The study of 10 adults with untreated RLS showed that BP rates increased with periodic leg movements (PLMs) at night.
Significant changes to BP could damage the vascular system and the heart, say the researchers.
PLMs involve rhythmic extension of the big toe and dorsiflexion of the ankle at 20 to 40 second intervals. In one out of three movements, arousal is noted in the brain, measured by electroencephalogram.
All the patients in the study underwent polysomnography and BP monitoring overnight.
This showed that for all types of PLMs, systolic BP increased by an average 22mmHg and diastolic BP by 11mmHg.
BP change was even greater in PLMs associated with arousal, boosting systolic BP by 25mmHg and diastolic BP by 13mmHg.
The magnitude of the effect of PLMs on BP also increased with age and duration of illness.