title: Incidence of low and high-energy fractures in persons with and without HIV infection:  a Danish population-based cohort study.
abstract: OBJECTIVE
  To compare fracture risk in persons with and without HIV infection and to examine the influence of highly active antiretroviral therapy (HAART) initiation on risk of fracture.
  
  
  METHODS
  Population-based nationwide cohort study using Danish registries.
  
  
  METHODS
  Outcome measures were time to first fracture at any site, time to first low-energy and high-energy fracture in HIV-infected patients (n = 5306) compared with a general population control cohort (n = 26 530) matched by sex and age during the study period 1995-2009. Cox regression analyses were used to estimate incidence rate ratios (IRRs).
  
  
  RESULTS
  HIV-infected patients had increased risk of fracture [IRR 1.5, 95% confidence interval (CI) 1.4-1.7] compared with population controls. The relative risk was lower in HIV-monoinfected patients (IRR 1.3, 95% CI 1.2-1.4) than in HIV/hepatitis C virus (HCV)-coinfected patients (IRR 2.9, 95% CI 2.5-3.4).Both HIV-monoinfected and HIV/HCV-coinfected patients had increased risk of low-energy fracture, IRR of 1.6 (95% CI 1.4-1.8) and 3.8 (95% CI 3.0-4.9). However, only HIV/HCV-coinfected patients had increased risk of high-energy fracture, IRR of 2.4 (95% CI 2.0-2.9). Among HIV-monoinfected patients the risk of low-energy fracture was only significantly increased after HAART exposure, IRR of 1.8 (95% CI 1.5-2.1). The increased risk in HAART-exposed patients was not associated with CD4 cell count, prior AIDS, tenofovir or efavirenz exposure, but with comorbidity and smoking.
  
  
  CONCLUSIONS
  HIV-infected patients had increased risk of fracture compared with population controls. Among HIV-monoinfected patients the increased risk was observed for low-energy but not for high-energy fractures, and the increased risk of low-energy fracture was only observed in HAART-exposed patients.
authors.affiliation: Department of Infectious Diseases, Copenhagen University Hospital Rigshospitalet, Denmark. ann-brit.eg.hansen@rh.regionh.dk
authors.forename: Ann-Brit E
authors.initials: AB
authors.lastname: Hansen
authors.forename: Jan
authors.initials: J
authors.lastname: Gerstoft
authors.forename: Gitte
authors.initials: G
authors.lastname: Kronborg
authors.forename: Carsten S
authors.initials: CS
authors.lastname: Larsen
authors.forename: Court
authors.initials: C
authors.lastname: Pedersen
authors.forename: Gitte
authors.initials: G
authors.lastname: Pedersen
authors.forename: Niels
authors.initials: N
authors.lastname: Obel
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D001851:Bone Diseases, Metabolic / Q000139:chemically induced / Q000453:epidemiology*; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D015897:Comorbidity; D003718:Denmark / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology*; D006526:Hepatitis C; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000139:chemically induced / Q000453:epidemiology*; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*