title: Changes in Bone Mineral Density in the Year after Critical Illness.
abstract: BACKGROUND
  Critical illness may be associated with increased bone turnover and loss of bone mineral density (BMD). Prospective evidence describing long-term changes in BMD after critical illness is needed to further define this relationship.
  
  
  OBJECTIVE
  To measure the change in BMD and bone turnover markers (BTMs) in subjects 1 year after critical illness compared with population-based control subjects.
  
  
  METHODS
  We studied adult patients admitted to a tertiary intensive care unit (ICU) who required mechanical ventilation for at least 24 hours. We measured clinical characteristics, BTMs, and BMD during admission and 1 year after ICU discharge. We compared change in BMD to age- and sex-matched control subjects from the Geelong Osteoporosis Study.
  
  
  RESULTS
  Sixty-six patients completed BMD testing. BMD decreased significantly in the year after critical illness at both femoral neck and anterior-posterior spine sites. The annual decrease was significantly greater in the ICU cohort compared with matched control subjects (anterior-posterior spine, -1.59%; 95% confidence interval, -2.18 to -1.01; P < 0.001; femoral neck, -1.20%; 95% confidence interval, -1.69 to -0.70; P < 0.001). There was a significant increase in 10-year fracture risk for major fractures (4.85 ± 5.25 vs. 5.50 ± 5.52; P < 0.001) and hip fractures (1.57 ± 2.40 vs. 1.79 ± 2.69; P = 0.001). The pattern of bone resorption markers was consistent with accelerated bone turnover.
  
  
  CONCLUSIONS
  Critically ill individuals experience a significantly greater decrease in BMD in the year after admission compared with population-based control subjects. Their bone turnover biomarker pattern is consistent with an increased rate of bone loss.
authors.affiliation: 1 Intensive Care Unit, University Hospital Geelong.|3 School of Medicine, Deakin University, and.|2 Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.
authors.forename: Neil R
authors.initials: NR
authors.lastname: Orford
authors.affiliation: 3 School of Medicine, Deakin University, and.|4 Biostatistics Unit, Barwon Health, Geelong, Australia.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Lane
authors.affiliation: 2 Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Bailey
authors.affiliation: 5 Epi-Centre for Healthy Ageing, School of Medicine, Deakin University, Geelong, Australia.|6 Barwon Health, Geelong, Australia.|7 Department of Medicine, The University of Melbourne, Melbourne, Australia.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Pasco
authors.affiliation: 1 Intensive Care Unit, University Hospital Geelong.|3 School of Medicine, Deakin University, and.
authors.forename: Claire
authors.initials: C
authors.lastname: Cattigan
authors.affiliation: 1 Intensive Care Unit, University Hospital Geelong.
authors.forename: Tania
authors.initials: T
authors.lastname: Elderkin
authors.affiliation: 5 Epi-Centre for Healthy Ageing, School of Medicine, Deakin University, Geelong, Australia.|7 Department of Medicine, The University of Melbourne, Melbourne, Australia.|8 Australian Institute for Musculoskeletal Science and Epidemiology Unit for Healthy Ageing, School of Medicine, University of Melbourne, Melbourne, Australia; and.|9 Institute for Health and Ageing, Australian Catholic University, Melbourne, Australia.
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Brennan-Olsen
authors.affiliation: 2 Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Bellomo
authors.affiliation: 2 Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Cooper
authors.affiliation: 5 Epi-Centre for Healthy Ageing, School of Medicine, Deakin University, Geelong, Australia.|6 Barwon Health, Geelong, Australia.|7 Department of Medicine, The University of Melbourne, Melbourne, Australia.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Kotowicz
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000502:physiology*; D016723:Bone Remodeling / Q000502:physiology*; D016022:Case-Control Studies; D016638:Critical Illness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000009:adverse effects*; D018570:Risk Assessment; D017678:Sex Distribution; D013995:Time; D014739:Victoria / Q000453:epidemiology
chemical_list: D015415:Biomarkers
keywords: bone loss; bone mineral density; critical illness; long-term outcomes; osteoporosis