title: No association between frequent apheresis donation and risk of fractures: a retrospective cohort analysis from Sweden.
abstract: Citrate anticoagulation during apheresis induces transient alterations in calcium homeostasis. It is unknown whether the repeated, transient alterations in calcium homeostasis experienced by repeated apheresis donors affects bone turnover to increase fracture risk. Our aim was to investigate the risk of osteoporotic and nonosteoporotic fracture among voluntary, frequent apheresis donors.
  
  
  
  All apheresis donors were identified from the Scandinavian Donations and Transfusions database (SCANDAT2), which includes information on over 1.6 million blood donors from Sweden and Denmark from the years 1968 and 1981, respectively. Only data from Sweden were used for these analyses. Information on fractures was obtained by linking SCANDAT2 to hospital registers. Poisson regression was used to compute incidence rate ratios of fractures in relation to the cumulative number of apheresis donations, both overall and in fixed time windows.
  
  
  
  In total, 140,289 apheresis donors (67,970 women and 72,319 men) were identified from the SCANDAT2 database and were followed for up to 23 years. We observed no association between the frequency of apheresis donation and the risk of fracture either in the overall study period or during fixed-length time windows. The incidence rate ratio of fractures in donors who had made 100 or more cumulative apheresis donations was 0.99 (95% confidence interval, 0.92-1.06) compared with donors who had made from 9 to 24 donations. The results were similar in analyses stratified by sex and restricted to postmenopausal women.
  
  
  
  The absence of an association between repeated apheresis donation and fracture risk indicates that apheresis collection is safe with regard to bone health.
authors.affiliation: Department of Epidemiology Research, Statens Serum Institute, Copenhagen, Denmark.
authors.forename: Katrine
authors.initials: K
authors.lastname: Grau
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Senthil K
authors.initials: SK
authors.lastname: Vasan
authors.affiliation: Department of Epidemiology Research, Statens Serum Institute, Copenhagen, Denmark.
authors.forename: Klaus
authors.initials: K
authors.lastname: Rostgaard
authors.affiliation: Blood Research and Medical Sciences Institutes, Blood Center of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Walter
authors.initials: W
authors.lastname: Bialkowski
authors.affiliation: Department of Immunology, Genetics, and Pathology, Uppsala University, Uppsala, Sweden.
authors.forename: Rut
authors.initials: R
authors.lastname: Norda
authors.affiliation: Department of Epidemiology Research, Statens Serum Institute, Copenhagen, Denmark.|Department of Hematology, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Hjalgrim
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.|Hematology Centre, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Gustaf
authors.initials: G
authors.lastname: Edgren
mesh_terms: D000328:Adult; D001781:Blood Component Removal / Q000009:adverse effects*; D001782:Blood Donors; D016208:Databases, Factual; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012042:Registries; D012189:Retrospective Studies; D013548:Sweden / Q000453:epidemiology