Higher nocturnal systolic blood pressure in patients with restless legs syndrome compared with patients with insomnia.

BACKGROUND

There is evidence linking restless legs syndrome (RLS) with increased blood pressure (BP), but the mechanism of this relation remains unclear. Is the BP increased due to some features of RLS or to deterioration of sleep caused by RLS? This study compared values of nocturnal BP in patients with RLS and patients with insomnia. If increased BP in RLS is a consequence of disordered sleep, then it should be similar to increased BP in insomnia.

METHODS

Polysomnographic recordings of patients admitted to a sleep center with RLS or insomnia were analyzed. Demographic and clinical data, objective sleep parameters, and nocturnal BP were compared.

RESULTS

Recordings of 35 patients with RLS and 33 patients with insomnia were analyzed. The groups did not significantly differ in terms of demographic traits or prevalence of other comorbidities. Patients with RLS had significantly higher systolic BP during the night (122.4 ± 13.8 vs 116.3 ± 13.4; p = 0.03) and during sleep (121.4 ± 13.3 vs 115.7 ± 13.3; p = 0.04). The only significant difference in sleep architecture was an increased number of periodic limb movements in sleep (PLMS) and PLMS with arousal in the RLS group (25.5 ± 24.6 vs 13.9 ± 22.7; p = 0.02 and 4.7 ± 5.4 vs 2.1 ± 3.4; p = 0.01).

CONCLUSION

Our results suggest that patients with RLS have higher nocturnal BP than patients with insomnia, and that increased PLMS is related to the increase in BP.