Polymorphisms within the ICAM1 structural gene have been shown to influence circulating levels of soluble intercellular adhesion molecule -1 (sICAM-1) but their relation to atherosclerosis has not been clearly established. We sought to determine whether ICAM1 SNPs are associated with circulating sICAM-1 concentration, coronary artery calcium (CAC), and common and internal carotid intima medial thickness (IMT).
Methods and Results
3,550 black and white Coronary Artery Risk Development in Young Adults (CARDIA) Study subjects who participated in the year 15 and/or 20 examinations and were part of the Young Adult Longitudinal Study of Antioxidants (YALTA) ancillary study were included in this analysis. In whites, rs5498 was significantly associated with sICAM-1 (p < 0.001) and each G-allele of rs5498 was associated with 5% higher sICAM-1 concentration. In blacks, each C-allele of rs5490 was associated with 6 % higher sICAM-1 level; this SNP was in strong linkage disequilibrium with rs5491, a functional variant. Subclinical measurements of atherosclerosis in either year 15 or year 20 were not significantly related to ICAM1 SNPs.
In CARDIA, ICAM1 DNA segment variants were associated with sICAM-1 protein level including the novel finding that levels differ by the functional variant rs5491. However, ICAM1 SNPs were not strongly related to either IMT or CAC. Our findings in CARDIA suggest that ICAM1 variants are not major early contributors to subclinical atherosclerosis.
cell adhesion molecules; atherosclerosis; coronary calcium; genetics; inflammation
Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) may be important contributors to the development and progression of atherosclerosis. Using a stratified random sample of 2,880 participants of the Multi-Ethnic Study of Atherosclerosis we investigated the relationship of 12 ICAM1 and 17 VCAM1 SNPs and coronary artery calcium (CAC) and ICAM1 SNPs and circulating levels of soluble ICAM-1 (sICAM-1). There were no ICAM1 or VCAM1 SNPs significantly associated with CAC in any of the four race/ethnic groups. In a subset of 1,451 subjects with sICAM-1 measurements, we observed a significant association with rs5491 in all four race/ethnic groups corroborating previous research that has shown that the T-allele of rs5491 interferes with the monoclonal antibody used to measure sICAM-1 in this study. After excluding all rs5491 T-allele carriers, several ICAM1 SNPs were significantly associated with sICAM-1 levels; rs5496 in African Americans, rs5498 and rs3093030 in European Americans, and rs1799969 in Hispanics. Our results identified ICAM1 polymorphisms that were significantly associated with sICAM-1 level but not CAC, a subclinical marker of atherosclerosis.
coronary artery calcium; intercellular adhesion molecule-1 (ICAM-1); vascular adhesion molecule-1 (VCAM-1); soluble intercellular adhesion molecule-1 (sICAM-1); gene; single nucleotide polymorphism (SNP); haplotypes
Endothelial cell-selective adhesion molecule (ESAM) is a junctional-type cellular adhesion molecule (CAM) that is uniquely expressed in vascular endothelium and activated platelets and mediates neutrophil and monocyte diapedesis across the endothelium. Given its role in endothelial pathobiology, we hypothesized that soluble ESAM (sESAM) would be independently associated with atherosclerosis and vascular stiffness.
Methods and Results
We measured sESAM, soluble intercellular adhesion molecule (sICAM)-1 and soluble vascular cell adhesion molecule (sVCAM)-1 in 3222 subjects participating in the Dallas Heart Study, a probability-based population sample. Coronary artery calcium (CAC) was measured by electron beam computed tomography, and abdominal aortic wall thickness (AWT), aortic plaque burden (APB), and aortic compliance (AC) by magnetic resonance imaging (MRI). Increasing levels of sESAM were associated with all major cardiovascular risk factors as well as with inflammatory markers such as monocyte chemoattractant protein-1, but only weakly correlated with sICAM-1 and sVCAM-1. In multivariate analyses, sESAM was independently associated with prevalent CAC (OR 1.2 per SD increase, 95% CI 1.1–1.3; p=0.005), AWT (p=0.035), and AC (p=0.006), but not APB (p=0.15). In contrast, no independent associations were observed between sICAM-1 or sVCAM-1 and any of the atherosclerosis phenotypes.
In this first reported clinical study of sESAM in humans, sESAM levels were independently associated with CAC, AWT, and AC, while sICAM-1 and sVCAM-1 were not. These findings support a unique role of this cellular adhesion molecule in atherosclerosis and suggest the need for further exploration of sESAM as a predictive biomarker and potential mediator of atherosclerosis.
Inflammation; Adhesion molecules; Atherosclerosis; Aortic compliance; Coronary calcium; Biomarkers
Atherogenesis is a chronic inflammatory process in which intercellular adhesion molecule 1 (ICAM-1) plays a critical role. Circulating soluble ICAM-1 (sICAM-1) is thought to be the result of cleavage of membrane-bound ICAM-1 and its concentration in serum/plasma has been shown to be heritable. Genome-wide linkage scans were conducted for quantitative trait loci influencing sICAM-1. Phenotype and genetic marker data were available for 2,617 white and 531 black individuals in the NHLBI Family Heart Study follow-up examination. Heritability for sICAM-1 was 0.39 in whites and 0.59 in blacks. Significant linkage was observed on chromosome 19 (LOD = 4.0 at 14 cM) in whites near the ICAM gene cluster that includes the structural gene for ICAM-1. The T-allele of ICAM-1 SNP rs5491 has been strongly associated with the specific sICAM-1 assay we used in our study. Through additional genotyping we were able to rule out rs5491 as the cause of the linkage finding. This study provides preliminary evidence linking genetic variation in the ICAM-1 structural gene to circulating sICAM-1 levels.
Intercellular adhesion molecule-1; Linkage (Genetics); ICAM gene cluster; inflammation; atherosclerosis
This study assessed the cross-sectional association between coronary artery calcification (CAC) and myocardial perfusion in an asymptomatic population.
Clinical studies showed that the prevalence of stress-induced ischemia increased with CAC burden among patients with coronary heart disease (CHD). Whether an association between CAC and myocardial perfusion exists in subjects without a history of CHD remains largely unknown.
A total of 222 men and women, ages 45 to 84 years old and free of CHD diagnosis, in the Minnesota field center of the MESA (Multi-Ethnic Study of Atherosclerosis) were studied. Myocardial blood flow (MBF) was measured using magnetic resonance imaging during rest and adenosine-induced hyperemia. Perfusion reserve was calculated as the ratio of hyperemic to resting MBF. Agatston CAC score was determined from chest multidetector computed tomography.
Mean values of hyperemic MBF and perfusion reserve, but not resting MBF, were monotonically lower across increasing CAC levels. After adjusting for age and gender, odds ratios (95% confidence intervals) of reduced perfusion reserve (<2.5) for subjects with CAC scores of 0, 0.1 to 99.9, 100 to 399, and ≥400 were 1.00 (reference), 2.16 (0.96 to 4.84), 2.81 (1.04 to 7.58), and 4.99 (1.73 to 14.4), respectively. Further adjustment for other coronary risk factors did not substantially modify the association. However, the inverse association between perfusion reserve and CAC attenuated with advancing age (p for interaction < 0.05).
Coronary vasodilatory response was associated inversely with the presence and severity of CAC in asymptomatic adults. Myocardial perfusion could be impaired by or manifest the progression to subclinical coronary atherosclerosis in the absence of clinical CHD.
Background and Aims
While a diet rich in anti-oxidant has been favorably associated with coronary disease and hypertension, limited data have evaluated the influence of such diet on subclinical disease. Thus, we sought to examine whether chocolate consumption is associated with calcified atherosclerotic plaque in the coronary arteries (CAC).
In a cross-sectional design, we studied 2,217 participants of the NHLBI Family Heart Study. Chocolate consumption was assessed by a semi-quantitative food-frequency questionnaire and CAC was measured by cardiac CT. We defined prevalent CAC using an Agatston score of at least 100 and fitted generalized estimating equations to calculate prevalence odds ratios of CAC.
There was an inverse association between frequency of chocolate consumption and prevalent CAC. Odds ratios (95% CI) for CAC were 1.0 (reference), 0.94 (0.66-1.35), 0.78 (0.53-1.13), and 0.68 (0.48-0.97) for chocolate consumption of 0, 1-3 times per month, once per week, and 2+ times per week, respectively (p for trend 0.022), adjusting for age, sex, energy intake, waist-hip ratio, education, smoking, alcohol consumption, ratio of total-to-HDL-cholesterol, non-chocolate candy, and diabetes mellitus. Controlling for additional confounders did not alter the findings. Exclusion of subjects with coronary heart disease or diabetes mellitus did not materially change the odds ratio estimates but did modestly decrease the overall significance (p = 0.07).
These data suggest that chocolate consumption might be inversely associated with prevalent CAC.
Chocolate; diet; epidemiology; coronary calcium; subclinical disease
BACKGROUND AND OBJECTIVES:
The initial step in atherosclerosis is the adhesion of leukocytes to activated endothelial cells mediated by intercellular adhesion molecule-1 (ICAM-1). This study aimed to investigate the association of K469E polymorphism of the ICAM-1 gene and soluble ICAM-1 (sICAM-1) serum level with coronary heart disease (CHD) in Egyptian subjects.
PATIENTS AND METHODS:
Using a case-control design, we studied 100 patients with CHD, including 73 patients with acute myocardial infarction (MI) and 27 with unstable angina (UA). The control group consisted of 50 healthy subjects with normal left ventricular function. All participants were genotyped for the ICAM-1 polymorphism by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Serum sICAM-1 was measured by enzyme-linked immunoassay (ELISA).
In CHD patients, the frequencies of K genotype (KK and EK) were significantly higher when compared to controls (P<.001) and were associated with an increased risk of disease development (OR=3.8, 95% CI: 1.7 to 8.5; P=.001). K genotype frequencies in patients with MI showed no significant difference when compared to patients with UA (P= .121). Serum sICAM-1 levels were comparable between CHD patients and controls (P= .37) and between MI and UA patients (P=.23). There were no significant differences in sICAM-1 levels among patients with different genotypes (P=.532). Men presented with higher sICAM-1 levels than women (P=.004).
ICAM-1 gene polymorphism in codon 469 is associated with a risk for CHD development in Egyptian subjects. Serum sICAM-1 is not influenced by this polymorphism and is not necessarily elevated in CHD.
Even among asymptomatic people at low risk (<10%) by Framingham Risk Score (FRS), high coronary artery calcium (CAC) scores signify higher predicted risk of coronary heart disease (CHD) events. We sought to determine non-invasive factors (without radiation exposure) significantly associated with CAC in low-risk, asymptomatic persons. In a cross-sectional analysis, we studied 3046 participants from MESA at low 10-year predicted risk (FRS <10%) for CHD events. Multivariable logistic regression was used to assess the association of novel markers with presence of any CAC (CAC >0) and advanced CAC (CAC ≥ 300). CAC >0 and CAC ≥ 300 were present in 30% and 3.5% of participants, respectively. Factor VIIIc, fibrinogen and sICAM were each associated with CAC presence (P ≤ 0.02); and C-reactive protein, D-dimer and carotid intima-media thickness (CIMT) with advanced CAC (P ≤ 0.03). The base model combining traditional risk factors had excellent discrimination for advanced CAC (C-statistic, 0.808). Addition of the 2 best-fit models combining biomarkers plus/minus CIMT improved the c-statistics to 0.822 and 0.820, respectively. All 3 models calibrated well, but were similar in estimating individual risk probabilities for advanced CAC (prevalence = 9.97%, 10.63% and 10.10% in the highest quartiles of predicted probabilities versus 0.26%, 0.26% and 0.26% in the lowest quartiles, respectively). In conclusion, in low risk individuals, traditional risk factors alone predicted advanced CAC with high discrimination and calibration. Biomarker combinations +/− CIMT were also significantly associated with advanced CAC, but improvement in prediction and estimation of clinical risk were modest compared to traditional risk factors alone.
coronary calcium; biomarkers; novel markers; low-risk; risk factors
Short stature is associated with increased risk of coronary heart disease (CHD); although the mechanisms for this relationship are unknown, shared genetic factors have been proposed. Subclinical atherosclerosis, measured by coronary artery calcification (CAC), is associated with CHD events and represents part of the biological continuum to overt CHD. Many molecular mechanisms of CAC development are shared with bone growth. Thus, we examined whether there was evidence of shared genes (pleiotropy) between adult stature and CAC.
877 asymptomatic white adults (46% men) from 625 families in a community-based sample had computed tomography measures of CAC. Pleiotropy between height and CAC was determined using maximum-likelihood estimation implemented in SOLAR.
Adult height was significantly and inversely associated with CAC score (P=0.01). After adjusting for age, sex, and CHD risk factors, the estimated genetic correlation between height and CAC score was -0.37 and was significantly different than 0 (P=0.001) and -1 (P<0.001). The environmental correlation between height and CAC score was 0.60 and was significantly different than 0 (P=0.024).
Further studies of shared genetic factors between height and CAC may provide important insight into the complex genetic architecture of CHD, in part through increased understanding of the molecular pathways underlying the process of both normal growth and disease development. Bivariate genetic linkage analysis may provide a powerful mechanism for identifying specific genomic regions associated with both height and CAC.
Genetics; Atherosclerosis; Calcium; Imaging; Stature
Soluble intercellular adhesion molecule-1 (sICAM-1) is a transmembrane protein involved in the migration and adhesion of leukocytes to the vascular endothelium. While some studies indicate that elevated baseline sICAM-1 levels predict cardiovascular events, most of these studies were done in men; moreover, uncertainty exists regarding whether sICAM-1 levels predict vascular events consistent with acute thrombosis versus atherosclerotic disease progression.
Methods and Results
In this prospective evaluation of 23, 984 apparently healthy women, we measured sICAM-1 levels and followed participants for the development of cardiovascular (CVD) endpoints typically associated with atherosclerotic disease progression with resultant vessel narrowing (percutaneous transluminal angioplasty and coronary artery bypass grafting) and endpoints typically associated with vascular thrombosis and vessel occlusion (myocardial infarction, ischemic stroke and death from a coronary cause). During a mean follow-up of 10 years, there were 741 events. For vascular events indicative of coronary atherosclerotic disease progression with luminal narrowing, Cox-proportional hazards models revealed an increase in vascular event rates from the lowest to highest quintile of baseline sICAM-1 after adjustment for CVD risk factors [Hazard Ratios (HR) 1.0, 1.4, 1.1, 1.6, 1.6, p trend=0.008]. By contrast, for endpoints reflective of acute vessel thrombosis, we found no association with sICAM-1 levels [HR for myocardial infarction (MI): 1.0, 1.2, 0.9, 1.2, 1.0, p trend=0.7; HR for stroke (CVA): 1.0, 0.9, 1.0, 1.0, 1.1, p trend = 0.6; HR for cardiovascular death: 1.0, 0.9, 0.7, 0.7, 0.8, p trend =0.7] except among smokers (RR= 1.0, 1.4, 2.8, 3.8, 3.7, p=0.007).
Among women without a history of cardiovascular disease, sICAM-1 levels are predictive of CVD events that reflect coronary atherosclerotic disease progression and vessel narrowing, but not those events associated with acute thrombosis/vessel occlusion.
Cellular adhesion molecule; Cardiovascular disease; Women
To measure levels of high-mobility group box −1 (HMGB1) and soluble receptor for advanced glycation end products (sRAGE) in the vitreous fluid from patients with proliferative diabetic retinopathy (PDR) and to correlate their levels with clinical disease activity and the levels of the inflammatory biomarkers monocyte chemoattractant protein-1 (MCP-1), soluble intercellular adhesion molecule-1 (sICAM-1), interleukin-1β (IL-1β), and granulocyte macrophage colony-stimulating factor (GM-CSF). In addition, we examined the expression of HMGB1 in the retinas of diabetic mice.
Vitreous samples from 29 PDR and 17 nondiabetic patients were studied by enzyme-linked immunosorbent assay. Retinas of mice were examined by immunofluorescence analysis and western blotting.
HMGB1 was detected in all vitreous samples and sRAGE was detected in 5 PDR samples. IL-1β was detected in 3PDR samples and GM-CSF was not detected. Mean HMGB1 levels in PDR with active neovascularization were twofold and threefold higher than that in inactive PDR and nondiabetic patients, respectively. Mean HMGB1 levels in PDR patients with hemorrhage were significantly higher than those in PDR patients without hemorrhage and nondiabetic patients (p=0.0111). There were significant correlations between levels of HMGB1 and levels of MCP-1 (r=0.333, p=0.025) and sICAM-1 (r=0.548, p<0.001). HMGB1 expression was also upregulated in the retinas of diabetic mice.
Subclinical chronic inflammation might contribute to the progression of PDR.
Higher plasma concentrations of soluble adhesion molecules have been shown to be associated with increased risk of cardiovascular events. We investigated the associations of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) with the ankle-brachial index (ABI), a measure of peripheral arterial disease (PAD), in a bi-ethnic cohort of adults without known coronary heart disease or stroke.
Participants included 1102 blacks (63 y, 74% women) and 1013 non-Hispanic whites (58 y, 59% women) belonging to hypertensive sibships. Plasma concentrations of sICAM-1 and sVCAM-1 were measured using high-sensitivity immunoassays. ABI was measured using a standard protocol and PAD was defined as ABI <0.9. Generalized estimating equations (GEE) were used to assess whether sICAM-1 and sVCAM-1 were associated with ABI and with PAD, independent of conventional risk factors.
After adjustment for conventional risk factors, blacks with sICAM-1 and sVCAM-1 concentrations in the highest quartiles had lower ABI than those in the lowest quartiles (mean ABI: 1.02 vs. 0.98, P=0.007 and 1.02 vs. 0.99, P=0.003, respectively). In multivariable logistic regression analysis, sICAM-1 and sVCAM-1 concentrations in the highest quartiles were each associated with a higher odds ratio of having PAD, compared with the lowest quartiles: odds ratio (95% CI): 5.2 (1.8–15.2) and 2.2 (1.0–4.8), respectively. In contrast, in non-Hispanic whites, sICAM-1 and sVCAM-1 concentrations were not associated with ABI or with PAD.
Higher sICAM-1 and sVCAM-1 concentrations were independently associated with a lower ABI and with PAD in blacks, but not in non-Hispanic whites.
ethnicity; sICAM-1; sVCAM-1; ankle-brachial index; peripheral arterial disease; hypertension
Intercellular adhesion molecule-1 (ICAM-1) is a cytoadhesion molecule implicated in the pathogenesis of Plasmodium falciparum malaria. Elevated levels of soluble ICAM-1 (sICAM-1) have previously been reported with increased malaria disease severity. However, studies have not yet examined both sICAM-1 concentrations and monocyte ICAM-1 expression in the same cohort of patients. To better understand the relationship of soluble and cellular ICAM-1 measurements in malaria, both monocyte ICAM-1 expression and sICAM-1 concentration were measured in children with P. falciparum infection exhibiting a spectrum of clinical severity.
Samples were analysed from 160 children, aged 0.5 to 10.8 years, with documented P. falciparum malaria in Kampala, Uganda. The patients belonged to one of three pre-study defined groups: uncomplicated malaria (UM), severe non-fatal malaria (SM-s), and fatal malaria (SM-f). Subset analysis was done on those with cerebral malaria (CM) or severe malaria anaemia (SMA). Monocyte ICAM-1 was measured by flow cytometry. sICAM-1 was measured by enzyme immunoassay.
Both sICAM-1 and monocyte cell-surface ICAM-1 followed a log-normal distribution. Median sICAM-1 concentrations increased with greater severity-of-illness: 279 ng/mL (UM), 462 ng/mL (SM-s), and 586 ng/mL (SM-f), p < 0.0001. sICAM-1 levels were not statistically different among children with CM compared to SMA. Monocyte ICAM-1 expression was significantly higher in cases of UM compared with SM-s or SM-f (p < 0.001) and was higher among the subset of patients with CM compared with SMA, p < 0.0014. The combination of sICAM-1 and cellular ICAM-1 identified distinct categories of patients (UM with low sICAM-1 and higher monocyte ICAM-1, CM with both sICAM-1 and monocyte ICAM-1 high, and SMA with sICAM-1 high but monocyte ICAM-1 low).
In this cohort of children with P. falciparum malaria, sICAM-1 levels were associated with severity-of-illness. Patients with UM had higher monocyte ICAM-1 expression consistent with a role for monocyte ICAM-1 in immune clearance during non-severe malaria. Among the subsets of patients with either SMA or CM, monocyte ICAM-1 levels were higher in CM, consistent with the role of ICAM-1 as a marker of cytoadhesion. Categories of disease in pediatric malaria may exhibit specific combinations of soluble and cellular ICAM-1 expression.
Major depression and depressive symptoms are associated with cardiovascular disease (CVD), but the impact of depression on early atherogenesis is less well known, particularly in women and minorities. This study examined whether depressive symptoms are associated with progression of coronary artery calcification (CAC) among women at mid-life.
The Study of Women’s Health Across the Nation (SWAN) is a longitudinal, multi-site study assessing health and psychological factors in mid-life women. An ancillary study (SWAN Heart) evaluated subclinical atherosclerosis in women who reported no history of CVD or diabetes. In 346 women, CAC was measured twice by electron beam computed tomography, an average of 2.3 years apart. Progression, defined as an increase by 10 Agatston units or more, was analyzed using relative risk regression. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression (CES-D) Scale.
Progression of CAC was observed in 67 women (19.1%). Each 1–SD higher CES-D score at baseline related to a 25% increased risk of CAC progression [RR 1.25, CI 1.06–1.47, p=0.007], adjusting for age, time between scans, ethnicity, education, menopausal status, and known CVD risk factors. This risk was similar to the risk induced by BMI [RR 1.31, CI 1.11–1.54, p=0.001] and systolic blood pressure [RR 1.28, CI 1.06–1.55, p=0.01].
Depressive symptoms were independently associated with progression of CAC in this cohort of midlife women. Depressive symptoms may represent a risk factor that is potentially modifiable for early prevention of CVD in women.
atherosclerosis; coronary calcium; women; depression; epidemiology
To examine whether the relationship between cardiovascular disease risk factors and coronary artery calcification (CAC) is modified by race among those with diabetes.
Data were pooled data from three studies (Multi-Ethnic Study of Atherosclerosis, Family Heart Study, Diabetes Heart Study) for a total of 835 blacks and 1122 whites with diabetes. CAC was quantified by cardiac computed tomography and risk factors were obtained using standard methods. Regression models examined the relationship between risk factors and presence and quantity of CAC.
The average age of the cohort was 60 years; 57% were women. Presence of CAC was lower in blacks compared to whites (odds ratio = 0.22 for men, 0.57 for women, p<0.01). HbA1c, duration of diabetes, LDL, smoking, and BMI were independently associated with presence of CAC; HDL, triglycerides and CRP were not. Race did not modify these associations. Adjustment for multiple risk factors did not explain the race disparity in CAC.
CAC was reduced in blacks compared to whites in persons with diabetes. This effect was most pronounced in men. The relationship between risk factors and CAC did not differ between races. Racial differences in CAC are likely due to unmeasured risk factors and/or genetic susceptibility.
coronary artery disease; diabetes mellitus; epidemiology; African Americans; cohort studies
Helicobacter pylori causes numerous extragastric manifestations, including coronary heart disease. The coronary artery calcification (CAC) score, measured using computed tomography (CT) has been used as a screening test for coronary atherosclerosis. This study investigated the association between H. pylori seropositivity and CAC scores in a screening population.
Patients who underwent a health checkup between October 2003 and July 2007 and who did not have a history of ischemic heart disease were enrolled in the study. Subjects were screened with a multidetector CT scan to determine the CAC score and for anti-H. pylori antibody immunoglobulin G; traditional risks for coronary heart disease were evaluated using a structured questionnaire, anthropometric measurements, and laboratory tests.
Of the 2,029 subjects enrolled (1,295 males), 1,214 (59.8%) subjects were H. pylori positive and 815 were H. pylori negative. There were no significant differences in the baseline characteristics of the seropositive and seronegative patients. When the CAC presence or absence scores were considered, multivariate analysis revealed that H. pylori seropositivity was statistically associated with the presence of CAC and that this association was stronger in the mild CAC score category.
H. pylori seropositive patients are at a higher risk for coronary atherosclerosis regardless of traditional cardiovascular risk factors. This association is particularly applicable for early coronary atherosclerosis.
Helicobacter pylori; Seropositivity; Coronary atherosclerosis; Screening
AIM: To study the levels of serum soluble intercellular adhesion molecule-1 (sICAM-1), plasma D-lactate and diamine oxidase (DAO) in patients with inflammatory bowel disease (IBD), and the potential clinical significance.
METHODS: Sixty-nine patients with IBD and 30 healthy controls were included in this study. The concentration of sICAM-1 was detected with enzyme-linked immunosorbent assay, the level of D-lactate and DAO was measured by spectroscopic analysis, and the number of white blood cells (WBC) was determined by routine procedure.
RESULTS: The levels of sICAM-l, DAO, and WBC in IBD patients were significantly higher than those in the control group (P < 0.01). sICAM-l in IBD patients was found to be closely related to the levels of DAO and D-lactate (212.94 ± 69.89 vs 6.35 ± 2.35, P = 0.000), DAO 212.94 ± 69.89 vs 8.65 ± 3.54, P = 0.000) and WBC (212.94 ± 69.89 vs 7.40 ± 2.61, P = 0.000), but no significant difference was observed between patients with ulcerative colitis and patients with Crohn’s disease. The post-treatment levels of sICAM-l, D-lactate and WBC were significantly lower than before treatment (sICAM-l 206.57 ± 79.21 vs 146.21 ± 64.43, P = 0.000), (D-lactate 1.46 ± 0.94 vs 0.52 ± 0.32, P = 0.000) and (WBC 7.24 ± 0.2.33 vs 5.21 ± 3.21, P = 0.000).
CONCLUSION: sICAM-1, D-lactate and DAO are closely related to the specific conditions of IBD, and thus could be used as a major diagnostic index.
Inflammatory bowel diseases; Intercellular adhesion molecule-1; D-lactate; Diamine oxidase
Body fat distribution may be differentially associated with subclinical cardiovascular disease. We sought to examine whether body mass index (BMI), waist circumference (WC), subcutaneous (SAT) and visceral (VAT) adipose tissue are associated with either prevalence of coronary (CAC) or abdominal aortic calcium (AAC) in the Framingham Heart Study. Participants (n=3130, mean age 52 years, 49% women) free of clinical cardiovascular disease from the Framingham Heart Study underwent multidetector computed tomography assessment for quantification of subcutaneous and visceral fat volume and coronary and abdominal aortic calcification. Coronary artery calcification (CAC) and abdominal aortic calcification (AAC) were examined in relation to BMI, WC, SAT, and VAT in age- sex- and multivariable-adjusted models. All measures of adiposity were associated with CAC in age-sex adjusted models (all p-values<0.008). All relations were attenuated in multivariable models (all p-value>0.14). BMI, WC, and VAT (but not SAT) were associated with abdominal aortic calcification in age- sex-adjusted models (all p-values<0.012). However, all relations were attenuated in multivariable models (all p-values>0.23). Similar findings were observed in quartile-based analyses. In conclusion, general measures of obesity and measures of central abdominal fat are related to CAC and AAC. However, these cross-sectional associations are attenuated by cardiovascular disease risk factors, possibly because they may mediate the association between adiposity measures and subclinical cardiovascular disease.
visceral fat; subcutaneous fat; obesity; calcification; epidemiology; risk factors
Chlamydia pneumoniae is a respiratory pathogen that has been associated with chronic inflammatory diseases such as asthma and atherosclerosis. Recent isolation of C. pneumoniae from human carotid and coronary atheromas provides additional support for a role of this organism in atherogenesis. We characterized the coronary strain C. pneumoniae A-03 by sequence analysis of the major outer membrane protein gene (omp1). In addition, the in vitro activities of A-03 and three respiratory strains of C. pneumoniae (BAL-16, TW-183, and T-2634) were examined in infected human umbilical vein endothelial cells (HUVEC) by analysis of the production of interleukin-8 (IL-8), monocyte chemotactic protein 1 (MCP-1), and soluble intercellular cell adhesion molecule 1 (sICAM-1). Sequence analysis of omp1 of C. pneumoniae A-03, compared to prototype strains TW-183 and AR-39, revealed five nucleotide changes resulting in nonsynonymous codons. Of interest was a nonconservative amino acid substitution (Ser to Pro) in position 61 of variable segment 1. In vitro, the extent of MCP-1, IL-8, and sICAM-1 production was dependent on the C. pneumoniae strain examined at low multiplicities of infection following 24 h of incubation. Strain A-03 displayed the lowest stimulatory activity in infected HUVEC, while T-2634 induced the highest levels of MCP-1, IL-8, and sICAM-1 among all strains examined. Heat-inactivated C. pneumoniae failed to stimulate production of these proteins by all strains tested. In contrast, only partial inhibition was observed by UV-inactivated organisms. Results from this study demonstrate that unlike prototype respiratory strains of C. pneumoniae, the coronary strain A-03 displays divergence in the omp1 gene. In addition, the stimulation of chemokines and adhesion molecules involved in the recruitment of leukocytes to sites of inflammation by C. pneumoniae may be important in the pathogenesis of diseases associated with this organism, including atherosclerosis.
Modern imaging technology allows us the visualization of coronary artery calcification (CAC), a marker of subclinical coronary atherosclerosis. The prevalence, quantity, and risk factors for CAC were compared between two studies with similar imaging protocols but different source populations: the Multi-Ethnic Study of Atherosclerosis (MESA) and the Heinz Nixdorf Recall Study (HNR).
Methods and results
The measured CAC in 2220 MESA participants were compared with those in 3126 HNR participants with the inclusion criteria such as age 45–75 years, Caucasian race, and free of baseline cardiovascular disease. Despite similar mean levels of CAC of 244.6 among participants in MESA and of 240.3 in HNR (P = 0.91), the prevalence of CAC > 0 was lower in MESA (52.6%) compared with HNR (67.0%) with a prevalence rate ratio of CAC > 0 of 0.78 [95% confidence interval (CI): 0.72–0.85] after adjustment for known risk factors. Consequently, among participants with CAC > 0, the participants in MESA tended to have higher levels of CAC than those in HNR (ratio of CAC levels: 1.39; 95% CI: 1.19–1.63), since many HNR participants have small (near zero) CAC values.
The CAC prevalence was lower in the United States (MESA) cohort than in the German (HNR) cohort, which may be explained by more favourable risk factor levels among the MESA participants. The predictors for increased levels of CAC were, however, similar in both cohorts with the exception that male gender, blood pressure, and body mass index were more strongly associated in the HNR cohort.
Epidemiology; Atherosclerosis; Coronary artery calcium; Risk factors; Screening
Comparison of atherosclerosis and its risk factors among diverse populations may provide insights into the pathogenesis of the disease. We investigated differences in traditional coronary artery disease (CAD) risk factors and presence and quantity of coronary artery calcification (CAC), a marker of subclinical coronary atherosclerosis, between two diverse non-Hispanic white populations living in the US.
Methods and Results
Members of the Old Order Amish (OOA), a unique culture with a physically active rural lifestyle who rarely use prescription medications, were compared to another non-Hispanic white population with a more typical US lifestyle, Epidemiology of Coronary Artery Calcification (ECAC) Study participants from Rochester, Minnesota. Although age- and sex-adjusted presence and quantity of CAC in those with detectable CAC were similar between study groups, there were significant differences in the distribution of many traditional CAD risk factors. OOA had significantly less abdominal adiposity and history of cigarette smoking but a less advantageous lipid profile than ECAC participants. Importantly, after adjusting for CAD risk factors, presence of CAC and quantity of CAC among those with detectable CAC were significantly higher among OOA than ECAC participants.
Identification of factors contributing to differences in subclinical disease across groups could increase our understanding of mechanisms for coronary atherosclerosis.
Coronary Artery Calcification; Atherosclerosis; Epidemiology; Risk Factors; Imaging; Lifestyle
Although occupational factors have been associated with symptomatic ischemic heart disease, associations between job strain (low decision latitude and high psychological demands) and risk for subclinical atherosclerosis measured by coronary artery calcium (CAC) has not been assessed.
CAC was measured in 3,695 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study in 2000-01 and 2005-06. Job characteristics measured by the demand-control model (psychological demands and decision latitude) were assessed in 1987-88 and in 1995-96. Associations between non-zero CAC and prior job characteristics and occupation were assessed, adjusting for potential covariates.
Low decision latitude, high psychological demands, and job strain at either earlier exam were not associated with a positive CAC, nor were changes in the status of these job characteristics between 1987/1988 and 1995/1996. However, participants whose jobs were classified as managerial or professional in 1995/1996 were less likely to have a positive CAC than those in laborer occupations.
Job strain measured at two earlier time points was not related to the presence of CAC at follow-up 5 to 18 years later. The association between earlier occupation and CAC may reflect socioeconomic differences or other occupational, industrial, or labor market characteristics.
coronary atherosclerosis; occupation; psychological stress; socioeconomic factors
Certain bone marrow-derived cell populations, termed endothelial progenitor cells (EPCs), have been reported to possess angiogenic activity. Experimental data suggest that depletion of these angiogenic cell populations may promote atherogenesis, but limited data are available regarding their relation to subclinical atherosclerotic cardiovascular disease in humans.
Methods and Results
We studied 889 participants of the Framingham Heart Study who were free of clinically apparent cardiovascular disease (mean age, 65 years; 55% women). Participants underwent EPC phenotyping using an early outgrowth colony forming unit (CFU) assay and cell surface markers. Participants also underwent non-contrast multidetector computed tomography to assess the presence of subclinical atherosclerosis, as reflected by burden of coronary artery calcification (CAC) and abdominal aortic calcification (AAC). In this study sample, we examined the association of EPC-related phenotypes with both CAC and AAC. Across decreasing tertiles of CFU, there was a progressive increase in median CAC and AAC scores. In multivariable analyses adjusting for traditional cardiovascular risk factors, each standard deviation increase in CFU was associated with an approximately 16% decrease in CAC (P=0.02) and 17% decrease in AAC (P=0.03). In contrast, neither CD34+/KDR+ nor CD34+ variation were associated with significant differences in coronary or aortic calcification.
In this large, community-based sample of men and women, lower CFU number was associated with a higher burden of subclinical atherosclerosis in the coronary arteries and aorta. Decreased angiogenic potential could contribute to the development of atherosclerosis in humans.
endothelial progenitors; atherosclerosis; risk factors; epidemiology
Hypertension during pregnancy (HDP) increases the risk of future coronary heart disease (CHD), but it is unknown whether this association is mediated by renal injury. Reduced renal function is both a complication of HDP and a risk factor for CHD.
Logistic regression models were fit to examine the association between a history of HDP and the presence and extent of coronary artery calcification (CAC), a measure of subclinical coronary artery atherosclerosis, in 498 women from the Epidemiology of Coronary Artery Calcification Study (mean age 63.3 ± 9.3 years).
Fifty-two (10.4%) women reported a history of HDP. After adjusting for age at time of study participation, HDP was associated with increased serum creatinine later in life (p = 0.014). HDP was positively associated with the presence of CAC after adjusting for age at time of study participation (OR = 2.7, 95% CI 1.4-5.4). This association was slightly attenuated with adjustment for body size and blood pressure (OR = 2.4, 95% CI 1.2-4.9) but was not further attenuated with adjustment for serum creatinine and urinary albumin/creatinine ratio (OR = 2.6, 95% CI 1.3-5.3). Results were similar for CAC extent.
HDP may increase a woman's risk of future CHD beyond traditional risk factors and renal function. Women with a history of HDP should be monitored for potential increased risk of CHD as they age.
Circulating soluble intercellular adhesion molecule-1 (sICAM-1) is a biochemical marker of inflammation. We performed variance-components-based quantitative genetic analyses in SOLAR of sICAM-1 in 1170 individuals from Mexican American families in the San Antonio Family Heart Study. The trait is heritable (h2 = 0.50±0.06, P<10-6). Multipoint linkage analysis using a ∼10-cM microsatellite map revealed a region on Chromosome 19p near marker D19S586 showing strong evidence of linkage for sICAM-1 (empirically adjusted univariate-equivalent LOD = 4.95), coincident with the structural gene ICAM1. This region has been identified previously as a QTL for inflammatory, autoimmune, and metabolic syndrome traits. There is significant evidence (P=0.0023) of locus heterogeneity for sICAM-1 in this sample: a subset of pedigrees contributes most of the linkage signal for sICAM-1 on Chromosome 19, suggesting a logical focus for future genetic dissection of the trait.
ICAM-1; inflammation; genetic heterogeneity; genome scan; quantitative trait locus; Mexican Americans