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/m(2)) had higher baseline leptin levels
(27.0 +/- 11.4 ng/ml) compared to their lean counterparts (BMI less than
or equal to 25 kg/m(2); leptin: 16.5 +/- 8.1 ng/ml, P = 0.0001). Neither
CEE nor CEEMPA 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 +/- 5.9 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). Conclusion: 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. (C) 2003 Elsevier
Ireland Ltd. All rights reserved
