Effects on serum lipid and leptin levels of three different doses of norethisterone continuously combined with a fixed dose of 17β-estradiol for nasal administration in postmenopausal women: a controlled, double-blind study

Abstract

To evaluate the effect of intranasal continuous combined hormone therapy on serum lipids and leptin levels in healthy postmenopausal women. Multicenter, double-blind, double-dummy, randomized, controlled study conducted in parallel groups. Outpatient clinics of three Spanish hospitals and two private health centers. A total of 333 healthy postmenopausal women aged 40 to 75 years. Women were randomly allocated to either one of three different doses of norethisterone (50 microg/day, 175 microg/day, or 550 microg/day) continuously combined with a fixed dose of 17beta-estradiol (350 microg/day) for nasal administration, or 17beta-estradiol at 2 mg/day combined with oral norethisterone acetate at 1 mg/day. Serum lipid, glucose, and leptin levels were assessed at baseline and after 12, 24, 36, and 52 weeks of treatment. Overweight women (body mass index >25 kg/m(2)) had higher baseline leptin levels, but these levels increased in all groups across the study unrelated to body mass index. Both intranasal and oral therapy had the effect of increasing the levels of leptin after 24 weeks in healthy postmenopausal women. As expected, total cholesterol and low-density lipoprotein cholesterol levels decreased and high-density lipoprotein levels increased in the four groups. Body mass index is a strong determinant of serum leptin levels in healthy postmenopausal women; serum leptin increased in all the hormone therapy regimes.