Aim: To characterize patients with weight loss-related amenorrhea and controls with respect to the pulsatility of neuropeptide Y (NPY) and luteinizing hormone (LH).
Subjects: Nine young women (aged 20.23+/-2.11 years) diagnosed with weight loss-related amenorrhea (body mass index (BMI) 17.52+/-2.43 kg/m2) and five age-matched (age 21.88+/-3.12 years) normally menstruating (every 28-33 days) controls with normal BMI (23.62+/-3.11 kg/m2) (mean value+/-standard deviation).
Methods: Basal hormonal evaluation included serum follicle-stimulating hormone (FSH), LH, estradiol (E2) and NPY. A pulsatility study investigated NPY and LH episodic release. Patients from control the group were studied during the mid-follicular phase (days 6-8) of the menstrual cycle.
Results: Patients with weight loss-related amenorrhea had lower FSH, LH and E2 levels than controls (p < 0.01). Basal serum NPY levels were lower in amenorrheic patients than in menstruating women (p < 0.01). The numbers of NPY and LH peaks were higher in patients with weigh loss-related amenorrhea than in controls (p < 0.01 and p < 0.05, respectively).
Conclusion: Increased NPY pulsatility may have pathophysiological significance in weight loss-related hypothalamic amenorrhea.