title: Estrogen replacement therapy increases plasma ghrelin levels.
abstract: Ghrelin is a novel peptide hormone that has GH releasing activity and also other endocrine and metabolic functions. The purpose of this study was to investigate the effects of estrogen replacement therapy on plasma active ghrelin levels in 64 hysterectomized postmenopausal women receiving peroral estrogen (PE) or transdermal estrogen therapy for 6 months. Active ghrelin was measured using commercial RIA. Estrogen therapy increased plasma active ghrelin from 479 +/- 118 to 521 +/- 123 pg/ml (P = 0.002) among all the study subjects. PE therapy increased plasma ghrelin levels from 465 +/- 99 to 536 +/- 104 pg/ml (P = 0.001). Transdermal estrogen therapy did not increase plasma ghrelin levels significantly (from 491 +/- 132 to 509 +/- 138 pg/ml; P = 0.332). The relative changes in plasma ghrelin levels were associated with the relative changes in serum estradiol concentrations (r = 0.299; P = 0.017). During the estrogen therapy, negative associations were found between plasma active ghrelin levels and several plasma lipids (total cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, total triglycerides, and very low-density lipoprotein triglycerides). As a conclusion, estrogen replacement therapy increased active plasma ghrelin levels, particularly PE therapy. Additional studies are needed to determine the possible underlying mechanisms.
authors.affiliation: Clinical Research Center, Department of Internal Medicine and Biocenter Oulu, University of Oulu, P.O. Box 5000, FIN-90014 Oulu, Finland. eija.kellokoski@oulu.fi
authors.forename: Eija
authors.initials: E
authors.lastname: Kellokoski
authors.forename: Seppo M
authors.initials: SM
authors.lastname: Pöykkö
authors.forename: Anna H
authors.initials: AH
authors.lastname: Karjalainen
authors.forename: Olavi
authors.initials: O
authors.lastname: Ukkola
authors.forename: Jorma
authors.initials: J
authors.lastname: Heikkinen
authors.forename: Y Antero
authors.initials: YA
authors.lastname: Kesäniemi
authors.forename: Sohvi
authors.initials: S
authors.lastname: Hörkkö
mesh_terms: D000368:Aged; D009320:Atrial Natriuretic Factor / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000008:administration & dosage; D005260:Female; D054439:Ghrelin; D019382:Human Growth Hormone / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D008875:Middle Aged; D036361:Peptide Hormones / Q000097:blood*
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D004967:Estrogens; D054439:Ghrelin; D007328:Insulin; D036361:Peptide Hormones; D019382:Human Growth Hormone; D009320:Atrial Natriuretic Factor