Sleep and sleepiness in environmental intolerances: a population-based study

Area of Science:

• Environmental Health
• Sleep Medicine
• Clinical Psychology

Background:

• Environmental intolerance (EI) affects approximately 25% of the population, manifesting as sensitivities to chemicals, EMFs, and sounds.
• Sleep disturbance is a common clinical feature among individuals with EI.
• The prevalence of sleep disturbance in EI sufferers compared to the general population is not well-established.

Purpose of the Study:

• To investigate and compare sleep aspects between individuals with environmental intolerance and a control group without EI.
• To determine if sleep disturbances are more pronounced in EI sufferers.

Main Methods:

• A population-based sample of 3406 individuals (aged 18-79) from Northern Sweden was recruited.
• The Karolinska Sleep Questionnaire assessed sleep quality, non-restorative sleep, daytime sleepiness, obstructive breathing, and nocturnal insomnia.
• Additional questions evaluated sleep duration, required sleep, and perceived sufficiency of sleep.

Main Results:

• All four EI groups reported significantly poorer sleep quality, more non-restorative sleep, increased daytime sleepiness, and higher prevalence of obstructive breathing and nocturnal insomnia compared to referents.
• Nocturnal insomnia was identified as a key symptom contributing to EI symptom attribution.
• While total sleep time did not differ, EI groups reported needing more sleep and perceiving less adequate sleep.

Conclusions:

• Individuals reporting EI exhibit a higher incidence of sleep disturbances and daytime sleepiness compared to individuals without EI.
• Nocturnal insomnia is a significant and independent symptom associated with various forms of EI.
• The findings suggest that sleep therapy could potentially mitigate the severity of environmental intolerance symptoms.