Crystal Methamphetamine Injection Predicts Slower HIV RNA Suppression among Injection Drug Users

1. Crystal Methamphetamine Injection Predicts Slower HIV RNA Suppression among Injection Drug Users • Nadia Fairbairn1 • Thomas Kerr1, 2 • M-J Milloy1 • Ruth Zhang1 • Julio Montaner1, 2 • Evan Wood1, 2 • 1 Urban Health Research Initiative of the British Columbia Centre for Excellence in HIV/AIDS • 2 Division of AIDS, Department of Medicine, University of British Columbia

2. Background • Crystal methamphetamine is a stimulant drug with higher purity than powdered methamphetamine • Reports of increasing crystal methamphetamine production and consumption globally • Major implications for HIV prevention and treatment strategies

3. Amphetamine-type stimulant seizures in 2008 UNODC World Drug Report 2010

4. Background • 66% Bangkok injection drug users (IDUs) reported injecting methamphetamine (Werb et al., 2009) • Methamphetamine injection associated with HIV risk behavior syringe sharing in Bangkok (Hayashi et al., IAC 2010 WEPE0269) • Australia and the U.S. have documented increases in crystal methamphetamine injection among drug users

5. Background • Injection and non-injection crystal methamphetamine use increasing in Vancouver, Canada Fairbairn et al., 2007

6. Background • Crystal methamphetamine use linked to: • Sexual risk behaviors • Increased likelihood of HIV seroconversion • Poor adherence to antiretroviral therapy • Injection of crystal methamphetamine associated with syringe sharing • Not much known about the impact of crystal methamphetamine use on the outcomes of HIV treatment

7. Objective • To examine the association between crystal methamphetamine injection and plasma HIV RNA suppression among a cohort of HIV-positive injection drug users initiating ART

8. Methods • The ACCESS cohort is an ongoing prospective cohort of HIV-positive individuals who inject drugs • Participants recruited through self-referral and street outreach from Vancouver’s Downtown Eastside since 1996 • At baseline and semi-annually participants provide blood sample and complete questionnaire

9. Methods • Primary endpoint of analysis: time to plasma viral load suppression <500 copies/mL from start of ART • Primary independent variable of interest: use of injection crystal methamphetamine • Variables: • Daily heroin and cocaine injection, crack smoking • Gender, age, ethnicity • Baseline viral load (per log10) • Baseline CD4 cell count (per 100 cells/mm3) • Multivariate model fit using an a priori defined model-building approach

10. Results • Sample characteristics (n=708): • 384 (54.2%) ART-naïve participants initiated HAART • 163 (42.5%) female respondents • Median follow-up 18 months (inter-quartile range 6 - 49) • Primary outcome of interest: Have you injected crystal methamphetamine in the last 6 months?  Yes  No  ACCESS Cohort (n=708) 36 (9.4%) reported crystal meth injection at any time during follow-up.

11. Multivariate Cox Regression analysis of factors independently associated with time to HIV RNA suppression <500 copies/mL. • Multivariate Cox Regression analyses Adjusted** Relative Hazard (95% CIs) 0.90 (0.84 – 0.96) p < 0.001 Baseline CD4 Count HIV RNA Suppression 0.86 (0.73 – 1.00) p = 0.064 Baseline Viral Load 0.63 (0.40 – 0.98) p = 0.039 Crystal methamphetamine injection* * Behaviors refer to activities in the last 6 months. ** Model was also adjusted for age, heroin injection and cocaine injection.

12. Interpretations • Crystal methamphetamine injection independently and negatively associated with plasma HIV RNA suppression • Psychopharmacological effects of crystal methamphetamine may undermine antiretroviral treatment adherence • Some evidence for direct effects on HIV disease progression

13. Interpretations • Crystal methamphetamine production is a highly profitable and easily concealable endeavor • Demand for the drug is increasing • Legal remedies and law enforcement may have negligible impact on use • Urgent need for evidence-based HIV prevention and treatment programs for crystal methamphetamine injectors

14. Limitations • Findings possibly conservative due to socially desirable reporting • Sample not randomly selected, findings may not generalize to other IDU • Further research needed to examine impact of methamphetamine use on HIV pathogenesis

15. Conclusion • These findings contribute further evidence to the negative health outcomes associated with crystal methamphetamine use • Expansion of treatment programs and implementation of novel interventions for crystal methamphetamine injectors urgently needed

16. Acknowledgements • ACCESS participants • ACCESS investigators and staff: Deborah Graham, Tricia Collingham, Caitlin Johnston, Steve Kain, and Calvin Lai • US National Institutes of Health • Canadian Institutes of Health Research