title: Predictors of longitudinal change in bone mineral density in a cohort of HIV-positive and negative patients.
abstract: Although low bone mineral density (BMD) is prevalent in HIV, changes in BMD over time remain unclear. We aimed to compare rates of, and factors associated with, BMD change between HIV-positive and HIV-negative patients.
  
  
  
  In a prospective, 3-year cohort, HIV-positive and HIV-negative patients provided annual demographic and clinical data, fasting bloods, and dual x-ray absorptiometry. Using longitudinal mixed models we compared and determined predictors of rate of change in BMD.
  
  
  
  Of 384 study participants (45.8% HIV positive), 120 contributed two and 264 contributed three BMD measurements. Those with HIV were younger [median interquartile range 39 (34-46) vs. 43 (35-50) years; P = 0.04], more often men (61 vs. 46%; P = 0.003), and less likely Caucasian (61 vs. 82%; P < 0.001). Although BMD was lower in those with HIV, BMD declined in both groups, with nonsignificant between-group difference in rate of BMD change over time. Within the HIV group, starting antiretroviral therapy (ART) within 3 months of enrolment was associated with greater BMD decline at all anatomical sites (all P < 0.001). Age more than 30 years, Caucasian ethnicity, and not being on ART during follow-up were associated with greater decline and higher parathyroid hormone associated with a smaller decline in BMD at the femoral neck. We found no association between BMD change and exposure to tenofovir disoproxil fumarate or protease inhibitors.
  
  
  
  We observed no difference in rate of BMD decline regardless of HIV status and in HIV-positive patient, having started ART within the previous 3 months was the only factor associated with greater BMD decline at all three sites.
authors.affiliation: aHIV Molecular Research Group, Catherine McAuley Education and Research Centre, School of Medicine, University College Dublin, Dublin, Ireland bDepartment of Community Medicine, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe cDepartment of Infectious Diseases, Mater Misericordiae University Hospital, Dublin, Ireland dResearch Department of Infection and Population Health, University College London, London, UK eDepartment of Radiology fDepartment of Clinical Chemistry and Diagnostic Endocrinology gDepartment of Rheumatology, Mater Misericordiae University Hospital, Dublin, Ireland hDepartment of Medicine, Cambridge Biomedical Campus, Cambridge, UK.
authors.forename: Willard
authors.initials: W
authors.lastname: Tinago
authors.forename: Aoife G
authors.initials: AG
authors.lastname: Cotter
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Sabin
authors.forename: Alan
authors.initials: A
authors.lastname: Macken
authors.forename: Eoin
authors.initials: E
authors.lastname: Kavanagh
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Brady
authors.forename: Geraldine
authors.initials: G
authors.lastname: McCarthy
authors.forename: Juliet
authors.initials: J
authors.lastname: Compston
authors.forename: Patrick W G
authors.initials: PW
authors.lastname: Mallon
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000453:epidemiology*; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies