The Implication of Coronary Artery Calcium Testing for Cardiovascular Disease Prevention and Diabetes

Artificial Intelligence in Coronary Artery Calcium Scoring Detection and Quantification

Coronary artery calcium (CAC) is a marker of coronary atherosclerosis, and the presence and severity of CAC have been shown to be powerful predictors of future cardiovascular events. Due to its value in risk discrimination and reclassification beyond traditional risk factors, CAC has been supported by recent guidelines, particularly for the purposes of informing shared decision-making regarding the use of preventive therapies. In addition to dedicated ECG-gated CAC scans, the presence and severity of CAC can also be accurately estimated on non-contrast chest computed tomography scans performed for other clinical indications. However, the presence of such "incidental" CAC is rarely reported. Advances in artificial intelligence have now enabled automatic CAC scoring for both cardiac and non-cardiac CT scans. Various AI approaches, from rule-based models to machine learning algorithms and deep learning, have been applied to automate CAC scoring. Convolutional neural networks, a deep learning technique, have had the most successful approach, with high agreement with manual scoring demonstrated in multiple studies. Such automated CAC measurements may enable wider and more accurate detection of CAC from non-gated CT studies, thus improving the efficiency of healthcare systems to identify and treat previously undiagnosed coronary artery disease.

Association of Strict Versus Lenient Cholesterol Lowering with Cardiac Outcomes, Diabetes Progression and Complications, and Mortality in Patients with Diabetes Treated with Statins: Is Less More?

INTRODUCTION

Whereas some guidelines recommend statin use to achieve low-density lipoprotein cholesterol (LDL-C) goal < 70 mg/dL for primary prevention of atherosclerotic cardiovascular disease (ASCVD) in patients at higher risk, others recommend against a target LDL-C level. Achieving a target level < 70 mg/dL commonly requires the use of high intensity statins, which has been associated with higher risk of diabetes progression. The objective of this study is to assess the association of strict (≤ 70 mg/dL) versus lenient (> 70 to100 mg/dL) LDL-C lowering on major adverse cardiovascular events (MACE), diabetes progression, diabetes microvascular complications, and total mortality in patients with diabetes.

METHODS

This was a retrospective propensity score (PS)-matched study from a national cohort of, predominantly male, veterans diagnosed with diabetes without prior cardiovascular disease (from fiscal years 2003-2015), who were initiated on a statin. We created PS to match strict (mean LDL-C during follow-up ≤ 70 mg/dL) versus lenient (mean LDL-C during follow up > 70-100 mg/dL) using 65 baseline characteristics including comorbidities, risk scores, medication classes usage, vital signs, and laboratory data. Outcomes included MACE, diabetes progression, microvascular diabetes complications, and total mortality.

RESULTS

From 80,110 eligible patients, we PS-matched 21,294 pairs of statin initiators with strict or lenient LDL-C lowering. The mean (SD) age was 64 (9.5) years and mean (SD) duration of follow-up was 6 (3) years. MACE was similar in the PS-matched groups [6.1% in strict versus 5.8% in lenient; odds ratio (OR): 1.06; 95% confidence interval (95% CI) 0.98-1.15, P = 0.17]. Diabetes progression was higher among the strict vs lenient group (66.7% in strict versus 64.1% in lenient; OR 1.12; 95% CI 1.08-1.17, P < 0.001). There was no difference in microvascular diabetes complications (22.3% in strict versus 21.9% in lenient; OR 1.02; 95% CI 0.98-1.07, P = 0.31) and no difference in total mortality (14.6% in strict versus 15% in lenient; OR 0.97; 95% CI 0.92-1.02, P = 0.20).

CONCLUSION

Strict compared with lenient lowering of LDL-C with statins in men with diabetes without preexisting ASCVD did not decrease the risk of MACE but was associated with an increased diabetes progression. Clinicians should monitor their patients for diabetes progression upon escalating statins to achieve LDL-C levels ≤ 70 mg/dL.

Subclinical Hypertension-Mediated Organ Damage (HMOD) in Hypertension: Atherosclerotic Cardiovascular Disease (ASCVD) and Calcium Score

Calcium controls numerous events within the vessel wall. Permeability of the endothelium is calcium dependent, as are platelet activation and adhesion, vascular smooth muscle proliferation and migration, and synthesis of fibrous connective tissue. Double-helix computerized tomography is a noninvasive technique that can detect, measure, and compare coronary calcification in the coronary arteries. Despite some convincing evidence about the prognostic value and usefulness of coronary artery calcium score (CACS) in the stratification of cardiovascular risk in the high risk general population and also in hypertensive patients, current guidelines for the management of hypertension, do not include such evaluation among the recommended procedures to be performed in the majority of patients even with the intent to detect hypertension-mediated organ damage (HMOD) in an early phase. On the contrary, the European Society of Cardiology guidelines for the diagnosis and management of chronic coronary syndromes, the 2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease, and the 2018 Cholesterol Clinical Practice Guidelines indicate that the evaluation of CACS may be of some usefulness in specific subpopulations, although this view is not accepted in the US Preventive Services Task Force document. Very recently, the European Society of Cardiology Guidelines on cardiovascular disease prevention in clinical practice stated that CACS estimation may be considered to improve risk classification around treatment decision thresholds. In conclusion, the use of CACS as a diagnostic tool is still controversial. While some evidence exists about is ability to improve stratification of cardiovascular risk in primary prevention, in particular in selected patients who are at intermediate or borderline risk of atherosclerotic cardiovascular disease, there is insufficient evidence to use it as a standard means to assess HMOD.

The role of cardiac computed tomography in predicting adverse coronary events

Cardiac computed tomography (CCT) is now considered a first-line diagnostic test for suspected coronary artery disease (CAD) providing a non-invasive, qualitative, and quantitative assessment of the coronary arteries and pericoronary regions. CCT assesses vascular calcification and coronary lumen narrowing, measures total plaque burden, identifies plaque composition and high-risk plaque features and can even assist with hemodynamic evaluation of coronary lesions. Recent research focuses on computing coronary endothelial shear stress, a potent modulator in the development and progression of atherosclerosis, as well as differentiating an inflammatory from a non-inflammatory pericoronary artery environment using the simple measurement of pericoronary fat attenuation index. In the present review, we discuss the role of the above in the diagnosis of coronary atherosclerosis and the prediction of adverse cardiovascular events. Additionally, we review the current limitations of cardiac computed tomography as an imaging modality and highlight how rapid technological advancements can boost its capacity in predicting cardiovascular risk and guiding clinical decision-making.

Impact of coronary artery calcium testing on patient management

BACKGROUND

Coronary artery calcium (CAC) scoring can identify individuals who may benefit from aggressive prevention therapies. However, there is a paucity of contemporary data on the impact of CAC testing on patient management.

METHODS

Retrospective cohort study of adults who underwent CAC testing at Brigham and Women's Hospital between 2015 and 2019. Information on baseline medications, follow-up medications, lifestyle modification, and downstream cardiovascular testing within one-year post-CAC were obtained from electronic health records.

RESULTS

Of the 839 patients with available baseline and follow-up data, 376 (45%) had a CAC ​= ​0, 289 (34%) had CAC ​= ​1-99, and 174 (21%) had CAC≥100. The mean age at time of CAC testing was 59 ​± ​9.7 years. Patients with higher CAC scores were more likely to be male, have diabetes and hypertension, and have higher low-density lipoprotein cholesterol and lower high-density lipoprotein cholesterol. A non-zero CAC score was associated with initiation of aspirin (41% increase, p ​< ​0.001), anti-hypertensives (9% increase, p ​= ​0.031), and lipid-lowering therapies (114% increase, p ​< ​0.001), whereas CAC ​= ​0 was not. Among individuals with CAC≥100, 75% were started on new or more intense lipid-lowering therapy. Higher calcium scores correlated with increased physician recommendations for diet (p ​= ​0.008) and exercise (p ​= ​0.004). The proportion of cardiovascular downstream testing following CAC was 9.1%, and the majority of patients who underwent additional testing post-CAC had CAC scores ≥100.

CONCLUSION

Approximately half of individuals referred for CAC testing had evidence of calcified coronary plaque, and of those who had significant calcifications (CAC≥100), nearly 90% were prescribed lipid-lowering therapies post-CAC. Rates of downstream non-invasive testing were low and such testing was mostly performed in patients who had at least moderate CAC.

The Influence of Obesity and Metabolic Health on Vascular Health

The prevalence of obesity is rapidly increasing worldwide. Obesity should not be understood only as the accumulation of fat in the body, but instead as a phenomenon that exerts different effects on our health according to the place of fat deposition and its stability. Obesity is the starting point of most metabolic diseases, such as diabetes, hypertension, metabolic syndrome, sleep apnea, and eventually cardiovascular disease. There are different kinds of obesity, ranging from simple obesity to sarcopenic obesity. The main purpose of intervening to address obesity is to decrease the ultimate consequence of obesity-namely, cardiovascular disease. The main mechanism through which obesity, especially abdominal obesity, increases cardiovascular risk is the obesity-induced derangement of metabolic health, leading to the development of metabolic diseases such as diabetes, non-alcoholic fatty liver disease, and metabolic syndrome, which are the main initiators of vascular damage. In this review, I discuss the influence of various types of obesity on the risk of metabolic diseases, and how these diseases increase cardiovascular disease risk.

Application of ensemble machine learning algorithms on lifestyle factors and wearables for cardiovascular risk prediction

This study looked at novel data sources for cardiovascular risk prediction including detailed lifestyle questionnaire and continuous blood pressure monitoring, using ensemble machine learning algorithms (MLAs). The reference conventional risk score compared against was the Framingham Risk Score (FRS). The outcome variables were low or high risk based on calcium score 0 or calcium score 100 and above. Ensemble MLAs were built based on naive bayes, random forest and support vector classifier for low risk and generalized linear regression, support vector regressor and stochastic gradient descent regressor for high risk categories. MLAs were trained on 600 Southeast Asians aged 21 to 69 years free of cardiovascular disease. All MLAs outperformed the FRS for low and high-risk categories. MLA based on lifestyle questionnaire only achieved AUC of 0.715 (95% CI 0.681, 0.750) and 0.710 (95% CI 0.653, 0.766) for low and high risk respectively. Combining all groups of risk factors (lifestyle survey questionnaires, clinical blood tests, 24-h ambulatory blood pressure and heart rate monitoring) along with feature selection, prediction of low and high CVD risk groups were further enhanced to 0.791 (95% CI 0.759, 0.822) and 0.790 (95% CI 0.745, 0.836). Besides conventional predictors, self-reported physical activity, average daily heart rate, awake blood pressure variability and percentage time in diastolic hypertension were important contributors to CVD risk classification.

Coronary Artery Calcium Score - A Reliable Indicator of Coronary Artery Disease?

Coronary artery disease (CAD) is caused by atheromatous blockage of coronary vessels leading to acute coronary events that usually occur when a plaque ruptures and a thrombus forms. CAD is a known cause of significant cardiovascular events, accounting for more than 50% of the deaths in western countries, and most of the patients with CAD remain asymptomatic. The coronary artery calcium (CAC) score has been created as a measure of coronary atherosclerosis. This article has compiled various studies that conclude the clinical relationship between coronary artery calcium and the development of cardiovascular (CV) events by using the CAC score as a reliable indicator of CAD. This article has reviewed the pathophysiology and risk factors of CAD, along with various methods of CAC scoring. It also underlined the reliability of CAC scoring for early detection of CAD in asymptomatic individuals. We emphasized the importance of age-dependent risk factor analysis combined with practical screening tools like CAC scoring for early diagnosis of CAD can help direct the treatment and prevent deaths in asymptomatic individuals.

Value of addition of coronary artery calcium to risk scores in the prediction of major cardiovascular events in patients with type 2 diabetes

BACKGROUND

The increased risk for cardiovascular events in diabetics is heterogeneous and contemporary clinical risk score calculators have limited predictive value. We therefore examined the additional value of coronary artery calcium score (CACS) in outcome prediction in type 2 diabetics without clinical coronary artery disease (CAD).

METHODS

The study examined a population-based cohort of type 2 diabetics (n = 735) aged 55-74 years, recruited between 2006 and 2008. Patients had at least one additional risk factor and no history or symptoms of CAD. Risk assessment tools included Pooled Cohort Equations (PCE) and Multi-Ethnic Study of Atherosclerosis (MESA) 10-year risk score calculators and CACS. The occurrence of myocardial infarction (MI), stroke or cardiovascular death (MACE) was assessed over 10-years.

RESULTS

Risk score calculators predicted MACE and MI and cardiovascular death individually but not stroke. Increasing levels of CACS predicted MACE and its components independently of clinical risk scores, glycated hemoglobin and other baseline variables: hazard ratio (95% confidence interval) 2.92 (1.06-7.86), 6.53 (2.47-17.29) and 8.3 (3.28-21) for CACS of 1-100, 101-300 and > 300 Agatston units respectively, compared to CACS = 0. Addition of CACS to PCE improved discrimination of MACE [AUC of PCE 0.615 (0.555-0.676) versus PCE + CACS 0.696 (0.642-0.749); p = 0.0024]. Coronary artery calcium was absent in 24% of the study population and was associated with very low event rates even in those with high estimated risk scores.

CONCLUSIONS

CACS in asymptomatic type 2 diabetics provides additional prognostic information beyond that obtained from clinical risk scores alone leading to better discrimination between risk categories.

Usefulness of skin advanced glycation end products to predict coronary artery calcium score in patients with type 2 diabetes

AIM

The early identification of type 2 diabetic (T2D) patients at risk of developing coronary artery disease (CAD) remains a challenge. The coronary artery calcium score (CACs) is considered the most sensitive tool for assessing CAD risk in diabetic population, and the identification of a more targeted population in which the CACs would be more cost-efficient seems warranted. The accumulation of advanced glycation end products plays an important role in the pathogenesis of cardiovascular disease (CVD) in patients with diabetes. The aim of this study was to evaluate whether the assessment of skin autofluorescence (SAF) could be useful tool to identify those diabetic patients in whom CACs assessment should be prioritized.

METHODS

Prospective case-control study, comprising 156 subjects with T2D with no history of clinical CVD and 52 non-diabetic subjects matched by age. A value of CACs ≥ 400 Agatston Units (AU) was considered as "high CVD risk." Logistic regression analysis to predict a CACs ≥ 400 AU was performed. Sensibility and specificity were calculated using the optimal cutoff point based on ROC curve.

RESULTS

T2D patients had higher value of SAF compared to controls (p = 0.011). Among subjects with diabetes, 122 presented CACs < 400 AU and 35 CACs ≥ 400 AU. SAF values were significantly higher among the group with CACs ≥ 400AU compared to patients with CACs < 400 (2.96 ± 0.86 vs. 2.59 ± 0.57; p = 0.0035). The logistic regression analysis showed that age, HDL-cholesterol and SAF values were independently related to CACs ≥ 400UA.

CONCLUSION

Our finding suggests that SAF could be useful in selecting T2D patients in whom the screening for CAD by means of CACs assessment would be more cost-effective.

The co-existence of diabetes and subclinical atherosclerosis in rural central Appalachia: Do residential characteristics matter?

Aim Disparities exist in cardiovascular diseases (CVD) and diabetes in the United States (U.S.) with Central Appalachia having disproportionate burden. This study examined prevalence and correlates of CVD risk-factors among patients with diabetes/subclinical atherosclerosis in Central Appalachia.

METHODS

During 2012-2016, 3000 patients from Central Appalachia were screened for subclinical atherosclerosis, using coronary artery calcium (CAC) scores; 419 participants had diabetes. Patients were categorized into four groups, with emphasis on those having subclinical atherosclerosis, CAC score ≥ 1. Descriptive statistics and multilevel multinomial logistic regression were conducted to identify CVD risk and spatial factors associated with co-existence of diabetes and subclinical atherosclerosis.

RESULTS

Among participants, prevalence of CVD risk-factors ranged from 11.7% for current smokers to 69.2% for those with CVD family history. Average BMI was 29.8. Compared to patients with diabetes only, age [RR = 1.07; p ≤ 0.0001], being male [RR = 5.33; p ≤ 0.0001], having hypertension [RR = 2.37; p ≤ 0.05] and being a former smoker were associated with increased likelihood of having diabetes/subclinical atherosclerosis. At the zip-code level, unemployment rate [RR = 1.37; p ≤ 0.05] was significantly associated with having diabetes/subclinical atherosclerosis.

CONCLUSION

Consistent with clinical guidelines, study results suggest the need to integrate CAC screening into primary care diabetes programs while addressing spatial issues that predispose patients to have diabetes/subclinical atherosclerosis.

Coronary Computed Tomography Angiography From Clinical Uses to Emerging Technologies: JACC State-of-the-Art Review

Evaluation of coronary artery disease (CAD) using coronary computed tomography angiography (CCTA) has seen a paradigm shift in the last decade. Evidence increasingly supports the clinical utility of CCTA across various stages of CAD, from the detection of early subclinical disease to the assessment of acute chest pain. Additionally, CCTA can be used to noninvasively quantify plaque burden and identify high-risk plaque, aiding in diagnosis, prognosis, and treatment. This is especially important in the evaluation of CAD in immune-driven conditions with increased cardiovascular disease prevalence. Emerging applications of CCTA based on hemodynamic indices and plaque characterization may provide personalized risk assessment, affect disease detection, and further guide therapy. This review provides an update on the evidence, clinical applications, and emerging technologies surrounding CCTA as highlighted at the 2019 National Heart, Lung and Blood Institute CCTA Summit.

Metformin, resveratrol, and exendin-4 inhibit high phosphate-induced vascular calcification via AMPK-RANKL signaling

Vascular calcification increases the risk of developing cardiovascular disease, and it is closely associated with metabolic disorders such as diabetes mellitus and non-alcoholic fatty liver disease. We investigated whether the activators of AMP-activated protein kinase (AMPK), metformin, resveratrol, and exendin-4, improved inorganic phosphate (Pi)-induced vascular calcification in rat vascular smooth muscle cells (VSMCs) and whether these effects were via AMPK. Pi increased calcium deposition in a dose-dependent manner, and metformin, resveratrol, and exendin-4 significantly decreased calcium deposition in the Pi-treated VSMCs. Moreover, metformin and exendin-4 increased the expression of a SMC marker gene, α-smooth muscle actin, and Ampk and reduced the receptor activator of nuclear factor kappa-Β ligand (Rankl)/osteoprotegerin ratio. Metformin, resveratrol, and exendin-4 reduced the expression of osteoblast differentiation-associated factors, such as runt-related transcription factor 2, bone morphogenic protein-2, p-small mothers against decapentaplegic 1/5/8, and Rankl. Inhibition of AMPK by siRNA adversely affected the anti-calcification effects of metformin, resveratrol, and exendin-4 and reversed the reduction of the expression of Rankl by metformin and exendin-4 in the Pi-treated VSMCs. These data suggest that metformin, resveratrol, and exendin-4 ameliorate Pi-induced vascular calcification by inhibiting osteoblast differentiation of VSMCs, which is mediated by AMPK.

Cardiovascular Risk Heterogeneity in Adults with Diabetes: Selective Use of Coronary Artery Calcium in Statin Use Decision-making

Current American College of Cardiology/American Heart Association and American Diabetes Association guidelines recommend statin therapy for all patients with diabetes between the ages of 40 and 75, including those without cardiovascular disease (CVD). While diabetes is a major CVD risk factor, not all patients with diabetes have an equal risk of CVD. Thus, a more risk-based approach warrants consideration when recommending statin therapy for the primary prevention of CVD. Coronary artery calcium (CAC) is a noninvasive imaging modality that can help risk stratify patients with diabetes for future CVD events. CAC has been extensively studied in large cohorts such as the Multi-Ethnic Study of Atherosclerosis and found to outperform other novel risk stratification tools including carotid intima-media thickness. Moreover, a CAC score of 0 has been shown to be useful in downgrading the estimated risk of a CVD event in patients with diabetes and an intermediate Pooled Cohort Equation score. As clinicians weigh the recommendation for a lifelong therapy and the problem of statin nonadherence and patients weigh concerns about adverse effects of statins, the decision to initiate statin therapy in patients with diabetes is ideally a shared one between patients and providers, and CAC could facilitate this discussion.

Usefulness of the Coronary Artery Calcium Score in Predicting Subsequent Coronary Interventions-A Ten-Year Single-Center Perspective

There is no consensus as to whether the Coronary Artery Calcium Score (CACS) results can affect the therapeutic approach that is selected for coronary artery disease. The aim of this study was to follow patients' management over a period of ten years after application of the CACS. Methods: The research was conducted as a prospective, single-center, long-distance study. In 174 asymptomatic patients (78M; aged 58.9 ± 7.86), a CACS examination using 64-slice computed tomography was performed between 2008 and 2009. The patients were divided into three subgroups according to the CACS results using Agatston Units (AU)-G1: CACS = 0 AU (52 pts); G2: CACS = 1-399 AU (64 pts) and G3: CACS ≥ 400 AU (58 pts). During the ten years of follow-up, the classical cardiovascular risk factors, drugs, diseases, and information about the therapeutic approach that was used (PCI-Percutaneous Coronary Intervention; CABG-Coronary Artery Bypass Graft) were also analyzed. Results: The average time until a percutaneous intervention (PCI) was 825.2 ± 1111.7 and for CABG, it was 529.0 ± 833.6. PCI was performed in 5.8% (G1), 4.7% (G2) and 32.6% (G3) of the cases, respectively; p = 0.0000. CABG was performed in 0% (G1), 1.6% (G2) and 18.9% (G3) of the cases, respectively; 0.0035 Yates. The area under the curve in PCI was 0.783 (95% CI: 0.714-0.841); in CABG, it was 0.825 (95% CI: 0.760-0.878) and the average for both groups was 0.838 (95% CI: 0.774-0.889). Conclusions: The coronary artery calcium score can potentially help to predict the best therapeutic approach for coronary artery disease in a ten-year perspective.

Diabetes, subclinical atherosclerosis and multiple cardiovascular risk factors in hard-to-reach asymptomatic patients

AIM

To examine the association of cardiovascular disease risk factors with and their cumulative effect on coronary artery calcium in hard-to-reach asymptomatic patients with diabetes.

METHODS

A total of 2563 community-dwelling asymptomatic subjects from Central Appalachia participated in coronary artery calcium screening at a heart centre. Binary variable was used to indicate that coronary artery calcium was either present or absent. Independent variables consisted of demographic and modifiable risk factors and medical conditions. Descriptive statistics and multinomial logistic regression analyses were conducted.

RESULTS

In total, 55.8% and 13.7% of study participants had subclinical atherosclerosis (coronary artery calcium ⩾1) and diabetes, respectively. The presence of coronary artery calcium was higher in subjects with diabetes (68.5%) than those without (53.8%). Compared to subjects without diabetes with coronary artery calcium = 0, obesity, hypertension, hypercholesterolaemia and smoking increased the odds of the presence of coronary artery calcium (coronary artery calcium score ⩾1) regardless of diabetes status; however, with larger odds ratios in subjects with diabetes. Compared to subjects without diabetes with coronary artery calcium score = 0, having 3, 4 and ⩾5 risk factors increased the odds of presence of coronary artery calcium in subjects with diabetes by 14.06 (confidence interval = 3.26-62.69), 32.30 (confidence interval = 7.41-140.82) and 47.12 (confidence interval = 10.35-214.66) times, respectively.

CONCLUSION

There is a need for awareness about subclinical atherosclerosis in patients with diabetes and more research about coronary artery calcium in subpopulations of patients.

CT coronary imaging-a fast evolving world

Computed tomography (CT) has become an important modality in the evaluation of coronary artery disease (CAD). The tremendous technological advances in CT in the last two decades has made it possible to obtain high quality images of coronary arteries with high spatial and temporal resolutions. Multiple trials have confirmed the accuracy of CT compared to invasive catheter angiography. CT is also able to evaluate beyond the lumen in characterizing and quantifying atherosclerotic plaques, including evaluation of high risk features. Although CTA has low specificity in identification of lesion-specific ischemia, functional techniques are now possible such as CT myocardial perfusion and CT-fractional flow reserve (FFR) which evaluate the hemodynamic significance of stenosis and help with revascularization strategies. Multi-energy CT provides additional information beyond what is possible with a conventional CT and is useful in variety of clinical applications, including myocardial perfusion imaging, lesion characterization and low contrast studies. Large trials have confirmed the ability of CT to predict major adverse cardiovascular events and recent trials have even demonstrated improved clinical outcomes by using CT for the evaluation of CAD. CT is also useful in structural heart disease and 3 D printing is now increasingly used for surgical/interventional planning. Machine learning is evolving rapidly and is likely to impact diagnosis and management.

Being Metabolically Healthy, the Most Responsible Factor for Vascular Health

The prevalence of obesity is rapidly increasing worldwide. One-thirds of world population is suffering from the deleterious effects of excessive fat and adipose tissue in their body. At the same time, the average life expectancy is becoming higher and higher every decade. Therefore, living healthy and longer is the dream for everyone. Simply being obese is not the primary cause for the consequence of obesity; rather, the depot where the fat is accumulated, is the primary key for the deleterious effects of obesity. Results from historical research suggest that visceral fat increases the risk for cardiovascular and metabolic diseases, such as diabetes, myocardial infarction and ischemic stroke, not subcutaneous fat. Therefore, body mass index (BMI), which reflects body weight relative to height might not reflect the appropriate size of metabolic burden of fat in our body. In contrast, waist circumference, which reflects abdominal obesity, would mirror the metabolic burden of fat better than BMI. Visceral fat is the marker of ectopic fat accumulation. In this review, I will introduce my researches mainly involved in uncovering the clues to the link between metabolic health and cardiovascular disease.

Association Between Coronary Artery Calcification and the Hemoglobin Glycation Index: The Kangbuk Samsung Health Study

CONTEXT

The hemoglobin glycation index (HGI) is known to be correlated with the risk for cardiovascular disease.

OBJECTIVE

To analyze the association between incident coronary artery calcification (CAC) and the changes in HGI among participants without diabetes, over 4 years.

DESIGN, SETTING, PARTICIPANTS, AND OUTCOME MEASURES

A retrospective study of 2052 nondiabetic participants in whom the coronary artery calcium score was measured repeatedly over 4 years, as part of a health checkup program in Kangbuk Samsung Hospital in Korea, and who had no CAC at baseline. The HGI was defined as the difference between the measured and predicted hemoglobin A1c (HbA1c) levels.

RESULTS

A total of 201 participants developed CAC after 4 years, and the mean baseline HGI was significantly higher in those patients. The incidence of CAC gradually increased from the first to the fourth quartile groups of baseline HGI. The odds ratio (OR) for incident CAC was the highest among the four groups divided by the quartiles of the baseline HGI and was significant after adjustment for confounding variables (vs first quartile group: OR, 1.632; 95% confidence interval, 1.024 to 2.601). The incidence of and risk for CAC development were significantly higher than in other groups compared with the low-to-low group after adjustment for confounding factors; however, when baseline HbA1c level was included in the model, only participants with a low-to-high HGI over 4 years showed a significantly increased OR for CAC development compared with the low-to-low group (OR, 1.722; 95% confidence interval, 1.046 to 2.833).

CONCLUSIONS

The participants with a high baseline HGI and consistently high HGI showed a higher risk for incident CAC than those with a low baseline HGI. An increased HGI over 4 years significantly increased the risk for CAC regardless of the baseline HbA1c levels.

Increased risk for development of coronary artery calcification in subjects with non-alcoholic fatty liver disease and systemic inflammation

Background

Recent studies have suggested the importance of non-alcoholic fatty liver disease (NAFLD) and systemic inflammation in the development of atherosclerosis. The aim of this study was to compare the risk for coronary artery calcification (CAC) development according to the status of NAFLD and inflammation over four years of follow-up in subjects without baseline CAC.

Methods

A total of 1,575 participants in a health screening program were divided into four groups according to baseline NAFLD state and high-sensitivity C-reactive protein (hs-CRP) (median 0.06 mg/L) levels as follows: no NAFLD and hs-CRP <0.06 mg/L, no NAFLD and hs-CRP ≥0.06 mg/L, NAFLD and hs-CRP <0.06 mg/L, and NAFLD and hs-CRP ≥0.06 mg/L. Coronary artery calcium score (CACS) was repeatedly measured by multi-detector computed tomography at four-year intervals and CAC development during those intervals was monitored in subjects with baseline CACS = 0.

Results

Over four years, 148 subjects (9.4%) developed CAC. The proportion of subjects who developed CAC was significantly higher in subjects with NAFLD at baseline compared with those without NAFLD at baseline (6.8 vs. 12.4%, p<0.01), and it was also higher in subjects with hs-CRP ≥0.06 mg/L compared with those with hs-CRP <0.06 mg/L (7.2 vs. 11.5%, p<0.01). In addition, the proportion of subjects who developed CAC was highest in subjects with NAFLD and hs-CRP ≥0.06 mg/dL, followed by subjects with NAFLD, subjects without NAFLD and hs-CRP ≥0.06 mg/L, and subjects without NALFD and hs-CRP <0.05 mg/L at baseline, in that order (13.7, 10.0, 8.3, and 5.8%, respectively; p for trend<0.01). The odds ratio for CAC development was highest in subjects with NAFLD and hs-CRP ≥0.06 mg/L (1.67, 95% CI 1.01–2.77), though it was attenuated after adjustment for body mass index.

Conclusions

The concomitant presence of NAFLD and systemic inflammation as assessed by hs-CRP increases the risk of CAC development over four years.