Association between arterial pressure and coronary artery calcification

Association between estimated glucose disposal rate and subclinical coronary atherosclerosis

BACKGROUND AND AIMS

The estimated glucose disposal rate (eGDR) is an easily accessible clinical parameter for assessing insulin resistance in patients with diabetes mellitus. In this study, we aimed to investigate the link between eGDR and subclinical coronary atherosclerosis in an asymptomatic middle-aged Korean population.

METHODS AND RESULTS

This study involved 4004 subjects who underwent routine health checkups with coronary multidetector computed tomography (MDCT) at Asan Medical Center from 2007 to 2011, among whom 913 had a follow-up analysis through 2014. The eGDR was calculated using: 21.16 - (0.09 ∗ waist circumference [cm]) - (3.41 ∗ hypertension) - (0.55 ∗ glycated hemoglobin [%]). Patients were categorized into three groups according to the tertiles of eGDR. Subclinical coronary atherosclerosis was defined by significant coronary stenosis (≥50%), presence of plaques, coronary artery calcification (CAC) score, and its progression. As a result, a lower eGDR level was associated with higher prevalence of significant coronary stenosis, plaques, moderate to severe CAC, and CAC progression. Compared to other markers or risk scores, eGDR was superior to other biomarkers of insulin resistance but did not provide additional information beyond classic cardiovascular risk models like the Framingham Risk Score and Pooled Cohort Equations.

CONCLUSION

Decreased eGDR values were significantly associated with higher subclinical coronary atherosclerosis burdens in an asymptomatic middle-aged Korean population. However, its clinical implications remain uncertain due to its weaker performance compared to established cardiovascular risk models.

Dietary patterns associated with subclinical atherosclerosis: a cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) study

OBJECTIVE

To identify dietary patterns associated with subclinical atherosclerosis measured as coronary artery calcification (CAC).

DESIGN

Cross-sectional analysis of data from the Brazilian Longitudinal Study of Adult Health. Dietary data were assessed using a FFQ, and a principal component factor analysis was used to derive the dietary patterns. Scree plot, eigenvalues > 1 and interpretability were considered to retain the factors. CAC was measured using a computed tomography scanner and an electrocardiography-gated prospective Ca score examination and was categorised into three groups based on the CAC score: 0, 1-100 and >100 Agatston units. Multinomial regression models were conducted for dietary patterns and CAC severity categories.

SETTING

Brazil, São Paulo, 2008-2010.

PARTICIPANTS

Active and retired civil servants who lived in São Paulo and underwent a CAC exam were included (n 4025).

RESULTS

Around 10 % of participants (294 men, 97 women) had a detectable CAC (>0), 6·5 % (182 men, 73 women) had a CAC of 1-100 and 3·5 % (110 men, 23 women) had a CAC > 100. Three dietary patterns were identified: convenience food, which was positively associated with atherosclerotic calcification; plant-based and dairy food, which showed no association with CAC; and the traditional Brazilian food pattern (rice, legumes and meats), which was inversely associated with atherosclerotic calcification.

CONCLUSIONS

Our results showed that a dietary pattern consisting of traditional Brazilian foods could be important to reducing the risk of atherosclerotic calcification and prevent future cardiovascular events, whereas a convenience dietary pattern was positively associated with this outcome.

Association Between Ambulatory Blood Pressure and Coronary Artery Calcification: The JHS

[Figure: see text].

Studies in Zebrafish Demonstrate That CNNM2 and NT5C2 Are Most Likely the Causal Genes at the Blood Pressure-Associated Locus on Human Chromosome 10q24.32

Background: Globally, high blood pressure (BP) is the most important risk factor for cardiovascular disease. Several genome-wide association studies (GWAS) have identified variants associated with BP traits at more than 535 chromosomal loci with genome-wide significance. The post-GWAS challenge is to annotate the most likely causal gene(s) at each locus. Chromosome 10q24.32 is a locus associated with BP that encompasses five genes: CYP17A1, BORCS7, AS3MT, CNNM2, and NT5C2 and warrants investigation to determine the specific gene or genes responsible for the phenotype. Aim: To identify the most likely causal gene(s) associated with BP at the 10q24.32 locus using zebrafish as an animal model. Results: We report significantly higher blood flow, increased arterial pulse, and elevated linear velocity in zebrafish larvae with cnnm2 and nt5c2 knocked down using gene-specific splice modification transcriptional morpholinos, compared with controls. No differences in blood-flow parameters were observed after as3mt, borcs7, or cyp17a1 knockdown. There was no effect on vessel diameter in animals with any of the four genes knocked down. At the molecular level, expression of hypertension markers (crp and ace) was significantly increased in cnnm2 and nt5c2 knockdown larvae. Further, the results obtained by morpholino knockdown were validated using zebrafish knockout (KO) lines with cnnm2 and nt5c2 deficiency, again resulting in higher blood flow, increased arterial pulse, and elevated linear velocity. Analysis of nt5c2a KO larvae demonstrated that lack of this gene resulted in reduced expression of cnnm2a, with reciprocal downregulation of nt5c2a in cnnm2a KO larvae. Staining of whole-blood smears from nt5c2 mutants revealed that KO of this gene might be associated with an acute lymphoblastic leukemia phenotype, consistent with literature reports. Additional experiments were designed based on previous literature on cnnm2a mutant zebrafish revealed impaired renal function, high levels of renin, and significantly increased expression of the ren gene, leading us to hypothesize that the observed elevated blood-flow parameters may be attributable to triggering of the renin-angiotensin-aldosterone signaling pathway. Conclusion: Our zebrafish data establish CNNM2 and NT5C2 as the most likely causal genes at the 10q24.32 BP locus and indicate that they trigger separate downstream mechanistic pathways.

Gla-Rich Protein (GRP) as an Early and Novel Marker of Vascular Calcification and Kidney Dysfunction in Diabetic Patients with CKD: A Pilot Cross-Sectional Study

Vascular calcification (VC) is one of the strongest predictors of cardiovascular risk in chronic kidney disease (CKD) patients. New diagnostic/prognostic tools are required for early detection of VC allowing interventional strategies. Gla-rich protein (GRP) is a cardiovascular calcification inhibitor, whose clinical utility is here highlighted. The present study explores, for the first time, correlations between levels of GRP in serum with CKD developmental stage, mineral metabolism markers, VC and pulse pressure (PP), in a cohort of 80 diabetic patients with mild to moderate CKD (stages 2–4). Spearman’s correlation analysis revealed a positive association of GRP serum levels with estimated glomerular filtration rate (eGFR) and α-Klotho, while a negative correlation with phosphate (P), fibroblast growth factor 23 (FGF-23), vascular calcification score (VCS), PP, calcium (x) phosphate (CaxP) and interleukin 6 (IL-6). Serum GRP levels were found to progressively decrease from stage 2 to stage 4 CKD. Multivariate analysis identified low levels of eGFR and GRP, and high levels of FGF-23 associated with both the VCS and PP. These results indicate an association between GRP, renal dysfunction and CKD-mineral and bone disorder. The relationship between low levels of GRP and vascular calcifications suggests a future, potential utility for GRP as an early marker of vascular damage in CKD.

Correlation between coronary artery calcification by non-cardiac CT and Framingham score in young patients

Background

Previous studies have established a correlation between coronary artery calcification (CAC) measured by ECG-gated chest computed tomography (CT) and cardiovascular disease. Recent reports which included asymptomatic patients suggest that CAC measured on non-ECG gated CT is similarly associated with cardiovascular risk. This study investigates the correlation between the Framingham Risk Score (FRS) and an incidental finding of CAC on a non-gated chest CT performed for non-cardiac indications in young and seemingly healthy adults.

Methods

A cross-sectional study that included 162 CT scans performed in young patients aged 18–50 years old for non-cardiac indications in our institution was conducted. CAC score (CACS) was calculated using the Agatston method. FRS was calculated and compared to the CACS using three different approaches. The correlations between the CACS and several specific factors (i.e. age, body mass index, smoking, statins, etc.), were also evaluated.

Results

Mean age of patients was 36.43 year old and 105 (64.8%) were male. We found a significant positive correlation between the CACS and the FRS in all three approaches (p<0.05). Increased age, smoking and statin use were the only individual factors clearly associated with an increase in CACS (p = 0.002, p = 0.045 and p = 0.009, respectively).

Conclusion

This is the first report indicating that incidental CACS identified in non-gated MDCT is also associated with cardiovascular risk evaluated by FRS in a young population. Our findings suggest that young asymptomatic individuals with incidental CAC should be seriously evaluated for cardiovascular risk factors despite presumption of belonging to a low cardiovascular risk category.

Diabetes and male sex are key risk factor correlates of the extent of coronary artery calcification: A Euro-CCAD study

BACKGROUND AND AIMS

Although much has been written about the conventional cardiovascular risk factor correlates of the extent of coronary artery calcification (CAC), few studies have been carried out on symptomatic patients. This paper assesses the potential ability of risk factors to associate with an increasing CAC score.

METHODS

From the European Calcific Coronary Artery Disease (Euro-CCAD) cohort, we retrospectively investigated 6309 symptomatic patients, 62% male, from Denmark, France, Germany, Italy, Spain and the USA. All had conventional cardiovascular risk factor assessment and CT scanning for CAC scoring.

RESULTS

Among all patients, male sex (OR = 4.85, p<0.001) and diabetes (OR = 2.36, p<0.001) were the most important risk factors of CAC extent, with age, hypertension, dyslipidemia and smoking also showing a relationship. Among patients with CAC, age, diabetes, hypertension and dyslipidemia were associated with an increasing CAC score in males and females, with diabetes being the strongest dichotomous risk factor (p<0.001 for both). These results were echoed in quantile regression, where diabetes was consistently the most important correlate with CAC extent in every quantile in both males and females. To a lesser extent, hypertension and dyslipidemia were also associated in the high CAC quantiles and the low CAC quantiles respectively.

CONCLUSION

In addition to age and male sex in the total population, diabetes is the most important correlate of CAC extent in both sexes.

Diabetes and Hypertension Consistently Predict the Presence and Extent of Coronary Artery Calcification in Symptomatic Patients: A Systematic Review and Meta-Analysis

Background: The relationship of conventional cardiovascular risk factors (age, gender, ethnicity, diabetes, dyslipidaemia, hypertension, obesity, exercise, and the number of risk factors) to coronary artery calcification (CAC) presence and extent has never before been assessed in a systematic review and meta-analysis. Methods: We included only English language studies that assessed at least three conventional risk factors apart from age, gender, and ethnicity, but excluded studies in which all patients had another confirmed condition such as renal disease. Results: In total, 10 studies, comprising 15,769 patients, were investigated in the systematic review and seven studies, comprising 12,682 patients, were included in the meta-analysis, which demonstrated the importance of diabetes and hypertension as predictors of CAC presence and extent, with age also predicting CAC presence. Male gender, dyslipidaemia, family history of coronary artery disease, obesity, and smoking were overall not predictive of either CAC presence or extent, despite dyslipidaemia being a key risk factor for coronary artery disease (CAD). Conclusion: Diabetes and hypertension consistently predict the presence and extent of CAC in symptomatic patients.

Is there a relationship between severity of coronary artery disease and severity of erectile dysfunction?

INTRODUCTION

The correlation between erectile dysfunction (ED) and coronary artery disease has been emphasized and ED has been recognized as a potential independent risk factor and/or predictor of coronary artery disease (CAD). We evaluated the association between the number of occluded coronary arteries in myocardial infarction (MI) patients with the severity of ED, and investigated the influence of related risk factors in our study group.

MATERIALS AND METHODS

183 male patients who underwent coronary angiography because of acute MI from November 2009 to May 2011 were included. Following the stabilization of patients after the treatment, each patient was evaluated for erectile functionality. Risk factors such as age, diabetes, smoking, waist circumference, hypertension, and hematologic parameters were recorded.

RESULTS

Among 183 patients with a mean age of 55.2 years who underwent coronary angiography due to acute MI, 100 (54.64 %) had ED, while the ED rate was 45.36 % (44/97) in cases of single-vessel disease, 64.5 % (31/48) in cases of two-vessel disease, and 65.7 % (25/38) in cases of three-vessel disease. The mean IIEF score was 24.2 ± 4.3, 20.4 ± 4.9 and 20.5 ± 4.2 for single or two or three-vessel disease, respectively. The presence of hypertension aggravated ED only in patients with three-vessel disease and increased total and LDL cholesterol levels in patients with single-vessel or two-vessel disease were accompanied by significantly decreasing IIEF scores.

CONCLUSION

The severity of ED correlated with the number of occluded vessels documented by coronary angiography, in male patients with acute myocardial infarction. In addition, the presence of hypertension had a significant influence over erectile function only in patients with three-vessel occlusion.

Coronary artery calcification is associated with the development of hypertension

BACKGROUND

Hypertension (HTN) is associated with coronary artery calcification (CAC). We hypothesized that preexisting CAC is associated with the development of HTN.

METHODS

This study included 483 normotensive subjects (mean age 54 years, 83% males) who underwent a baseline evaluation of their CAC score with ungated dual-section computed tomography during 2001-2002 and returned for at least the first annual follow-up. All subjects underwent an annual examination and were followed for a mean period of 6.6 ± 3.2 years to identify newly developed HTN. Data on the patient's medical history, physical examination and laboratory evaluations were collected.

RESULTS

During the follow-up, 104 subjects developed HTN. The rate of newly developed HTN was significantly higher among those with CAC (60 of 223 subjects; 27%) than among those without CAC (44 of 260; 17%) (P < 0.01). The presence of CAC predicted the development of HTN with a hazard ratio of 1.73 (95% confidence interval, 1.17-2.56; P < 0.01). After adjustment for age, sex, body mass index, smoking, baseline systolic blood pressure, and levels of glucose, triglycerides, and low-density lipoprotein cholesterol, the presence of CAC still predicted the development of HTN with a hazard ratio of 1.63 (95% confidence interval, 1.02-2.60; P = 0.04).

CONCLUSIONS

Preexisting CAC is associated with the development of HTN.

Pulse pressure and presence of coronary artery calcification

BACKGROUND

Coronary calcification (CAC) is found in early stages of CKD. Pulse pressure (PP) predicts CAC in dialysis patients. This study evaluates the accuracy of PP in predicting CAC in patients not yet on dialysis (CKD patients).

METHODS

CKD patients (n = 388) underwent coronary calcium score (CAC score) and abdominal x-ray (n = 128) for estimating aorta calcification (AAC). Biochemistry and PP were measured every 3 and 6 months in patients with stage 4 to 5 and 2 to 3 CKD, respectively. The accuracy of PP and AAC was assessed by receiver operating characteristics analysis.

RESULTS

PP correlated with CAC score in the whole cohort and in patients with stages 2 to 3 and stages 4 to 5 CKD. PP >60 mmHg predicted CAC score >0 (OR: 2.14; P < 0.001), > or =100 (OR: 2.92; P < 0.001), > or =400 (OR: 6.17; P < 0.001) after multivariable adjustment. Area under the curve (AUC) was 0.626 for CAC score >0, 0.676 for score >100, and 0.746 for score >400. PP >60 mmHg reduced the rate of event-free survival. AAC was found in 58% of patients and correlated with CAC score. AUC was 0.628 for CAC score >0, 0.652 for score >100, 0.831 for score >400.

CONCLUSION

PP may identify CKD patients with subclinical CAC who need further evaluation. Accuracy of PP and AAC is nearly similar in predicting CAC. High PP indicates vessel wall alterations leading to adverse outcome.

Association between PPARα gene polymorphisms and myocardial infarction

PPARα (peroxisome-proliferator-activated receptor α) regulates the expression of genes that are involved in lipid metabolism, tissue homoeostasis and inflammation. Consistent rodent and human studies suggest a link between PPARα function and cardiovascular disease, qualifying PPARα [PPARA in HUGO (Human Genome Organisation) gene nomenclature] as a candidate gene for coronary artery disease. In the present study, we comprehensively evaluated common genetic variations within the PPARα gene and assessed their association with myocardial infarction. First, we characterized the linkage disequilibrium within the PPARα gene in an initial case-control sample of 806 individuals from the Regensburg Myocardial Infarction Family Study using a panel of densely spaced SNPs (single nucleotide polymorphisms) across the gene. Single SNP analysis showed significant association with the disease phenotype [OR (odds ratio)=0.74, P=0.012, 95% CI (confidence interval)=0.61–0.94 for rs135551]. Moreover, we identified a protective three-marker haplotype with an association trend for myocardial infarction (OR=0.76, P=0.067, 95% CI=0.56–1.02). Subsequently, we were able to confirm the single SNP and haplotype association results in an independent second case-control cohort with 667 cases from the Regensburg Myocardial Infarction Family Study and 862 control individuals from the WHO (World Health Organization) MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease) Augsburg project (OR=0.87, P=0.046, 95% CI=0.72–0.99 for rs135551 and OR=0.80, P=0.034, 95% CI=0.65–0.98 for the three-marker haplotype respectively). From these cross-sectional association results, we provide evidence that common variations in the PPARα gene may influence the risk of myocardial infarction in a European population.

Prediabetes is associated with abnormal circadian blood pressure variability

Blood pressure (BP) exhibits a circadian variation characterized by a morning increase, followed by a small postprandial valley and a deeper descent during nocturnal rest. Although abnormal 24-h variability (abnormal circadian variability (ACV)) predicts adverse cardiovascular disease (CVD) outcomes, a 7-day automatic ambulatory BP monitoring (ABPM) and subsequent chronobiologic analysis of the gathered data, permits identification of consistency of any abnormal circadian variation. To test whether normal overweight healthy men and women with prediabetes differed from subjects with normoglycemia in having ACV with a 7-day ABPM. Consent for a 7-day ABPM was obtained from subjects with family history of diabetes mellitus, who were participating in the screening phase for a randomized, double blind, placebo-controlled weight loss trial in prediabetics to prevent progression to diabetes mellitus. The automatic 7-day ABPM device recorded BP and heart rate every 30 min during the day and every 60 min during the night. Normoglycemic and prediabetic subjects matched for age, sex, race, BP, BMI, waist circumference and glycemic control, differed statistically significantly only in their fasting and/or 2-h postprandial serum glucose concentrations. Chronobiologically-interpreted 7-day ABPM uncovered no abnormalities in normoglycemics, whereas prediabetics had a statistically significantly higher incidence of high mean BP (MESOR-hypertension), excessive pulse pressure and/or circadian hyper-amplitude-tension (CHAT) (P<0.001). ACV detected with 7-day ABPM may account for the enhanced CVD risk in prediabetes. These findings provide a basis for larger-scale studies to assess the predictive value of 7-day ABPM over the long term.