Interrelationships between HPA axis and sleep architecture are well documented and increased glucocorticoid levels seem associated with quantitative and qualitative sleep disruptions. The knowledge about sleep parameters in chronic hypercortisolism in humans is scanty. Our aim was to evaluate sleep efficiency in patients with Cushings syndrome (CS) at time of diagnosis, without ongoing specific therapy, using wrist actigraphy, a methodology that provides good estimations of sleep duration and consolidation. In 12 CS patients with different etiology (eight ACTH-secreting pituitary adenoma, CD, and four cortisol-secreting adrenal adenoma, AA) (11 F, 1 M, 40.0±10.9 year) and in 12 age- and sex-matched healthy control subjects (NS), sleep recording was performed by Actiwatch (Mini Mitter Co, Inc.; Bend, OR, USA) on three consecutive working days under free living conditions. Data were analysed using Actiware-Sleep Software. All the subjects completed questionnaires about sleep habits. In CS patients morning circulating levels of ACTH, cortisol and free urinary cortisol (UFC) levels were measured. Wrist actigraphy revealed no significant difference between CS and NS in terms of time in bed ((mean±S.D.) 8 h4±0 h55 vs 7 h40±0 h53), actual sleep time (7 h8±0 h 54 vs 6 h48±0 h44), sleep efficiency (88.47±2.44 vs 88.9±2.88%), sleep latency (0 h6±0h3 vs 0h8±0h7). However, some sleep parameters were deranged in CS, such as an higher actual wake time (0h43±0h10 vs 0h33±0h12), total activity score (8318±4308 vs 4971±2372), mean activity score (8.67±4.23 vs 5.44±2.16), mean score in activity time (104.83±39.23 vs 74.81±23.15), sleep fragmentation (16.17±4.21 vs 13.01±3.6). compared to NS (P<0,05). No positive correlation between sleep efficiency parameters and UFC was found. In conclusion, these results, though preliminary, indicate that hypercortisolism is associated with a deranged sleep efficiency, in a dose-independent manner. Further studies in a larger cohort of patients and the use of more accurate instruments, such as in-home polysomnography, are needed to confirm these findings.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.
05 - 09 May 2012
European Society of Endocrinology