title: Serum insulin-like growth factor type 1 concentrations in healthy dogs and dogs with spontaneous primary hypothyroidism.
abstract: Circulating insulin-like growth factor type 1 (IGF-1) concentrations in dogs have been correlated with standard breed bodyweight (SBBW or breed size). Thyroid and somatotropic functions, which have common effects and regulatory mechanisms, were investigated in hypothyroid dogs. IGF-1 was measured in 495 adult healthy dogs (N) and in 220 primary hypothyroid dogs (HOT) with clinical and biological signs of primary hypothyroidism. IGF-1 was determined as a function of SBBW (kg): ≤15 (group A); 15<SBBW≤25 (group B); 25<SBBW≤40 (group C); and >40 (group D). In HOT dogs, median fT4 and c-TSH values were 9pmol/L and 1.5ng/mL, respectively. A significant correlation between bodyweight (BW) and IGF-1 was observed in both HOT and N dogs. The median IGF-1 value (ng/mL) was significantly higher (P<0.01) in HOT dogs compared to N in groups B, C and D (230 vs. 182; 316 vs. 230; 606 vs. 306 respectively). In conclusion, IGF-1 concentration should be interpreted in the context of SBBW in dogs and increases in spontaneous primary hypothyroidism. However, it remains unclear if this association is directly due to hypothyroidism or is the result of the weight gain accompanying hypothyroidism.
authors.affiliation: Oniris, Department of Biology, Pathology and Food Sciences, Nantes Atlantic College of Veterinary Medicine, Food Science and Engineering, Nantes F-44307, France; Université Nantes Angers Le Mans, France. Electronic address: laetitia.jaillardon@oniris-nantes.fr.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Jaillardon
authors.affiliation: Oniris, Department of Biology, Pathology and Food Sciences, Nantes Atlantic College of Veterinary Medicine, Food Science and Engineering, Nantes F-44307, France; Université Nantes Angers Le Mans, France.
authors.forename: Lucile
authors.initials: L
authors.lastname: Martin
authors.affiliation: Oniris, Department of Biology, Pathology and Food Sciences, Nantes Atlantic College of Veterinary Medicine, Food Science and Engineering, Nantes F-44307, France; Université Nantes Angers Le Mans, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Nguyen
authors.affiliation: Oniris, Department of Biology, Pathology and Food Sciences, Nantes Atlantic College of Veterinary Medicine, Food Science and Engineering, Nantes F-44307, France; Université Nantes Angers Le Mans, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Siliart
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D001835:Body Weight; D016022:Case-Control Studies; D004283:Dog Diseases / Q000097:blood*; D004285:Dogs; D005260:Female; D007037:Hypothyroidism / Q000097:blood / Q000662:veterinary*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D016014:Linear Models; D008297:Male; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; D007334:Insulin-Like Growth Factor I