title: Prevalence and possible causes of anemia in the elderly: a cross-sectional analysis of a large European university hospital cohort.
abstract: BACKGROUND
  Anemia in later life is associated with increased morbidity and mortality. The purpose of this study was to evaluate the prevalence and possible causes of anemia in the elderly in a well defined hospital cohort.
  
  
  METHODS
  Participants in this cross-sectional, retrospective analysis included all inpatients and outpatients aged ≥64 years with complete blood counts treated at Innsbruck Medical University Hospital between October 1, 2004 and September 29, 2005 (n=19,758, median age 73 years).
  
  
  RESULTS
  According to World Health Organization criteria, 21.1% of these patients were anemic, ie, 30.7% and 37.0% at 80+ years and 90+ years, respectively. The prevalence of anemia was significantly correlated with advanced age (r=0.21; P<0.001) and male sex (P<0.001). In anemic patients, renal insufficiency with a glomerular filtration rate <30 mL/min/1.73 m(2) (11.3% versus 2.1%), hyperinflammation (62.1% versus 31.4%), absolute (14.4% versus 6.9%) or functional (28.2% versus 11.8%) iron deficiency, and folate deficiency (6.7% versus 3.0%) were observed significantly more often than in nonanemic subjects (P<0.001). The pathogenesis of anemia was multifactorial, with decreased renal function (glomerular filtration rate <60 mL/min/1.73 m(2)), signs of inflammation, and functional iron deficiency detected in 11.4% of anemic patients. Hemoglobin was significantly correlated with elevated C-reactive protein (r= -0.296; P<0.001) and low transferrin saturation (r=0.313; P<0.001). Mean corpuscular volume correlated only weakly with the various anemia subtypes. Cytopenias and morphologic alterations suggestive of underlying myelodysplastic syndromes were found in a substantial proportion of anemic patients, including thrombocytopenia (5.4%), leukopenia (8.26%), and macrocytic alterations (18.4%).
  
  
  CONCLUSIONS
  Anemia was frequently diagnosed in this series of elderly patients. Partly treatable nutritional deficiencies, such as iron or folate deficiency, were identified as possible causes. A complex and heterogeneous interplay of chronic inflammation, functional iron deficiency, and renal impairment was identified in a large proportion of patients. A hitherto undiagnosed myelodysplastic syndrome can be assumed in a relevant proportion of patients. Morphologic classification based on mean corpuscular volume is inadequate from the standpoint of pathogenesis. New parameters are needed to differentiate the multifactorial pathogenesis of anemia in the elderly.
authors.affiliation: Department of Internal Medicine V (Hematology and Oncology), Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Veronika
authors.initials: V
authors.lastname: Bach
authors.affiliation: Department of Internal Medicine V (Hematology and Oncology), Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Guenter
authors.initials: G
authors.lastname: Schruckmayer
authors.affiliation: Department of Internal Medicine V (Hematology and Oncology), Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Ines
authors.initials: I
authors.lastname: Sam
authors.affiliation: Department of Biological Psychiatry, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Kemmler
authors.affiliation: Department of Internal Medicine V (Hematology and Oncology), Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Stauder
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018798:Anemia, Iron-Deficiency / Q000453:epidemiology* / Q000209:etiology*; D003430:Cross-Sectional Studies; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007249:Inflammation / Q000150:complications / Q000453:epidemiology; D007297:Inpatients / Q000706:statistics & numerical data; D007674:Kidney Diseases / Q000150:complications / Q000453:epidemiology; D008297:Male; D044342:Malnutrition / Q000150:complications / Q000453:epidemiology; D008875:Middle Aged; D009017:Morbidity; D009190:Myelodysplastic Syndromes / Q000150:complications* / Q000453:epidemiology*; D010045:Outpatients / Q000706:statistics & numerical data; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors
keywords: anemia; causes; elderly; myelodysplastic syndromes; prevalence
references.citation: J Am Med Dir Assoc. 2007 Mar;8(3 Suppl 2):e9-e15
references.pmid: 17352999
references.citation: Int J Hematol. 2012 Mar;95(3):248-56
references.pmid: 22351246
references.citation: Nephrol Dial Transplant. 2007 Oct;22(10):2900-8
references.pmid: 17556407
references.citation: Haematologica. 2010 Nov;95(11):1849-56
references.pmid: 20534701
references.citation: Age Ageing. 2007 Mar;36(2):177-83
references.pmid: 17189285
references.citation: Br J Haematol. 1989 Mar;71(3):437-42
references.pmid: 2930723
references.citation: Am J Hematol. 2012 Apr;87(4):392-400
references.pmid: 22290531
references.citation: Blood. 2006 Mar 1;107(5):1747-50
references.pmid: 16189263
references.citation: Haematologica. 2004 Mar;89(3):357-8
references.pmid: 15020276
references.citation: Am J Med. 2005 Nov;118(11):1288
references.pmid: 16271918
references.citation: Transfus Clin Biol. 2010 Dec;17(5-6):375-81
references.pmid: 21067951
references.citation: Ann Oncol. 2013 Jul;24(7):1886-1892
references.pmid: 23567147
references.citation: J Gerontol A Biol Sci Med Sci. 2006 May;61(5):474-9
references.pmid: 16720744
references.citation: Blood. 2013 Oct 24;122(17):2943-64
references.pmid: 23980065
references.citation: Intern Med J. 2004 Jan-Feb;34(1-2):20-3
references.pmid: 14748909
references.citation: Br J Haematol. 2012 Jan;156(2):173-85
references.pmid: 22050828
references.citation: J Gerontol A Biol Sci Med Sci. 2011 Aug;66(8):925-32
references.pmid: 21659341
references.citation: Blood. 2004 Oct 15;104(8):2263-8
references.pmid: 15238427
references.citation: Int J Cancer. 2010 Sep 1;127(6):1429-36
references.pmid: 20020493
references.citation: J Am Geriatr Soc. 2012 Dec;60(12):2362-3
references.pmid: 23231554
references.citation: Leuk Res. 2011 Dec;35(12):1591-6
references.pmid: 21708407
references.citation: BMC Geriatr. 2008 Jan 14;8:1
references.pmid: 18194534
references.citation: Curr Opin Hematol. 2013 May;20(3):222-30
references.pmid: 23449069
references.citation: Ann Intern Med. 1999 Mar 16;130(6):461-70
references.pmid: 10075613
references.citation: Arch Intern Med. 2005 Oct 24;165(19):2222-7
references.pmid: 16246987
references.citation: CMAJ. 2009 Aug 4;181(3-4):151-7
references.pmid: 19635749
references.citation: Leuk Res. 2013 Aug;37(8):900-6
references.pmid: 23623559
references.citation: J Am Geriatr Soc. 2004 Sep;52(9):1589-90
references.pmid: 15341579
references.citation: Semin Hematol. 2008 Oct;45(4):225-34
references.pmid: 18809092
references.citation: Ann Oncol. 2012 Aug;23(8):1954-1962
references.pmid: 22575608
references.citation: N Engl J Med. 2005 Mar 10;352(10):1011-23
references.pmid: 15758012
references.citation: Arch Intern Med. 2008 Nov 10;168(20):2238-44
references.pmid: 19001201
references.citation: J Am Geriatr Soc. 2004 May;52(5):719-24
references.pmid: 15086651
references.citation: World Health Organ Tech Rep Ser. 1968;405:5-37
references.pmid: 4975372
references.citation: Gerontology. 1992;38(1-2):111-7
references.pmid: 1612458
references.citation: Am J Med. 2004 Apr 5;116 Suppl 7A:3S-10S
references.pmid: 15050882
references.citation: Clin Med Res. 2006 Sep;4(3):236-41
references.pmid: 16988104
references.citation: Blood. 2006 May 15;107(10):3841-6
references.pmid: 16403909
references.citation: J Am Geriatr Soc. 2014 Jan;62(1):199-201
references.pmid: 25180389
references.citation: Am J Med. 2006 Apr;119(4):327-34
references.pmid: 16564775
references.citation: JAMA. 1999 May 12;281(18):1714-7
references.pmid: 10328071
references.citation: PLoS One. 2013;8(3):e58050
references.pmid: 23483967
references.citation: Gerontology. 2000 Nov-Dec;46(6):323-7
references.pmid: 11044787