EFFECTS OF INSOMNIA AND RESTLESS LEGS SYNDROME ON NIGHTTIME ARTERIAL BLOOD PRESSURE: A SYSTEMATIC REVIEW AND META-ANALYSIS

Objective: Nocturnal hypertension and blunted blood pressure (BP) dipping during nighttime sleep are associated with increased cardiovascular risk. Chronic insomnia and restless legs syndrome (RLS) are highly prevalent disorders that might affect the 24 hours BP profile including nocturnal dipping, but data on this issue are still controversial. In this systematic review and meta-analysis we aimed at evaluating the association of insomnia and RLS with nighttime and daytime BP values and the BP dipping pattern. Design and method: We searched for relevant articles in 4 different databases using the following inclusion criteria: 1) observational studies and randomized clinical trials, comparing patients with either chronic insomnia or RLS with matched control subjects free of sleep disorders; 2) evaluation of OSA comorbidity; 3) nighttime BP measured by means of either 24-hour ambulatory or nocturnal beat-to-beat BP monitoring; 4) English language; 5) full-length retrievable papers. Results: Of the 811 studies originally retrieved, 6 were selected. Three studies enrolled insomnia subjects, who at meta-analysis displayed a reduced diastolic BP dipping compared to controls (-1.66%, 95% confidence interval (CI) -2.80 - -0.52), while no difference was found on daytime and nighttime blood pressure levels. Three studies enrolled RLS patients, who showed increased nighttime systolic BP (5.61 mm Hg, 95% CI 0.13–11.09) compared to controls, with no difference in daytime BP, nighttime diastolic BP, and dipping pattern. Conclusions: The limited available evidence suggests that insomnia and RLS are both associated with altered nocturnal BP control. Further clinical studies are warranted to replicate and clarify this association.