Objectives

A cluster of metabolic abnormalities termed metabolic syndrome (MetS) is associated with vascular endothelial dysfunction and oxidative internal milieu. We examined whether the association of MetS with subclinical atherosclerosis is explained by biomarkers of endothelial damage and oxidative stress.

Methods

MESA is a population based study of 45-84 year old individuals of four US ethnicities without clinical cardiovascular disease. A random sample of 997 MESA participants had data on the following biomarkers: von Willebrand Factor, soluble intercellular adhesion molecule-1 (sICAM1), CD40 ligand, soluble thrombomodulin, E-selectin, and oxidized LDL (oxLDL). We examined whether the associations of MetS with B-mode ultrasound-defined common and internal carotid intimal medial thickness (IMT) and coronary artery calcium (CAC) measured using computerized tomography were explained by the biomarkers using multiple regression methods.

Results

MetS was associated with higher levels of each of the biomarkers (p<0.001, CD40L suggestive association p=0.004), with greater IMT (p<0.001), and with greater extent of CAC in those in whom CAC was detectable (p=0.01). The association of MetS with measures of subclinical atherosclerosis remained unchanged after adjustment for the biomarkers. After adjusting for MetS, oxLDL was suggestively associated with greater prevalence of detectable CAC (p=0.005) and thicker internal carotid IMT (p=0.002), while sICAM-1was significantly associated with greater prevalence of detectable CAC (p=0.001).

Conclusions

The association of MetS with subclinical atherosclerosis was independent of its association with biomarkers of endothelial damage and oxidative stress, suggesting that metabolic abnormalities and oxidative endothelial damage may lead to atherosclerotic disease through distinct mechanisms.

Background

In cross-sectional analyses, C-reactive protein (CRP) levels are inversely related to levels of kidney function. The relationship between kidney function and subsequent changes in CRP is unknown.

Methods

We studied 4,364 individuals from the Cardiovascular Health Study, a longitudinal cohort of community-dwelling older adults. Baseline eGFRcys was estimated using cystatin C. CRP was measured at baseline and after 3 and 7 years of follow-up; slopes of change in CRP were calculated.

Results

The mean (SD) age of the cohort was 72 (5.2) years; mean (SD) eGFRcys was 78.9 (18.4) ml/min/1.73 m2. The median (interquartile range IQR) baseline CRP was 2.39 (1.22, 4.33) mg/l; the median (IQR) yearly change in CRP was −0.0051 (−0.020 to 0.27) mg/l/year. After adjustment for demographic characteristics and the initial level of CRP, each standard deviation lower baseline eGFR was associated with a small and non-significant yearly increase in CRP (0.032 mg/l/year; 95% CI: −0.005 to 0.070, p = 0.094).

Conclusions

We did not find a relationship between eGFR and subsequent changes in CRP. The association between kidney function and CRP in cross-sectional analyses may reflect unmeasured confounding by atherosclerosis; alternatively, the burden of comorbidity and interval mortality in this population may have masked a stronger longitudinal association between kidney function and change in CRP. Further study in younger populations may clarify whether impaired kidney function leads to change in inflammation over time.

Several models for estimating risk of incident diabetes in US adults are available. The authors aimed to determine the discriminative ability and calibration of published diabetes risk prediction models in a contemporary multiethnic cohort. Participants in the Multi-Ethnic Study of Atherosclerosis without diabetes at baseline (2000–2002; n = 5,329) were followed for a median of 4.75 years. The predicted risk of diabetes was calculated using published models from the Framingham Offspring Study, the Atherosclerosis Risk in Communities (ARIC) Study, and the San Antonio Heart Study. The mean age of participants was 61.6 years (standard deviation, 10.2); 29.3% were obese, 53.1% had hypertension, 34.9% had a family history of diabetes, 27.5% had high triglyceride levels, 33.8% had low high density lipoprotein cholesterol levels, and 15.3% had impaired fasting glucose. There were 446 incident cases of diabetes (fasting glucose level ≥126 mg/dL or initiation of antidiabetes medication use) diagnosed during follow-up. C statistics were 0.78, 0.84, and 0.83 for the Framingham, ARIC, and San Antonio risk prediction models, respectively. There were significant differences between observed and predicted diabetes risks (Hosmer-Lemeshow goodness-of-fit chi-squared test for each model: P < 0.001). The recalibrated and best-fit models achieved sufficient goodness of fit (each P > 0.10). The Framingham, ARIC, and San Antonio models maintained high discriminative ability but required recalibration in a modern, multiethnic US cohort.

Objective

To examine associations between lipoprotein-associated phospholipase A2 (Lp-PLA2) antigen level (mass) and enzymatic activity (activity) and cardiovascular disease (CVD) in older adults.

Methods

We examined associations of Lp-PLA2 mass and activity with incident myocardial infarction (MI; n=508), stroke (n= 565) and CVD death (n=665) using Cox regressions adjusted for age, sex, ethnicity and CVD risk factors in 3,949 older adults, aged ≥ 65 years at baseline, from the Cardiovascular Health Study (CHS).

Results

Lp-PLA2 was associated with incident CVD events in these older adults. Hazard ratios (95% confidence intervals) for highest versus lowest tertiles of Lp-PLA2 mass were 1.49 (1.19–1.85) for MI, 1.21 (0.98–1.49) for stroke and 1.11 (0.92–1.33) for CVD death. The highest tertile of Lp-PLA2 activity was associated with MI (1.36; 1.09–1.70) and CVD death (1.23; 1.02–1.50). Combined Lp-PLA2 tertile 3 and CRP >3mg/l, compared to Lp-PLA2 tertile 1 and CRP <1 mg/l, was associated with MI (2.29; 1.49–3.52) for Lp-PLA2 mass and MI (1.66; 1.10–2.51) and CVD death (1.57; 1.08–2.26) for activity. For MI, both mass and activity added excess risk to elevated CRP alone (~20% excess risk) and activity added excess risk for CVD death (~12%).

Conclusion

Lp-PLA2 mass and activity were associated with incident CVD events in older adults in CHS. Lp-PLA2 and CRP were independent and additive in prediction of events. While associations were modest, these results support further exploration of Lp-PLA2 to identify older individuals at risk for CVD.

Objective

Inflammatory markers predict coronary heart disease (CHD). However, associations with coronary artery calcium (CAC), a marker of subclinical CHD, are not established.

Methods

We examined cross-sectional associations of C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen with CAC presence (Agatston score > 0 by computed tomography) in 6,783 Multi-Ethnic Study of Atherosclerosis (MESA) participants.

Results

In all participants, those in the highest, compared to lowest, quartile of CRP had a relative risk (RR, 95% confidence interval) of 1.13 (1.06-1.19; p<0.01) for CAC in age, sex and ethnicity adjusted models. For highest versus lowest quartiles, relative risks were 1.22 (1.15-1.30; p<0.01) for IL-6 and 1.18 (1.11-1.24; p<0.01) for fibrinogen. Adjusting for CHD risk factors (smoking, diabetes, blood pressure, obesity and dyslipidemia) attenuated RRs. RRs for CAC were 1.05 (0.99-1.12; p=0.63) for CRP, 1.12 (1.06-1.20; p<0.01) for IL-6 and 1.09 (1.02-1.16; p=0.01) for fibrinogen in multivariable adjusted models. Results were similar for men and women and across ethnic groups.

Conclusion

Inflammatory markers were weakly associated with CAC presence and burden in MESA. Our data support the hypothesis that inflammatory biomarkers and CAC reflect distinct pathophysiology.

Background

Inflammation may be an etiologic factor in congestive heart failure (CHF). Lipoprotein associated phospholipase A2 (Lp-PLA2) is an inflammation marker associated with vascular risk. One previous study showed an association of Lp-PLA2 activity with CHF risk, but there were only 94 CHF cases and Lp-PLA2 antigen, which is available clinically in the US, was not measured.

Methods and Results

We measured baseline Lp-PLA2 antigen and activity in 3991 men and women without baseline CHF or cardiovascular disease, participating in the Cardiovascular Health Study, a prospective observational study of adults ≥65 years old. Cox proportional hazards models adjusted for age, sex, clinic site, race, LDL and HDL cholesterol, body-mass index, systolic and diastolic blood pressure, hypertension, smoking status, pack-years and diabetes were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CHF. Further models adjusted for coronary disease events during follow up and C-reactive protein (CRP). 829 participants developed CHF over 12.1 years. Adjusted HRs for CHF with Lp-PLA2 in the fourth compared to first quartile, were 1.44 (CI 1.16–1.79) for Lp-PLA2 antigen and 1.06 (CI 0.84–1.32) for activity. Adjustment for incident coronary disease attenuated the HR for Lp-PLA2 antigen to 1.26 (CI 1.02–1.57), adjustment for CRP had minimal impact.

Conclusions

Lp-PLA2 antigen was associated with risk of future CHF in older people, independent of CHF and coronary risk factors, and partly mediated by coronary disease events. Further clinical and basic research is needed to better understand the role of Lp-PLA2 in CHF.

Cardioprotective effects of long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) and fish consumption have been observed. However, data on the specific associations of these dietary factors with inflammation and endothelial activation are sparse. We conducted a cross-sectional study of 5,677 men and women from the MESA cohort including African Americans, Caucasians, Chinese and Hispanics, aged 45-84 years, and free of clinical cardiovascular disease. Dietary information was collected by self-administered food frequency questionnaire. Multivariable linear regression analyses were used to examine relations between intake of LC n-3 PUFAs, non-fried fish and fried fish and biomarkers of inflammation and endothelial activation. LC n-3 PUFA intakes were inversely associated with plasma concentrations of interleukin-6 (IL-6, P=0.01) and matrix metalloproteinase-3 (MMP-3, P=0.03) independent of age, body mass index, physical activity, smoking, alcohol consumption and dietary variables. Non-fried fish consumption was found inversely related to C-reactive protein (CRP, P=0.045) and IL-6 (P<0.01); and fried fish was observed being inversely related to soluble intercellular adhesion molecules-1 (sICAM-1) (P<0.01) but not associated with other biomarkers after adjustment for potential confounders. In conclusion, this study suggests that dietary intakes of LC n-3 PUFAs and fish are inversely associated with concentrations of some biomarkers reflecting lower levels of inflammation and endothelial activation. These results may partially explain the cardioprotective effects of fish consumption.

Objective

We examined associations of pentraxin 3 (PTX3), a vascular inflammation marker, with incident cardiovascular disease (CVD) and all cause death.

Methods and Results

1,583 Cardiovascular Health Study participants free of prevalent CVD were included. Non-exclusive case groups were angina (n=476), myocardial infarction (MI; n=237), stroke (n=310), CVD death (n=282) and all cause death (n=772). 535 participants had no events. PTX3 levels were higher in those with subclinical CVD (1.90 ± 1.89 ng/ml) than those without (1.71 ± 1.88 ng/ml; p=0.001). Using Cox regression adjusted for age, sex and ethnicity, a standard deviation increase in PTX3 (1.89 ng/ml) was associated with CVD death (hazard ratio 1.11; 95% confidence interval 1.02–1.21) and all cause death (1.08; 1.02–1.15). PTX3 was not associated with angina (1.09; 0.98–1.20), MI (0.96; 0.81–1.12) or stroke (1.06; 0.95–1.18). Adding C-reactive protein (CRP) or CVD risk factors to the models had no significant effects on associations.

Conclusions

In these older adults, PTX3 was associated with CVD and all cause death independent of CRP and CVD risk factors. PTX3 likely reflects different aspects of inflammation than CRP and may provide insight into vascular health in aging and chronic diseases of aging that lead to death.

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.

Background

Inflammation markers and MetS are associated with risk of CHF. We evaluated whether combining inflammation markers and metabolic syndrome (MetS) provided additive information for incident congestive heart failure (CHF), and if incorporating inflammation markers to the MetS definition added prognostic information.

Methods and Results

We studied 4017 men and women ≥ 65 years old, without baseline CHF or diabetes, participating in the Cardiovascular Health Study, an observational study with 12.2 years follow-up and 966 cases of incident CHF. Baseline “C-reactive protein (CRP)-MetS” or “interleukin-6 (IL-6)-MetS” were defined as presence of 3 out of 6 components, with elevated CRP (≥3 mg/L) or IL-6 (≥2.21 pg/mL) as a 6th component added to ATPIII criteria. Cox models adjusted for CHF risk factors and incident coronary disease, were used to calculate HRs for CHF. MetS and elevated inflammation markers were independently associated with CHF risk (HRs, 95 % CI: 1.32, 1.16–1.51 for MetS; 1.53, 1.34–1.75 for CRP; 1.37, 1.19–1.55 for IL-6). There was a 20% relative excess risk attributed to the combination of MetS and CRP (95% CI −44% to 88%). CRP-MetS and IL-6-MetS definitions reclassified 18% and 13%, respectively of participants as MetS. Both CRP-MetS and IL-6-MetS increased risk of CHF by 60% compared to those without MetS.

Conclusion

MetS and inflammation markers provided additive information on CHF risk in this elderly cohort. Inflammation-incorporated MetS definitions identified more participants with the same risk level as ATPIII MetS. Considering inflammation markers and MetS together may be useful in clinical and research settings.

Summary

Telomere length has emerged as a marker of exposure to oxidative stress and aging. Race/ethnic differences in telomere length have been infrequently investigated. Leucocyte telomere length (LTL) was assessed 981 white, black and Hispanic men and women aged 45-84 years participating in the Multi-Ethnic Study of Atherosclerosis. Direct measurement and questionnaire were used to assess covariates. Linear regression was used to estimate associations of LTL with race/ethnicity and age after adjustment for sex, income, education, smoking, physical activity, diet, and body mass index. On average blacks and Hispanics had shorter telomeres than whites (adjusted mean differences (standard error) in T/S ratio compared to whites: -0.041 (0.018) for blacks and -0.044 (0.018) for Hispanics). Blacks and Hispanics showed greater differences in telomere length associated with age than whites (adjusted mean differences in T/S ratio per one year increase in age -0.0018, -0.0047, and -0.0055 in whites, blacks, and Hispanics respectively). Differences in age associations were more pronounced and only statistically significant in women. Race/ethnic differences in LTL may reflect the cumulative burden of differential exposure to oxidative stress (and its predictors) over the lifecourse.

Background:

Left Ventricular Hypertrophy (LVH) is associated with end-stage renal disease and chronic kidney disease, but the association of LVH with mild impairment in kidney function is not known. We hypothesized that mild and moderate reductions in kidney function, reflected in higher serum cystatin C concentrations, would be linearly associated with a higher prevalence of LVH.

Study Design:

Cross-sectional observational study.

Settings and Participants:

4,971 participants participating in baseline examinations in the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study with several sites in the U.S.

Predictor:

Cystatin C-based estimated glomerular filtration rate (eGFRcysC)

Outcomes:

LVH and left ventricular (LV) mass index.

Measurements:

Serum cystatin C and creatinine, LV mass obtained by magnetic resonance imaging (MRI). LVH cutoffs for males and females were defined by the upper 95th percentile of LV mass index of all MESA participants without hypertension.

Results:

LVH was distinctly more prevalent (>12%) only in the lowest two deciles of eGFRcysC (<75 ml/min/1.73 m2). When participants with stage III or higher chronic kidney disease (creatinine eGFR <60 ml/min/1.73 m2) were excluded, the odds for LVH increased for each lower category of eGFRcysC below 75 ml/min/1.73 m2: 1.6 the odds for LVH with an eGFRcysC between 60-75 ml/min/1.73 m2 (95% confidence interval 1.20-2.07, P = 0.001), and 2.0 the odds for an eGFRcysC <60 ml/min/1.73 m2 (1.03-3.75, P = 0.04), after adjustment for demographic factors, study site, diabetes, and smoking. The association of the a lower eGFRcysC with LVH was attenuated after further adjustment for hypertension.

Limitations:

Cross-sectional, rather than longitudinal design, lack of participants with more advanced kidney disease, lack of a direct measurement of glomerular filtration rate.

Conclusions:

Among subjects without CKD, eGFRcysC ≤ 75 ml/min/1.73 m2 was associated with a higher odds of LVH.

SUMMARY

Context

Statin use and type has been variably associated with impaired or improved cognitive performance.

Objective

To assess the association of statin use and type (lipophilic vs hydrophilic) and cognitive impairment

Design

Cross-sectional analysis of 24595 (7191 statin users and 17404 non-users) participants (age >45), from a population-based national cohort study (REasons for Geographic And Racial Differences in Stroke) enrolled from January 2003-October 2008 with over-sampling from the southeastern Stroke Belt, and African Americans.

Main Outcomes

Statin use and type were documented in participants’ homes by a trained health professional. Cognitive performance was assessed with a prior validated instrument of global cognitive status (Six-Item Screener). Cognitive impairment was defined as a score of < 4. .

Results

Overall, an association of cognitive impairment and statin use was observed (8.6% of users vs 7.7% or non-users had cognitive impairment p=.014) but, after adjusting for variables known to be associated with cognition (age, gender, race, income, levels of education, and cardiovascular disease) the association was attenuated (OR 0.98, CI; 0.87;1.10). No association was observed between statin type (lipophilic vs hydrophilic) and cognition (OR 1.03, CI; 0.86;1.24), and there were no regional differences in cognitive impairment in statin users (8% in the stroke belt and 7.9% other regions p=0.63).

Conclusions

Statin use and type was marginally associated with cognitive impairment. After adjusting for known variables that affect cognition, no association was observed. No regional differences were observed. This large study found no evidence to support an association between statins and cognitive performance.

Objective

Biological evidence suggests that inflammation might induce type 2 diabetes (T2D), and epidemiological studies have shown an association between higher white blood cell count (WBC) and T2D. However, the association has not been systematically investigated.

Research Design and Methods

Studies were identified through computer-based and manual searches. Previously unreported studies were sought through correspondence. 20 studies were identified (8,647 T2D cases and 85,040 non-cases). Estimates of the association of WBC with T2D were combined using random effects meta-analysis; sources of heterogeneity as well as presence of publication bias were explored.

Results

The combined relative risk (RR) comparing the top to bottom tertile of the WBC count was 1.61 (95% CI: 1.45; 1.79, p = 1.5*10−18). Substantial heterogeneity was present (I2 = 83%). For granulocytes the RR was 1.38 (95% CI: 1.17; 1.64, p = 1.5*10−4), for lymphocytes 1.26 (95% CI: 1.02; 1.56, p = 0.029), and for monocytes 0.93 (95% CI: 0.68; 1.28, p = 0.67) comparing top to bottom tertile. In cross-sectional studies, RR was 1.74 (95% CI: 1.49; 2.02, p = 7.7*10−13), while in cohort studies it was 1.48 (95% CI: 1.22; 1.79, p = 7.7*10−5). We assessed the impact of confounding in EPIC-Norfolk study and found that the age and sex adjusted HR of 2.19 (95% CI: 1.74; 2.75) was attenuated to 1.82 (95% CI: 1.45; 2.29) after further accounting for smoking, T2D family history, physical activity, education, BMI and waist circumference.

Conclusions

A raised WBC is associated with higher risk of T2D. The presence of publication bias and failure to control for all potential confounders in all studies means the observed association is likely an overestimate.