Decreased Nocturnal Levels of Prolactin and Growth Hormone in Women with Fibromyalgia

Abstract

Fibromyalgia (FM) is a complex syndrome, primarily of women, characterized by chronic pain, fatigue, and sleep disturbance. Altered function of the somatotropic axis has been documented in patients with FM, but little is known about nocturnal levels of PRL. As part of a laboratory study of sleep patterns in FM, we measured the serum concentrations of GH and PRL hourly from 2000–0700 h in a sample of 25 women with FM (mean, 46.9 6 7.6 yr) and in 21 control women (mean, 42.6 6 8.1 yr). The mean (6SEM) serum concentrations (mi-crograms per L) of GH and of PRL during the early sleep period were higher in control women than in patients with FM [GH, 1.6 6 0.4 vs. 0.6 6 0.2 (P, 0.05); PRL, 23.2 6 2.2 vs. 16.9 6 2.0 (P, 0.025)]. The mean serum concentrations of GH and PRL increased more after sleep onset in control women than in patients with FM [GH, 1.3 6 0.4 vs. 0.3 6 0.2 (P, 0.05); PRL, 16.2 6 2.4 vs. 9.7 6 1.5 (P, 0.025)]. Sleep