Elevated Serum Fibroblast Growth Factor 21 Levels in Patients With Hyperthyroidism.

CONTEXT

Recent evidence from animal studies indicates that fibroblast growth factor 21 (FGF21), an endocrine hormone that regulates glucose, lipid metabolism, and energy homeostasis, is regulated by T3. However, the role of FGF21 in hyperthyroid patients is unknown.

OBJECTIVE

The objective was to study serum FGF21 levels in hyperthyroid patients and the association of serum FGF21 levels with hyperthyroidism.

DESIGN AND SETTING

This was a case-control study.

PATIENTS AND INTERVENTIONS

A total of 119 hyperthyroid patients and 108 healthy subjects were recruited. Of them, 41 hyperthyroid patients received thionamide treatment for 3 months until euthyroidism was obtained.

MAIN OUTCOME MEASURES

Serum FGF21 levels were determined using the ELISA method.

RESULTS

Serum FGF21 levels were significantly elevated in hyperthyroid patients as compared with normal subjects [median 290.67 (interquartile range, 156.60-502.33) vs 228.10 (169.85.25-320.10) pg/mL; P < .001]. After thionamide treatment, serum FGF21 levels in hyperthyroid patients declined markedly from 249.10 (139.10-444.00) to 106.90 (38.70-196.15) pg/mL (P < .001). Logistic regression revealed that FGF21, basal metabolic rate, low-density lipoprotein cholesterol, and alanine transaminase were significantly associated with hyperthyroidism. With adjustment for potential confounders, serum FGF21 remained independently associated with hyperthyroidism, with an adjusted odds ratio of 3.123 (95% confidence interval, 1.306-7.468) (P = .010).

CONCLUSION

Serum FGF21 levels were elevated in patients with hyperthyroidism and declined after thionamide treatment. And serum FGF21 level was independently associated with hyperthyroidism.