Pituitary LH reserve suggests high risk of bulimia in amenorrheic women

The present study was aimed at investigating a) the risk of having bulimia in a heterogeneous population of secondary amenorrhea; b) the LH and FSH se cretion under basal and stimulated conditions (GnRH challenge) according to the presence of bulimic risk in our study population; c) the clinical and endocrine factors predictive of the bulimic risk in amenorrheic women. Amenorrheic women (n=73; age: 23.1 +/-4.8 yrs; BMI:20.2 +/-2.2 kg/m(2)) fil led in a self rating scale for bulimia (BITE) and were classified according ly, as being at low risk (score < 10), at medium risk (score between 10 and 24), and at high risk (score greater than or equal to 25) of having bulimi a. In each subject basal mean plasma LH levels were calculated over one hou r, sampling every 10 minutes, while in a subgroup of 45 patients the area u nder the curve (AUC) of plasma LH and FSH levels following a challenge with two doses of GnRH (10+10 mug, every two hours), sampling every 15 minutes, was also evaluated. High risk of bulimia was present in 12.3% of the population whereas 45.2% s howed a low risk and 42.5% were at medium risk of developing the disorder. Mann-Whitney U test revealed that basal LH values were differently distribu ted with significantly lower levels (P <0.046) in amenorrheic women at high risk of bulimia in comparison with amenorrheic women at low risk. The AUC of LH secretion following the first challenge of GnRH was significantly hig her in amenorrheic women with a high risk of bulimia in respect with both g roups of women at low (P <0.034) and medium (P <0.009) risk. A similar resu lt was found with FSH AUC following the first GnRH challenge (P <0.04 high risk vs low risk and medium risk). In a multiple regression analysis, the b est model predicting the risk of bulimia (BITE total score) included both t he LH response to GnRH challenge and BMI. In conclusion, when facing secondary amenorrhea at first consultation, long before a precise pathophysiologic diagnosis of the disease, low basal plas ma LH levels and LH response to GnRH challenge may allow one to suspect the presence of abnormal eating pattern of bulimic type. (C) 2001 Elsevier Sci ence Ltd. All rights reserved.