Psoriasis and Sleep: Does Severity Affect Sleep and Quality of Life?
Getting enough sleep is essential to maintaining optimal health and health–related quality of life (HRQoL). The physical symptoms of psoriasis may affect sleep and by association impair quality of life. Poor sleep is a risk factor for depression, cardiovascular disease, hypertension and diabetes. Insomnia, the most common sleep disorder, is defined as difficulty falling asleep and/or maintaining sleep and/or poor sleep quality despite adequate hours of sleep.
A recent study hypothesized that psoriasis may lead to decreased sleep quality and therefore affect HRQoL. The authors examined the prevalence of sleep disturbance in patients with psoriasis compared to a control group, and evaluated the associations of sleep disturbance HRQoL in the study group. The majority of the participants had moderate-to-severe psoriasis and received systemic treatment. The authors captured HRQoL using the Dermatology Life Quality Index (DLQI) and sleep quality and insomnia were each measured on separate validated scales. For sleep quality the Pittsburgh Sleep Quality Index (PSQI) measures items such as subjective sleep quality, sleep duration, sleep disturbances, use of sleep medications and daytime dysfunction.
The results showed that in the study group, about 25% reported sleep difficulty that was characterized as clinical insomnia, compared with 10% of the control group. Regarding sleep quality, more than half of the patients with psoriasis were characterized as poor sleepers compared with only two in 10 controls; controls slept an average of 68 minutes longer than the patient group. Itch and depressive symptoms were the most consistent statistical predictors of insomnia and poor sleep quality in the patients with psoriasis.
The authors state that their results support the conclusion that patients with psoriasis are at higher risk of experiencing sleep disturbance and support previous findings that sleep disturbance is associated with both itch and depressive symptoms. They note that because itch was the most consistent predictor found in our study, controlling for itch with state-of-the-art biological treatment may improve sleep quality in patients with psoriasis.