ABNORMAL SLEEP EEC IN IDIOPATHIC SHORT STATURE

Abstract

Polysomnographic recordings were obtained in six patients with idiopathic short stature (ISS), aged 4-10/12 to 16-1/2 yrs and seven patients with growth hormone deficiency (GHD) aged 6-3/12 to 10-5/12 yrs. ISS patients had GH levels ≥ 10 ng/ml and GHD patients had GH levels ≤ 7 ng/ml during provocative testing. Both groups had growth velocities below the 50th percentile and all patients were euthyroid. The results of the polysomnographic recordings (mean ± SD) are shown below for ISS, GHD and normals aged 6-13 yrs. ISS and GHD patients had identical percentages of stages of 1-4 and REM sleep. Both groups had significantly less REM and more stage 1 and 3 sleep (%) than normals. ISS patients had qualitatively, poorer sleep with an average of 66.7 minutes of wake-time during the sleep period as compared with <10 min. in GHD and normals. There was no correlation between wake-time and mean GH concentrations or secretory rates, although some ISS patients had very low mean GH range (2.0-9.5 ng/ml). Conclusions: Sleep architecture is abnormal in ISS and is indistinguishable from that seen in GHD. Coupled with low mean GH seen in some ISS patients, these abnormalities may be the cause(s) for the growth retardation in ISS.