title: Assessment of Apelin Serum Levels in Persistent Atrial Fibrillation and Coronary Artery Disease.
abstract: BACKGROUND
  Apelin, the endogenous ligand of orphan receptor APJ (gene symbol APLNR), is an adipokine that was suggested to have a direct correlation with obesity. This peptide might play a role in obesity-related disorders, especially in the cardiovascular system. Currently, few data are available on levels and potential metabolic functions of apelin in different cardiac diseases including atrial fibrillation (AF) and coronary artery disease (CAD), which have common underlying pathophysiological mechanisms. This study aimed to investigate apelin levels in patients with AF and CAD that were overweight or obese, as well as its relationship with anthropometry and metabolic profile.
  
  
  METHODS
  This preliminary investigation was compromised of 41 patients with AF and 39 with CAD aged > 50 years and body mass index (BMI) > 25kg/m2. Serum levels of apelin, fasting plasma glucose, insulin, homeostatic model assessment, triglyceride, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and very-low-density lipoprotein were measured.
  
  
  RESULTS
  The apelin serum levels were not statistically different between patients with AF and CAD. A negative correlation was observed between apelin with weight (r = -0.257, P = 0.023) and BMI (r = -0.258, P = 0.023). Moreover, apelin showed an inverse correlation with insulin (r =-0.227, P = 0.045) and marginally with homeostatic model assessment (r = -0.21, P = 0.066). There was a negative association between apelin and triglyceride (r = -0.238, P = 0.036) and very-low-density lipoprotein (r = -0.25, P = 0.027).
  
  
  CONCLUSIONS
  Apelin serum levels were not significantly different among patients with AF and CAD. The unexpected inverse correlation of apelin with weight and BMI might indicate the dominant effects of pathophysiological conditions such as AF and CAD on serum levels of apelin compared with BMI and adipose tissue. Understanding the precise role of apelin in modulating obesity-induced disorders including AF and CAD requires further studies.
authors: Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
authors: Mehrnaz
authors: M
authors: Riazian
authors: Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
authors: Elnaz
authors: E
authors: Khorrami
authors: Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
authors: Elham
authors: E
authors: Alipoor
authors: Department of Cardiology, Amiralam Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors: Sina
authors: S
authors: Moradmand
authors: Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors: Mehdi
authors: M
authors: Yaseri
authors: Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: Hosseinzadeh.md.phd@gmail.com.
authors: Mohammad Javad
authors: MJ
authors: Hosseinzadeh-Attar
mesh_terms: D000368:Aged; D000073861:Apelin; D001281:Atrial Fibrillation / Q000097:blood* / Q000150:complications; D003324:Coronary Artery Disease / Q000097:blood* / Q000150:complications; D005260:Female; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000150:complications
chemical_list: C115436:APLN protein, human; D000073861:Apelin; D036341:Intercellular Signaling Peptides and Proteins
keywords: Apelin; Atrial fibrillation (AF); Coronary artery disease (CAD); Obesity; Overweight