The Adrenergic Influence on Sleep Stage Shifting in High-Endurance Athletes After Exercise

Abstract

Results: 3.1. Catecholamine Levels Two of the 15 athlethes had catecholamine levels on the competition day below the minimum levels because they were in a overtraining syndrome. The following data is expressed without the results of these two athlethes. Daytime catecholamines as expression of catecholamine levels until beginning of the night were significantly different for epinephrine, norepinephrine and dopamine on the competition day (C) and the rest day (R). The average value for epinephrine was 45.5 ng/min (C) versus 17.8 ng/min (R), p< 0.001. For norepinephrine 133.3 ng/min (C) versus 49.2 ng/min (R), p= 0.004, and for dopamine 609.9ng/min (C) versus 223.7 ng/min (R), p= 0.03. Nighttime levels were significantly different for epinephrine and norepinephrine but not for dopamine. Epinephrine was 15.7ng/min (C) versus 8.4 ng/min (R), p= 0.006; norepinephrine 54. lng/min (C) versus 28.4ng/min (R), p= 0.03; dopamine 304.6ng/min (C) versus 221.9 (R), p= 0.14. 3.2. Sleep Staging In the comparison of polysomnographic data between competition day and rest day the total sleep stage values as percentage of total sleep time (TST) were significantly different only for stage 3 Non-Rem- sleep: In the average stage 3 was 13.9% ofTST (C) versus 11.4% ofTST (R), p= 0.03. REM showed a tendency to be decreased on competition day: 15.5% of TST (C) versus 17:6% of TST (R), P = 0.09. In the first two NonREM/ REM cyCle of the night ,however REM was sigrTIficantly dBcreased (p=0.05) and stage 2 Non-REM sleep significantly'increased (p=O.0'3) on competition day versus rest day, REM then showed a tendencY;, to be decreased in the second two Non-REM/REM cycles of the night (p= 0.1). The absolute sleep latency (wake until slage 1) was not different between competition day and rest day [19.1 min (C) versus 19.2 min (R)]. However the REM onset latency was significantly different [124.0 min (C) versus 97.2min (R), p = 0.05]. There were no differences at all for sleep efficiency (total sleep time /sleep period or bed- time). 3.3. Respiratory Analysis No differences for respiratory data were found between competition and rest day. Except one individual the athlethes had no respiratory events and oxygen desaturations at all or less than 10 events and desaturations during the whole night (TST). 3.4. Heartfrequency Analysis The heartfrequency was significantly different at the start of bedtime between competition and rest day: 54.7 /min (C) versus 50. 5/min (R). During the rest of the night the heartfrequency was not significantly different between competition and rest day. 3.5. Correlations between Catecholamine Levels and Sleep Staging Data The only significant correlations between sleep staging and catecholamine levels were found for REM- sleep onset latency and catecholamine levels and for REM distribution in the first two REMlNon-REM cycles of the night and catecholamine levels. The spearman correlation coefficient was r = 0.53 (p= 0.04) for the changes of REM- sleep latency and epinephrine between competition to rest daytime urine level. For norepinephrine nighttime urine levels and REM- onset latency the correlation coefficient was r = 0.45 (p= 0.09). Absolutely seen without comparing differences between competition day and rest day there was a correlation between norepinephrine levels in nighttime urine and REM-onset latency (r = 0.36, p= 0.06), there was only a mild correlation for epinephrine in nighttime urine and REM-onset latency (r = 0.26, p= 0.19). The correlation between REM percentage in the first two REM/Non-REM cycles and nightime urine levels for norepinephrine was r = - 0.46 (p < 0.01), for daytime norepinephrine r = -0.46 (p< 0.01), for nighttime epinephrine r = -0.35 (p= 0.06) and for daytime epinephrine r = -0.35 (p = 0.06).