title: Correlates of knee bone marrow lesions in younger adults.
abstract: BACKGROUND
  Subchondral bone marrow lesions (BMLs) play a key role in the pathogenesis of osteoarthritis (OA) and are associated with pain and structural progression in knee OA. However, little is known about clinical significance and determinants of BMLs of the knee joint in younger adults. We aimed to describe the prevalence and environmental (physical activity), structural (cartilage defects, meniscal lesions) and clinical (pain, stiffness, physical dysfunction) correlates of BMLs in younger adults and to determine whether cholesterol levels measured 5 years prior were associated with current BMLs in young adults.
  
  
  METHODS
  Subjects broadly representative of the Australian young adult population (n = 328, aged 31-41 years, female 48.7 %) underwent T1- and proton density-weighted fat-suppressed magnetic resonance imaging (MRI) in their dominant knee. BMLs, cartilage defects, meniscal lesions and cartilage volume were measured. Knee pain was assessed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and physical activity was measured by the International Physical Activity Questionnaire (IPAQ). Cholesterol levels including high-density lipoprotein (HDL) were assessed 5 years prior to MRI.
  
  
  RESULTS
  The overall prevalence of BML was 17 % (grade 1: 10.7 %, grade 2: 4.3 %, grade 3: 1.8 %). BML was positively associated with increasing age and previous knee injury but not body mass index. Moderate physical activity (prevalence ratio (PR):0.93, 95 % CI: 0.87, 0.99) and HDL cholesterol (PR:0.36, 95 % CI: 0.15, 0.87) were negatively associated with BML, while vigorous activity (PR:1.02, 95 % CI: 1.01, 1.03) was positively associated with medial tibiofemoral BMLs. BMLs were associated with more severe total WOMAC knee pain (>5 vs ≤5, PR:1.05, 95 % CI: 1.02, 1.09) and WOMAC dysfunction (PR:1.75, 95 % CI: 1.07, 2.89), total knee cartilage defects (PR:2.65, 95 % CI: 1.47, 4.80) and total meniscal lesion score (PR:1.92, 95 % CI: 1.13, 3.28).
  
  
  CONCLUSIONS
  BMLs in young adults are associated with knee symptoms and knee structural lesions. Moderate physical activity and HDL cholesterol are beneficially associated with BMLs; in contrast, vigorous physical activity is weakly but positively associated with medial tibiofemoral BMLs.
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, TAS 7000, Australia. Benny.EathakkattuAntony@utas.edu.au.
authors.forename: Benny
authors.initials: B
authors.lastname: Antony
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, TAS 7000, Australia. Alison.Venn@utas.edu.au.
authors.forename: Alison
authors.initials: A
authors.lastname: Venn
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, 99 Commercial Road, Melbourne, VIC, 3004, Australia. Flavia.Cicuttini@monash.edu.
authors.forename: Flavia
authors.initials: F
authors.lastname: Cicuttini
authors.affiliation: Institute of Bone and Joint Research, University of Sydney, Sydney, NSW, 2006, Australia. Lyn.March@sydney.edu.au.
authors.forename: Lyn
authors.initials: L
authors.lastname: March
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, TAS 7000, Australia. Leigh.Blizzard@utas.edu.au.
authors.forename: Leigh
authors.initials: L
authors.lastname: Blizzard
authors.affiliation: Murdoch Children's Research Institute, 50 Flemington Road, Melbourne, VIC, 3052, Australia. Terry.Dwyer@mcri.edu.au.
authors.forename: Terence
authors.initials: T
authors.lastname: Dwyer
authors.affiliation: Department of Radiology, Royal Hobart Hospital, 48 Liverpool Street, Hobart, TAS, 7000, Australia. andrew.halliday@dhhs.tas.gov.au.
authors.forename: Andrew
authors.initials: A
authors.lastname: Halliday
authors.affiliation: Institute of Bone and Joint Research, University of Sydney, Sydney, NSW, 2006, Australia. maritac@med.usyd.edu.au.
authors.forename: Marita
authors.initials: M
authors.lastname: Cross
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, TAS 7000, Australia. Graeme.Jones@utas.edu.au.
authors.forename: Graeme
authors.initials: G
authors.lastname: Jones
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, TAS 7000, Australia. Changhai.Ding@utas.edu.au.|Department of Epidemiology and Preventive Medicine, Monash University, 99 Commercial Road, Melbourne, VIC, 3004, Australia. Changhai.Ding@utas.edu.au.
authors.forename: Changhai
authors.initials: C
authors.lastname: Ding
mesh_terms: D000328:Adult; D001315:Australia / Q000453:epidemiology; D001853:Bone Marrow / Q000473:pathology*; D001855:Bone Marrow Diseases / Q000175:diagnosis* / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys / Q000639:trends; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis* / Q000453:epidemiology*; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000639:trends; D008297:Male
references.citation: Clin Chem. 1972 Jun;18(6):499-502
references.pmid: 4337382
references.citation: Ann Rheum Dis. 2009 Jun;68(6):850-5
references.pmid: 18625617
references.citation: Ann Rheum Dis. 2005 Apr;64(4):556-63
references.pmid: 15374855
references.citation: Ann Intern Med. 2003 Sep 2;139(5 Pt 1):330-6
references.pmid: 12965941
references.citation: Osteoarthritis Cartilage. 2013 Feb;21(2):322-30
references.pmid: 23151457
references.citation: Arthritis Res Ther. 2010;12(6):R222
references.pmid: 21190554
references.citation: Arthritis Res Ther. 2010;12(6):R223
references.pmid: 21190555
references.citation: Rheumatology (Oxford). 2008 Sep;47(9):1392-6
references.pmid: 18606620
references.citation: Radiology. 2010 Feb;254(2):509-20
references.pmid: 20019141
references.citation: Semin Arthritis Rheum. 2013 Oct;43(2):187-94
references.pmid: 24157092
references.citation: Osteoarthritis Cartilage. 2005 Mar;13(3):198-205
references.pmid: 15727885
references.citation: Osteoarthritis Cartilage. 2009 Dec;17(12):1562-9
references.pmid: 19583959
references.citation: J Clin Epidemiol. 2008 May;61(5):481-8
references.pmid: 18394542
references.citation: Arthritis Res Ther. 2009;11(1):R11
references.pmid: 19171047
references.citation: Arthritis Res Ther. 2012;14(1):R13
references.pmid: 22257370
references.citation: J Rheumatol. 2005 Jun;32(6):1156-8; discussion 1158-9
references.pmid: 15977355
references.citation: Ann Rheum Dis. 2010 Oct;69(10):1796-802
references.pmid: 20421344
references.citation: Osteoarthritis Cartilage. 2004 Mar;12(3):177-90
references.pmid: 14972335
references.citation: Osteoarthritis Cartilage. 2007 Dec;15(12):1437-42
references.pmid: 17560134
references.citation: Arthritis Rheum. 2006 May;54(5):1529-35
references.pmid: 16646037
references.citation: Osteoarthritis Cartilage. 2009 Jun;17(6):743-7
references.pmid: 19097919
references.citation: Ann Rheum Dis. 2009 Jun;68(6):904-8
references.pmid: 18677011
references.citation: Ann Rheum Dis. 2009 Sep;68(9):1461-5
references.pmid: 18829615
references.citation: Arthritis Res Ther. 2009;11(6):R181
references.pmid: 19961577
references.citation: Radiology. 2000 Jun;215(3):835-40
references.pmid: 10831707
references.citation: Semin Arthritis Rheum. 2007 Oct;37(2):112-8
references.pmid: 17391738
references.citation: Rheumatology (Oxford). 2010 Dec;49(12):2362-9
references.pmid: 20719882
references.citation: Arthritis Rheum. 2006 Apr 15;55(2):264-71
references.pmid: 16583417
references.citation: Circulation. 1994 Apr;89(4):1539-44
references.pmid: 8149519
references.citation: Semin Arthritis Rheum. 2014 Apr;43(5):600-12
references.pmid: 24287353
references.citation: Arthritis Care Res (Hoboken). 2013 Dec;65(12):1951-8
references.pmid: 23925995
references.citation: Arthritis Rheum. 2011 Mar;63(3):691-9
references.pmid: 21360498
references.citation: Arthritis Rheum. 2007 Feb 15;57(1):6-12
references.pmid: 17266077
references.citation: Arthritis Res Ther. 2014;16(4):R149
references.pmid: 25022807
references.citation: Osteoarthritis Cartilage. 2003 Jun;11(6):387-93
references.pmid: 12801478
references.citation: Radiology. 2005 Dec;237(3):998-1007
references.pmid: 16251398
references.citation: Arthritis Rheumatol. 2015 Feb;67(2):414-22
references.pmid: 25358676
references.citation: Arthritis Res Ther. 2013;15(5):R112
references.pmid: 24020939
references.citation: BMJ Open. 2013 May 14;3(5):null
references.pmid: 23674445
references.citation: Ann Intern Med. 2001 Apr 3;134(7):541-9
references.pmid: 11281736
references.citation: Ann Rheum Dis. 2013 Jul;72(7):1170-5
references.pmid: 22896739
references.citation: Osteoarthritis Cartilage. 2010 Jun;18(6):776-86
references.pmid: 20202488
references.citation: Clin Rheumatol. 2015 Aug;34(8):1463-72
references.pmid: 25119865
references.citation: J Rheumatol. 1997 Mar;24(3):524-30
references.pmid: 9058660
references.citation: Ann Rheum Dis. 2015 Apr;74(4):711-7
references.pmid: 24347570
references.citation: Ann Rheum Dis. 2015 Jun;74(6):1164-70
references.pmid: 25596158
references.citation: Ann Rheum Dis. 2012 Aug;71(8):1322-8
references.pmid: 22355040
references.citation: Ann Rheum Dis. 2009 Nov;68(11):1696-700
references.pmid: 19033292
references.citation: Osteoarthritis Cartilage. 2012 Dec;20(12):1519-26
references.pmid: 22940708
references.citation: JAMA. 1995 Feb 1;273(5):402-7
references.pmid: 7823386
references.citation: Ann Rheum Dis. 2011 Jan;70(1):60-7
references.pmid: 20829200
references.citation: Med Sci Sports Exerc. 2003 Aug;35(8):1381-95
references.pmid: 12900694
references.citation: Osteoarthritis Cartilage. 2013 Sep;21(9):1207-13
references.pmid: 23973132
references.citation: Arthritis Rheum. 2007 Oct 15;57(7):1261-8
references.pmid: 17907212
references.citation: Rheumatology (Oxford). 2007 Dec;46(12):1763-8
references.pmid: 17693442
references.citation: Age Ageing. 2001 Sep;30(5):374-8
references.pmid: 11709373