Associations between chemical odor intolerance and sleep disturbances in community-living adults

To investigate associations between sleep disturbances and chemical odor intolerance (COI), which is the subjective report of feeling ill from common odors, such as carpet glue or pesticides.

This cross-sectional study consisted of government employees and their family members (n=140; 61% women, mean age=46.3 years) derived from a stratified cluster population living in Pima County, Tucson, AZ. Subjects completed a standard survey that included sleep symptoms, a validated measure of COI, and two questions regarding anxiety and depression. Odds ratios (OR) with 95% confidence intervals (CI) were computed to test the association between COI and sleep symptoms. Stratification according to the Mantel-Haenszel method and logistic regression models were used to test for confounding and/or effect modification.

After adjusting for age and gender, subjects with COI were significantly more likely to report difficulty staying asleep (OR=3.06; CI=1.17-8.03), insufficient sleep (OR=3.93; CI=1.43-10.79), and nightmares (OR=3.17; CI=1.14-8.81) compared to persons without COI. Associations between COI, sleep maintenance problems and insufficient sleep were still significant after adjusting for gender and depression; however, the association between COI and nightmares became borderline.

Compared to the non-COI, persons with COI are more likely to report sleep maintenance insomnia and insufficient sleep independent of self-reported depression. Nightmares appear to be related more to depression than to COI.