Multiple complaints of physical symptoms including sleep disturbance and daytime fatigue are frequently reported by persons who report adverse reactions from exposure to low levels of environmental chemicals. As part of a larger study which investigates and compares patterns of objective physiological and subjective rating characteristics in persons with reported chemical intolerance, this study examined self-reported sleep variables and compared them to PSG variables. Three groups of otherwise healthy, non-smoking, non-alcoholic, non-disabled middle-aged persons (primarily women) were compared: (1) Persons who had made lifestyles changes because of their chemical intolerance (CIL); (2) persons with chemical intolerance who had not made lifestyle changes (CI); (3) normal controls without CI (N).

Methods. Subjects were recruited through newspaper ads and posted flyers. The CIL (n=9; 9F, 0M; mean age=52), CI (n=8; 6F, 2M; mean age=40), and N (n=10; 7F, 3M; mean age=46) groups underwent two identical one-night sessions, of laboratory PSG spaced five to nine days apart. A 14-item morning questionnaires assessing subjective sleep measures was administered in the morning after each laboratory night. PSG records were visually scored using Rechtschaffen & Kales (1968) criteria.

Results. One 2-factor, 3x2 ANOVA (Group x Night ) was used to analyze the morning questionnaire data (Table 1, reporting group means). Pearson's rs were computed for each pair of subjective and PSG measures (Table 2). See Bootzin et al. (1997)¹ for PSG analyses.

Table 1 - Selected Morning Questionnaire Items

	CIL			CI			N
	M1	M2		M1	M2		M1	M2
1. Time took to fall asleep (min.)	34	29		17	20		28	20	ns
2. WASO (min.)	62	43		33	29		24	23	g$
3. TST - Length slept (min.)	301	351		345	353		294	303	n$
4. Sleep quality rating (1-5; 1=excellent)	3.8	3.3		2.9	3.1		2.9	2.6	g$
5. Rested/refreshed rating (1-5; 1=rested)	3.6	3.2		3.4	3.5		2.6	2.8	ns
6. Alertness rating (1-5; 1=wide awake)	3.3	3.1		3.6	3.5		2.4	2.6	g$
7. Difficulty waking up (1-5; 1=easy)	1.7	1.9		2.8	2.9		2.4	2.4	g$
8. Acheness (0=none; 1=yes)	.6	.8		.4	.3		.3	.2	g#
9. Stiffness (0=none; 1=yes)	.8	.3		.3	.1		.1	.1	n#

g = group main effect; n = night main effect
ns p>.20; $ p<.20; # p<.10

Table 2 - Selected Correlations Between Self-reported and PSG Sleep Variables

		Night 1			Night 2
Self-reported	PSG	CIL	CI	N	CIL	CI	N
SL	SL	.86**	.09	.31	.91**	.63	.71*
WASO	WASO	.54	.17	.28	.67*	.40	.57
TST	TST	.58	.90**	.87**	.68*	.85**	.97**

SL = 3 consecutive epochs of NREM or REM sleep.

Discussion. The self-reported ratings in persons with complaints of chemical odor intolerance are not significantly different, regardless of whether they made life style changes to manage their intolerance. The self-report sleep data confirm the PSG data¹ that CIL subjects had more WASO and poorer quality sleep than subjects in the other groups. However, both CI groups woke up not feeling rested nor feeling alert, compared to controls. These results are statistical trends, but are reported here because of the small sample size. Finally, self-reported quantitative measures of sleep such as sleep latency and total sleep time had strong correlations with the corresponding PSG measures. In contrast, qualitative measures (e.g. quality of sleep, how rested) appear not to be related to PSG measures.
____________________
¹Bootzin, R.R., Bell, I.R., DiCenso, D.R., Szarek, M.J., Kuo, T.F., Loewy, D., Baldwin, C.M., and Schwartz, G.E., Goldenson, M., Clayton, B., and Banks, O. (1997) Objective sleep disturbance in chemically-intolerant individuals with associated lifestyle changes. Sleep Research.

Research supported by the Wallace Genetic Foundation.