Table 2.
Effects of age and diagnostic group on objective sleep measuresa
| Variable | Younger Controls (N=58) |
Older Controls (N=29) |
Younger Alcoholics (N=123) |
Older Alcoholics (N=16) |
|---|---|---|---|---|
| RDI b,c,d | 2.5 (13.1) | 10.2 (25.8) | 3.0 (7.3) | 17.6 (24.2) |
| PLM Index b,c,d | 1.9 (8.8) | 3.6 (5.4) | 2.9 (7.6) | 16.8 (40.0) |
| Total Sleep Time (min)b,c | 357.1 (54.4) | 316.0 (49.0) | 313.9 (48.4) | 277.7 (58.7) |
| Sleep Latency (min) | 26.5 (36.5) | 31.7 (32.9) | 34.6 (31.7) | 43.5 (43.9) |
| Sleep Efficiency (%) e | 87.2 (12.2) | 78.0 (11.5) | 81.2 (10.8) | 71.6 (15.0) |
| Stage 1 Sleep (%) b,c,d | 14.2 (10.5) | 28.3 (18.3) | 21.7 (10.4) | 42.5 (23.2) |
| Delta Sleep (%) c | 13.1 (9.8) | 8.1 (10.0) | 8.5 (8.8) | 4.3 (7.8) |
| REM Sleep Latency (min) c | 77.4 (45.3) | 63.7 (38.3) | 79.7 (52.7) | 48.6 (57.3) |
| REM Sleep (%) | 19.8 (5.5) | 18.5 (7.2) | 20.0 (6.2) | 20.4 (8.3) |
a
Variables are expressed as means (S.D.).
b
Significant diagnostic group effect (alcoholics vs. controls) after controlling for age group, gender, race, body mass index, psychiatric-related sleep symptoms, and other sleep variables.
c
Significant age effect (<55 vs. 55+ yr) after controlling for diagnostic group, gender, race, body mass index, psychiatric-related sleep symptoms, and other sleep variables.
d
Significant age by diagnostic group interaction after controlling for gender, race, body mass index, psychiatric-related sleep symptoms, and other sleep variables.
e
Not entered into the multivariate analysis due to its high correlations with both total sleep time and sleep latency.