Circulating adipocyte fatty acid-binding protein is a predictor of cardiovascular events in patients with stable angina undergoing percutaneous coronary intervention

The Association and Joint Effect of Adipocyte Fatty Acid Binding Protein and Obesity Phenotype With Cardiovascular Events

CONTEXT

There is little evidence regarding the joint effect of serum adipocyte fatty acid binding protein (A-FABP) levels and obesity phenotype on the risk of cardiovascular events.

OBJECTIVE

To explore the association between serum A-FABP levels and obesity phenotype defined by fat percentage (fat%) and visceral fat area (VFA), and their joint impact on incident cardiovascular events.

METHODS

A total of 1345 residents (579 men and 766 women) without previous cardiovascular diseases at baseline, with body composition and serum A-FABP data available, were included. A bioelectrical impedance analyzer and magnetic resonance imaging were used to assess fat% and VFA, respectively.

RESULTS

During a mean follow-up of 7.6 years, 136 cases of cardiovascular events (13.9 per 1000 person-years) occurred. Per 1-unit increase in loge-transformed A-FABP levels was associated with an increase in cardiovascular events risk (hazard ratio [HR] 1.87, 95% CI 1.33-2.63). The highest tertiles of fat% and VFA levels were related to higher risks of cardiovascular events (fat%: HR 2.38, 95% CI 1.49-3.81; VFA: HR 1.79, 95% CI 1.09-2.93). The association between A-FABP levels and cardiovascular events was more pronounced in participants with low fat%, regardless of VFA levels. The joint effect of high A-FABP levels and obesity resulted in a greater risk of cardiovascular events.

CONCLUSION

Serum A-FABP levels were significantly associated with the risk of cardiovascular events, and this pattern of association was more prominent among the population with low fat%, which was independent of VFA.

Fatty Acid Binding Proteins 3 and 4 Predict Both All-Cause and Cardiovascular Mortality in Subjects with Chronic Heart Failure and Type 2 Diabetes Mellitus

Subjects with type 2 diabetes mellitus (T2D) are at increased risk for heart failure (HF). The cardiac-specific (FABP3) and adipose-tissue-specific (FABP4) types of the fatty acid binding proteins have been associated with both all-cause and cardiovascular (CV) mortality. The aim of this study was to explore the prognosis value of FABP3 and FABP4 in ambulatory subjects with chronic HF (CHF), with and without T2D. A prospective study involving 240 ambulatory CHF subjects was performed. Patients were followed-up for a mean of 5.78 ± 3.30 years and cause of death (if any) was recorded. Primary endpoints were defined as all-cause and CV death, and a composite endpoint that included CV death or hospitalization for HF was included as a secondary endpoint. Baseline serum samples were obtained and the serum FABP3 and FABP4 concentrations were assessed by sandwich enzyme-linked immunosorbent assay. Survival analysis was performed with multivariable Cox regressions, using Fine and Gray competing risks models when needed, to explore the prognostic value of FABP3 and FABP4 concentrations, adjusting for potential confounders. Type 2 diabetes mellitus was highly prevalent, accounting for 47.5% for total subjects with CHF. Subjects with T2D showed higher mortality rates (T2D: 69.30%; non-T2D: 50.79%, p = 0.004) and higher serum FABP3 (1829.3 (1104.9–3440.5) pg/mL vs. 1396.05 (820.3–2362.16) pg/mL, p = 0.007) and FABP4 (45.5 (27.6–79.8) ng/mL vs. 34.1 (24.09–55.3) ng/mL, p = 0.006) concentrations compared with non-T2D CHF subjects. In the whole study cohort, FABP3 was independently associated with all-cause death, and both FABP3 and FABP4 concentrations were associated with CV mortality. The predictive values of these two molecules for all-cause (FABP3: HR 1.25, 95% CI 1.09–1.44; p = 0.002. FABP4: HR 2.21, 95% CI 1.12–4.36; p = 0.023) and CV mortality (FABP3: HR 1.28, 95% CI 1.09–1.50; p = 0.002. FABP4: HR 4.19, 95% CI 2.21–7.95; p < 0.001) were only statistically significant in the subgroup of subjects with T2D. Notably, FABP4 (HR 2.07, 95% CI 1.11–3.87; p = 0.022), but not FABP3, also predicted the occurrence of the composite endpoint (death or hospitalization for HF) only in subjects with T2D. All these associations were not found in CHF subjects without T2D. Our findings support the usefulness of serum FABP3 and FABP4 concentrations as independent predictors for the occurrence of all-cause and CV mortality in ambulatory subjects with CHF with T2D.

Circulating Biomarkers for Cardiovascular Disease Risk Prediction in Patients With Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of death globally. Risk assessment is crucial for identifying at-risk individuals who require immediate attention as well as to guide the intensity of medical therapy to reduce subsequent risk of CVD. In the past decade, many risk prediction models have been proposed to estimate the risk of developing CVD. However, in patients with a history of CVD, the current models that based on traditional risk factors provide limited power in predicting recurrent cardiovascular events. Several biomarkers from different pathophysiological pathways have been identified to predict cardiovascular events, and the incorporation of biomarkers into risk assessment may contribute to enhance risk stratification in secondary prevention. This review focuses on biomarkers related to cardiovascular and metabolic diseases, including B-type natriuretic peptide, high-sensitivity cardiac troponin I, adiponectin, adipocyte fatty acid-binding protein, heart-type fatty acid-binding protein, lipocalin-2, fibroblast growth factor 19 and 21, retinol-binding protein 4, plasminogen activator inhibitor-1, 25-hydroxyvitamin D, and proprotein convertase subtilisin/kexin type 9, and discusses the potential utility of these biomarkers in cardiovascular risk prediction among patients with CVD. Many of these biomarkers have shown promise in improving risk prediction of CVD. Further research is needed to assess the validity of biomarker and whether the strategy for incorporating biomarker into clinical practice may help to optimize decision-making and therapeutic management.

Positive Associations between Adipocyte Fatty Acid-Binding Protein Level and Central Arterial Stiffness in Peritoneal Dialysis Patients

Background

Adipocyte fatty acid-binding protein (A-FABP) plays essential roles in lipolysis, insulin resistance, and atherosclerosis. This study aimed to evaluate the relationship between serum A-FABP levels and carotid-femoral pulse wave velocity (cfPWV) in peritoneal dialysis (PD) patients.

Methods

This study obtained fasting blood samples from 76 PD patients. A validated tonometry system was used to measure cfPWV. Patients with cfPWV values >10 m/s were classified into the high arterial stiffness group, whereas patients with values ≤10 m/s were classified into the low arterial stiffness group, according to the ESH-ESC 2013 guidelines. Serum A-FABP levels were measured using a commercial enzyme-linked immunosorbent assay kit.

Results

Twenty-five (32.9%) of the 76 PD patients were classified in the high arterial stiffness group. Compared with the patients in the low arterial stiffness group, the high arterial stiffness group was older (P = 0.002) and had a longer PD vintage (P = 0.011), higher diastolic blood pressure (DBP, P = 0.036), higher fasting glucose levels (P = 0.012), higher serum C reactive protein levels (P = 0.001), and higher serum A-FABP levels (P < 0.001). A multivariate logistic regression analysis of the factors significantly associated with central arterial stiffness revealed that A-FABP (odds ratio (OR): 1.165, 95% confidence interval (CI): 1.056–1.284, P = 0.002), age (OR: 1.423, 95% CI: 1.153–1.757, P = 0.001), PD vintage (OR: 1.049, 95% CI: 1.015–1.085, P = 0.005), and DBP (OR: 1.152, 95% CI: 1.033–1.285, P = 0.011) were independent predictors of central arterial stiffness in PD patients. Furthermore, serum A-FABP levels (β = 0.476, adjusted R² change: 0.197, P < 0.001) were significantly positively correlated with cfPWV according to the multivariable forward stepwise linear regression analysis.

Conclusions

A-FABP levels are an independent marker of central arterial stiffness in PD patients.

Fatty Acid Binding Protein-4 and Risk of Cardiovascular Disease: The Cardiovascular Health Study

Background

FABP‐4 (fatty acid binding protein‐4) is a lipid chaperone in adipocytes and has been associated with prognosis in selected clinical populations. We investigated the associations between circulating FABP‐4, risk of incident cardiovascular disease (CVD), and risk of CVD mortality among older adults with and without established CVD.

Methods and Results

In the Cardiovascular Health Study, we measured FABP4 levels in stored specimens from the 1992–993 visit and followed participants for incident CVD if they were free of prevalent CVD at baseline and for CVD mortality through June 2015. We used Cox regression to estimate hazard ratios for incident CVD and CVD mortality per doubling in serum FABP‐4 adjusted for age, sex, race, field center, waist circumference, blood pressure, lipids, fasting glucose, and C‐reactive protein. Among 4026 participants free of CVD and 681 with prevalent CVD, we documented 1878 cases of incident CVD and 331 CVD deaths, respectively. In adjusted analyses, FABP‐4 was modestly associated with risk of incident CVD (mean, 34.24; SD, 18.90; HR, 1.10 per doubling in FABP‐4, 95% CI, 1.00–1.21). In contrast, FABP‐4 was more clearly associated with risk of CVD mortality among participants without (HR hazard ratio 1.24, 95% CI, 1.10–1.40) or with prevalent CVD (HR hazard ratio 1.57, 95% CI, 1.24–1.98). These associations were not significantly modified by sex, age, and waist circumference.

Conclusions

Serum FABP‐4 is modestly associated with risk of incident CVD even after adjustment for standard risk factors, but more strongly associated with CVD mortality among older adults with and without established CVD.

Barth Syndrome: Exploring Cardiac Metabolism with Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Barth syndrome (BTHS) is an X-linked recessive multisystem disorder caused by mutations in the TAZ gene (TAZ, G 4.5, OMIM 300394) that encodes for the acyltransferase tafazzin. This protein is highly expressed in the heart and plays a significant role in cardiolipin biosynthesis. Heart disease is the major clinical manifestation of BTHS with a high incidence in early life. Although the genetic basis of BTHS and tetralinoleoyl cardiolipin deficiency in BTHS-affected individuals are well-established, downstream metabolic changes in cardiac metabolism are still uncovered. Our study aimed to characterize TAZ-induced metabolic perturbations in the heart. Control (PGP1-TAZWT) and TAZ mutant (PGP1-TAZ517delG) iPS-CM were incubated with 13C6-glucose and 13C5-glutamine and incorporation of 13C into downstream Krebs cycle intermediates was traced. Our data reveal that TAZ517delG induces accumulation of cellular long chain acylcarnitines and overexpression of fatty acid binding protein (FABP4). We also demonstrate that TAZ517delG induces metabolic alterations in pathways related to energy production as reflected by high glucose uptake, an increase in glycolytic lactate production and a decrease in palmitate uptake. Moreover, despite mitochondrial dysfunction, in the absence of glucose and fatty acids, TAZ517delG-iPS-CM can use glutamine as a carbon source to replenish the Krebs cycle.

Macrophage fatty acid metabolism and atherosclerosis: The rise of PUFAs

Among the pathways involved in the regulation of macrophage functions, the metabolism of unsaturated fatty acids is central. Indeed, unsaturated fatty acids act as precursors of bioactive molecules such as prostaglandins, leukotrienes, resolvins and related compounds. As components of phospholipids, they have a pivotal role in cell biology by regulating membrane fluidity and membrane-associated cellular processes. Finally, polyunsaturated fatty acids (PUFAs) are also endowed with ligand properties for numerous membrane or nuclear receptors. Although myeloid cells are dependent on the metabolic context for the uptake of essential FAs, recent studies showed that these cells autonomously handle the synthesis of n-3 and n-6 long chain PUFAs such as arachidonic acid and eicosapentaenoic acid. Moreover, targeting PUFA metabolism in macrophages influences pathological processes, including atherosclerosis, by modulating macrophage functions. Omics evidence also supports a role for macrophage PUFA metabolism in the development of cardiometabolic diseases in humans. Currently, there is a renewed interest in the role of n-3/n-6 PUFAs and their oxygenated derivatives in the onset of atherosclerosis and plaque rupture. Purified n-3 FA supplementation appears as a potential strategy in the treatment and prevention of cardiovascular diseases. In this context, the ability of immune cells to handle and to synthesize very long chain PUFA must absolutely be integrated and better understood.

Atherogenic Index of Plasma: Novel Predictive Biomarker for Cardiovascular Illnesses

BACKGROUND/AIM

Cardiovascular diseases (CVD) are the most important cause of mortality globally. Nevertheless, the World Health Organization have declared that a precise and quick recognition of susceptible individuals to develop CVD is imperative to combat those illnesses. Additionally, developing countries need affordable alternatives to effectively prognosticate cardiovascular events. Therefore, the objective of this study was to assess well-established clinical prognostic markers in Mexican women to identify affordable, specific, and useful tools to predict cardiovascular events.

MATERIAL AND METHODS

A cross-sectional study was performed including 340 healthy women. Anthropometric and clinical measurements were acquired from all enrolled individuals. Also, a blood sample of each participant women was obtained to complete biochemical analyses (triglycerides, glucose, total cholesterol, LDL cholesterol, and HDL cholesterol), and serum asymmetric dimethylarginine (ADMA), and adipocyte-fatty acid binding protein (FABP4) determinations. Finally, with anthropometric, clinical and biochemical determinations, atherogenic indices (Framingham risk score, Castelli's risk index, and atherogenic index of plasma) were estimated.

RESULTS

A mean value of 6.5 ± 7.2 was detected for the Framingham risk score, 3.7 ± 1.3 for Castelli's risk index, and 0.12 ± 0.22 for the atherogenic index of plasma (AIP). Circulating mean ADMA and FABP4 levels found in assessed women were 0.68 ± 0.34 mmol/L and 20.3 ± 16.6 ng/mL, respectively. Furthermore, strong positive relationships (p <0.05) between AIP and serum FABP4 and ADMA concentrations were detected after adjustment by traditional CVD risk factors.

CONCLUSION

In conclusion, AIP could be recommended as a potential biomarker in the early diagnosis of CVD events in developing countries.

Serum fatty acid binding protein 4 is positively associated with early stroke recurrence in nondiabetic ischemic stroke

Adipocyte fatty acid–binding protein (FABP4) played critical roles in metabolic syndrome, inflammatory responses and cardiovascular diseases. It aimed to investigate the associations of serum FABP4 levels with early stroke recurrence. This study included the 206 acute ischemic stroke patients hospitalized in our institution. Stroke recurrence events were assessed at the 3-month follow-up. The median of FABP level was 22.6 (IQR, 17.9-31.6) ng/mL in patients with stroke recurrence (N=36), which was higher than in patients without stroke recurrence [16.9 (IQR, 11.8-21.4) ng/mL] (P<0.001). As a continuous variable, the unadjusted and adjusted risk of stroke recurrence would be increased by 12% (OR=1.12 [95% CI 1.06–1.17], P<0.001) and 8% (1.08 [1.02–1.14], P=0.006) for every 1 ng/ml increment of FABP4. The Area under the curve (AUC) of serum FABP4 and NIH Stroke Scale (NIHSS) score for predicting stroke recurrence was 0.73 (95% CI: 0.64–0.82) and 0.72 (95% CI: 0.64–0.81), presenting no discriminating capacity (P=0.45). In the combining model, the AUC of NIHSS score was further improved to 0.77 by FABP4 (0.77; 95% CI: 0.69–0.85), which was significant (P=0.01). The risk of stroke recurrence can be predicted by elevated FABP4 levels in serum of nondiabetic patients with first-ever ischemic stroke.

High Levels of Serum Adipocyte Fatty Acid-binding Protein Predict Cardiovascular Events in Coronary Artery Disease Patients

Background: Adipocyte fatty acid-binding protein (A-FABP) is a cardiometabolic predictor of cardiovascular (CV) disease in humans. We evaluated the association between serum A-FABP levels and future CV events in patients with coronary artery disease (CAD). Methods: A total of 106 CAD patients were enrolled in this study between January and December 2012 and were followed-up until June 30, 2017. The primary endpoint was the incidence of major adverse CV events. Results: During a median follow-up period of 53 months, 44 CV events occurred. Patients with CV events presented higher systolic blood pressure (p = 0.020), total serum cholesterol (p = 0.047), and serum A-FABP levels (p < 0.001) compared with patients without CV events. Kaplan-Meier analysis showed that the cumulative incidence of CV events in the high A-FABP group (median A-FABP concentration of >17.63 ng/mL) was higher than that in the low A-FABP group (log-rank p < 0.001). Multivariate Cox analysis showed that triglycerides (hazard ratio (HR): 1.008, 95% confidence interval (CI): 1.001-1.016, p = 0.026) and serum A-FABP levels (HR: 1.027, 95% CI: 1.009-1.047, p = 0.004) were independently associated with CV events. Conclusion: Serum A-FABP level is a biomarker for future CV events in patients with CAD. Further prospective studies are needed to confirm the mechanisms underlying this association.

Relationship of Selected Adipokines with Markers of Vascular Damage in Patients with Type 2 Diabetes

BACKGROUND

In this study we compared levels of selected adipokines between patients with type 2 diabetes (T2D) and healthy individuals and we determined their relationship with early vascular damage markers.

METHODS

Seventy-seven subjects: 56 patients with T2D (34 men and 22 women) and 21 healthy controls (8 men and 13 women) were examined in this cross-sectional study. Selected adipokines [adiponectin, adipocyte fatty acid-binding protein (A-FABP), fibroblast growth factor 21 (FGF-21), C1q/TNF-related protein 9 (CTRP-9), and allograft inflammatory factor-1 (AIF-1)] with possible cardiovascular impact were measured in all participants. To identify markers of vascular damage von Willebrand factor (vWF), plasminogen activator inhibitor-1 (PAI-1) and arterial stiffness parameters were examined in all the subjects.

RESULTS

When compared with healthy controls, T2D had significantly higher levels of A-FABP [50.0 (38.1-68.6) vs. 28.6 (23.6-32.9) ng/mL, P < 0.0001] and lower levels of adiponectin [5.9 (4.3-9.0) vs. 11.3 (8.7-14.8) μg/mL, P < 0.0001]. Differences in other adipokines were not statistically significant. Adiponectin level correlated negatively with vWF levels (ρ = -0.29, P < 0.05) and PAI-1 (ρ = -0.36, P < 0.05) and A-FABP positively with vWF (ρ = 0.61, P < 0.05) and PAI-1 (ρ = 0.47, P < 0.05) and augmentation index (ρ = 0.26, P < 0.05). Multivariate regression analysis showed independent association between A-FABP and vWF (b = 0.24, P < 0.05).

CONCLUSIONS

Patients with T2D have significantly higher levels of A-FABP and lower levels of adiponectin. These adipokines correlate with indicators of vascular damage and could contribute to cardiovascular risk in patients with T2D. A-FABP may participate in direct endothelium damage.