title: [The prevalence and etiology of anemia in urban community dwelling elderly population in Beijing].
abstract: OBJECTIVE
  To estimate the prevalence of anemia in urban community dwelling elderly population.
  
  
  METHODS
  This study was a cross-sectional survey of prevalence of anemia in randomly selected community dwelling residents aged over 65 years in Beijing. Anemia was defined as hemoglobin concentration less than 130 g/L in men and 120 g/L in women.
  
  
  RESULTS
  The hemoglobin concentration was (135.65±14.48) g/L in total of 1 947 eligible participants and was much higher in men than in women [(142.56±15.56) g/L vs (130.95±11.53) g/L, P<0.001]. There were 288 (14.8%) patients with anemia, including 16.3%(129/789) in men and 13.7%(159/1 158) in women. The prevalence of anemia increased significantly with age, which was 7.6% in 65-69 years, 10.8% in 70-74 years, 18.8% in 75-79 years and 24.1% over 80 years (P<0.001). Two hundred and seventy-nine (96.9%) subjects were mild anemia, 8 (2.8%) moderate, only 1 subject (0.3%) severe. Unexplained anemia was predominant, which accounted for 63.2%. Only 16.7% people were diagnosed as nutritional anemia, renal anemia 5.2%, anemia of chronic disease (ACD) 12.2%. There were 2.4% people with overlapped renal anemia and ACD. Compared with non-anemic subjects, more subjects with unexplained anemia represented macrocytosis (7.1% vs 3.2%, P=0.007).
  
  
  CONCLUSIONS
  Anemia is a common health problem in urban community dwelling elderly population. Most subjects have anemia with unknown origin. Further investigation is needed to explore the mechanism and related factors of elderly anemia.
authors.forename: S Y
authors.initials: SY
authors.lastname: Ning
authors.affiliation: Department of Hematology, Beijing Hospital, Beijing 100730, China.
authors.forename: N B
authors.initials: NB
authors.lastname: Chang
authors.forename: X Y
authors.initials: XY
authors.lastname: Han
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.forename: Y W
authors.initials: YW
authors.lastname: Duan
authors.forename: Y H
authors.initials: YH
authors.lastname: Liu
authors.forename: T
authors.initials: T
authors.lastname: Liu
authors.forename: X L
authors.initials: XL
authors.lastname: Duan
authors.forename: N H
authors.initials: NH
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Guo
authors.forename: W
authors.initials: W
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Fan
authors.forename: J T
authors.initials: JT
authors.lastname: Li
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000453:epidemiology* / Q000209:etiology*; D000068476:Beijing / Q000453:epidemiology; D016022:Case-Control Studies; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D057187:Independent Living; D008297:Male; D015995:Prevalence; D011897:Random Allocation; D012720:Severity of Illness Index; D017678:Sex Distribution; D014505:Urban Population