Elevated C-reactive protein levels and cardiovascular risk in prurigo nodularis patients with sleep disturbance: a multi-center cohort study.

Patients with prurigo nodularis (PN) present with pruritus which may lead to sleep disturbances and systemic comorbidities. The objective of our study was to determine the risk of sleep disorders in PN and its association with systemic inflammation and adverse cardiovascular outcomes. We conducted a retrospective population-level cohort using a global health records database to analyze the development of sleep disorders, C-reactive protein (CRP) levels, and risk of cardiovascular disease and mortality in PN compared to controls. PN patients had increased risk of general sleep disorders (RR 1.47, 95%CI 1.42-1.52, obstructive sleep apnea (1.61, 1.54-1.69), insomnia (1.37, 1.29-1.45), hypersomnia (1.47, 1.32-1.64), and restless legs syndrome (1.45, 1.28-1.65). Additionally, PN with sleep disorders had higher CRP levels than PN without sleep disorders (16.2 mg/L vs. 10.6 mg/L). PN patients with sleep disorders were more likely to develop cardiovascular comorbidities, including type 2 diabetes mellitus (RR 2.45, 95%CI 2.25-2.66), metabolic syndrome (4.16, 3.31-5.22), myocardial infarction (2.87, 2.52-3.22), venous thromboembolism (2.93, 2.55-3.39), and greater mortality (HR 1.47, 95%CI 1.34-1.62) compared to PN patients without sleep disorders. Our findings suggest that PN patients are at greater risk of developing various sleep disorders that are associated with adverse cardiovascular outcomes.