Table 2.

Effects of sleep restriction on 24 h profiles of NEFA, GH, noradrenaline and cortisol

Variable	Normal sleep	Sleep restriction	p value
NEFA
Nocturnal onset, mmol/l	0.15 ± 0.01	0.15 ± 0.01	0.820
Nocturnal peak, mmol/l	0.66 ± 0.03	0.69 ± 0.04	0.436
Duration of nocturnal increase, min	210 ± 15	262 ± 15	0.003
Mean nocturnal (04:00–05:45 hours), mmol/l	0.44 ± 0.02	0.51 ± 0.03	0.014
Mean early morning (07:15–09:00 hours), mmol/l	0.24 ± 0.02	0.31 ± 0.02	0.019
Mean daytime (09:00–21:30 hours), mmol/l	0.10 ± 0.01	0.09 ± 0.01	0.565
GH
Duration of nocturnal secretion, min	307 ± 18	359 ± 20	0.004
Nocturnal amount secreted, μg	726 ± 59	614 ± 57	0.156
Daytime amount secreted, μg	127 ± 21	103 ± 17	0.336
Noradrenaline
Mean early night (23:00–01:00 hours), pmol/l	633 ± 52	833 ± 94	0.002
Mean early morning (05:30–07:30 hours), pmol/l	676 ± 50	868 ± 90	0.038
Mean daytime (09:00–21:30 hours), pmol/l	1,064 ± 74	1,085 ± 98	0.781
Cortisol
Mean early night (23:00–01:00 hours), nmol/l	51 ± 5	75 ± 9	0.008
Mean evening (19:00–21:30 hours), nmol/l	119 ± 12	146 ± 12	0.047

Data represent mean ± SEM hormone levels during the time interval indicated within parentheses, unless otherwise specified (N=19) NEFA: non-esterified fatty acid, GH: growth hormone