (χ²=11.5, P<0.001) in both black and white subjects as well as in males and females.

Conclusions

Our findings provide compelling prospective evidence that blacks may have thicker IMT compared to whites as young adults. These racial differences could not be explained by traditional risk factors. This implies that differences in this precursor of atherosclerosis may explain racial disparity in cerebrovascular disease.

Sex Differences in Prevalence of and Risk Factors for Carotid Plaque among Adults: A Population-based Cross-Sectional Study in Rural China

Although the associations between carotid plaque and cardiovascular disease risk factors have been identified in previous studies, there is limited information on sex-related differences in factors associated with the development of carotid plaque. We aimed to determine sex differences in the prevalence of carotid plaque and associated risk factors in rural China. A total of 3,789 subjects aged ≥45 years without history of stroke or cardiovascular disease were recruited to the study. B-mode ultrasonography was performed to determine the presence of carotid plaque. The mean age of male subjects was greater than that of female subjects. In addition, there was a higher prevalence of carotid plaque in men than in women (50.1% vs. 35.5%; P < 0.001) irrespective of age group, education level, and presence of risk factors. Older age, hypertension, diabetes mellitus, and high concentrations of low-density lipoprotein cholesterol were pronouncedly associated with the risk of carotid plaque in both men and women. These findings suggest that it is vital for physicians to be aware that conventional risk factors and other related factors are of equal importance among rural residents in China; patients should thus be treated accordingly so that reduce the burden of stroke and cardiovascular disease.

Prevalence and determinants of carotid plaque in the cross-sectional REFINE-Reykjavik study

OBJECTIVE

Carotid plaque and intima-media thickness are non-invasive arterial markers that are used as surrogate end points for cardiovascular disease. The aim was to assess the prevalence and severity of carotid plaque, and examine its determinant risk factors and their association to the common carotid artery intima-media thickness (CCA-IMT) in a general population.

METHODS

We examined 6524 participants aged 25-69 years in the population-based REFINE (Risk Evaluation For INfarct Estimates)-Reykjavik study. Plaques at the bifurcation and internal carotid arteries were evaluated. Mean CCA-IMT was measured in the near and far walls of the common carotid arteries.

RESULTS

The prevalence of minimal, moderate and severe plaque was 35.0%, 8.9% and 1.1%, respectively, and the mean CCA-IMT was 0.73 (SD 0.14) mm. Age, sex, smoking and type 2 diabetes mellitus (T2DM) were the strongest risk factors associated with plaque, followed by systolic blood pressure, total cholesterol, body mass index and family history of myocardial infarct. Low educational level was also strongly and independently associated with plaque. CCA-IMT shared the same risk factors except for a non-significant association with T2DM and family history of myocardial infarction (MI). Participants with T2DM had greater plaque prevalence, 2-fold higher in those <50 years and 17-30% greater in age groups 50-54 to 60-64, and more significant plaques (moderate or severe) were the difference in prevalence was 24% in age group 50-54 and ≥60% in older age groups, compared with non-T2DM.

CONCLUSIONS

Carotid plaque and CCA-IMT have mostly common determinants. However, T2DM and family history of MI were associated with plaque but not with CCA-IMT. Greater prevalence and more severe plaques in individuals with T2DM raise the concern that with increasing prevalence of T2DM we may expect an increase in atherosclerosis and its consequences.

Low-level exposure to lead, blood pressure, and hypertension in a population-based cohort

BACKGROUND

Environmental lead exposure is a possible causative factor for increased blood pressure and hypertension, but large studies at low-level exposure are scarce, and results inconsistent.

OBJECTIVE

We aimed to examine the effects of environmental exposure to lead in a large population-based sample.

METHODS

We assessed associations between blood lead and systolic/diastolic blood pressure and hypertension in 4452 individuals (46-67 years) living in Malmö, Sweden, in 1991-1994. Blood pressure was measured using a mercury sphygmomanometer after 10min supine rest. Hypertension was defined as high systolic (≥140mmHg) or diastolic (≥90mmHg) blood pressure and/or current use of antihypertensive medication. Blood lead was calculated from lead in erythrocytes and haematocrit. Multivariable associations between blood lead and blood pressure or hypertension were assessed by linear and logistic regression. Two-thirds of the cohort was re-examined 16 years later.

RESULTS

At baseline, mean blood pressure was 141/87mmHg, 16% used antihypertensive medication, 63% had hypertension, and mean blood lead was 28µg/L. Blood lead in the fourth quartile was associated with significantly higher systolic and diastolic blood pressure (point estimates: 1-2mmHg) and increased prevalence of hypertension (odds ratio: 1.3, 95% confidence interval: 1.1-1.5) versus the other quartiles after adjustment for sex, age, smoking, alcohol, waist circumference, and education. Associations were also significant with blood lead as a continuous variable. Blood lead at baseline, having a half-life of about one month, was not associated with antihypertensive treatment at the 16-year follow-up.

CONCLUSIONS

Low-level lead exposure increases blood pressure and may increase the risk of hypertension.

Socioeconomic inequalities in knee pain, knee osteoarthritis, and health-related quality of life: a population-based cohort study in southern Sweden

OBJECTIVES

To determine socioeconomic inequalities in frequent knee pain (FKP), knee osteoarthritis (OA), and associated health-related quality of life (HRQoL) in Sweden.

METHOD

In 2007 a postal questionnaire about knee pain was sent to a random sample of 10 000 residents of Malmö, Sweden (7402 individuals responded). Subjects reporting pain with duration ≥ 4 weeks in one or both knees in the past 12 months were classified as having FKP. A random sample of 1527 subjects with and without FKP attended a clinical and radiographic knee examination and responded to generic and disease-specific HRQoL questionnaires. We used the individuals' level of education and occupation as socioeconomic status (SES) measures, and we calculated the relative index of inequality (RII) using Poisson regression with robust standard errors adjusted for age and gender. We applied weighting to account for a possible selection bias that might arise from non-responses in the study.

RESULTS

With education, the RIIs for FKP and knee OA were 0.71 [95% confidence interval (CI) 0.61-0.84] and 0.56 (95% CI 0.34-0.93), respectively. With occupation, the corresponding figures were 0.70 (95% CI 0.60-0.82) and 0.59 (95% CI 0.37-0.94), respectively. There were socioeconomic gradients in HRQoL in favour of people with better SES. RIIs for FKP and HRQoL but not knee OA were essentially similar after additional adjustment for mediators.

CONCLUSIONS

In Sweden there are socioeconomic gradients related to both FKP and knee OA as well as HRQoL in favour of people with better SES. SES should be taken into account in health resource allocation pertaining to knee-related disorders.

The effect of smoking on carotid intima-media thickness progression rate and rate of lumen diameter reduction

OBJECTIVE

The purpose of the study was to investigate the long-term associations between smoking habits, environmental tobacco smoke exposure (ETS), carotid intima-media thickness (IMT) progression rate, and rate of lumen diameter reduction in the carotid artery during a 16-year follow-up. Another objective was to investigate if an effect of smoking on progression rate could be explained by increased low grade inflammation.

METHODS

The study population included 2992 middle-aged men and women in the 1991-1994 (baseline) and the 2007-2012 (re-examination) investigation of the Malmö Diet and Cancer Study cardiovascular cohort. Associations between smoking, progression of carotid IMT and lumen diameter reduction due to plaque protrusion were assessed by linear regression.

RESULTS

IMT progression rates and rate of lumen diameter reduction increased from never smokers with no ETS through former, moderate and heavy smokers, even after adjustment for traditional risk factors (e.g., differences in yearly progression rates (mm/year) of maximal IMT in the carotid bifurcation compared to never smokers; former smokers 0.0074 (95% CI: 0.0018-0.0129), moderate smokers 0.0106 (95% CI: 0.0038-0.0175), and heavy smokers 0.0146 (95% CI: 0.0061-0.0230)). Former smokers showed distinct lowering of progression rates after more than five years since smoking cessation. Smoking and former smoking was associated with increased low grade inflammation, however, the effect of smoking on atherosclerotic progression rate remained fairly unchanged after such adjustment.

CONCLUSION

The effect of smoking and former smoking on carotid IMT progression rates and change in lumen reduction due to plaque protrusion could not be explained by differences in traditional risk factors or low grade inflammation.

Total and Differential Leukocyte Counts in Relation to Incidence of Diabetes Mellitus: A Prospective Population-Based Cohort Study

Objective

High concentrations of leukocytes in blood have been associated with diabetes mellitus. This prospective study aimed to explore whether total and differential leukocyte counts are associated with incidence of diabetes. A missense variant R262W in the SH2B3 (SH2B adaptor protein 3) gene, coding for a protein that negatively regulates hematopoietic cell proliferation, was also studied in relation to incidence of diabetes.

Methods and Results

Leukocyte count and its subtypes (neutrophils, lymphocytes and mixed cells) were analyzed in 26,667 men and women, 45–73 years old, from the population-based Malmö Diet and Cancer study. Information about the R262W polymorphism (rs3184504) in SH2B3 was genotyped in 24,489 subjects. Incidence of diabetes was studied during a mean follow-up of 14 years. Cox proportional hazards regression was used to examine incidence of diabetes by total and differential leukocyte counts. Mendelian randomization analysis using R262W as an instrumental variable was performed with two-stage least squares regression. A total of 2,946 subjects developed diabetes during the follow-up period. After taking several possible confounders into account, concentrations of total leukocyte count, neutrophils and lymphocytes were all significantly associated with incidence of diabetes. The adjusted hazard ratios (95% confidence interval; quartile 4 vs quartile 1) were 1.37 (1.22–1.53) for total leukocytes, 1.33 (1.19–1.49) for neutrophils and 1.29 (1.15–1.44) for lymphocytes. The R262W polymorphism was strongly associated with leukocytes (0.11x10⁹ cells/l per T allele, p = 1.14 x10^-12), lymphocytes (p = 4.3 x10^-16), neutrophils (p = 8.0 x10^-6) and mixed cells (p = 3.0 x10^-6). However, there was no significant association between R262W and fasting glucose, HbA_1c or incidence of diabetes.

Conclusions

Concentrations of total leukocytes, neutrophils and lymphocytes are associated with incidence of diabetes. However, the lack of association with the R262W polymorphism suggests that the associations may not be causal, although limitations in statistical power and balancing pleiotropic effects cannot be excluded.

Carotid Intima-Media Thickness for Atherosclerosis

The carotid intima-media thickness (IMT) is a widely used surrogate marker for atherosclerosis worldwide. The carotid IMT can be simply, noninvasively, and reproducibly measured through B-mode carotid ultrasound. The carotid IMT is also a strong predictor of future cerebral and cardiovascular events. In addition, regressions of increased carotid IMT by lipid-lowering and antihypertensive drugs have been reported. Despite the strong association between increased carotid IMT and cardiovascular disease, it remains unclear whether routine carotid IMT measurement is useful for the detection of subclinical atherosclerosis in clinical practice. Researches should consider other methodological aspects, such as the definition of carotid plaques, the choice of measurement sites on the common or internal carotid artery, and the assessment of maximum or minimum IMT. The detailed guidelines for measuring carotid IMT vary by county. Thus, the usefulness of the carotid IMT may be assessed in different countries taking racial differences into account. Other important parameters revealed by carotid ultrasound, such as artery stenosis and the characteristics and size of plaques, should also be considered. Physicians should comprehensively interpret the results of carotid ultrasonography. Therefore, carotid ultrasonography is an essential tool for assessing cardiovascular risk in clinical settings.

Race/Ethnic Differences in the Associations of the Framingham Risk Factors with Carotid IMT and Cardiovascular Events

Background

Clinical manifestations and outcomes of atherosclerotic disease differ between ethnic groups. In addition, the prevalence of risk factors is substantially different. Primary prevention programs are based on data derived from almost exclusively White people. We investigated how race/ethnic differences modify the associations of established risk factors with atherosclerosis and cardiovascular events.

Methods

We used data from an ongoing individual participant meta-analysis involving 17 population-based cohorts worldwide. We selected 60,211 participants without cardiovascular disease at baseline with available data on ethnicity (White, Black, Asian or Hispanic). We generated a multivariable linear regression model containing risk factors and ethnicity predicting mean common carotid intima-media thickness (CIMT) and a multivariable Cox regression model predicting myocardial infarction or stroke. For each risk factor we assessed how the association with the preclinical and clinical measures of cardiovascular atherosclerotic disease was affected by ethnicity.

Results

Ethnicity appeared to significantly modify the associations between risk factors and CIMT and cardiovascular events. The association between age and CIMT was weaker in Blacks and Hispanics. Systolic blood pressure associated more strongly with CIMT in Asians. HDL cholesterol and smoking associated less with CIMT in Blacks. Furthermore, the association of age and total cholesterol levels with the occurrence of cardiovascular events differed between Blacks and Whites.

Conclusion

The magnitude of associations between risk factors and the presence of atherosclerotic disease differs between race/ethnic groups. These subtle, yet significant differences provide insight in the etiology of cardiovascular disease among race/ethnic groups. These insights aid the race/ethnic-specific implementation of primary prevention.

Subclinical Carotid Atherosclerosis Burden in the Japanese: Comparison between Okinawa and Nagano Residents

AIM

The prevalence of overweight and a change in atherosclerotic lipid profiles may be linked to region-specific differences in atherosclerotic diseases. We evaluated whether the lipid phenotype could be linked to region- and sex-specific differences in the degree of atherosclerosis.

METHODS

Non-diabetic subjects included Okinawa (n=1674) and Nagano (n=1392) residents aged 30-75 years who underwent carotid ultrasonography for the measurement of maximum intima-media thickness (max IMT).

RESULTS

Average max IMT was higher in Okinawa men and women, and the increase in max IMT with age was enhanced in men. Multiple regression analysis showed that in addition to age and systolic blood pressure, low-density lipoprotein cholesterol and non-high-density lipoprotein cholesterol were IMT determinants only in men for both Okinawa and Nagano. Meanwhile, HDL-cholesterol was a determinant for Okinawa men and women, but not for Nagano men and women.

CONCLUSIONS

This is the first report to show region- and sex-specific differences in the determinants for max IMT in a Japanese population. The evaluation of the relationship between lipid profile patterns and region- and sex-specific differences in carotid atherosclerosis burden may be required.

Low anthropometric measures and mortality--results from the Malmö Diet and Cancer Study

AIM

To study the association between anthropometric measures: body mass index (BMI), percent body fat, waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), waist-to-hip-to-height ratio (WHHR), and A Body Shape Index (ABSI); to see if individuals in the lowest 5 percentiles for these measures have an increased risk of mortality.

METHODS

A population-based prospective cohort study (10,304 men and 16,549 women), the Malmö Diet and Cancer study (MDC), aged 45-73 years.

RESULTS

During a mean follow-up of 14 ± 3 years, 2,224 men and 1,983 women died. There was a significant increased mortality risk after adjustments for potential confounders in the group with the 5% lowest BMI (referent 25%-75%); hazard ratios (HR) with 95% confidence intervals were 1.33 (1.10-1.61) for women and 1.27 (1.07-1.52) for men. A similar significant increased mortality risk was seen with the 5% lowest percent body fat, HR 1.31 (1.07-1.60) for women and 1.25 (1.04-1.50) for men. Women with an ABSI in the lowest 5 percentiles had a lower mortality risk HR 0.64 (0.48-0.85).

CONCLUSION

These results imply that BMI or percent body fat could be used to identify lean individuals at increased mortality risk.

Red cell distribution width in relation to incidence of stroke and carotid atherosclerosis: a population-based cohort study

Background

Increased red cell distribution width (RDW) has been related to poor prognosis in patients with cardiovascular disease, and is a predictor of cardiovascular mortality in the general population. The purpose of the present study was to investigate if RDW is associated with increased incidence of stroke and its subtypes in individuals from the general population.

Methods

Red cell distribution width was measured in 26,879 participants (16,561 women and 10,318 men aged 45–73 years) without history of coronary events or stroke, from the population-based Malmö Diet and Cancer Study. Incidences of total stroke and stroke subtypes over a mean follow-up of 15.2 years were calculated in relation to sex-specific quartiles of RDW. The presence of carotid plaque and intima–media thickness, as assessed by ultrasound, was studied in relation to RDW in a randomly selected subcohort (n = 5,309).

Results

Incidences of total stroke (n = 1,869) and cerebral infarction (n = 1,544) were both increased in individuals with high RDW. Hazard ratios (HRs) in the highest compared to the lowest quartile were 1.31 for total stroke (95% confidence interval [CI]: 1.11–1.54, p for trend = 0.004) and 1.32 for cerebral infarction (95% CI: 1.10–1.58, p for trend = 0.004) after adjustment for stroke risk factors and hematological parameters. The adjusted HR for intracerebral hemorrhage (n = 230) was 1.44 (95% CI: 0.90–2.30) and the HR for subarachnoid hemorrhage (n = 75) was 0.94 (95% CI: 0.43–2.07), in the highest compared to the lowest quartile of RDW. Red cell distribution width was positively associated with intima–media thickness of the common carotid artery (p for trend = 0.011).

Conclusions

Red cell distribution width in the highest quartile was associated with increased incidence of total stroke and cerebral infarction. There was no significant association between RDW and incidence of intracerebral or subarachnoid hemorrhage.