Hemoglobin a1c and the progression of coronary artery calcification among adults without diabetes

Exploring the mediating role of calcium homeostasis in the association between diabetes mellitus, glycemic traits, and vascular and valvular calcifications: a comprehensive Mendelian randomization analysis

BACKGROUND

The interplay between diabetes mellitus (DM), glycemic traits, and vascular and valvular calcifications is intricate and multifactorial. Exploring potential mediators may illuminate underlying pathways and identify novel therapeutic targets.

METHODS

We utilized univariable and multivariable Mendelian randomization (MR) analyses to investigate associations and mediation effects. Additionally, the multivariable MR analyses incorporated cardiometabolic risk factors, allowing us to account for potential confounders.

RESULTS

Type 2 diabetes mellitus (T2DM) and glycated hemoglobin (HbA1c) were positively associated with both coronary artery calcification (CAC) and calcific aortic valvular stenosis (CAVS). However, fasting glucose (FG) was only linked to CAVS and showed no association with CAC. Additionally, CAVS demonstrated a causal effect on FG. Calcium levels partially mediated the impact of T2DM on both types of calcifications. Specifically, serum calcium was positively associated with both CAC and CAVS. The mediation effects of calcium levels on the impact of T2DM on CAC and CAVS were 6.063% and 3.939%, respectively. The associations between T2DM and HbA1c with calcifications were influenced by body mass index (BMI) and smoking status. However, these associations were generally reduced after adjusting for hypertension.

CONCLUSION

Our findings suggest a genetically supported causal relationship between DM, glycemic traits, and vascular and valvular calcifications, with serum calcium playing a critical mediating role.

The Significance of Coronary Artery Calcification for Percutaneous Coronary Interventions

The prevalence of calcium deposits in coronary arteries grows with age. Risk factors include, e.g., diabetes and chronic kidney disease. There are several underlying pathophysiological mechanisms of calcium deposition. Severe calcification increases the complexity of percutaneous coronary interventions. Invasive techniques to modify the calcified atherosclerotic plaque before stenting have been developed over the last years. They include balloon- and non-balloon-based techniques. Rotational atherectomy has been the most common technique to treat calcified lesions but new techniques are emerging (orbital atherectomy, intravascular lithotripsy, laser atherectomy). The use of intravascular imaging (intravascular ultrasound and optical coherence tomography) is especially important during the procedures in order to choose the optimal strategy and to assess the final effect of the procedure. This review provides an overview of the role of coronary calcification for percutaneous coronary interventions.

Association between hemoglobin A1c and abdominal aortic calcification: results from the National Health and Nutrition Examination Survey 2013-2014

BACKGROUND

Hemoglobin A1c (HbA1c), a "gold standard" for the assessment of glycemic control, was associated with an increased risk of cardiovascular disease and coronary artery calcification. However, its effects on abdominal aortic calcification (AAC) are uncertain. The present study comprehensively investigated the association between HbA1c and AAC in the 2013-2014 National Health and Nutrition Examinations Surveys.

METHODS

Among 1,799 participants ≥ 40 years, dual-energy X-ray absorptiometry-derived AAC was quantified using the Kauppila score (AAC-24). Severe AAC was defined as a total AAC-24 > 6. Weighted linear regression models and logistic regression models were used to determine the effects of HbA1c on AAC. The restricted cubic spline model was used for the dose-response analysis.

RESULTS

The mean AAC-24 of participants was 1.3, and 6.7% of them suffered from severe AAC. Both AAC-24 and the prevalence of severe AAC increased with the higher tertile of HbA1c (P < 0.001). Elevated HbA1c levels would increase the AAC-24 (β = 0.73, 95% CI: 0.30-1.16) and the risk of severe AAC (OR = 1.63, 95% CI: 1.29-2.06), resulting in nearly linear dose-response relationships in all participants. However, this positive correlation were not statistically significant when participants with diabetes were excluded. Furthermore, subgroup analysis showed significant interactions effect between HbA1c and hypertension on severe AAC with the OR (95% CI) of 2.35 (1.62-3.40) for normotensives and 1.39 (1.09-1.79) for hypertensives (P for interaction = 0.022).

CONCLUSION

Controlling HbA1c could reduce AAC scores and the risk of severe AAC. Glycemic management might be a component of strategies for preventing AAC among all participants, especially normotensives.

Synergistic effects of overweight/obesity and high hemoglobin A1c status on elevated high-sensitivity C-reactive protein in Chinese adults: a cross-sectional study

Background

High-sensitivity C-reactive protein (hs-CRP) is an inflammatory marker that has been suggested as a predictor of cardiovascular diseases. High glycated hemoglobin (HbA1c) levels and overweight/obesity are independently associated with elevated hs-CRP; meanwhile, high HbA1c levels are frequently accompanied by overweight or obesity. However, their joint effect on elevated hs-CRP levels has not been well-established. Therefore, we evaluated whether overweight/obesity modified the association between high HbA1c levels and elevated hs-CRP.

Methods

Based on cross-sectional data from the Chinese Urban Adults Diet and Health Study (CUADHS) in 2016, we included 1,630 adults aged 18-75 years (mean age 50.16 years and 33.6% male). Elevated hs-CRP was defined as serum hs-CRP ≥ 3 and <10 mg/L. The interactive effects of BMI and HbA1c levels on the risk of elevated hs-CRP levels were calculated by using multiple logistic regression models, followed by strata-specific analyses.

Results

Individuals with elevated hs-CRP had a higher rate of HbA1c level than those without elevated (25.3 vs. 11.3%, P < 0.001), as well as a higher rate of overweight/obesity (67.1 vs. 43.5%, P < 0.001). Higher HbA1c levels were independently associated with an increased risk of elevated hs-CRP [adjusted odds ratio (aOR) = 2.31, 95% confidence interval (CI): 1.47, 3.65], as well as overweight/obesity with the risk of elevated hs-CRP (aOR = .31, 95% confidenc-3.73). Furthermore, overweight/obesity showed a significant synergistic effect on high HbA1c levels with a higher aOR of 5.25 (2.77, 9.95) (P_interaction < 0.001). This synergistic effect was more prominent when stratified by age (in 18-44 years old, aOR, 95% CI = 30.90, 4.40-236.47 for interaction vs. 6.46, 1.38-30.23 for high HbA1c only) and gender (in women, aOR, 95% CI = 8.33, 3.80-18.23 for interaction vs. 2.46,1.38-4.40 for high HbA1c only).

Conclusion

There are synergistic effects of high HbA1c levels and overweight/obesity on the risk of elevated hs-CRP in Chinese adults, with more significant effects in adults aged 18-44 years or females. Intervention strategies for preventing high blood glucose levels and body weight simultaneously may be important for reducing hs-CRP-related diseases. Further studies are needed to confirm this finding in other populations, and its molecular mechanisms need to be elucidated.

The association between time in the glucose target range and abnormal ankle-brachial index: a cross-sectional analysis

BACKGROUND

Time in range (TIR), a novel proxy measure of glucose control, is found closely related to diabetic microangiopathy and some other chronic complications, but the correlation between TIR and lower limb angiopathy has not been studied yet. Our purpose is to explore the relationship between TIR and abnormal ankle-brachial index(ABI) in type 2 diabetes.

METHODS

We retrospectively collected patients' information from the database and performed cross-sectional analysis. A total of 405 type 2 diabetes patients were enrolled in this study. ABI was measured and patients were stratified into low, normal, and high groups according to ≤ 0.9, > 0.9 and < 1.3, ≥ 1.3 ABI values. All patients underwent continuous glucose monitoring(CGM), and TIR was defined as the percentage of time in which glucose was in the range of 3.9-10 mmol/L during a 24-h period. Correlations between TIR and abnormal ABI were analyzed using Spearman analysis. And logistic regression was used to explore whether TIR is an independent risk factor for abnormal ABI.

RESULTS

The overall prevalence of abnormal ABI was 20.2% (low 4.9% and high 15.3%). TIR was lower in patients with abnormal ABI values (P = 0.009). The prevalence of abnormal ABI decreased with increasing quartiles of TIR (P = 0.026). Abnormal ABI was negatively correlated with TIR and positively correlated with hypertension, age, diabetes duration, UREA, Scr, ACR, TAR, MBG, and M values (P < 0.05). The logistic regression revealed a significant association between TIR and abnormal ABI, while HbA1C and blood glucose variability measures had no explicit correlation with abnormal ABI. Additionally, there was a significant difference in LDL between the low and high ABI groups (P = 0.009), and in Scr between normal and low groups (P = 0.007). And there were significant differences in TIR (P = 0.003), age (P = 0.023), UREA (P = 0.006), ACR (P = 0.004), TAR (P = 0.015), and MBG (P = 0.014) between normal and high ABI groups, and in diabetes duration between both normal and low (P = 0.023) and normal and high (P = 0.006) groups.

CONCLUSIONS

In type 2 diabetes patients, abnormal ABI is associated with lower TIR, and the correlation is stronger than that with HbA1C. Therefore, the role of TIR should be emphasized in the evaluation of lower limb vascular diseases.

Association between the weight-adjusted-waist index and abdominal aortic calcification in United States adults: Results from the national health and nutrition examination survey 2013–2014

Background

Abdominal aortic calcification (AAC) is recognized as a strong predictor of cardiovascular disease (CVD) events. This study aimed to evaluate the association between weight-adjusted-waist index (WWI) and AAC in United States adults aged ≥ 40 years.

Materials and methods

Data were derived from the 2013–2014 National Health and Nutrition Examination Survey (NHANES). WWI was calculated as waist circumference divided by the square root of weight. AAC scores were quantified by the Kauppila scoring system, and severe AAC was defined as an AAC score ≥ 6. Weighted multivariable regression analysis and subgroup analysis were performed to evaluate the relationship between WWI with AAC scores and severe AAC. The restricted cubic spline model was used for the dose-response analysis.

Results

A total of 2,772 participants were included with the mean WWI of 11.17 ± 0.73 cm/√kg and mean AAC score of 1.48 ± 3.27. The prevalence of severe AAC was 9.64%. WWI was positively associated with higher AAC scores [β = 0.95, 95% confidence interval (CI): 0.65–1.25, P < 0.001] and increased risk of severe AAC [odds ratio (OR) = 1.82; 95% CI: 1.20–2.75; P = 0.005]. A nearly linear relationship between the WWI and the odds of severe AAC was found after adjustment for multiple potential covariates (P for non-linear = 0.625). Subgroup analysis indicated that the association between WWI and AAC was similar in different population settings.

Conclusion

Higher WWI was associated with higher AAC score and increased risk of severe AAC in United States adults. Further studies are needed to confirm this relationship.

The clinical impact of serum 1,5-anhydro-D-glucitol levels on coronary artery calcification and adverse outcomes assessed by coronary optical coherence tomography in diabetic patients

Background

Serum 1,5-anhydro-D-glucitol (1,5-AG) is a novel biomarker for short-term glycemic status and postprandial hyperglycemia. The association between serum 1,5-AG levels and coronary artery calcification (CAC) through a quantitative assessment using optical coherence tomography (OCT) is unclear. We aimed to evaluate this association using OCT in patients with diabetes mellitus (DM).

Methods

From June 2016 to December 2019, we prospectively enrolled 256 patients who underwent OCT-guided percutaneous coronary intervention (PCI). Half of the patients had diabetes. Patients were followed up for a mean period of 1.8 ± 0.8 years (median: 2.2 years). The relative calcium index and relative lipid core index measured by quantitative OCT analysis were used to evaluate the intra-plaque calcium and lipid levels of culprit plaques. We also analyzed the correlation between serum 1,5-AG levels and long-term major adverse cardiovascular events.

Results

Serum 1,5-AG levels were significantly lower in diabetic patients than in non-diabetic patients (DM vs. non-DM: 55.6 ± 27.9 μg/mL vs. 63.7 ± 26.1 μg/mL, p = 0.016), and lower in fibrocalcified lesions than in fibrotic or fibrolipidic lesions (fibrocalcified vs. fibrotic or fibrolipidic: 42.8 ± 19.1 vs. 72.9 ± 25.2 or 66.4 ± 27.5 μg/mL, p &lt; 0.001, respectively). In addition, we found a significant inverse correlation between serum 1,5-AG levels and relative calcium index (r = −0.729, p &lt; 0.001). In multivariate Cox regression analysis, low serum 1,5-AG level was identified as an independent predictor for major adverse cardiovascular events in diabetic patients (p = 0.043), but not in non-diabetic patients (p = 0.748) after adjusting for age and sex.

Conclusion

This study revealed that low serum 1,5-AG levels were associated with an increased risk of CAC as assessed by OCT, especially in diabetic patients. Low serum 1,5-AG levels may predict future major adverse cardiovascular events in diabetic patients undergoing OCT-guided PCI.

The metabolic signature of cardiovascular disease and arterial calcification in patients with chronic kidney disease

BACKGROUND AND AIMS

The relationship between chronic kidney disease (CKD) and cardiovascular events is well-established. Clinically recognised risk factors of cardiovascular disease cannot fully explain this association. The objective of the present cross-sectional study was to investigate associations between serum metabolites and prevalent cardiovascular disease, as well as subclinical cardiovascular disease measured as coronary artery calcium score (CACS) in patients with CKD.

METHODS

More than 200 preselected metabolites were quantified using nuclear magnetic resonance spectroscopy in 725 patients and 174 controls from the Copenhagen CKD Cohort. CACS was determined by computed tomography.

RESULTS

Mean age of patients was 57.8 years, and 444 (61.3%) were men. Most of patients had hypercholesterolemia, and 133 (18.3%) had type 2 diabetes. Overall, 85 metabolites were significantly associated with prevalent cardiovascular disease in a model adjusted for eGFR, age, and sex, as well as Bonferroni correction for multiple testing (p < 0.001). After further adjusting for diabetes, BMI, smoking, and cholesterol-lowering medication, the significance was lost for all but six metabolites (concentration of ApoA-1, cholesterol in total HDL and HDL2, total lipids and phospholipids in large HDL particles, and the ratio of phospholipids to total lipids in smaller VLDL particles). Of the 85 metabolites associated with prevalent cardiovascular disease, 71 were also associated with CACS in a similar pattern. Yet, in the model adjusted for all seven cardiovascular risk factors, only serum glucose levels and the ratio of triglycerides to total lipids in larger LDL particles remained significant.

CONCLUSIONS

In patients with CKD, associations with prevalent cardiovascular disease were mainly found for HDL-related metabolites, while CACS was associated with glucose levels and increased triglycerides to total lipids ratio in LDL particles.

Evaluating the Independent Impact of Renal Function Decline on Coronary Artery Calcification in Patients Undergone Cardiac CT Scan

Background: Cardiovascular events are the leading global cause of death. Calcification of coronary arteries is a common complication of renal failure and the leading cause of death in this population. However, its multifactorial mechanism is not fully understood. Objectives: The current study aimed to, firstly, investigate the association between renal dysfunction and the calcification of coronary arteries in patients with severe and milder stages of renal failure and, secondly, to determine the role of this variable by eliminating the effect of established confounding factors. Methods: Following a retrospective design, 261 patients with cardiovascular risk factors or atypical symptoms were investigated. Estimated GFR (glomerular filtration rate) was calculated using both Cockcroft-Gault and MDRD equations. An ECG-gated multidetector CT scan was performed to calculate CACS (coronary artery calcification score) using the Agatston method. The presence of significant CAC (coronary artery calcification) was defined as CACS > 100. Univariate and multivariate analyses were performed using binary logistic regression. Results: A total of 134 cases were diagnosed with CAC, and the mean CACS was 83.4 ± 18. According to univariate analysis, older age, male gender, systolic and diastolic blood pressure, and higher TG levels were correlated with the degree of CAC. HbA1C showed a weak correlation with CACS (P-value = 0.04). Renal insufficiency resulted in increased CAC, and lower eGFR (calculated with both Cockgraft-Gault and MDRD equations) was associated with higher calcification (P-value < 0.01). Our analysis shows that serum Ca, P, LDL, and HDL levels do not have a significant influence on calcification changes. After adjusting for confounding factors, male sex, age, triglyceride level, and eGFR were recognized as independent risk factors for CACS ≥ 100, a marker of coronary artery atherosclerosis. However, HbA1C and systolic and diastolic blood pressure were no longer considered as factors that contribute to the risk of CAC. Conclusions: We observed a gradual and independent association between lower eGFR and higher CAC scores.

Protein glycation - biomarkers of metabolic dysfunction and early-stage decline in health in the era of precision medicine

Protein glycation provides a biomarker in widespread clinical use, glycated hemoglobin HbA1c (A1C). It is a biomarker for diagnosis of diabetes and prediabetes and of medium-term glycemic control in patients with established diabetes. A1C is an early-stage glycation adduct of hemoglobin with glucose; a fructosamine derivative. Glucose is an amino group-directed glycating agent, modifying N-terminal and lysine sidechain amino groups. A similar fructosamine derivative of serum albumin, glycated albumin (GA), finds use as a biomarker of glycemic control, particularly where there is interference in use of A1C. Later stage adducts, advanced glycation endproducts (AGEs), are formed by the degradation of fructosamines and by the reaction of reactive dicarbonyl metabolites, such as methylglyoxal. Dicarbonyls are arginine-directed glycating agents forming mainly hydroimidazolone AGEs. Glucosepane and pentosidine, an intense fluorophore, are AGE covalent crosslinks. Cellular proteolysis of glycated proteins forms glycated amino acids, which are released into plasma and excreted in urine. Development of diagnostic algorithms by artificial intelligence machine learning is enhancing the applications of glycation biomarkers. Investigational glycation biomarkers are in development for: (i) healthy aging; (ii) risk prediction of vascular complications of diabetes; (iii) diagnosis of autism; and (iv) diagnosis and classification of early-stage arthritis. Protein glycation biomarkers are influenced by heritability, aging, decline in metabolic, vascular, renal and skeletal health, and other factors. They are applicable to populations of differing ethnicities, bridging the gap between genotype and phenotype. They are thereby likely to find continued and expanding clinical use, including in the current era of developing precision medicine, reporting on multiple pathogenic processes and supporting a precision medicine approach.

Association of Quantified Costal Cartilage Calcification and Long-Term Cumulative Blood Glucose Exposure: The Multi-Ethnic Study of Atherosclerosis

AIMS

Anecdotal reports have suggested increased soft tissue calcification in individuals with long-term exposures to high blood glucose. The association of costal cartilage calcification (CCC), a reliably quantifiable marker obtainable from non-contrast cardiac computed tomography (CT) with cumulative fasting blood glucose (FBG) exposure, is unknown. In this study, we aimed to determine the association between quantified CCC and cumulative glucose exposure using non-contrast coronary artery calcium (CAC) scoring computed tomography (CT) images in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

The volume of bilateral CCC was quantified in high-density pixels (threshold of Hounsfield Unit>180) using the CAC scoring CT images acquired in the 5^th MESA exam. Prior long-term cumulative exposure to FBG was calculated by area under the FBG-time curve over ten years before the time of the CT exam.

RESULTS

A total of 2,305 participants (mean age: 69, female/male: 1.3) were included in this study. The median CCC volume was lower in females than males (1158 mm³ [IQR: 1751] vs. 3054 mm³ [3851], p<0.001). In cross-sectional analysis, quantified CCC was associated with FBG (9% increase per SD) and HbA1c (7% increase per SD) at the CT exam only in female participants after adjustment for age, race, BMI, and glomerular filtration rate. Only in female participants, quantified CCC was also associated with prior cumulative FBG (3% increase per decile change). In the subgroup of females with zero CAC scores, the adjusted CCC was still associated with FBG (13% increase per SD) at the time of CT exam and with prior cumulative FBG exposure (4% increase per decile change) before the CT exam.

CONCLUSIONS

The CCC, a reliably quantified marker in non-contrast cardiac CT, is associated with 10-year cumulative FBG exposure only in female participants, even those with zero CAC.

Triglyceride Glucose-Waist Circumference Better Predicts Coronary Calcium Progression Compared with Other Indices of Insulin Resistance: A Longitudinal Observational Study

The triglyceride glucose (TyG) index, a product of triglyceride and fasting glucose, is a reliable marker for insulin resistance. We aimed to investigate the association between the TyG-related markers and coronary artery calcification (CAC) progression. We enrolled 1145 asymptomatic participants who underwent repeated CAC score measurements during routine health examinations. Homeostasis model assessment of insulin resistance (HOMA-IR), TyG index, TyG-BMI (body mass index), and TyG-WC (waist circumference) were calculated. Progression of CAC was defined as (1) incident CAC in a CAC-free population, or an (2) increase of ≥2.5 units between the baseline and final square root of the CAC scores in participants with detectable CAC. According to the quartiles of parameters, we stratified the subjects into four groups. The prevalence of progression increased with the TyG-WC quartile (15.0%, 24.1%, 31.0%, and 32.2% for each of the groups; p < 0.001). The multivariate-adjusted odds ratio (95% confidence interval) for CAC score progression was 1.66 (1.01–2.77) when the highest and lowest TyG-WC index quartiles were compared. Furthermore, the predictability of TyG-WC for CAC progression was better than the other indices in terms of the area under the curve. The TyG-WC index predicted CAC progression better than other indices and could be a potential marker of future coronary atherosclerosis.

Association between noninvasive assessment of liver fibrosis and coronary artery calcification progression in patients with nonalcoholic fatty liver disease

Advanced liver fibrosis and coronary artery calcification (CAC) progression has been reported to correlate with cardiovascular disease. This study investigated the association between noninvasive liver fibrosis score and CAC progression in patients with nonalcoholic fatty liver disease (NAFLD). We included 1173 asymptomatic adults with CAC scores from 2007–2013. CAC progression was defined as newly incident CAC or a ≥ 2.5-unit increase in the final CAC score square root. Liver fibrosis was assessed using fibrosis-4 index (FIB-4) score and NAFLD fibrosis score (NFS). A total of 293 (25.0%) subjects developed CAC. Mean baseline FIB-4 score was significantly higher in subjects with CAC. CAC progressed in 20.5% of subjects without NAFLD, 27.5% of those with NAFLD and low FIB-4 scores, and 35.9% of those with NAFLD and intermediate/high FIB-4 scores. On multivariate logistic regression analysis, the odds ratio for CAC progression was 1.70 (95% confidence interval, 1.12–2.58) for subjects with NAFLD plus intermediate/high FIB-4 scores versus those without NAFLD. In the sensitivity analysis, the odds ratio for CAC progression was 1.57 (95% confidence interval, 1.02–2.44) for subjects with NAFLD plus an intermediate/high NFS versus those without NAFLD. Advanced liver fibrosis stage assessed using noninvasive markers is associated with a higher risk of CAC progression in subjects with NAFLD.

Association Between Fasting Glucose Variability in Young Adulthood and the Progression of Coronary Artery Calcification in Middle Age

OBJECTIVE

To investigate whether intraindividual variability of fasting glucose (FG) in young adulthood is associated with coronary artery calcification (CAC) progression in middle age.

RESEARCH DESIGN AND METHODS

We included 2,256 CARDIA (Coronary Artery Risk Development Study in Young Adults) participants with CAC assessment by computed tomography scanner at baseline (2000-2001) and 10 years later (2010-2011). CAC progression was assessed for each individual as the difference of logarithmic CAC scores at follow-up and baseline (log[CAC (follow-up) + 1] - log[CAC (baseline) + 1]). FG variability was defined by the coefficient of variation about the mean FG (FG-CV), the SD of FG (FG-SD), and the average real variability of FG (FG-ARV) during the 10-year follow-up. We investigated the association between FG variability and CAC progression with adjustment for demographics, clinical risk factors, mean FG level, change in FG level, diabetes incidence, and medication use.

RESULTS

After multivariable adjustment, 1-SD increment in FG-CV was associated with worse progression of CAC as demonstrated as percent change in CAC, with incident CAC 5.9% (95% CI 1.0, 10.7) and any CAC progression 6.7% (95% CI 2.3, 11.1) during 10 years. Similar findings were also observed in FG-SD and FG-ARV.

CONCLUSIONS

Higher FG variability during young adulthood was associated with greater CAC progression in middle age, suggesting its value in predicting risk for subclinical coronary artery diseases.

Relationship between glycated hemoglobin and low Ankle-Brachial Index: a cross-sectional observational study from the Beijing Vascular Disease Evaluation Study (BEST Study)

BACKGROUND

Studies have confirmed that the low Ankle Brachial Index (ABI) and high glycated hemoglobin (HbA1c) level were both risk factors of cardiovascular disease (CVD). However, the association has rarely been explored between ABI and HbA1c. This study was to evaluate the independent relationship between HbA1c and low ABI.

METHODS

A total of 3102 subjects (male 1539, female 1563, aged 67.72±10.69 years) were enrolled into the study from 2010 to 2018. The odds ratio (OR) and linear regression coefficient of low ABI group (defined as ABI≤0.9) and ABI value in associations with the HbA1c were modelled using multivariable logistic and linear regression analyses by adjusting for possible confounders.

RESULTS

Compared with participants with normal ABI, those presenting the low ABI showed a significantly older age, smoking rate, higher level of heart rate (HR), systolic blood pressure (SBP), pulse pressure (PP), fasting plasma glucose (FPG), triglyceride (TG), highly sensitive C-reactive protein (hs-CRP), HbA1c and carotid femoral pulse wave velocity (CF-PWV); and higher prevalence rate of hypertension, diabetes, coronary artery disease (CAD); and higher rate on medication of statins, diabetes drug and cardiovascular drug (all P<0.001). After multiple adjustment for age, sex, smoke, FPG, blood lipids, hs-CRP, SBP, diastolic blood pressure (DBP), PP, CF-PWV, hypertension, diabetes, CAD and medications, the OR of HbA1c for low ABI was of statistical significance (95% CI: 1.204-1.410, P<0.001). After further multivariate adjustment analysis by linear regression, with left and right ABI as dependent variables, the results showed that HbA1c was independently linearly correlated to left and right ABI (all P<0.001).

CONCLUSIONS

HbA1c was an independent associated factor of lower ABI and linearly correlated to ABI level independent of fasting plasma glucose and other cardiovascular factors. We should not only focus on the HbA1c in diabetes mellitus patients, but also people with lower ABI.

Impact of serum 1,5-anhydro-D-glucitol level on the prediction of severe coronary artery calcification: an intravascular ultrasound study

BACKGROUND

A low 1,5-anhydro-D-glucitol (AG) blood level is considered a clinical marker of postprandial hyperglycemia. Previous studies reported that 1,5-AG levels were associated with vascular endothelial dysfunction and coronary artery disease (CAD). However, the association between 1,5-AG levels and coronary artery plaque in patients with CAD is unclear.

METHODS

This study included 161 patients who underwent percutaneous coronary intervention for CAD. The culprit plaque characteristics and the extent of coronary calcification, which was measured by the angle of its arc, were assessed by preintervention intravascular ultrasound (IVUS). Patients with chronic kidney disease or glycosylated hemoglobin ≥ 7.0 were excluded. Patients were divided into 2 groups according to serum 1,5-AG levels (< 14.0 μg/mL vs. ≥ 14 μg/mL).

RESULTS

The total atheroma volume and the presence of IVUS-attenuated plaque in the culprit lesions were similar between groups. Calcified plaques were frequently observed in the low 1,5-AG group (p = 0.06). Compared with the high 1,5-AG group, the low 1,5-AG group had significantly higher median maximum calcification (144° vs. 107°, p = 0.03) and more frequent calcified plaques with a maximum calcification angle of ≥ 180° (34.0% vs. 13.2%, p = 0.003). Multivariate logistic regression analysis showed that a low 1,5-AG level was a significant predictor of a greater calcification angle (> 180°) (OR 2.64, 95% CI 1.10-6.29, p = 0.03).

CONCLUSIONS

Low 1,5-AG level, which indicated postprandial hyperglycemia, was associated with the severity of coronary artery calcification. Further studies are needed to clarify the effects of postprandial hyperglycemia on coronary artery calcification.

Thoracic aortic calcification across the clinical dysglycemic continuum in a large Asian population free of cardiovascular symptoms

Thoracic aortic calcification (TAC) is tightly linked to pathological atherosclerosis and associated with certain cardiovascular diseases. While diabetes mellitus (DM) is known as a coronary heart disease equivalent, we examined the presence of TAC across the dysglycemic spectrum of diabetes mellitus (DM). We consecutively studied 3003 asymptomatic ethnic Asians underwent annual cardiovacular health survey, and further categorized them into: 1) 1760 normo-glycemic, 2) 968 pre-diabetic, and 3) 274 overt DM based on dysglycemic indices and medical histories. Several TAC parameters were assessed using non-contrast multi-detector computed tomography (MDCT), and related to dysglycemic indices or diabetes mellitus status. A remarkably graded increases of adjusted total TAC calcium burden, volume and density were seen across Non-diabetes, Pre-diabetes, and diabetes mellitus categories and positively correlated with all dysglycemic profiles (all p<0.001). Multi-variate logistic and linear regression models demonstrated independent associations between greater TAC density and all dysglycemic indices (Coef: 2.5, 1.4, 6.8 for fasting, postprandial sugar and HbA1c) and diabetes mellitus status (all p<0.05). Furthermore, Receiver-operating characteristic curves (ROC) showed fasting sugar and postprandial sugar set at 103mg/dL and 111mg/dL, separately, with HbA1c set at 5.8% all predict the presence of aortic calcification. Dysglycemic status, even without overt diabetes mellitus, were tighly linked to subclinical, pathological thoracic aortic calcification.

Echolucency-based phenotype in carotid atherosclerosis disease for risk stratification of diabetes patients

AIM

The study investigated the association of carotid ultrasound echolucent plaque-based biomarker with HbA1c, measured as age-adjusted grayscale median (AAGSM) as a function of chronological age, total plaque area, and conventional grayscale median (GSM_conv).

METHODS

Two stages were developed: (a) automated measurement of carotid parameters such as total plaque area (TPA); (b) computing the AAGSM as a function of GSM_conv, age, and TPA. Intra-operator (novice and experienced) analysis was conducted.

RESULTS

IRB approved, 204 patients' left/right CCA (408 images) ultrasound scans were collected: mean age: 69 ± 11 years; mean HbA1c: 6.12 ± 1.47%. A moderate inverse correlation was observed between AAGSM and HbA1c (CC of -0.13, P = 0.01), compared to GSM (CC of -0.06, P = 0.24). The RCCA and LCCA showed CC of -0.18, P < 0.01 and -0.08; P < 0.24. Female and males showed CC of -0.29, P < 0.01 and -0.10, P = 0.09. Using the threshold for AAGSM and HbA1c as: low-risk (AAGSM > 100; HbA1c < 5.7%), moderate-risk (40 < AAGSM < 100; 5.7% < HbA1c < 6.5%) and high-risk (AAGSM < 40; HbA1c > 6.5%), the area under the curve showed a better performance of AAGSM over GSM_conv. A paired t-test between operators and expert (P < 0.0001); inter-operator CC of 0.85 (P < 0.0001).

CONCLUSIONS

Echolucent plaque in patients with diabetes can be more accurately characterized for risk stratification using AAGSM compared to GSM_conv.

The impact of non-alcoholic fatty liver disease and metabolic syndrome on the progression of coronary artery calcification

It is unclear whether non-alcoholic fatty liver disease (NAFLD) is an independent risk factor for cardiovascular disease. We examined the independent impact of NAFLD on the progression of the coronary artery calcification (CAC) score, a well-known marker of atherosclerosis progression. We examined 1,173 asymptomatic participants who underwent repeated CAC score measurement during routine health examinations. The subjects were categorised into four groups based on the presence (+) or absence (−) of NAFLD and metabolic syndrome (MetS). The progression of CAC score was defined as either incident CAC in a CAC-free population at baseline or an increase of ≥2.5 units between the baseline and the final square roots of the CAC scores of participants with detectable CAC at baseline. CAC progression was seen in 18.6% (98/526), 28.3% (77/272), 29.1% (30/103) and 32.0% (87/272) of the subjects with NAFLD(−)/MetS(−), NAFLD(+)/MetS(−), NAFLD(−)/MetS(+) and NAFLD(+)/MetS(+), respectively. The subjects with NAFLD(+)/MetS(+) and NAFLD(+)/MetS(−) had a significantly higher risk of CAC progression than those with NAFLD(−)/MetS(−) (multivariate-adjusted odds ratio [OR]: 1.76; 95% confidence interval [CI]: 1.18–2.62 and multivariate-adjusted OR: 1.53, 95% CI: 1.05–2.23, respectively). NAFLD is an independent risk factor for CAC progression, irrespective of the presence of MetS.

Relationship between left main and left anterior descending arteries bifurcation angle and coronary artery calcium score in chronic kidney disease: A 3-dimensional analysis of coronary computed tomography

Background

A high coronary artery calcium score (CACS) predicts a poor prognosis in patients with coronary artery disease. We examined the relationship between the bifurcation angle and the CACS of the left main (LM) and left anterior descending (LAD) arteries in patients suffering from chronic kidney disease (CKD).

Methods

We analyzed the data of 121 patients who underwent coronary computed tomography between October 2014 and June 2015 and whose estimated glomerular filtration rate (eGFR) was <60 ml/min/1.73 m². The LM-LAD bifurcation angle was measured by 3-dimensional coronary computed tomography. The CACS of the LM-LAD arteries was also calculated. We excluded stent recipients and patient who had undergone coronary artery bypass graft surgery.

Results

In the overall sample, the mean ± standard deviation (range) LM-LAD bifurcation angle was 35.9 ± 11.4° (6.8–79.4°) and mean CACS was 227 ± 351 (0 to 1,695). The mean LM-LAD arteries angle was 40.3° ± 10.0° in 39 patients whose CACS was ≥200, versus 33.8° ± 11.6° in 82 patients with CACS <200 (p = 0.003). A weak, but positive correlation (r = 0.269, p = 0.003) was observed between the LM-LAD arteries angle and CACS of the LM-LAD arteries. By multiple variable analysis, hemoglobin A1c, triglycerides, eGFR and the LM-LAD arteries angle were independent predictors of a high CACS of the LM-LAD arteries.

Conclusion

In patients with CKD, a wide LM-LAD arteries angle was associated with a high CACS of the LM-LAD arteries. The prognostic value of this observation warrants further evaluation.

Evaluation of the impact of glycemic status on the progression of coronary artery calcification in asymptomatic individuals

BACKGROUND

Data on the influence of glycemic status on the progression of coronary calcification, an important marker for future adverse cardiovascular events, are limited.

METHODS

Data from the Korea Initiatives on Coronary Artery Calcification (KOICA) registry on 12,441 asymptomatic Korean adults (52 ± 9 years, 84.2% males) without previous history of coronary artery disease and stroke, who underwent serial coronary artery calcification (CAC) screening examinations, were included in this study. The median inter-scan period was 3.0 (2.0-4.8) years. All participants were categorized into three groups based on their glycemic status: normal (n = 6578), pre-diabetes (n = 4146), and diabetes (n = 1717). CAC progression was defined as a difference ≥ 2.5 between the square roots (√) of the baseline and follow-up CAC scores.

RESULTS

The incidence of CAC progression was significantly different between the three groups (normal, 26.3%; pre-diabetes, 30.9%; and diabetes, 46.9%; p < 0.001). In the univariate logistic analysis, the risk of CAC progression was higher in the pre-diabetes (odds ratio [OR] 1.253; 95% confidential interval [CI] 1.150-1.366) and diabetes (OR 2.471; 95% CI 2.215-2.758) groups than in the normal group (p < 0.001, both). In the multivariate logistic analysis, the risk of CAC progression was not significantly different between the normal and pre-diabetes groups but was significantly higher in the diabetes group than in the normal group.

CONCLUSIONS

In asymptomatic subjects, diabetes had an incremental impact on CAC progression; however, pre-diabetes did not increase the risk of CAC progression after adjusting for confounding factors.

Fatty liver disease determines the progression of coronary artery calcification in a metabolically healthy obese population

OBJECTIVES

Metabolically healthy obese (MHO) phenotype describes an obese state with a favorable metabolic profile. However, the prognosis of this subpopulation remains controversial. We aimed to examine whether MHO phenotype is associated with progression of atherosclerotic activity, reflected as the changes in coronary artery calcification (CAC) over time. If so, we sought to determine the role of fatty liver disease (FLD), the hallmark of hepatic steatosis, in this progression.

METHODS

We enrolled 1,240 asymptomatic subjects who underwent repeated CAC score measurement during routine health examinations. CAC score progression was defined as either incident CAC in a population free of CAC at baseline, or an increase by ≥2.5 units between the baseline and final square root of CAC scores in participants with detectable CAC at baseline. Subjects were stratified by body mass index (cut-off, 25.0 kg/m2) and metabolic health state using Adult Treatment Panel-III criteria. FLD was assessed via ultrasonography.

RESULTS

Over 2.9 years of follow-up, 25.2% of total subjects exhibited CAC score progression. The MHO phenotype was not significantly associated with CAC score progression (multivariate adjusted-odds ratio [OR], 1.45; 95% confidence interval [CI], 0.93-2.25), as compared to the metabolically healthy non-obese (MHNO) phenotype. However, subgroup analysis indicated that the MHO/FLD phenotype was significantly associated with CAC score progression (multivariate adjusted-OR, 2.37; 95% CI, 1.34-4.16), as compared to the MHNO/no FLD phenotype, whereas the MHO/no FLD phenotype was not (multivariate adjusted OR, 1.25; 95% CI, 0.71-2.24).

CONCLUSIONS

Obese individuals with FLD have an increased risk of atherosclerosis progression, despite their healthy metabolic profile. Preventive interventions targeting cardiometabolic risk factors should be considered in such individuals, regardless of the weight status.

Association between metformin use and below-the-knee arterial calcification score in type 2 diabetic patients

Background

Vascular calcification (VC) is common in type 2 diabetes, and is associated with cardiovascular complications. Recent preclinical data suggest that metformin inhibits VC both in vitro and in animal models. However, metformin’s effects in patients with diabetic VC have not previously been characterized. The present study investigated the association between metformin use and lower-limb arterial calcification in patients with type 2 diabetes and high cardiovascular risk.

Methods

The DIACART cross-sectional cohort study included 198 patients with type 2 diabetes but without severe chronic kidney disease. Below-the-knee calcification scores were assessed by computed tomography and supplemented by colour duplex ultrasonography. Data on anti-diabetic drugs were carefully collected from the patients’ medical records and during patient interviews. Biochemical and clinical data were studied as potential confounding factors.

Results

Metformin-treated patients had a significantly lower calcification score than metformin-free patients (mean ± standard deviation: 2033 ± 4514 and 4684 ± 9291, respectively; p = 0.01). A univariate analysis showed that metformin was associated with a significantly lower prevalence of severe below-the-knee arterial calcification (p = 0.02). VC was not significantly associated with the use of other antidiabetic drugs, including sulfonylureas, insulin, gliptin, and glucagon like peptide-1 analogues. A multivariate logistic regression analysis indicated that the association between metformin use and calcification score (odds ratio [95% confidence interval] = 0.33 [0.11–0.98]; p = 0.045) was independent of age, gender, tobacco use, renal function, previous cardiovascular disease, diabetes duration, neuropathy, retinopathy, HbA_1c levels, and inflammation.

Conclusions

In patients with type 2 diabetes, metformin use was independently associated with a lower below-the-knee arterial calcification score. This association may contribute to metformin’s well-known vascular protective effect. Further prospective investigations of metformin’s potential ability to inhibit VC in patients with and without type 2 diabetes are now needed to confirm these results.

Progression of coronary artery calcification is stronger in poorly than in well controlled diabetes: Results from the Heinz Nixdorf Recall Study

AIM

To assess associations between HbA1c and progression of coronary artery calcification (CAC) in persons with and without diabetes.

METHODS

In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany (N=3453, aged 45-74years), CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. At baseline, participants were divided into five groups: poorly (HbA1c≥7.0%) and well (HbA1c<7.0%) controlled previously known diabetes (group I/II); no previously known diabetes with HbA1c ≥6.5% (group III), HbA1c 5.7-6.4% (group IV), and HbA1c <5.7% (group V). We fitted linear, logistic and robust Poisson regression models to assess associations between diabetes group and PF₅ (factor by which CAC after 5-year follow-up is larger than baseline CAC), and categories of CAC change, respectively.

RESULTS

Relative to group V, adjusted percentage increase of the geometric mean of PF₅ (95% CI) was: 69.1% (33.9%;113.6%), 15.4% (-5.6%;41.1%), -4.1% (-22.2%;18.2%), 4.2% (-5.4%;14.8%) for groups I-IV, respectively. The corresponding odds ratios for annual CAC increase ≥100 Agatston units (reference: <10) were 10.0 (4.8;20.6), 4.0 (2.1;7.6), 1.5 (0.7;3.2), and 1.1 (0.7;1.8).

CONCLUSIONS

In known diabetes, CAC progression was stronger in poor diabetes control. For newly detected diabetes diagnosed by HbA1c ≥6.5%, associations with CAC progression were weak.

Pathology of Human Coronary and Carotid Artery Atherosclerosis and Vascular Calcification in Diabetes Mellitus

The continuing increase in the prevalence of diabetes mellitus in the general population is predicted to result in a higher incidence of cardiovascular disease. Although the mechanisms of diabetes mellitus-associated progression of atherosclerosis are not fully understood, at clinical and pathological levels, there is an appreciation of increased disease burden and higher levels of arterial calcification in these subjects. Plaques within the coronary arteries of patients with diabetes mellitus generally exhibit larger necrotic cores and significantly greater inflammation consisting mainly of macrophages and T lymphocytes relative to patients without diabetes mellitus. Moreover, there is a higher incidence of healed plaque ruptures and positive remodeling in hearts from subjects with type 1 diabetes mellitus and type 2 diabetes mellitus, suggesting a more active atherogenic process. Lesion calcification in the coronary, carotid, and other arterial beds is also more extensive. Although the role of coronary artery calcification in identifying cardiovascular disease and predicting its outcome is undeniable, our understanding of how key hormonal and physiological alterations associated with diabetes mellitus such as insulin resistance and hyperglycemia influence the process of vascular calcification continues to grow. Important drivers of atherosclerotic calcification in diabetes mellitus include oxidative stress, endothelial dysfunction, alterations in mineral metabolism, increased inflammatory cytokine production, and release of osteoprogenitor cells from the marrow into the circulation. Our review will focus on the pathophysiology of type 1 diabetes mellitus- and type 2 diabetes mellitus-associated vascular disease with particular focus on coronary and carotid atherosclerotic calcification.

Update on pre-diabetes: Focus on diagnostic criteria and cardiovascular risk

Pre-diabetes, which is typically defined as blood glucose concentrations higher than normal but lower than the diabetes threshold, is a high-risk state for diabetes and cardiovascular disease development. As such, it represents three groups of individuals: Those with impaired fasting glucose (IFG), those with impaired glucose tolerance (IGT) and those with a glycated haemoglobin (HbA_1c) between 39-46 mmol/mol. Several clinical trials have shown the important role of IFG, IGT and HbA_1c-pre-diabetes as predictive tools for the risk of developing type 2 diabetes. Moreover, with regard to cardiovascular disease, pre-diabetes is associated with more advanced vascular damage compared with normoglycaemia, independently of confounding factors. In view of these observations, diagnosis of pre-diabetes is mandatory to prevent or delay the development of the disease and its complications; however, a number of previous studies reported that the concordance between pre-diabetes diagnoses made by IFG, IGT or HbA_1c is scarce and there are conflicting data as to which of these methods best predicts cardiovascular disease. This review highlights recent studies and current controversies in the field. In consideration of the expected increased use of HbA_1c as a screening tool to identify individuals with alteration of glycaemic homeostasis, we focused on the evidence regarding the ability of HbA_1c as a diagnostic tool for pre-diabetes and as a useful marker in identifying patients who have an increased risk for cardiovascular disease. Finally, we reviewed the current evidence regarding non-traditional glycaemic biomarkers and their use as alternatives to or additions to traditional ones.

2013 ACC/AHA Cholesterol Guideline Versus 2004 NCEP ATP III Guideline in the Prediction of Coronary Artery Calcification Progression in a Korean Population

BACKGROUND

Since the release of the 2013 American College of Cardiology/American Heart Association (ACC/AHA) guidelines, significant controversy has surrounded the applicability of the new cholesterol guidelines and the Pooled Cohort Equations. In this present study, we investigated whether eligibility for statin therapy determined by the 2013 ACC/AHA guidelines on the management of blood cholesterol is better aligned with the progression of coronary artery calcification (CAC) detected by coronary computed tomography angiography (CCTA) than the previously recommended 2004 National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III guidelines.

METHODS AND RESULTS

We enrolled 1246 asymptomatic participants who underwent repeated CAC score measurement during routine health examinations. The CAC score progression was defined as either incident CAC in a population free of CAC at baseline or increase ≥2.5 units between the baseline and final square root of CAC scores participants who had detectable CAC at baseline examination. Application of the ACC/AHA guidelines to the study population increased the proportion of statin-eligible subjects from 20.5% (according to ATP III) to 54.7%. Statin-eligible subjects, as defined by ACC/AHA guidelines, showed a higher odds ratio for CAC score progression than those considered statin eligible according to ATP III guidelines (2.73 [95% CI, 2.07-3.61] vs 2.00 [95% CI, 1.49-2.68]).

CONCLUSIONS

Compared with the ATP III guidelines, the new ACC/AHA guidelines result in better discrimination of subjects with cardiovascular risk detected by CAC score progression in an Asian population.

Relationship of Insulin Resistance to Prevalence and Progression of Coronary Artery Calcification Beyond Metabolic Syndrome Components: Shiga Epidemiological Study of Subclinical Atherosclerosis

OBJECTIVE

The association between insulin resistance (IR) and coronary artery calcification (CAC) has been uncertain after adjustment for metabolic syndrome components. We aimed to evaluate whether IR is associated with CAC prevalence or progression independently of metabolic syndrome components.

APPROACH AND RESULTS

We conducted a population-based study in a random sample of Japanese men aged 40 to 79 years and determined IR using the homeostasis model assessment of insulin resistance (HOMA-IR). The associations of HOMA-IR and other diabetic parameters per 1-SD increase with CAC prevalence and progression were evaluated using multivariable logistic regression. Of 1006 total participants at baseline (mean age, 64±10 years), CAC prevalence was observed in 646 (64.2%), and of 789 participants at follow-up (mean duration, 4.9±1.3 years), CAC progression was observed in 365 (46.3%). After adjustment for covariates including metabolic syndrome components, higher HOMA-IR was independently associated with CAC prevalence (adjusted odds ratio 1.34, 95% confidence interval 1.10-1.63; P=0.003) and progression (odds ratio 1.32, 95% confidence interval 1.09-1.60; P=0.004). In participants without diabetes mellitus, positive associations were similarly observed (prevalence: odds ratio 1.29, 95% confidence interval 1.04-1.60; P=0.022; and progression: odds ratio 1.25, 95% confidence interval 1.01-1.55; P=0.042), whereas glucose and hemoglobin A1c were not associated with CAC prevalence and progression.

CONCLUSIONS

Higher IR was associated with CAC prevalence and progression independently of metabolic syndrome components in Japanese men and also in those without diabetes mellitus. Among diabetic measures, IR and fasting insulin, but not glucose and hemoglobin A1c, predicted CAC progression in men without diabetes mellitus.

Mechanisms of ectopic calcification: implications for diabetic vasculopathy

Vascular calcification (VC) is the deposition of calcium/phosphate in the vasculature, which portends a worse clinical outcome and predicts major adverse cardiovascular events. VC is an active process initiated and regulated via a variety of molecular signalling pathways. There are mainly two types of calcifications: the media VC and the intima VC. All major risk factors for cardiovascular disease (CVD) have been linked to the presence/development of VC. Besides the risk factors, a genetic component is also operative to determine arterial calcification. Several events take place before VC is established, including inflammation, trans-differentiation of vascular cells and homing of circulating pro-calcific cells. Diabetes is an important predisposing factor for VC. Compared with non-diabetic subjects, patients with diabetes show increased VC and higher expression of bone-related proteins in the medial layer of the vessels. In this review we will highlight the mechanisms underlying vascular calcification in diabetic patients.

The association of hemoglobin A1c and high risk plaque and plaque extent assessed by coronary computed tomography angiography

The objective of this study was to investigate the relationship of Hemoglobin A1c (HbA1c) and plaque characteristics including high risk plaque and plaque extent. We retrospectively examined 1079 consecutive coronary computed tomography (CT) angiography scans and the HbA1c results. We divided the patients into four groups by the HbA1c status: non-diabetic, ≤6.0; borderline, 6.1-6.4; diabetic low, 6.5-7.1; diabetic high, >7.1. We determined segment involvement score >4 as extensive disease. High risk plaque was defined as two feature positive (FP) plaque which consists of positive remodeling (remodeling index >1.1) and low attenuation (<30 HU). Univariate and multivariate analysis including conventional cardiovascular risk factors, symptoms and medication was performed. Univariate analysis showed that diabetic patients as well as borderline patients were significantly related with 2FP plaque and extensive disease. Although the relationship of borderline patients and 2FP plaque was marginal in multivariate analysis [odds ratio (OR) 1.53, 95% confidence interval (CI) 0.95-2.40, p = 0.07], the elevation of HbA1c was strongly associated with 2FP plaque (diabetic low, OR 2.19, 95% CI 1.37-3.45, p < 0.005; diabetic high, OR 4.14, 95% CI 2.57-6.67, p < 0.0005). The association of HbA1c elevation and extensive disease was quite similar between borderline and diabetic patients (borderline, OR 1.96, 95% CI 1.29-2.95, p < 0.005; diabetic low, OR 1.94, 95% CI 1.25-3.01, p < 0.005; diabetic high, OR 2.19, 95% CI 1.39-3.43, p < 0.005). Patients with elevated HbA1c of >6.0 are potentially at risk for future cardiovascular events due to increased high risk plaque and extensive disease, even below the diabetic level of 6.5. Coronary CT could be used for risk stratification of these patients.

Oxidized LDL and Fructosamine Associated with Severity of Coronary Artery Atherosclerosis in Insulin Resistant Pigs Fed a High Fat/High NaCl Diet

Background

Insulin-resistant subjects develop more severe and diffuse coronary artery atherosclerosis than insulin-sensitive controls but the mechanisms that mediate this atherosclerosis phenotype are unknown.

Research Objective

To determine the metabolic parameters that associate with the severity of coronary atherosclerosis in insulin resistant pigs fed a high fat/high NaCl diet.

Key Methods

The primary endpoint was severity of coronary atherosclerosis in adult pigs (Sus scrofa, n = 37) fed a high fat diet that also contained high NaCl (56% above recommended levels) for 1 year.

Principal Findings

Twenty pigs developed severe and diffuse distal coronary artery atherosclerosis (i.e., severe = intimal area as a percent medial area > 200% in at least 2 coronary artery cross sections and diffuse distal = intimal area as a percent medial area ≥ 150% over 3 sections separated by 2 cm in the distal half of the coronary artery). The other 17 pigs had substantially less coronary artery atherosclerosis. All 37 pigs had blood pressure in a range that would be considered hypertensive in humans and developed elevations in total and LDL and HDL cholesterol, weight gain, increased backfat, and increased insulin resistance (Bergman Si) without overt diabetes. Insulin resistance was not associated with atherosclerosis severity. Five additional pigs fed regular pig chow also developed increased insulin resistance but essentially no change in the other variables and little to no detectible coronary atherosclerosis. Most importantly, the 20 high fat/high NaCl diet -fed pigs with severe and diffuse distal coronary artery atherosclerosis had substantially greater increases (p< 0.05) in oxidized LDL (oxLDL) and fructosamine consistent with increased protein glycation.

Conclusion

In pigs fed a high fat/high NaCl diet, glycated proteins are induced in the absence of overt diabetes and this degree of increase is associated with the development of severe and diffuse distal coronary artery atherosclerosis.

Individuals with prediabetes identified by HbA1c undergoing coronary angiography have worse cardiometabolic profile than those identified by fasting glucose

BACKGROUND

Type 2 diabetes mellitus has well known deleterious effects on coronary artery disease (CAD). The role of milder hyperglycemic states such as prediabetes (PD) on CAD is debatable. Glycated hemoglobin (HbA1c) has recently been advocated as a diagnostic tool for diabetes mellitus (DM) and PD. This study aims to assess the cardiometabolic risk profile and coronary lesions of patients with PD undergoing coronary angiography identified either by fasting plasma glucose (FPG) or HbA1c levels.

METHODS

We studied 514 individuals without previously known glucose disturbances. Their glycemic status was assessed by FPG and HbA1c (HPLC) and classified according to ADA guidelines, using each parameter independently, as having normal glucose tolerance (N), PD, or DM. CAD was defined as stenosis greater than 50% in one major coronary vessel or branch. Framingham score was calculated.

RESULTS

Subjects with PD had a similar frequency of CAD compared do N individuals by both FPG (61 vs. 59.3%) and HbA1c (55.4 vs 61.2%) (p non-significant for linear-by-linear association). PD individuals identified by FPG had worse HOMA2B (mean [95% CI] 65.4 [60.9-69.9] vs. 76.6 [71.4-81.9]) and HOMA2-IR (1.10 [0.98-1.22] vs. 0.80 [0.72-0.89]) when compared to N controls. PD individuals identified by HbA1c had higher frequency of Framingham risk above 20% (25.4 vs 11.8%), arterial hypertension (87.8 vs 72.6%), and dyslipidemia (83.8 vs 72%) compared to N individuals. PD associated with an increased number of coronary lesions only when diagnosed by HbA1c (median [interquartile interval] 2 [0-4] PD versus 1 [0-3.75] N, p = 0.03 for trend).

CONCLUSIONS

HbA1c was more effective than FPG in identifying individuals with PD associated with high cardiovascular risk profile in a sample of individuals undergoing coronary angiography.