title: Renal function is independently associated with circulating betatrophin.
abstract: OBJECTIVE
  Betatrophin has been identified as a marker linking liver with beta cell function and lipid metabolism in murine models. Until now, the regulation of circulating betatrophin in humans is not entirely clear. We here analyzed the relation of betatrophin levels to phenotypes of the metabolic syndrome and speculated that renal function might influence circulating betatrophin levels and explain age-dependent changes of betatrophin.
  
  
  METHODS
  We analyzed blood samples from 535 individuals participating in the Metabolic Syndrome Berlin Potsdam study.
  
  
  RESULTS
  In a crude analysis we found a positive correlation between betatrophin levels and HbA1c (r = 0.24; p < 0.001), fasting glucose (r = 0.20; p < 0.001) and triglycerides (r = 0.12; p = 0.007). Furthermore betatrophin was positively correlated with age (r = 0.47; p <0.001), systolic blood pressure (r = 0.17; p < 0.001), intima media thickness (r = 0.26; p < 0.001) and negatively correlated with CKD-EPI eGFR (r = -0.33; p < 0.001) as an estimate of renal function. Notably, eGFR remained highly associated with betatrophin after adjustment for age, waist circumference, gender, HbA1c and lipid parameters in a multivariate linear regression model (β = -0.197, p< 0.001).
  
  
  CONCLUSIONS
  Our data suggest that circulating levels of betatrophin depend on age, gender, waist circumference, total/HDL cholesterol ratio and renal function. Especially the association to eGFR highlights the importance for future studies to address renal function as possible influence on betatrophin regulation and consider eGFR as potential confounder when analyzing the role of betatrophin in humans.
authors.affiliation: Dept. of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany.|Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin and Max-Delbrück Zentrum, Berlin-Buch, Germany.|Charité Center for Cardiovascular Research (CCR), Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Maurer
authors.affiliation: Dept. of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany.|Charité Center for Cardiovascular Research (CCR), Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Schwarz
authors.affiliation: Dept. of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany.|Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin and Max-Delbrück Zentrum, Berlin-Buch, Germany.|Charité Center for Cardiovascular Research (CCR), Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Fischer-Rosinsky
authors.affiliation: Dept. of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany.|Charité Center for Cardiovascular Research (CCR), Charité-Universitätsmedizin Berlin, Berlin, Germany.|DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Schlueter
authors.affiliation: Dept. of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany.|Charité Center for Cardiovascular Research (CCR), Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Brachs
authors.affiliation: Dept. of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Möhlig
authors.affiliation: Dept. of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany.|DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany.|Dept. of Clinical Nutrition, German Institute of Human Nutrition, Nuthetal, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Pfeiffer
authors.affiliation: Dept. of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany.|Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin and Max-Delbrück Zentrum, Berlin-Buch, Germany.
authors.forename: Knut
authors.initials: K
authors.lastname: Mai
authors.affiliation: Dept. of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany.|Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin and Max-Delbrück Zentrum, Berlin-Buch, Germany.|Charité Center for Cardiovascular Research (CCR), Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Joachim
authors.identifier: http://orcid.org/0000-0002-8900-4467
authors.initials: J
authors.lastname: Spranger
authors.affiliation: Dept. of Endocrinology, Diabetes and Nutrition, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bobbert
mesh_terms: D000328:Adult; D000368:Aged; D000091306:Angiopoietin-Like Protein 8; D000075802:Angiopoietin-like Proteins; D001786:Blood Glucose; D001794:Blood Pressure; D059168:Carotid Intima-Media Thickness; D066246:ErbB Receptors / Q000097:blood; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000378:metabolism* / Q000503:physiopathology; D050356:Lipid Metabolism; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood* / Q000473:pathology; D008875:Middle Aged; D036361:Peptide Hormones / Q000097:blood*; D014280:Triglycerides / Q000097:blood
chemical_list: D000091306:Angiopoietin-Like Protein 8; D000075802:Angiopoietin-like Proteins; D001786:Blood Glucose; D066246:ErbB Receptors; D006442:Glycated Hemoglobin; D036361:Peptide Hormones; D014280:Triglycerides; C576683:ANGPTL8 protein, human; C517652:hemoglobin A1c protein, human; C512478:EGFR protein, human