Table 3.

Sleep characteristics as recorded by polysomnography in the Sleep groups.

Sleep Measure	Young Adults	Older Adults	p-value
Across the Night (mins)
TST	407.60 (68.02)	396.33 (55.43)	0.521
Sleep Latency	13.33 (16)	11.30 (10.58)	0.601
WASO	17.59 (19.35)	45.70 (33.21)	0.001
Sleep Efficiency (%)	88.23 (15.54)	87.21 (8.72)	0.764
Total SWS	124.73 (45.53)	115.48 (33.33)	0.416
Total NREM	291.17 (58.50)	270.65 (38.98)	0.153
Total REM	71.08 (25.86)	69.70 (24.89)	0.845
Sleep Cycle Characteristics
# Cycles	3.46 (1.25)	3.30 (1.13)	0.664
Average Cycle Length (mins)	111.39 (44.28)	88.55 (18.34)	0.037
TCT	357.88 (90.92)	303.98 (76.05)	0.041
TCT/TST (%)	86.18 (15.71)	73.80 (14.52)	0.010
First Half of the Night (mins)
Total SWS	89.41 (36.45)	77.78 (24.84)	0.223
Total NREM	159.59 (38.33)	144.28 (30.73)	0.149
Total REM	15.45 (12.35)	30.83 (15.30)	< 0.001
Second Half of the Night (mins)
Total SWS	34.09 (20.91)	39.23 (25.18)	0.445
Total NREM	131.64 (26.98)	121.10 (21.61)	0.155
Total REM	55.78 (21.83)	42.28 (21.89)	0.040
Delta Power Density of SWS (μV2/Hz)
Across the Night	176.11 (86.14)	80.89 (46.57)	<0.001
First Half of the Night	204.77 (102.27)	87.92 (56.75)	<0.001

Values in parentheses represent standard deviations. p-values in bold represent p< 0.05.