title: Acceleration of cardiovascular-biological age by amphetamine exposure is a power function of chronological age.
abstract: BACKGROUND
  Amphetamine abuse is becoming more widespread internationally. The possibility that its many cardiovascular complications are associated with a prematurely aged cardiovascular system, and indeed biological organism systemically, has not been addressed.
  
  
  METHODS
  Radial arterial pulse tonometry was performed using the SphygmoCor system (Sydney). 55 amphetamine exposed patients were compared with 107 tobacco smokers, 483 non-smokers and 68 methadone patients (total=713 patients) from 2006 to 2011. A cardiovascular-biological age (VA) was determined.
  
  
  RESULTS
  The age of the patient groups was 30.03±0.51-40.45±1.15 years. This was controlled for with linear regression. The sex ratio was the same in all groups. 94% of amphetamine exposed patients had used amphetamine in the previous week. When the (log) VA was regressed against the chronological age (CA) and a substance-type group in both cross-sectional and longitudinal models, models quadratic in CA were superior to linear models (both p<0.02). When log VA/CA was regressed in a mixed effects model against time, body mass index, CA and drug type, the cubic model was superior to the linear model (p=0.001). Interactions between CA, (CA)2and (CA)3on the one hand and exposure type were significant from p=0.0120. The effects of amphetamine exposure persisted after adjustment for all known cardiovascular risk factors (p<0.0001).
  
  
  CONCLUSIONS
  These results show that subacute exposure to amphetamines is associated with an advancement of cardiovascular-organismal age both over age and over time, and is robust to adjustment. That this is associated with power functions of age implies a feed-forward positively reinforcing exacerbation of the underlying ageing process.
authors.affiliation: School of Psychiatry and Clinical Neurosciences , University of Western Australia , Crawley, Western Australia , Australia.
authors.forename: Albert Stuart
authors.identifier: 0000-0002-3256-720X
authors.initials: AS
authors.lastname: Reece
authors.affiliation: School of Psychiatry and Clinical Neurosciences , University of Western Australia , Crawley, Western Australia , Australia.
authors.forename: Amanda
authors.initials: A
authors.lastname: Norman
authors.affiliation: School of Psychiatry and Clinical Neurosciences , University of Western Australia , Crawley, Western Australia , Australia.
authors.forename: Gary Kenneth
authors.initials: GK
authors.lastname: Hulse
keywords: AORTA; GREAT VESSELS AND TRAUMA