Effect of growth hormone treatment on sleep EEGs in growth hormone-deficient children

Total sleep time, sleep stages 1-4, REM, REM latency, and sleep efficiency were analyzed in seven children with growth hormone deficiency (GHD) before and after growth hormone (GH) therapy. Before GH therapy, GHD children spent 19.5% of their total sleep time in REM sleep, 9.7% in stage 1, 41.0% in stage 2, 10.0% in stage 3, and 19.7% in stage 4. GHD children had more stage 1 and 3 sleep and less REM as compared with age-matched normal children reported by Williams et al. After GH therapy was initiated, six of the seven patients had decreases in the duration of stage 3 sleep, with an average decrease of 21.8 min. The difference between stage 3 sleep before and during GH treatment was significant, with a p value of < 0.025. When the results were expressed as the percentage of the total sleep period, the difference was also significant, (10.0 ± 2.0 to 7.5 ± 3.1%, mean ± SD; p < 0.05). No other sleep parameters were significantly affected by GH therapy. The changes observed in stage 3 sleep, non-REM sleep, and the lack of any other changes in sleep before and after GH therapy have not been described before in GH-deficient children. They differ from studies in normal humans and animals which showed that REM sleep increased with administration of growth hormone. These differences suggest that GH deficiency is associated with a specific sleep EEG anomaly that is corrected in part by GH therapy.