Reduced serum acylated ghrelin levels in patients with hyperthyroidism.
OBJECTIVE
Recent studies have revealed that circulating ghrelin levels seem to play a role in energy homeostasis. The effect of hyperthyroidism on ghrelin levels is not fully known.


METHODS
Serum levels of ghrelin and its relationship with insulin resistance were evaluated in 48 patients with hyperthyroidism and 43 euthyroid healthy controls. Thyroid hormones, insulin, glucose, ghrelin levels and lipid parameters were measured in all subjects. Insulin sensitivity was determined using the homeostasis model assessment.


RESULTS
Serum ghrelin levels were significantly decreased in hyperthyroid patients than in controls (32.5 +/- 23.3 vs. 54.1 +/- 35.5 pg/ml, p < 0.001). Circulating ghrelin levels significantly correlated with age (r = -0.26, p = 0.01), fasting glucose (r = -0.21, p = 0.01), free triiodothyronine (r = -0.18, p = 0.04), free thyroxine (r = -0.23, p = 0.02) and thyroid stimulating hormone (r = 0.21, p = 0.04), but not with blood pressure, body mass index, lipid parameters, insulin and homeostasis model assessment (p > 0.05). Multiple regression analysis revealed glucose level to be the most important predictor of circulating ghrelin level.


CONCLUSIONS
These results indicate that hyperthyroidism has effect on serum ghrelin levels. Further studies are needed for the exact mechanism.
Altinova
Alev E
AE
Department of Endocrinology and Metabolism, Gazi Medical University School of Medicine, Ankara, Turkey. alevaltinova@yahoo.com
Törüner
Füsun B
FB
Aktürk
Müjde
M
Elbeğ
Sehri
S
Yetkin
Ilhan
I
Cakir
Nuri
N
Arslan
Metin
M
D000215:Acylation; D000293:Adolescent; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D005260:Female; D054439:Ghrelin; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood*; D007333:Insulin Resistance / Q000502:physiology; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D036361:Peptide Hormones / Q000097:blood*; D013963:Thyroid Hormones / Q000097:blood
D001786:Blood Glucose; D054439:Ghrelin; D008055:Lipids; D036361:Peptide Hormones; D013963:Thyroid Hormones; D002784:Cholesterol