Hypothalamic Dysfunction in Secondary Amenorrhea Associated with Simple Weight Loss

Abstract

We tested hypothalamic, pituitary and endocrine function in 19 patients with secondary amenorrhea associated with simple weight loss who did not have anorexia nervosa to evaluate the effects of weight loss on these systems. Thermoregulation at 10°C and 49°C was abnormal and correlated with the percentage below ideal body weight (r = 0.62, P<0.02, and r = 0.55, P<0.05, respectively). Partial diabetes insipidus was found in 27 per cent of patients with simple weight loss. They had delayed peak plasma luteinizing hormone levels after 10 μg of luteinizing-hormone-releasing factor, which was correlated with percentage below ideal body weight (r = 0.49, P<0.05). Delayed peak plasma thyrotropin levels after 500 μg of thyrotropin-releasing factor were found. No prolactin, pituitary, thyroid or adrenal abnormalities were present.