Low Plasma Levels of Fibroblast Growth Factor-21 in Patients with Peripheral Artery Disease

Fibroblast growth factor 21 in heart failure

Fibroblast growth factor 21 (FGF21) is a peptide hormone involved in energy homeostasis that protects against the development of obesity and diabetes in animal models. Its level is elevated in atherosclerotic cardiovascular diseases (CVD) in humans. However, little is known about the role of FGF21 in heart failure (HF). HF is a major global health problem with a prevalence that is predicted to rise, especially in ageing populations. Despite improved therapies, mortality due to HF remains high, and given its insidious onset, prediction of its development is challenging for physicians. The emergence of cardiac biomarkers to improve prediction, diagnosis, and prognosis of HF has received much attention over the past decade. Recent studies have suggested FGF21 is a promising biomarker candidate for HF. Preclinical research has shown that FGF21 is involved in the pathophysiology of HF through the prevention of oxidative stress, cardiac hypertrophy, and inflammation in cardiomyocytes. However, in the available clinical literature, FGF21 levels appear to be paradoxically raised in HF, potentially implying a FGF21 resistant state as occurs in obesity. Several potential confounding variables complicate the verdict on whether FGF21 is of clinical value as a biomarker. Further research is thus needed to evaluate whether FGF21 has a causal role in HF, and whether circulating FGF21 can be used as a biomarker to improve the prediction, diagnosis, and prognosis of HF. This review draws from preclinical and clinical studies to explore the role of FGF21 in HF.

The role of FGF21 in the pathogenesis of cardiovascular disease

ABSTRACT

The morbidity and mortality of cardiovascular diseases (CVDs) are increasing worldwide and seriously threaten human life and health. Fibroblast growth factor 21 (FGF21), a metabolic regulator, regulates glucose and lipid metabolism and may exert beneficial effects on the cardiovascular system. In recent years, FGF21 has been found to act directly on the cardiovascular system and may be used as an early biomarker of CVDs. The present review highlights the recent progress in understanding the relationship between FGF21 and CVDs including coronary heart disease, myocardial ischemia, cardiomyopathy, and heart failure and also explores the related mechanism of the cardioprotective effect of FGF21. FGF21 plays an important role in the prediction, treatment, and improvement of prognosis in CVDs. This cardioprotective effect of FGF21 may be achieved by preventing endothelial dysfunction and lipid accumulating, inhibiting cardiomyocyte apoptosis and regulating the associated oxidative stress, inflammation and autophagy. In conclusion, FGF21 is a promising target for the treatment of CVDs, however, its clinical application requires further clarification of the precise role of FGF21 in CVDs.

Lipid profiles of patients with manifest coronary versus peripheral atherosclerosis - Is there a difference?

AIM

Peripheral arterial disease (PAD) and coronary artery disease (CAD) are both caused by atherosclerosis. Serum lipids and lipoproteins are predictive of the development of atherosclerosis but it is not clear if they differ in the two manifestations, PAD and CAD. We tested whether a more detailed characterization of the lipid and lipoprotein patterns of PAD and CAD allows a clear differentiation between the two atherosclerotic phenotypes.

METHODS

A cohort of 274 statin-naïve patients with either newly diagnosed imaging proven PAD (n = 89) or stable CAD (n = 185) was characterized using nuclear magnetic resonance- and liquid chromatography-tandem mass spectrometry-based advanced lipid and lipoprotein analysis. An independent cohort of 1239 patients with PAD and CAD was used for validation.

RESULTS

We found a significant difference in markers of inflammation as well as ceramide and phosphatidylcholine levels between patients with PAD and CAD. In contrast, basic lipid markers including total cholesterol, LDL cholesterol, HDL cholesterol, lipoprotein(a) or detailed lipoprotein profiles did not differ significantly between patients with PAD and CAD. Applying ratios and scores derived from ceramides and phosphatidylcholines further improved the discrimination between PAD and CAD. These significant differences were independent of body composition, from the status of smoking or type 2 diabetes mellitus, and also from apolipoprotein C-III and other inflammatory parameters which were different between CAD and PAD.

CONCLUSION

The present study clearly suggests that PAD and CAD differ in terms of their ceramide- and phosphatidylcholine-based lipid patterns but not in lipoprotein characteristics.

Is serum Fibroblast Growth Factor 21 associated with the severity or presence of coronary artery disease?

Background

Recent studies have shown that increased circulating concentrations of fibroblast growth factor 21 (FGF21) are associated with obesity, metabolic disorder, and atherosclerosis. However the relationship between FGF21 and coronary artery disease (CAD) is controversial This study was planned to investigate the role of FGF21 in CAD development and CAD severity.

Methods

Seventy-eight patients with stable angina pectoris (SAP) (lesion positive) and 40 control patients (lesion negative) with similar cardiovascular risk factors were included in the study. Serum FGF21 levels were measured by ELISA method. CAD severity was evaluated by using SYNTAX and GENSINI risk scores.

Results

FGF21 concentrations were found significantly higher in the SAP group than in the control group. [101.18 ± 141.62 vs. 47.93 ± 58.74 pg/mL; p = 0.03], no correlation was found between the SYNTAX (r = 0.146 and p = 0.134) and GENSINI (r = 0.211 and p = 0.084) scores with serum FGF21 levels. There was a negative relationship between serum FGF21 and serum HDL-C levels in correlation analysis (r = - 0.272; p = 0.026).

Conclusions

The serum FGF21 levels are different between SAP and control patients. FGF21 is a marker for CAD diagnosis, but not for the evaluation of CAD severity.

Adipokines and Inflammation: Focus on Cardiovascular Diseases

It is well established that adipose tissue, apart from its energy storage function, acts as an endocrine organ that produces and secretes a number of bioactive substances, including hormones commonly known as adipokines. Obesity is a major risk factor for the development of cardiovascular diseases, mainly due to a low grade of inflammation and the excessive fat accumulation produced in this state. The adipose tissue dysfunction in obesity leads to an aberrant release of adipokines, some of them with direct cardiovascular and inflammatory regulatory functions. Inflammation is a common link between obesity and cardiovascular diseases, so this review will summarise the role of the main adipokines implicated in the regulation of the inflammatory processes occurring under the scenario of cardiovascular diseases.

Increased levels of circulating fibroblast growth factor 21 in children with Kawasaki disease

The purpose of this study was to examine the serum levels of fibroblast growth factor 21 (FGF21) in children with acute Kawasaki disease (KD) and to investigate its relationship with coronary artery lesions (CALs). Blood samples from 58 children with KD before intravenous immunoglobulin treatment and from 28 healthy children as control group were collected. Serum FGF21 levels in all participants were measured using enzyme-linked immunosorbent assay, and clinical parameters were tested in all KD patients. Serum FGF21 levels were significantly increased in acute KD patients as compared to the control group. Serum levels of FGF21 were substantially higher in the group of KD patients with CALs (KD-CALs) than in KD patients without CALs (KD-NCALs). Positive relationships between serum levels of FGF21 and percentage of leukomonocytes (L %), C-reactive protein, activated partial thromboplastin time and D-dimer were observed in KD patients. Furthermore, serum FGF21 levels were negatively correlated with red blood cell counts, hemoglobin (Hb), percentage of neutrophils (N %) and albumin. Serum level of FGF21 is associated with inflammation and coagulation. The paradoxical increase in serum FGF21 in acute KD patients may indicate a protective compensatory response.

Relationship of fibroblast growth factor 21 with subclinical atherosclerosis and cardiovascular events: Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Fibroblast growth factor 21 (FGF21) has been suggested as a novel biomarker for cardiovascular disease (CVD), especially in people with high CVD risk. However, it is not known whether FGF21 is a CVD biomarker in an initially healthy cohort. We therefore investigated the relationship of plasma FGF21 levels with measures of subclinical atherosclerosis and cardiovascular events in Multi-Ethnic Study of Atherosclerosis participants without known CVD at baseline.

METHODS

A total of 5788 participants had plasma FGF21 levels measured at the baseline exam (2000-2002). Carotid intima-media thickness (IMT), ankle-brachial index (ABI) and coronary artery calcification (CAC) were measured at baseline. Participants were followed up for incident CVD events over a median period of 14 years.

RESULTS

In cross-sectional analyses adjusting for socio-demographic variables, participants with higher FGF21 levels had higher carotid IMT, lower ABI, and higher prevalence of CAC (p < 0.001). However, these associations were not significant after simultaneously adjusting for demographic, socioeconomic and lifestyle factors, traditional CVD risk factors, and biomarkers of inflammation and hemostasis. Among 5768 patients with follow-up data, 820 developed incident CVD endpoints. Higher baseline FGF21 levels were not associated with the risk for incident CVD endpoints after adjusting for multiple confounding factors (odds ratio 1.03; 95% confidence interval, 0.94-1.12, per SD increase in ln-transformed FGF21 levels).

CONCLUSIONS

Although FGF21 has been suggested as a CVD biomarker for people with high CVD risk, our findings do not support a role of FGF21 as a CVD biomarker in those without a history of CVD.

High plasma FGF21 levels predicts major cardiovascular events in patients treated with atorvastatin (from the Treating to New Targets [TNT] Study)

BACKGROUND

Higher plasma fibroblast growth factor 21 (FGF21) levels predict incident cardiovascular events in type 2 diabetes patients. However, whether FGF21 levels predict cardiovascular events in statin-treated patients in the general population is unknown. We investigated whether FGF21 levels predict major cardiovascular event (MCVE) in the Treating to New Targets (TNT) trial participants.

METHODS

After 8-week run-in on atorvastatin 10 mg/day, 10,001 patients with stable coronary disease in the TNT trial were randomized to 10 mg or 80 mg/day of atorvastatin for a median of 4.9 years. We analyzed data from 1996 patients with plasma FGF21 levels measured at randomization. Among them, 1835 patients had FGF21 measured one-year post-randomization.

RESULTS

Higher ln-transformed FGF21 levels at randomization were associated with higher risk of incident MCVE (adjusted hazards ratio per SD increase = 1.18, P = 0.019). At 1-year post-randomization, FGF21 levels were lower in patients randomized to receive 80 mg versus 10 mg atorvastatin (186.9 versus 207.5 pg/mL respectively, P = 0.006). Higher ln-transformed FGF21 levels at 1-year post-randomization were also associated with higher subsequent risk of MCVEs (adjusted hazards ratio per SD increase = 1.24, P = 0.009). However, changes in FGF21 levels over 1-year were not related to subsequent MCVE risk. FGF21 levels had significant incremental value in net reclassification improvement in MCVE risk prediction.

CONCLUSIONS

Higher plasma FGF21 levels are associated with higher CVD risk in statin-treated high-risk patients. Higher dose atorvastatin is associated with a reduction in FGF21 levels. FGF21 provides incremental value in CVD risk prediction in statin-treated patients.

Fibroblast growth factor 21 association with subclinical atherosclerosis and arterial stiffness in type 2 diabetes

AIM

To evaluate the association of serum FGF21 with subclinical atherosclerosis and pulse wave velocity, a marker of arterial stiffness, in type 2 diabetes Egyptian patients.

PATIENTS AND METHODS

Fasting serum FGF21 was measured in 120 type 2 diabetes patients without clinical atherosclerotic cardiovascular disease (mean age 51.1 ± 7.7 years; 63.3 women). In addition to basic laboratory tests, serum adiponectin and ultrasonographic examination of CIMT, ankle brachial index (ABI) and carotid-femoral pulse wave velocity (cfPWV) were performed.

RESULTS

Patients with subclinical atherosclerosis have higher serum FGF21 than those without (218 ± 66.8 pg/mL Vs 170 ± 43.1 pg/mL, P < 0.001). FGF21 correlated positively with CIMT and cfPWV (P < 0.001) regardless of patient gender. In logistic regression analysis, circulating FGF21 was found to be an independent predictor for subclinical atherosclerosis (P = 0.023) in addition to dyslipidemia, hypertension and adiponectin. FGF21 was also found to be an independent determinant of cfPWV in stepwise multiple regression analysis. ROC curve analysis was done and cutoff high risk FGF21 level of 184 pg/mL for the prediction of subclinical atherosclerosis with a sensitivity and specificity of 66.7%.

CONCLUSIONS

Serum FGF21 levels correlated with carotid intima media thickness and predict subclinical atherosclerosis. Serum FGF21 is also correlated positively with cfPWV and arterial stiffness in type 2 diabetes patients.

Plasma Heme Oxygenase-1 Levels in Patients with Coronary and Peripheral Artery Diseases

Aims

Heme oxygenase-1 (HO-1) is an intracellular enzyme that catalyzes the oxidation of heme to generate CO, biliverdin, and iron. Since these products have antiatherogenic properties, HO-1 may play a protective role against the progression of atherosclerosis. However, plasma HO-1 levels in patients with atherosclerotic diseases, such as coronary artery disease (CAD) and peripheral artery disease (PAD), have not been clarified yet.

Methods

We investigated plasma HO-1 levels by ELISA in 410 consecutive patients undergoing elective coronary angiography who also had an ankle-brachial index (ABI) test for PAD screening.

Results

Of the 410 study patients, CAD was present in 225 patients (55%) (1-vessel (1-VD), n = 91; 2-vessel (2-VD), n = 66; 3-vessel disease (3-VD), n = 68). PAD (ABI < 0.9) was found in 36 (9%) patients. Plasma HO-1 levels did not differ between 225 patients with CAD and 185 without CAD (median 0.44 versus 0.35 ng/mL), but they were significantly lower in 36 patients with PAD than in 374 without PAD (0.27 versus 0.41 ng/mL, P < 0.02). After excluding the 36 patients with PAD, HO-1 levels were significantly higher in 192 patients with CAD than in 182 without CAD (0.45 versus 0.35 ng/mL, P < 0.05). HO-1 levels in 4 groups of CAD(−), 1-VD, 2-VD, and 3-VD were 0.35, 0.49, 0.44, and 0.44 ng/mL, respectively, and were highest in 1-VD (P < 0.05). In the multivariate analysis, HO-1 levels were inversely associated with PAD, whereas they were also associated with CAD. The odds ratios for PAD and CAD were 2.12 (95% CI = 1.03–4.37) and 0.65 (95% CI = 0.42–0.99) for the HO-1 level of <0.35 ng/mL, respectively.

Conclusions

Plasma HO-1 levels were found to be low in patients with PAD, in contrast to high levels in patients with CAD.