Heart failure is associated with low circulating levels of secreted frizzled receptor protein 5 (Sfrp5)

Background/Introduction

Obesity and metabolic dysregulation are closely associated with the pathophysiology of multiple cardiovascular diseases (CVD). To date, the pathophysiological mechanism(s) of obesity and its link with cardiovascular systems remain largely unknown. Adipose tissue inflammation as a result of excessive fat expansion in obesity, leading to increased systemic production of growth factors and recruitment of inflammatory cells have been postulated to be a major factor. Secreted frizzled-related protein 5 (SFRP5) is an anti-inflammatory adipokine that is linked with obesity and metabolic regulation and has been indicated to affect cardiovascular functions. Currently, the role of circulating SFRP5 levels as a biomarker for cardiovascular diseases are poorly understood, with studies yielding discordant results.

Purpose

This study aims to evaluate the relationship between circulating SFRP5 and cardiovascular functions in a cohort of patients with established CVD.

Methods

Patients (n=262, 148 male (56.5%), age (68±11 yrs)) presenting to the cardiology unit for cardiovascular investigations were recruited into the study. Plasma SFRP5 levels were measured via enzyme-linked immunosorbent assay (ELISA). Associations between plasma SFRP5 levels, cardiovascular functions, and patients' co-morbidities were analysed using univariate and multivariate analyses.

Results

Plasma SFRP5 levels were significantly lower in patients presenting with: heart failure (HF) vs non-HF (median; (10.7 vs 31.0; p<0.001); coronary artery disease (CAD) vs non-CAD; (11.0 vs 33.8; p<0.001); and atrial fibrillation (AF) vs non-AF; (11.2 vs 23.2; p=0.001). On univariate analyses, SFRP5 levels also significantly positively correlated with left ventricular ejection fraction (LVEF) (r=0.52, p<0.001), estimated glomerular filtration rate (eGFR) (r=0.16, p=0.02), total cholesterol levels and triglycerides (r=0.29, p<0.001; r=0.17, p<0.01 respectively). Low SFRP5 levels were correlated with high C-reactive protein (CRP) and E/E' (r=−0.29, p<0.001, r=−0.30, p<0.001, respectively). Patients with HF, CAD, statin use, low LVEF, low triglycerides, high CRP and high eGFR were associated with lower SFRP5 levels independent of age, BMI or diabetes on multivariate analysis (overall model r=0.729, SE=0.638).

Conclusion

Our results show that low plasma SFRP5 levels are independently associated with HF, CAD, and impaired systolic and diastolic functions. These results suggest that SFRP5 may regulate cardiovascular functions independent of obesity and metabolic regulations.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Heart Foundation of Australia Future Leader FellowshipsNSW Ministry of Health EMC FellowshipHeart Foundation of Australia Future Leader Fellowship

Follistatin-like 3 (FSTL3) levels are increased in acute heart failure patients

Introduction

Follistatin-like 3 (FSTL3) is a secreted protein that has been suggested to play an important role in modulating cardiac remodeling and hypertrophy. In this study, we aim to determine whether: 1) FSTL3 is incrementally elevated in patients with HF vs those with other cardiovascular disease (CVD); and 2) increased FSTL3 is associated with 2 or more hospital admissions due to major adverse CV events (MACE) within 1 year.

Methods and results

We measured circulating levels of FSTL3 using commercially available ELISA (R&D systems) in a total of n=696 patients. FSTL3 levels were compared between: 1) healthy-aging volunteers with no prior major CVD (n=267, age 67±6 years) and 2) patients admitted to cardiology unit for various CVD (n=429, age 66±14 years); among those (n=178, age 68±13 years) had HF. Patients with HF had 2-fold higher FSTL3 levels vs healthy age-matched controls vs those with other CVD (p<0.001). Occurrences of MACE were recorded up to 1 year for patients admitted to cardiology unit. On univariate analyses, patient with 2 or more MACE within 1 year (n=91, 27%) had significant elevated FSTL3 levels (P=0.003), is associated with older age (P<0.005). On multivariate analysis, high FSTL3 levels (P=0.034) is an independent predictor of 2 or more MACE admissions within 1 year after adjusting for age, clinical comorbidities and medications.

Conclusions

FSTL3 is incrementally increased in patients with HF and is associated with poorer prognosis. Elevated FSTL3 levels is associated with increased risks of cardiac hospital readmissions for patients with multiple CV morbidities.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NSW Ministry of Health EMC Fellowship (Australia)