title: [Polymedication in institutionalized elderly and its effect on vitamin B12, folate, and homocysteine levels].
abstract: OBJECTIVE
  To determine drug consumption in institutionalized elderly living in the Region of Madrid (Spain) and to assess the relationship between drug intake and biochemical parameters for vitamin B12 (Cobalamin and Holotranscobalamin), serum folate (SF) and homocysteine (Hcy).
  
  
  METHODS
  167 subjects (32% men), mean age 83 ± 7 years, were classified according to biochemical parameter levels (in or out of reference range) and drugs were classified according to ATC system. The relationship between drug intake and biochemical levels was studied by means of the Fisher exact test.
  
  
  RESULTS
  The daily mean drug intake was 5. Psicoleptic and antiacid drugs were the most consumed (both 53%). Cobalamin (median 158.2 pg/mL; 10.7% of individuals), SF (5.3 ng/mL; 52.1%) and holotranscobalamin (11.76 pmoL/L; 7.8%) deficiencies were observed. Hyperhomocysteinaemia (19.4 μmoL/L) was present in 65% of population. Antiaenemic drug intake normalized cobalamin, urologic drug and corticosteroids SF and psicoanaleptics holotranscobalamin levels. Drugs against pulmonar obstruction increased Hcy concentration (all p < 0.05).
  
  
  CONCLUSIONS
  There is a high prevalence of SF deficiency and hyperhomocysteinaemia in the studied population. The elevated number of drugs taken simultaneously by each subject makes it difficult to analyze which drugs are responsible for those alterations.
authors.affiliation: ImFINE Research Group, Department of Health and Human Performance, Universidad Politécnica de Madrid, Madrid, Spain.
authors.forename: U
authors.initials: U
authors.lastname: Albers
authors.forename: G
authors.initials: G
authors.lastname: Palacios
authors.forename: R
authors.initials: R
authors.lastname: Pedrero-Chamizo
authors.forename: A
authors.initials: A
authors.lastname: Meléndez
authors.forename: K
authors.initials: K
authors.lastname: Pietrzik
authors.forename: M
authors.initials: M
authors.lastname: González-Gross
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D005492:Folic Acid / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000453:epidemiology; D007326:Institutionalization; D008297:Male; D019338:Polypharmacy; D014805:Vitamin B 12 / Q000097:blood*; D014815:Vitamins / Q000097:blood*
chemical_list: D014815:Vitamins; D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12