title: Obese patients have higher circulating protein levels of dipeptidyl peptidase IV.
abstract: Dipeptidyl peptidase IV (DPPIV) is a protease with broad distribution involved in various homeostatic processes such as immune defense, psychoneuroendocrine functions and nutrition. While DPPIV protein levels were investigated in patients with hyporectic disorders, less is known under conditions of obesity. Therefore, we investigated DPPIV across a broad range of body mass index (BMI). Blood samples from hospitalized patients with normal weight (BMI 18.5-25 kg/m(2)), anorexia nervosa (BMI <17.5 kg/m(2)) and obesity (BMI 30-40, 40-50 and >50 kg/m(2), n = 15/group) were tested cross-sectionally and DPPIV concentration and total enzyme activity and the DPPIV targets, pancreatic polypeptide (PP) and glucagon-like peptide (GLP-1) were measured. DPPIV protein expression was detected in human plasma indicated by a strong band at the expected size of 110 kDa and another major band at 50 kDa, likely representing a fragment comprised of two heavy chains. Obese patients had higher DPPIV protein levels compared to normal weight and anorexics (+50%, p<0.05) resulting in a positive correlation with BMI (r = 0.34, p = 0.004). DPPIV serum activity was similar in all groups (p>0.05), while the concentration/activity ratio was higher in obese patients (p<0.05). Plasma PP levels were highest in anorexic patients (∼ 2-fold increase compared to other groups, p<0.05), whereas GLP-1 did not differ among groups (p<0.05). Taken together, circulating DPPIV protein levels depend on body weight with increased levels in obese resulting in an increased concentration/activity ratio. Since DPPIV deactivates food intake-inhibitory hormones like PP, an increased DPPIV concentration/activity ratio might contribute to reduced food intake-inhibitory signaling under conditions of obesity.
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany. Electronic address: andreas.stengel@charite.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Stengel
authors.affiliation: Department of Internal Medicine, Institute of Neurogastroenterology and Motility, Martin-Luther Hospital, Academic Teaching Institution of Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Goebel-Stengel
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
authors.forename: Pauline
authors.initials: P
authors.lastname: Teuffel
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Hofmann
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Buße
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Kobelt
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Rose
authors.affiliation: Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
authors.forename: Burghard F
authors.initials: BF
authors.lastname: Klapp
mesh_terms: D000856:Anorexia Nervosa / Q000097:blood; D015992:Body Mass Index; D018819:Dipeptidyl Peptidase 4 / Q000097:blood*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D006801:Humans; D008297:Male; D009765:Obesity / Q000097:blood*; D010191:Pancreatic Polypeptide / Q000097:blood; D015398:Signal Transduction
chemical_list: D010191:Pancreatic Polypeptide; D052216:Glucagon-Like Peptide 1; C042807:DPP4 protein, human; D018819:Dipeptidyl Peptidase 4
keywords: Anorexia; Body mass index; Glucagon-like peptide 1; Hormone; Pancreatic polypeptide; Plasma