title: Plasma FGF21 levels are increased in patients with hypothyroidism independently of lipid profile.
abstract: Thyroid hormone is a potent regulator of metabolic and energy homeostasis implicated in various metabolic diseases. Fibroblast growth factor 21(FGF21) is a systemic metabolic regulator known to modulate various biological functions similar to the actions of thyroid hormone. We investigated the differences in plasma FGF21 concentrations in patients with varying thyroid function. Ninety drug-naïve subjects who underwent thyroid evaluation at Seoul National University Bundang Hospital were enrolled and classified into euthyroid, subclinical hypothyroid, and overtly hypothyroid groups. Biochemical markers and plasma FGF21 levels were measured and analyzed. The mean age of the subjects was 42.6 ± 9.1 years. The mean body mass index (BMI), waist circumference, and fasting glucose concentrations were similar between groups. Overtly hypothyroid subjects exhibited significantly higher concentrations of total cholesterol, triglyceride, and LDL-cholesterol than the other groups (p<0.01). Mean plasma FGF21 concentrations in euthyroid, subclinical hypothyroid and overtly hypothyroid groups were 43.2 ± 39.2 pg/mL, 63.6 ± 73.6 pg/mL, and 101.5 ± 74.9 pg/mL, respectively (p<0.01 between groups). Plasma FGF21 concentrations remained significantly higher in overtly hypothyroid subjects after adjusting for serum triglyceride concentrations (p<0.005). Multivariate analysis revealed a significant positive linear relationship between serum TSH concentrations and plasma FGF21 concentrations (β = 0.192, p = 0.002) and a significant negative linear relationship between free T4 and plasma FGF21 concentrations (β = -0.382, p = 0.037) after adjusting for gender, BMI and serum concentrations of triglycerides and glucose. Plasma FGF21 levels were significantly increased in patients with hypothyroidism independently of BMI, or lipid or glucose metabolism.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yenna
authors.initials: Y
authors.lastname: Lee
authors.forename: Young Joo
authors.initials: YJ
authors.lastname: Park
authors.forename: Hwa Young
authors.initials: HY
authors.lastname: Ahn
authors.forename: Jung Ah
authors.initials: JA
authors.lastname: Lim
authors.forename: Kyoung Un
authors.initials: KU
authors.lastname: Park
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Choi
authors.forename: Do Joon
authors.initials: DJ
authors.lastname: Park
authors.forename: Byung-Chul
authors.initials: BC
authors.lastname: Oh
authors.forename: Hak C
authors.initials: HC
authors.lastname: Jang
authors.forename: Ka Hee
authors.initials: KH
authors.lastname: Yi
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D005346:Fibroblast Growth Factors; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood; D007037:Hypothyroidism / Q000097:blood; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood
chemical_list: D008078:Cholesterol, LDL; D008055:Lipids; D014280:Triglycerides; C414620:fibroblast growth factor 21; D005346:Fibroblast Growth Factors; D002784:Cholesterol