Sleep disturbances, daytime sleepiness and quality of life in adults with growth hormone deficiency

Low energy and fatigue are frequent complaints in subjects with GH deficiency (GHD). Since interrelations between sleep and GH regulation are well documented, these complaints could partly reflect alterations of sleep quality. Therefore we sought to determine objective and subjective sleep quality and daytime sleepiness in adult GHD patients compared to age, gender and BMI-matched controls, and in a subset of these GHD patients undergoing recombinant human GH (rhGH) therapy compared to placebo. Thirty patients, aged 19-74 yr, with untreated GHD (primary pituitary defects confirmed or likely in 26 patients, hypothalamic origin in 4 patients), and 30 healthy controls individually matched for gender, age and body mass index were enrolled in the study. Patients with associated pituitary hormonal deficiencies were on appropriate replacement therapy. Polygraphic sleep recordings were performed at baseline and after 4 months on recombinant human GH or placebo. Subjective sleep quality and quality of life were evaluated by means of the Pittsburgh Sleep Quality Index (PSQI) and Quality of Life-Assessment for GHD in Adults (QoL-AGHDA). Irrespective of etiology, GHD patients had a PSQI score above the clinical cut-off for poor sleep and lower QoL-AGHDA scores than controls, with tiredness being the most affected domain. Patients with pituitary GHD spent more time in slow-wave sleep (SWS) and had a higher intensity of SWS than their controls. Amongst these patients, older individuals obtained less total sleep than controls and their late sleep was more fragmented. Contrasting with pituitary GHD, the 4 patients with hypothalamic GHD had lower intensity of SWS than their controls. Thirteen patients were reevaluated after 4 months rhGH and 4 months placebo. Compared to placebo, SWS duration was decreased in younger patients after rhGH, and a trend for a decrease in SWS intensity was observed in the whole group. PSQI scores decreased, while QoL ratings improved. In conclusion, GHD is associated with sleep disorders that may be caused by specific hormonal alterations, as well as with poor subjective sleep quality and daytime sleepiness. Disturbed sleep is likely to be partly responsible for increased tiredness, a major component of QoL in GHD. Partial reversal of the sleep alterations was observed after 4 months of rhGH treatment, which was paralleled by an improvement in QoL and reports of tiredness, as well as subjective sleep quality.