title: Short-term effects of manipulation to the upper thoracic spine of asymptomatic subjects on plasma concentrations of epinephrine and norepinephrine-a randomized and controlled observational study.
abstract: OBJECTIVE
  The purpose of this study was to investigate the short-term effects of spinal manipulation applied to a hypomobile segment of the upper thoracic spine (T1-T6), on plasma concentrations of norepinephrine (NE) and epinephrine (E) in asymptomatic subjects, under strictly controlled conditions.
  
  
  METHODS
  Fifty-six asymptomatic subjects were randomly assigned to receive either a chiropractic manipulative intervention or a sham intervention in the upper thoracic spine. A 20-gauge catheter fitted with a saline lock was used to sample blood before, immediately after, and 15 minutes after intervention. Plasma NE and E concentrations were determined using an enzyme-linked immunosorbent assay. Changes in plasma catecholamine concentrations were analyzed within and between groups using 1- and 2-sample t tests, respectively.
  
  
  RESULTS
  The plasma samples of 36 subjects (18 treatment, 18 control) were used in the analysis. Mean plasma concentrations of NE and E did not significantly differ between the 2 groups at any time point and did not change significantly after either the manipulative or sham intervention.
  
  
  CONCLUSIONS
  The results of this study indicate that a manipulative thrust directed to a hypomobile segment in the upper thoracic spine of asymptomatic subjects does not have a measurable effect on the plasma concentrations of NE or E. These results provide a baseline measure of the sympathetic response to spinal manipulation.
authors.affiliation: Canadian Memorial Chiropractic College, Toronto, Ontario, Canada.
authors.forename: Aaron A
authors.initials: AA
authors.lastname: Puhl
authors.forename: H Stephen
authors.initials: HS
authors.lastname: Injeyan
mesh_terms: D000328:Adult; D000367:Age Factors; D004797:Enzyme-Linked Immunosorbent Assay; D004837:Epinephrine / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D020393:Manipulation, Spinal / Q000379:methods*; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood*; D009864:Ontario; D011446:Prospective Studies; D012016:Reference Values; D012737:Sex Factors; D016037:Single-Blind Method; D013904:Thoracic Vertebrae; D013997:Time Factors; D055815:Young Adult
chemical_list: D009638:Norepinephrine; D004837:Epinephrine