Effect of hormone replacement therapy and tibolone on serum leptin levels in postmenopausal women.
OBJECTIVE
To evaluate the effect of estrogen replacement therapy (ERT), continuous combined hormone replacement therapy (HRT) and tibolone on serum leptin levels in healthy postmenopausal women.


METHODS
Eighty-four healthy postmenopausal women aged 43-63 years were studied prospectively. Hysterectomized women (n = 16) received conjugated equine estrogens (CEE) 0.625 mg. Women with an intact uterus were randomly allocated either to CEE+medroxyprogesterone acetate (CEE/MPA) 5 mg or tibolone 2.5 mg. Serum leptin levels were assessed at baseline and after 6 months of treatment.


RESULTS
The three groups did not differ with respect to age, body mass index (BMI) or baseline serum leptin levels. Overweight women (BMI > 25 kg/m2) had higher baseline leptin levels (27.0 +/- 11.4 ng/ml) compared to their lean counterparts (BMI < or = 25 kg/m2; leptin: 16.5 +/- 8.1 ng/ml, P = 0.0001). Neither CEE nor CEE/MPA had any effect on serum leptin levels at the end of 6 months either in overweight or in lean women (overweight: CEE baseline 34.4 +/- 13.3 ng/ml, 6 months 36.9 +/- 15.8, P = 0.89, CEE/MPA baseline 22.4 +/- 9.8 ng/ml, 6 months 26.8 +/- 8.7 ng/ml, P = 0.1; lean: CEE baseline 12.6 +/- 4.4 ng/ml, 6 months 13.2 +/- 5.8 ng/ml, P = 0.36, CEE/MPA baseline 17.2 +/- 10.6 ng/ml, 6 months 18.8 +/- 8.8 ng/ml, P = 0.31). Similarly serum leptin remained unchanged at the end of the study in both lean and overweight women on tibolone (overweight: baseline 22.9 +/- 8.1 ng/ml, 6 months 18.5 +/- 12 ng/ml, P = 0.37; lean: baseline 13.2 +/- 5.6 ng/ml, 6 months 17.3 +/- 8.4 ng/ml).


CONCLUSIONS
BMI is a strong determinant of serum leptin levels in healthy postmenopausal women. Neither ERT/HRT nor tibolone exert any effect on serum leptin after 6 months in lean or overweight postmenopausal women. Further studies are required to verify the exact role of estrogen and tibolone on leptin production and function in postmenopausal women.
Lambrinoudaki
Irene V
IV
Second Department of Obstetrics and Gynecology, Aretaieion Hospital, University of Athens, 3 Neofytou Douka Street, GR-10674, Greece.
Christodoulakos
George E
GE
Panoulis
Constantinos P
CP
Rizos
Demetrius A
DA
Dendrinos
Spyros G
SG
Liakakos
Theodor
T
Augoulea
Areti D
AD
Creatsas
George C
GC
D000328:Adult; D015992:Body Mass Index; D020847:Estrogen Receptor Modulators / Q000008:administration & dosage*; D004966:Estrogens, Conjugated (USP) / Q000008:administration & dosage*; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D020738:Leptin / Q000097:blood*; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage; D008875:Middle Aged; D009652:Norpregnenes / Q000008:administration & dosage*; D017698:Postmenopause; D011446:Prospective Studies; D016896:Treatment Outcome
D020847:Estrogen Receptor Modulators; D004966:Estrogens, Conjugated (USP); D020738:Leptin; D009652:Norpregnenes; D017258:Medroxyprogesterone Acetate; C027385:tibolone