Objectively recorded hot flushes in patients with pituitary insufficiency

A study was conducted of 2 young adult women with pituitary insufficiency and complaints of hot flushes. Both underwent continuous recordings of skin temperature of the finger and skin resistance over the sternum as objective indices of flushing episodes. Frequent blood samples were also obtained during the recordings for the measurement of serum LH and FSH levels. During the 10 h of recording, 12 subjective hot flushes occurred and each was associated with a rise of finger temperature of greater than 1 C. Eighty-five percent of the temperature rises were associated with measurable decreases in skin resistance. The mean interval between flushes, the magnitude of the skin temperature and resistance changes, and the relationship of these changes to the onset of subjective flushes were identical to those observed in symptomatic postmenopausal women. Circulating gonadotropin levels were in the low to low normal range in comparison to values observed in premenopausal women and showed minimal pulsatile release. There were no significant correlations between finger temperature changes and LH levels in either subject. These results suggest that the previously described association of pulsatile LH release and the occurrence of hot flushes in postmenopausal women cannot be attributed to augmented LH secretion per se and, therefore, may be due to hypothalamic factors responsible for pulsatile LH release.