title: Lower ambulatory blood pressure in chronic fatigue syndrome.
abstract: OBJECTIVE
  To examine blood pressure circadian rhythm in subjects with chronic fatigue syndrome (CFS) and appropriate normal and fatigued controls to correlate parameters of blood pressure regulation with perception of fatigue in an observational cohort study. The cause of CFS remains unknown and there are no effective treatments.
  
  
  METHODS
  To address whether inactivity was a confounder, we performed a 24-hour ambulatory blood pressure monitoring in the following three subject groups: 1) CFS patients (Fukuda Diagnostic criteria) (n = 38); 2) normal controls (n = 120); and 3) a fatigue comparison group (n = 47) with the autoimmune liver disease primary biliary cirrhosis (PBC). All patients completed a measure of fatigue severity (Fatigue Impact Scale). In view of the different demographics between the patient groups, patients were age- and sex-matched on a case-by-case basis to normal controls and blood pressure parameters were compared.
  
  
  RESULTS
  Compared with the control population, the CFS group had significantly lower systolic blood pressure (p < .0001) and mean arterial blood pressure (p = .0002) and exaggerated diurnal variation (p = .009). There was a significant inverse relationship between increasing fatigue and diurnal variation of blood pressure in both the CFS and PBC groups (p < .05).
  
  
  CONCLUSIONS
  Lower blood pressure and abnormal diurnal blood pressure regulation occur in patients with CFS. We would suggest the need for a randomized, placebo-controlled trial of agents to increase blood pressure such as midodrine in CFS patients with an autonomic phenotype.
authors.affiliation: Cardiovascular Investigation Unit, Institute of Cellular Medicine, Newcastle University, Newcastle NE2 4HH, UK. julia.newton@nuth.northy.nhs.uk
authors.forename: Julia L
authors.initials: JL
authors.lastname: Newton
authors.forename: Amish
authors.initials: A
authors.lastname: Sheth
authors.forename: Jane
authors.initials: J
authors.lastname: Shin
authors.forename: Jessie
authors.initials: J
authors.lastname: Pairman
authors.forename: Katharine
authors.initials: K
authors.lastname: Wilton
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Burt
authors.forename: David E J
authors.initials: DE
authors.lastname: Jones
mesh_terms: D018660:Blood Pressure Monitoring, Ambulatory; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007022:Hypotension / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D008105:Liver Cirrhosis, Biliary / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008879:Midodrine / Q000627:therapeutic use; D014662:Vasoconstrictor Agents / Q000627:therapeutic use*
chemical_list: D014662:Vasoconstrictor Agents; D008879:Midodrine