title: Impact of Restless Legs Syndrome on Cardiovascular Autonomic Control.
abstract: OBJECTIVE
  To examine whether patients with restless legs syndrome demonstrate specific alterations in cardiovascular autonomic control.
  
  
  METHODS
  Patients with moderate-severe restless legs syndrome (n = 20, 80% female) and controls (n = 20) matched for age, sex, body mass index, and free of hypertension and cardiovascular disease were enrolled. We assessed cardiovagal baroreflex gain via the modified Oxford technique, sympathetically mediated vascular responses to isometric exercise to fatigue, bradycardiac response to Valsalva maneuver, and respiratory sinus arrhythmia during paced breathing. Standard electrocardiography, beat-by-beat arterial pressure, respiration, and popliteal blood flow velocity were recorded continuously.
  
  
  RESULTS
  Resting blood pressure and heart rate were similar between groups. However, baroreflex gain averaged 14.3 ± 1.4 msec/mm Hg in restless legs syndrome and was lower than in controls (22.6 ± 3.5 msec/mm Hg, P = 0.04). Hemodynamic responses to isometric exercise were similar between groups, though participants with restless legs syndrome had lower leg blood flow (P < 0.001), with greater leg vascular resistance (P < 0.0001), before and during isometric exercise. Respiratory sinus arrhythmia and Valsalva ratios were similar between groups. Neither baroreflex gain nor vascular resistance was correlated with sleep duration, sleep quality, or symptom duration.
  
  
  CONCLUSIONS
  Patients with restless legs syndrome demonstrate compromised cardiovagal control, specific to the arterial baroreflex, with greater peripheral vascular resistance, potentially due to heightened sympathetic outflow. These autonomic alterations may directly relate to the higher prevalence of cardiovascular disease in restless legs syndrome.
authors.affiliation: Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.|Cardiovascular Research Laboratory, Spaulding Hospital Cambridge, Cambridge, MA.
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Bertisch
authors.affiliation: Cardiovascular Research Laboratory, Spaulding Hospital Cambridge, Cambridge, MA.
authors.forename: Cristen
authors.initials: C
authors.lastname: Muresan
authors.affiliation: Departments of Psychiatry and Neurology, Sleep Disorders Clinical Research Program, Massachusetts General Hospital, Boston, MA.
authors.forename: Laura
authors.initials: L
authors.lastname: Schoerning
authors.affiliation: Departments of Psychiatry and Neurology, Sleep Disorders Clinical Research Program, Massachusetts General Hospital, Boston, MA.|Department of Psychiatry, Harvard Medical School, Boston, MA.
authors.forename: John W
authors.initials: JW
authors.lastname: Winkelman
authors.affiliation: Cardiovascular Research Laboratory, Spaulding Hospital Cambridge, Cambridge, MA.|Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA.
authors.forename: J Andrew
authors.initials: JA
authors.lastname: Taylor
mesh_terms: D000328:Adult; D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology*; D017704:Baroreflex; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002318:Cardiovascular Diseases / Q000150:complications* / Q000503:physiopathology*; D002319:Cardiovascular System / Q000503:physiopathology*; D016022:Case-Control Studies; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology; D005221:Fatigue; D005260:Female; D006339:Heart Rate; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D012119:Respiration; D012146:Rest; D012148:Restless Legs Syndrome / Q000150:complications* / Q000503:physiopathology*; D014636:Valsalva Maneuver; D055815:Young Adult
keywords: baroreflex; heart rate variability; periodic leg movements of sleep; restless legs syndrome; sleep