Serum leptin levels in patients with premenstrual syndrome treated with GnRH analogues alone and in association with tibolone

Abstract

Objective: Leptin seems to regulate reproductive function and it has been hypothesised that its secretion may be induced by oestrogens. Changes in its levels has been advocated as a determinant in the pathogenesis of premenstrual syndrome (PMS). We evaluated serum leptin levels in patients affected by PMS and in controls to establish: (i) if induced hypoestrogenism has an impact on leptin concentrations; (ii) if the administration of tibolone modifies the effects of hypoestrogenism on serum leptin levels; and (iii) if the improvement in PMS symptomatology can be correlated to changes in serum leptin levels.

Design: Prospective, randomized study.

Patients: Twenty-eight women affected by PMS and 20 unaffected controls. Affected patients were randomly assigned to two groups to receive leuprolide acetate (3.75 mg intramuscularly) plus tibolone (2.5 mg/day) (group A; n = 14) or plus placebo (group B; n = 14), at the onset of the vasomotor symptoms.

Measurements: Serum leptin, oestradiol and progesterone levels, PMS signs and symptoms evaluated during a 2 months' pretreament period and after 2 months of therapy.

Results: No differences in leptin levels among the three groups and within the same group at all time evaluated were observed. Oestradiol and progesterone concentrations were significantly lower in all groups during treatment in comparison with pretreatment values. Before therapy, leptin levels were positively correlated both with oestradiol and progesterone in the follicular and luteal phase in all groups. This correlation was lost after treatment. All PMS patients showed a significant improvement of the symptomatology.

Conclusions: Hypoestrogenism induced by GnRH analogues (GnRHa) does not seem to influence leptin levels in normal women and those with PMS, and the addition of tibolone does not impact on these levels. Because PMS symptomatology did significantly improve during treatment with GnRHa alone, or in associtation with tibolone, it is unlikely that changes in leptin levels could have an important role in the pathophysiology of PMS.