Low-level exposure to lead and atherosclerosis in the carotid arteries: Results from the Swedish population-based cohort SCAPIS

BACKGROUND

Lead exposure is associated with cardiovascular disease. Atherosclerosis has been hypothesized to be one of the underlying mechanisms behind this association.

AIM

To investigate whether lead exposure is associated with an increased risk of atherosclerosis in the carotid arteries in a large Swedish population-based cohort.

METHODS

We performed a cross-sectional study using data from the population-based Swedish CardioPulmonary bioImage Study (SCAPIS), including 5622 middle-aged men and women, enrolled 2013-2018. Blood lead (B-Pb), measured by inductively coupled plasma mass spectrometry, was used as exposure biomarker. The presence of atherosclerotic plaque in the carotid arteries (yes/no), total plaque area (mm2) and the presence of large plaques (>25 mm2) were determined by ultrasonography. Associations between B-Pb and the different outcomes were analysed using Poisson and linear regression models, adjusted for potential confounders.

RESULTS

Atherosclerotic plaque was present in 57% of the individuals, for whom the median total plaque area was 16 mm2 (range: 0.2-222). The median B-Pb concentration was 14 μg/L (range: 0.75-203). After adjusting for potential confounders, individuals in the fourth quartile of B-Pb (Q4) had a prevalence ratio (PR) for plaque of 1.08 (95% CI: 1.01, 1.16) when compared with the first quartile (Q1). A 10 μg/L increase in B-Pb concentrations was associated with an increase of 0.92 mm2 (95% CI: 0.14, 1.71) in total plaque area. The PR for large plaque was 1.09 (95% CI: 0.84, 1.42 for Q4 vs Q1).

CONCLUSIONS

This study shows an association between B-Pb and atherosclerosis in the carotid arteries providing some support for the hypothesis that atherosclerosis is one of the mechanisms underlying the association between lead exposure and cardiovascular disease.

Long-term exposure to air pollution, coronary artery calcification, and carotid artery plaques in the population-based Swedish SCAPIS Gothenburg cohort

Long-term exposure to air pollution is associated with cardiovascular events. A main suggested mechanism is that air pollution accelerates the progression of atherosclerosis, yet current evidence is inconsistent regarding the association between air pollution and coronary artery and carotid artery atherosclerosis, which are well-established causes of myocardial infarction and stroke. We studied associations between low levels of long-term air pollution, coronary artery calcium (CAC) score, and the prevalence and area of carotid artery plaques, in a middle-aged population-based cohort. The Swedish CArdioPulmonary bioImage Study (SCAPIS) Gothenburg cohort was recruited during 2013-2017 and thoroughly examined for cardiovascular risk factors, including computed tomography of the heart and ultrasonography of the carotid arteries. In 5070 participants (age 50-64 years), yearly residential exposures to air pollution (PM_2.5, PM₁₀, PM_coarse, NO_x, and exhaust-specific PM_2.5 1990-2015) were estimated using high-resolution dispersion models. We used Poisson regression to examine associations between long-term (26 years' mean) exposure to air pollutants and CAC score, and prevalence of carotid artery plaques, adjusted for potential confounders. Among participants with carotid artery plaques, we also examined the association with plaque area using linear regression. Mean exposure to PM_2.5 was low by international standards (8.5 μg/m³). There were no consistent associations between long-term total PM_2.5 exposure and CAC score or presence of carotid artery plaques, but an association between total PM_2.5 and larger plaque area in participants with carotid plaques. Associations with traffic-related air pollutants were consistently positive for both a high CAC score and bilateral carotid artery plaques. These associations were independent of road traffic noise. We found stronger associations among men and participants with cardiovascular risk factors. The results lend some support to atherosclerosis as a main modifiable pathway between low levels of traffic-related ambient air pollution and cardiovascular disease, especially in vulnerable individuals.

Air pollution and biomarkers of cardiovascular disease and inflammation in the Malmö Diet and Cancer cohort

INTRODUCTION

Air pollution is associated with increased risk of cardiovascular disease, possibly through chronic systemic inflammation that promotes the progression of atherosclerosis and the risk of cardiovascular events. This study aimed to investigate the associations between air pollution and established biomarkers of inflammation and cardiovascular disease.

METHODS

The Cardiovascular Subcohort of the Malmö Diet and Cancer cohort includes 6103 participants from the general population of Malmö, Sweden. The participants were recruited 1991-1994. Annual mean residential exposure to particulate matter < 2.5 and < 10 μm (PM_2.5 and PM₁₀), and nitrogen oxides (NO_x) at year of recruitment were assigned from dispersion models. Blood samples collected at recruitment, including blood cell counts, and biomarkers (lymphocyte- and neutrophil counts, C-reactive protein (CRP), soluble urokinase-type plasminogen activator receptor (suPAR), lipoprotein-associated phospholipase A₂ (Lp-PLA₂), ceruloplasmin, orosomucoid, haptoglobin, complement-C3, and alpha-1-antitrypsin) were analyzed. Multiple linear regression models were used to investigate the cross-sectional associations between air pollutants and biomarkers.

RESULTS

The mean annual exposure levels in the cohort were only slightly or moderately above the new WHO guidelines of 5 μg/m³ PM_2.5 (10.5 μg/m³ PM_2.5). Residential PM_2.5 exposure was associated with increased levels of ceruloplasmin, orosomucoid, C3, alpha-1-antitrypsin, haptoglobin, Lp-PLA₂ and the neutrophil-lymphocyte ratio. Ceruloplasmin, orosomucoid, C3 and alpha-1-antitrypsin were also positively associated with PM₁₀. There were no associations between air pollutants and suPAR, leukocyte counts or CRP. The associations between particles and biomarkers were still significant after removing outliers and adjustment for CRP levels. The associations were more prominent in smokers.

CONCLUSION

Long-term residential exposure to moderate levels of particulate air pollution was associated with several biomarkers of inflammation and cardiovascular disease. This supports inflammation as a mechanism behind the association between air pollution and cardiovascular disease.

Review of cadmium exposure and smoking-independent effects on atherosclerotic cardiovascular disease in the general population

BACKGROUND

Exposure to cadmium (Cd) via food and smoking is associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD). Blood and urine levels of Cd are established biomarkers of exposure.

OBJECTIVES

To review (1) the smoking-independent associations between Cd exposure and ASCVD, including the possible presence of a nonlinear dose-response relationship with Cd exposure and (2) the causal effects of Cd exposure on different stages of atherosclerosis.

METHODS

Narrative review.

RESULTS

Cd confers increased risk of ASCVD and asymptomatic atherosclerosis in the carotid and coronary arteries above B-Cd >0.5 μg/L or U-Cd >0.5 μg/g creatinine, but it has not been shown below a threshold of these exposure levels. Adjustment for smoking does not exclude the possibility of residual confounding, but several studies in never-smoking cohorts have shown associations between Cd and ASCVD, and experimental studies have demonstrated pro-atherosclerotic effects of Cd. Cd accumulates in arterial walls and atherosclerotic plaques, reaching levels shown to have proatherosclerotic effects. Suggested early effects are increased subendothelial retention of atherogenic lipoproteins, which become oxidized, and endothelial dysfunction and damage with increased permeability for monocytes, which in the intima turn to macrophages and then to foam cells. Later, Cd may contribute to plaque rupture and erosion by endothelial apoptosis and degradation of the fibrous cap. Finally, by having prothrombotic and antifibrinolytic effects, the CVD risk may be further increased.

CONCLUSIONS

There is strong evidence that Cd causes ASCVD above a suggested exposure level via mechanisms in early as well as the late stages of atherosclerotic disease.

Prevalence of Subclinical Coronary Artery Atherosclerosis in the General Population

Supplemental Digital Content is available in the text.

Background:

Early detection of coronary atherosclerosis using coronary computed tomography angiography (CCTA), in addition to coronary artery calcification (CAC) scoring, may help inform prevention strategies. We used CCTA to determine the prevalence, severity, and characteristics of coronary atherosclerosis and its association with CAC scores in a general population.

Methods:

We recruited 30 154 randomly invited individuals age 50 to 64 years to SCAPIS (the Swedish Cardiopulmonary Bioimage Study). The study includes individuals without known coronary heart disease (ie, no previous myocardial infarctions or cardiac procedures) and with high-quality results from CCTA and CAC imaging performed using dedicated dual-source CT scanners. Noncontrast images were scored for CAC. CCTA images were visually read and scored for coronary atherosclerosis per segment (defined as no atherosclerosis, 1% to 49% stenosis, or ≥50% stenosis). External validity of prevalence estimates was evaluated using inverse probability for participation weighting and Swedish register data.

Results:

In total, 25 182 individuals without known coronary heart disease were included (50.6% women). Any CCTA-detected atherosclerosis was found in 42.1%; any significant stenosis (≥50%) in 5.2%; left main, proximal left anterior descending artery, or 3-vessel disease in 1.9%; and any noncalcified plaques in 8.3% of this population. Onset of atherosclerosis was delayed on average by 10 years in women. Atherosclerosis was more prevalent in older individuals and predominantly found in the proximal left anterior descending artery. Prevalence of CCTA-detected atherosclerosis increased with increasing CAC scores. Among those with a CAC score >400, all had atherosclerosis and 45.7% had significant stenosis. In those with 0 CAC, 5.5% had atherosclerosis and 0.4% had significant stenosis. In participants with 0 CAC and intermediate 10-year risk of atherosclerotic cardiovascular disease according to the pooled cohort equation, 9.2% had CCTA-verified atherosclerosis. Prevalence estimates had excellent external validity and changed marginally when adjusted to the age-matched Swedish background population.

Conclusions:

Using CCTA in a large, random sample of the general population without established disease, we showed that silent coronary atherosclerosis is common in this population. High CAC scores convey a significant probability of substantial stenosis, and 0 CAC does not exclude atherosclerosis, particularly in those at higher baseline risk.

Cadmium Exposure and Coronary Artery Atherosclerosis: A Cross-Sectional Population-Based Study of Swedish Middle-Aged Adults

BACKGROUND

The general population is ubiquitously exposed to the toxic metal cadmium through the diet and smoking. Cadmium exposure is associated with increased morbidity and mortality in myocardial infarction and stroke. Atherosclerosis is the main underlying mechanism of myocardial infarction. However, associations between cadmium and coronary artery atherosclerosis have not been examined.

OBJECTIVES

Our study sought to examine the hypothesis that blood cadmium (B-Cd) is positively associated with coronary artery calcification, as a measure of coronary artery atherosclerosis in the population-based Swedish SCAPIS study.

METHODS

Our analysis included 5,627 individuals (51% women), age 50-64 y, enrolled from 2013 to 2018. The coronary artery calcium score (CACS) was obtained from computed tomography. Blood cadmium was determined by inductively coupled plasma mass spectrometry (ICP-MS). Associations between B-Cd and coronary artery calcium score (CACS Agatston score) were evaluated using prevalence ratios (PRs) in models adjusted for sex, age, smoking, hypertension, diabetes, low-density cholesterol/high-density cholesterol ratio, and family history.

RESULTS

The median B-Cd concentration was 0.24μg/L. The prevalence of positive coronary artery calcium (CACS>0) was 41% and the prevalence of CACS≥100 was 13%. Relative to the lowest quartile (Q) of B-Cd (<0.16μg/L), the highest quartile (median 0.63μg/L) was associated with a small but significant increase in CACS>0 (PR 1.1; 95% CI: 1.0, 1.3), and a greater relative increase in CACS≥100 (PR 1.6; 95% CI: 1.3, 2.0). When restricted to 2,446 never-smokers, corresponding PRs were 1.1 (95% CI 0.9, 1.3) for CACS>0 (63 cases in Q4) and 1.7 (95% CI 1.1, 2.7) for CACS≥100 (17 cases in Q4).

DISCUSSION

Blood cadmium in the highest quartile was associated with CACS in a general population sample with low to moderate cadmium exposure. This supports the hypothesis that atherosclerosis is an important mechanism underlying the associations between cadmium and incident cardiovascular disease. The findings suggest that public health measures to reduce cadmium exposure are warranted. https://doi.org/10.1289/EHP8523.

[Air pollution may exacerbate covid-19]

Several published and pre-print studies report associations between exposure to air pollution and COVID-19 mortality. While further epidemiological and experimental studies are still needed to prove causality, the association is plausible and consistent with the literature: Air pollution is associated with inferior outcomes in other respiratory infections, may act as carrier for the virus, exerts negative effects on the airways and is associated with cardiopulmonary comorbidities that lead to a poorer prognosis in COVID-19 patients. The lockdown to inhibit the spread of COVID-19 has led to substantial decreases in air pollution levels in many countries.

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.

Smoking-induced risk of future cardiovascular disease is partly mediated by cadmium in tobacco: Malmö Diet and Cancer Cohort Study

BACKGROUND

Smoking is a strong risk factor for cardiovascular disease (CVD) and causes exposure to cadmium, which is a pro-atherosclerotic metal. Cadmium exposure has also been shown to increase the risk of CVD, even after adjustment for smoking. Our hypothesis was that part of the risk of CVD in smokers may be mediated by cadmium exposure from tobacco smoke. We examined this hypothesis in a mediation analysis, trying to assess how much of the smoking-induced CVD risk could be explained via cadmium.

METHODS

We used prospective data on CVD (incidence and mortality) in a Swedish population-based cohort of 4304 middle-aged men and women (the Malmö Diet and Cancer Study). Blood cadmium was analyzed in base-line samples from 1991, and clinical events were followed up for 16-19 years based on registry data. Mediation analysis was conducted to evaluate the indirect effect (via cadmium) of smoking on CVD. Survival was analyzed by the accelerated failure time (AFT) model and the Aalen additive hazard model.

RESULTS

The mean blood cadmium level in the study population was 0.43 μg/L (median 0.24 μg/L) and increased with recent and current smoking. As expected, shorter survival time (AFT model) and higher incidence rate (Aalen model) were found in current smokers for all CVD outcomes and this effect seemed to be partly mediated by cadmium. For the sum of acute myocardial infarction, bypass grafts and percutaneous coronary intervention, and death in ischemic heart disease, about half of the increased risk of such events in current smokers was mediated via cadmium, with similar results for the AFT and Aalen models.

CONCLUSIONS

Cadmium plays an important role in smoking-induced CVDs. This provides evidence for mechanisms and is of importance for both individuals and policy makers.

Biomarkers of blood cadmium and incidence of cardiovascular events in non-smokers: results from a population-based proteomics study

Background

Cadmium is a toxic metal with multiple adverse health effects, including risk of cardiovascular disease (CVD). The mechanistic link between cadmium and CVD is unclear. Our aim was to examine the associations between blood cadmium (B-Cd) and 88 potential protein biomarkers of CVD.

Methods

B-Cd and 88 plasma proteins were measured in a community-based prospective cohort, the Malmö Diet and Cancer study. The primary analysis was performed in never smokers (n = 1725). Multiple linear regression was used with adjustments for age and sex, and correction for multiple comparisons using the false discovery rate method. Proteins significantly associated with B-Cd were replicated in long-term former smokers (n = 782). Significant proteins were then studied in relation to incidence of CVD (i.e., coronary events or ischemic stroke) in never smokers.

Results

Fifteen proteins were associated with B-Cd in never smokers. Eight of them were replicated in long-term former smokers. Kidney injury molecule-1, fibroblast growth factor-23 (FGF23), tumor necrosis factor receptor-2, matrix metalloproteinase-12, cathepsin L1, urokinase plasminogen activator receptor, C-C motif chemokine-3 (CCL3), and chemokine (C-X3-C motif) ligand-1 were associated with B-Cd both in never smokers and long-term former smokers. Except for CCL3 and FGF23, these proteins were also significantly associated with incidence of CVD.

Conclusions

B-Cd in non-smokers was associated with eight potential plasma biomarkers of CVD and kidney injury. The results suggest pathways for the associations between B-Cd and CVD and kidney injury.

[Climate-smart and effective health care reduces green-house gas emissions]

Health care is associated with a considerable climate impact and this short review describes approaches to reduce this impact. Reviews from WHO and World Bank Group end up with recommendations on low-carbon and resilient health care which is beneficial for health, economy and climate. The concept of climate-smart healthcare has been suggested as new way of describing this much needed work. In Skåne Region, Sweden a four-step method has been developed to reduce the climate impact of hospital care: to map and identify areas of greatest impact, to work with measures to reduce impact and evaluate the results. A test of this method showed a significant reduction in emission of CO2. In another project, fast-track access for patients with hematuria for diagnosis of bladder cancer showed that the median time from referral to diagnosis was reduced in comparison with conventional care with less costs and less use of resources associated with climate impact.

[Climate impact of healthcare]

The Swedish healthcare's share of public sector greenhouse gas emissions is approximately 20 per cent and this climate impact is mainly due to indirect emissions of purchased goods and services. In Region Västra Götaland, consumables used in healthcare are one of the largest single sources responsible for greenhouse gas emissions, similar to findings in other regions and countries. The focus on reducing the carbon footprint of healthcare is on measures to reduce disposables, to reduce need of transport and to save energy for heating, light, use of computers and medical devices.

Non-alcoholic fatty liver disease is a strong predictor of coronary artery calcification in metabolically healthy subjects: A cross-sectional, population-based study in middle-aged subjects

Objectives

This study aims to estimate the relationship between non-alcoholic fatty liver disease (NAFLD) and measures of atherosclerotic cardiovascular disease (ASCVD), and to determine to what extent such relationships are modified by metabolic risk factors.

Methods

The study was conducted in the population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) pilot cohort (n = 1015, age 50–64 years, 51.2% women). NAFLD was defined as computed tomography liver attenuation ≤40 Hounsfield Units, excluding other causes of liver fat. Coronary artery calcification score (CACS) was assessed using the Agatston method. Carotid plaques and intima media thickness (IMT) were measured by ultrasound. Metabolic status was based on assessments of glucose homeostasis, serum lipids, blood pressure and inflammation. A propensity score model was used to balance NAFLD and non NAFLD groups with regards to potential confounders and associations between NAFLD status and ASCVD variables in relation to metabolic status were examined by logistic and generalized linear regression models.

Results

NAFLD was present in 106 (10.4%) of the subjects and strongly associated with obesity-related traits. NAFLD was significantly associated with CACS after adjustment for confounders and metabolic risk factors (OR 1.77, 95% CI 1.07–2.94), but not with carotid plaques and IMT. The strongest association between NAFLD and CACS was observed in subjects with few metabolic risk factors (n = 612 [60% of all] subjects with 0–1 out of 7 predefined metabolic risk factors; OR 5.94, 95% CI 2.13–16.6).

Conclusions

NAFLD was independently associated with coronary artery calcification but not with measures of carotid atherosclerosis in this cohort. The association between NAFLD and CACS was most prominent in the metabolically healthy subjects.

Impact of socioeconomic status on coronary artery calcification

Background

Low socioeconomic status is associated with an increased risk of coronary artery disease, but few studies have investigated the potential link between living in an area with a low versus a high socioeconomic status and coronary artery calcification, a marker of subclinical coronary artery disease.

Design

The design of this study was a cross-sectional study.

Methods

We evaluated 1067 participants with no history of coronary artery disease from the pilot phase of the Swedish CArdioPulmonary bioImage Study (SCAPIS). Men and women aged 50–64 years were recruited from three high-socioeconomic status ( n = 541) and three low-socioeconomic status ( n = 526) areas in the city of Gothenburg (550,000 inhabitants). The coronary artery calcification score was assessed with the Agatston method using computed tomography, with individuals classified into either no coronary calcification ( n = 625; mean age, 57 years) or any coronary artery calcification ( n = 442; mean age, 59 years (men, 68.5%)).

Results

Coronary artery calcification was present in 244 (46.3%) and 198 (36.6%) individuals from the low- and high-socioeconomic status areas, respectively. Participants from the low-socioeconomic status areas had a significantly higher risk factor burden. In a multivariable logistic regression model with adjustment for age, sex and cardiovascular risk factors, the odds for coronary artery calcification were not significantly higher among persons living in low-socioeconomic status areas (odds ratio = 1.18, 95% confidence interval = 0.87–1.60).

Conclusion

In this relatively small cross-sectional study, we observed an association between living in a low-socioeconomic status area and coronary artery calcification. However, this was mostly explained by higher levels of cardiovascular disease risk factors, indicating that the effect of socioeconomic status on the atherosclerotic process works through an increased burden of cardiovascular disease risk factors.

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.

Insulin Sensitivity and Hemostatic Factors in Clinically Healthy 58-year-old Men

The objective of this cross-sectional study was to investigate the relationship between factors of the coagulation- and fibrinolysis systems and insulin sensitivity in 104 clinically healthy, 58-years-old men. Insulin sensitivity (hyperinsulinemic euglycemic clamp) adjusted for lean body mass, the metabolic syndrome according to a suggested definition, and different factors in the coagulation- and fibrinolysis system were determined. Subjects with the metabolic syndrome were characterised by increases in PAI-1 activity, tPA antigen, protein C and protein S and low concentrations of tPA activity. Insulin sensitivity was independently and reversibly associated with PAI-1 (p = 0.014) and directly with tPA activity (p = 0.001). Insulin sensitivity was also significantly negatively associated with protein S and protein C and several components in the metabolic syndrome, however not remaining significant in multivariate analyses. Protein C and protein S were significantly associated with PAI-1 activity, tPA activity (negatively), tPA antigen and antithrombin III. In conclusion, the data indicated that insulin resistance and several of the clustering components in the metabolic syndrome are accompanied by increased plasma concentrations of the anticoagulatory proteins C and S which may represent a mechanism which counteracts the concomitantly occurring hypofibrinolysis.

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.

Biomarkers of food intake and nutrient status are associated with glucose tolerance status and development of type 2 diabetes in older Swedish women

Background: Diet is frequently associated with both the development and prevention of type 2 diabetes (T2D), but there is a lack of objective tools for assessing the relation between diet and T2D. Biomarkers of dietary intake are unconfounded by recall and reporting bias, and using multiple dietary biomarkers could help strengthen the link between a healthy diet and the prevention of T2D.Objective: The objective of this study was to explore how diet is related to glucose tolerance status (GTS) and to future development of T2D irrespective of common T2D and cardiovascular disease risk factors by using multiple dietary biomarkers.Design: Dietary biomarkers were measured in plasma from 64-y-old Swedish women with different GTS [normal glucose tolerance (NGT; n = 190), impaired glucose tolerance (IGT; n = 209), and diabetes (n = 230)]. The same subjects were followed up after 5 y to determine changes in glucose tolerance (n = 167 for NGT, n = 174 for IGT, and n = 159 for diabetes). ANCOVA and logistic regression were used to explore baseline data for associations between dietary biomarkers, GTS, and new T2D cases at follow-up (n = 69).Results: Of the 10 dietary biomarkers analyzed, β-alanine (beef) (P-raw < 0.001), alkylresorcinols C17 and C19 (whole-grain wheat and rye) (P-raw = 0.003 and 0.011), eicosapentaenoic acid (fish) (P-raw = 0.041), 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF) (fish) (P-raw = 0.002), linoleic acid (P-raw < 0.001), oleic acid (P-raw = 0.003), and α-tocopherol (margarine and vegetable oil) (P-raw < 0.001) were associated with GTS, and CMPF (fish) (OR: 0.72; 95% CI: 0.56, 0.93; P-raw = 0.013) and α-tocopherol (OR: 0.71; 95% CI: 0.51, 0.98; P-raw = 0.041) were inversely associated with future T2D development.Conclusions: Several circulating dietary biomarkers were strongly associated with GTS after correction for known T2D risk factors, underlining the role of diet in the development and prevention of T2D. To our knowledge, this study is the first to use multiple dietary biomarkers to investigate the link between diet and disease risk.

Predicting participation in the population-based Swedish cardiopulmonary bio-image study (SCAPIS) using register data

AIMS

To illustrate the importance of access to register data on determinants and predictors of study participation to assess validity of population-based studies. In the present investigation, we use data on sociodemographic conditions and disease history among individuals invited to the Swedish cardiopulmonary bio-image study (SCAPIS) in order to establish a model that predicts study participation.

METHODS

The pilot study of SCAPIS was conducted within the city of Gothenburg, Sweden, in 2012, with 2243 invited individuals (50% participation rate). An anonymous data set for the total target population ( n = 24,502) was made available by register authorities (Statistics Sweden and the National Board of Health and Welfare) and included indicators of invitation to and participation in SCAPIS along with register data on residential area, sociodemographic variables, and disease history. Propensity scores for participation were estimated using logistic regression.

RESULTS

Residential area, country of birth, civil status, education, occupational status, and disposable income were all associated with participation in multivariable models. Adding data on disease history only increased overall classification ability marginally. The associations with disease history were diverse with some disease groups negatively associated with participation whereas some others tended to increase participation.

CONCLUSIONS

The present investigation stresses the importance of a careful consideration of selection effects in population-based studies. Access to detailed register data also for non-participants can in the statistical analysis be used to control for selection bias and enhance generalizability, thereby making the results more relevant for policy decisions.

[Nanoparticles for cancer therapy]

Nanoparticles for cancer therapy Nanoparticles carry a big promise in oncology, for diagnosis/imaging, therapy, or both (theragnostics). As common in medical history, there is a huge gap between the exciting experimental possibilities and data and clinical studies making use of it. Of the cell-containing nanoparticles, only one formulation using gene-directed enzyme prodrug therapy (GDEPT) with CYP2B1 and ifosfamide was used in early clinical studies. Of the cell-free nanoparticles, some drug-releasing (doxorubicin) ones are in clinical use for trans-arterial chemo-embolization (TACE) in liver tumors and metastasis. Using liposomes, both paclitaxel and irinotecan have been used in pancreatic cancer as the model indication. Nanoparticle-albumin-bound paclitaxel (NAB-paclitaxel) has also been developed and is now registered as a drug for first-line therapy of pancreatic cancer, as is the liposomal irinotecan. The novel nanoparticle formulations carry a big promise for even better performance, both in diagnosis and therapy; however, few of these has entered the clinic as of today.