The relationship between coronary atherosclerosis and body fat distribution measured using dual energy X-ray absorptiometry

The relationship of circulating neuregulin 4 and irisin, and traditional and novel cardiometabolic risk factors with the risk and severity of coronary artery disease

BACKGROUND AND AIMS

Neuregulin 4 (NRG4) and irisin are adipokines that have been suggested to be associated with cardiometabolic risk factors and coronary artery disease (CAD), but the data are inconclusive. This study aimed to investigate the relationship between circulating NRG4 and irisin and cardiometabolic risk factors with CAD risk and severity.

METHODS AND RESULTS

In this cross-sectional study, the presence of CAD and the severity of stenosis (gensini score) were documented based on coronary angiography in 166 adults. Circulating NRG4 and irisin, glucose homeostasis markers, hs-CRP, lipid profiles, blood pressure, and anthropometric measurements were assessed as well. Age (p = 0.005), sex (p = 0.008), SBP (p = 0.033), DBP (p = 0.04), MAP (p = 0.018), FBG (p = 0.012), insulin (p = 0.039) and HOMA-IR (p = 0.01) were significantly associated with odds of having CAD. The final logistic regression model showed that age, sex, HOMA-IR, and MAP were the most important determinants of having CAD. There were no significant associations between circulating irisin and NRG4 with odds of having CAD. The final general linear model showed that being men (β = 17.303, 95% CI: 7.086-27.52, P = 0.001), age (Aβ = 0.712, 95% CI: 0.21-1.214, P = 0.006), HOMA-IR (Aβ = 2.168, 95% CI: 0.256 to 4.079, P = 0.027), and NRG4 level (β = 1.836, 95% CI: 0.119-3.553, P = 0.036) were directly associated with higher gensini score. Participants with the three-vessel disease had a mean increase of about 5 units in circulating irisin compared to those with no clinical CAD (β = 5.221, 95% CI: 0.454-9.987, p = 0.032).

CONCLUSIONS

This study showed that the adipokines NRG4 and Irisin might be associated with the severity of coronary stenosis.

Heart rate reactivity to acute mental stress is associated with adiposity, carotid distensibility, sleep efficiency, and autonomic modulation in young men

Acute mental stress (AMS) increases heart rate (HR) and blood pressure. Since obesity can impair the cardiovascular reactivity to AMS, a better understanding of the mechanisms involved in this response is needed. We aimed to evaluate the cardiovascular reactivity to AMS in young men with normal or excess body fat. We also assessed the association between cardiovascular reactivity to AMS and cardiovascular risk factors, including autonomic modulation, carotid artery distensibility, physical activity levels, and sleep efficiency. Sixty-six young men (26.1 ± 4.1 years old) underwent anthropometric and body fat assessment (dual-energy X-ray absorptiometry) and had right-carotid artery ultrasonography. Accelerometers assessed physical activity levels and sleep efficiency. AMS was induced through the Stroop color-word test while blood pressure, HR, and cardiac interval were measured. Analyses were performed in Normal and Excess fat groups divided by fat mass index (FMI). Continuous data was used for multiple linear regression analyses. An interaction between FMI and time for HR reactivity was observed. Cardiac interval variability analysis showed that only participants with normal fat displayed parasympathetic withdrawal during AMS (P < 0.05). Multiple linear regression analysis supported the role of adiposity and autonomic modulation in the HR reactivity to AMS and showed involvement of carotid distensibility and sleep efficiency (P < 0.05). Carotid distensibility was the only predictor for blood pressure reactivity (P < 0.05). Physical activity was not associated with AMS's cardiovascular reactivity. We conclude that increased adiposity is associated with reduced HR reactivity to AMS, which is possibly linked to an impaired parasympathetic withdrawal. Carotid distension and sleep efficiency seem to contribute to this response.

Association of Body Fluid Volumes and Body Fat Distribution with Abnormal Ankle-Brachial Index

Background

Ankle-brachial index (ABI) is a simple, non-invasive and easy-to-obtain measure for the evaluation of atherosclerotic peripheral arterial disease (PAD). This study aimed to investigate the relationships between body fluid volumes, body composition, body fat distribution and ABI at a population perspective.

Results

Using the US National Health and Nutrition Examination Survey Data (NHANES) during 1999–2000, 2001–2002, and 2003–2004, adults ≥ 40 years old were eligible for inclusion. Univariate and multivariable linear and logistic regression analyses were performed to determine the associations between ABI, body fluid volume and body composition assessed by bioelectrical impedance analysis (BIA), and body fat distribution assessed by dual-energy X-ray absorptiometry (DEXA). After exclusion, the final analytic sample contained 1535 participants who were representative of totally 28,572,458 subjects in the US. After adjustments for relevant confounders, estimated fat mass was significantly and inversely associated with ABI (beta: − 0.0009, 95% CI = − 0.0015, − 0.0003). Total percent fat (beta: − 0.0024, 95% CI = − 0.0033, − 0.0014), trunk percent fat (beta: − 0.0016, 95% CI = − 0.0023, − 0.0009), and percent fat at the four limbs were also significantly and inversely associated with ABI (p < 0.001). In addition, subjects with higher estimated fat mass, total percent fat, trunk percent fat and higher percent fat at the four limbs were all significantly more likely to have abnormal ABI < 0.9. No significant association between parameters of body fluid volume and abnormal ABI was observed.

Conclusions

Estimated fat mass, total percent fat, trunk percent fat and percent fat at the four limbs were significantly and inversely associated with ABI. Subjects with abnormal ABI are more likely to have higher total percent fat, trunk percent fat and the limb fat. These findings fill the knowledge gap on the relationships between atherosclerosis and body fat distribution. Further well-designed prospective studies are needed to confirm the present findings.

Challenges in Optimizing Lipid Management in Women

While there are physiologic differences in lipid metabolism in men and women, pharmacologic therapy is very effective in both with similar management strategies recommended in the current guidelines for the management of dyslipidemia. Despite similar guidelines for treatment, studies have shown that women have worse control of dyslipidemia than their male counterparts. This may stem from multiple contributing factors including underestimation of cardiovascular disease risk in women, decreased prescription and utilization of lipid-lowering therapies, decreased medication adherence, and higher risk of statin intolerance, all of which may contribute to lower attainment of lipid targets. Furthermore, heart disease is the leading cause of mortality in women, with heart disease noted an average of 7-10 years later than in men. This has historically led to the misperception that women are protected from heart disease and can be treated less aggressively. In fact, traditional risk factors for atherosclerotic cardiovascular disease often impact risk in women to a greater extent than they do in men. Unique risk factors such as pregnancy-related disorders also contribute to the level of risk and therefore warrant consideration in risk stratification. This review summarizes the efficacy of contemporary lipid-lowering therapies in women versus men and discusses the challenges that arise with lipid management in women along with potential ways to tackle these obstacles.

Volumes of coronary plaque disease in relation to body mass index, waist circumference, truncal fat mass and epicardial adipose tissue in patients with type 2 diabetes mellitus and controls

OBJECTIVES

Coronary atherosclerosis in patients with type 2 diabetes mellitus may be promoted by regional fat distribution. We investigated the association between anthropometric measures of obesity, truncal fat mass, epicardial adipose tissue and coronary atherosclerosis in asymptomatic patients and matched controls.

METHODS

We examined 44 patients and 59 controls [mean (standard deviation) age 64.4 ± 9.9 vs 61.8 ± 9.7, male 50% vs 47%, diabetes duration mean (standard deviation) 7.7 ± 1.5] with coronary computed tomography angiography. Coronary plaques were quantified as total, calcified, non-calcified and low-density non-calcified plaque volumes (mm³). Regional fat distribution was assessed by dual-energy X-ray absorptiometry, body mass index (kg/m²), waist circumference (cm) and epicardial fat volume (mm³). Endothelial function and systemic inflammation were evaluated by peripheral arterial tonometry (log transformed Reactive Hyperemia Index) and C-reactive protein (mg/L).

RESULTS

Body mass index and waist circumference (p < 0.02) were associated with coronary plaque volumes. Body mass index was associated with low-density non-calcified plaque volume after adjustment for age, sex and diabetes status (p < 0.01). Truncal fat mass (p > 0.51), waist circumference (p > 0.06) and epicardial adipose tissue (p > 0.17) were not associated with coronary plaque volumes in adjusted analyses.

CONCLUSION

Body mass index is associated with coronary plaque volumes in diabetic as well as non-diabetic individuals.

Impact of body fat distribution on long-term clinical outcomes after drug-eluting stent implantation

Background and objective

The distribution of body fat is closely related to cardiovascular disease and outcomes, although its impact on patient prognosis after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) has not been evaluated. We investigated the impact of truncal fat distribution on long-term clinical outcomes after DES treatment.

Methods

In 441 DES-treated patients, dual energy X-ray absorptiometry was performed to assess total and regional body fat distribution after index PCI. The ratio of truncal fat to total body fat mass (%FM_trunk/FM_total) was calculated as a representative parameter for truncal fat distribution. The primary endpoint was major adverse cardiac events (MACE), a composite of ischemia-driven target vessel revascularization (TVR), non-procedural myocardial infarction, cardiac death at 5 years.

Results

During the median follow-up duration of 1780 days, MACE occurred in 22.0% of patients, with the highest-quartile group of %FM_trunk/FM_total having a higher rate than the lowest quartile group (27.8% vs. 15.3%; log rank p = 0.026). The difference was driven by a higher rate of ischemia-driven TVR (25.9% vs. 9.9%; log rank p = 0.008). In multivariable Cox regression analyses, %FM_trunk/FM_total was independently associated with MACE (hazard ratio: 1.075; 95% CI: 1.022–1.131; p = 0.005), but body mass index (BMI) was not.

Conclusions

In DES-treated patients, truncal fat distribution is associated with unfavorable clinical outcomes and is more clinically relevant than BMI.

Anatomic fat depots and cardiovascular risk: a focus on the leg fat using nationwide surveys (KNHANES 2008-2011)

BACKGROUND

Although central fat is a well-known risk factor for cardiovascular disease (CVD) and cardiometabolic disorders, the effect of other regional fats or muscle distribution on CVD risk has not been fully investigated.

METHODS

This was a cross-sectional study using nationally representative samples of 15,686 subjects from the 2008-2011 Korea National Health and Nutrition Examination Survey. Individual CVD risk was evaluated in adults aged ≥20 without prior CVD, using atherosclerotic cardiovascular disease (ASCVD) risk equations according to the 2013 ACC/AHA guidelines. Body composition was assessed by dual X-ray absorptiometry.

RESULTS

Ratio of leg fat to total fat (LF/TF ratio) was the most predictive for CVD among body fat or muscle distribution parameters (AUC = 0.748, 95% CI 0.741-0.755). ASCVD risk score was gradually increased with decreased LF/TF ratio (P < 0.001), and individuals whose LF/TF ratio in lowest tertile tended to belong to the high-risk (10-year risk >10%) group compared to those in the highest tertile (OR = 6.25, 95% CI 5.60-6.98). Subjects in the lowest tertile showed increased risk of cardiometabolic risk factor components including obesity, hypertension, diabetes, dyslipidemia, chronic kidney disease, and albuminuria (OR range 2.57-11.24, all P < 0.001). In addition, a higher LF/TF ratio was associated with decreased ASCVD risk, even in subjects with multiple CVD risk factors. Multiple logistic regression analyses also demonstrated this association (OR = 1.85, 95% CI 1.36-2.52).

CONCLUSIONS

Among various body composition parameters, LF/TF ratio was superior in predicting higher CVD risk and a higher LF/TF ratio was independently associated with decreased risk of CVD and each cardiometabolic risk factor.