8 DESYNCHRONIZATION OF LUTEINIZING HORMONE (LH) FROM SLEEP IN ADOLESCENTS WITH POLYCYSTIC OVARY SYNDROME (PCOS)

Abstract

PCOS is associated with disordered ovulation, absence of monthly LH surge, and elevated plasma LH. At puberty, the diurnal rhythm of LH secretion normally undergoes a complex ontogeny during which time ovulation begins and becomes cyclic. This study was undertaken to determine if a disturbance in the diurnal rhythm of LH secretion could be defined in adolescents with PCOS. 24 hour profiles of LH secretion were determined in 8 adolescents (age 13-19) with PCOS by measuring plasma LH every 20 minutes and sleep with polygraphic monitoring. Criteria for PCOS included presence of cystic ovaries by laparoscopy or ultrasonography, normal estrogenization, oligoamenorrhea, normal urinary 17-hydroxycorticosteroids and pregnanetriol, minimal or no elevation of urinary 17-ketosteroids, normal thyroid function and no hormonal therapy or other illness. 2 of 8 adolescents (age 13&15) showed a marked LH surge beginning 1-2 hours after awakening and lasting 7-8 hours. This surge was similar to the normal sleep-associated LH rise in mid-pubertal girls except desynchronized from sleep by 8-9 hours. The other 6 adolescents had no marked diurnal variation in LH secretion. 24 hour mean plasma LH levels were elevated in patients with abnormal diurnal variation (38,63mIu/ml) and in all but one of the others (11,23,25,33,38,52mIu/ml). This study identifies a subgroup of adolescents with PCOS with pubertal LH surges desynchronized from sleep and suggests the possibility of a chronobiological disturbance as an etiologic factor in PCOS.