title: Independent associations of vitamin D metabolites with anemia in patients referred to coronary angiography: the LURIC study.
abstract: OBJECTIVE
  Anemia and vitamin D deficiency are both frequent in adult patients. Whether low vitamin D metabolite levels are an independent risk factor for different subtypes of anemia remains to be studied in detail.
  
  
  METHODS
  In 3299 patients referred for coronary angiography, we investigated the association of 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D [1,25(OH)2D] with anemia [hemoglobin (Hb) <12.5 g/dl] of specific subtypes.
  
  
  RESULTS
  Compared with patients with 25OHD levels in the adequate range (50-125 nmol/l), patients with deficient 25OHD concentrations (<30 nmol/l; 33.6 % of patients) had 0.6 g/dl lower Hb levels. Hb values were 1.3 g/dl lower in patients with 1,25(OH)2D levels <40 pmol/l (5.4 % of patients), compared with patients in the highest 1,25(OH)2D category (>70 pmol/l). Of the participants, 16.7 % met the criteria for anemia. In multivariate-adjusted regression analyses, the odds ratios for anemia in the lowest 25OHD and 1,25(OH)2D categories were 1.52 (95 % CI 1.15-2.02) and 3.59 (95 % CI 2.33-5.52), compared with patients with 25OHD levels in the adequate range and patients with 1,25(OH)2D levels >70 pmol/l. The probability of anemia was highest in patients with combined 25OHD and 1,25(OH)2D deficiency [multivariable-adjusted odds ratio 5.11 (95 % CI 2.66-9.81)]. Patients with anemia of chronic kidney disease had the highest prevalence of 25OHD deficiency and 1,25(OH)2D concentrations of <40 pmol/l.
  
  
  CONCLUSIONS
  Low 25OHD and 1,25(OH)2D concentrations are independently associated with anemia. Patients with poor kidney function are most affected. Interventional trials are warranted to prove whether administration of plain or activated vitamin D can prevent anemia.
authors.affiliation: Clinic for Thoracic and Cardiovascular Surgery, Heart and Diabetes Center North Rhine-Westphalia, Ruhr University Bochum, Bad Oeynhausen, Germany.
authors.forename: J B
authors.initials: JB
authors.lastname: Ernst
authors.affiliation: Clinic for Thoracic and Cardiovascular Surgery, Heart and Diabetes Center North Rhine-Westphalia, Ruhr University Bochum, Bad Oeynhausen, Germany. azittermann@hdz-nrw.de.
authors.forename: A
authors.initials: A
authors.lastname: Zittermann
authors.affiliation: Department of Internal Medicine, Division of Endocrinology and Metabolism, Medical University of Graz, Graz, Austria.|Department of Epidemiology and Biostatistics, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Pilz
authors.affiliation: Medical Clinic V (Nephrology, Hypertensiology, Endocrinology, Diabetology, Rheumatology) Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany.
authors.forename: M E
authors.initials: ME
authors.lastname: Kleber
authors.affiliation: Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria.
authors.forename: H
authors.initials: H
authors.lastname: Scharnagl
authors.affiliation: Department of Cardiology, University Hospital of the RWTH Aachen, Aachen, Germany.
authors.forename: V M
authors.initials: VM
authors.lastname: Brandenburg
authors.affiliation: Department of Internal Medicine II - Cardiology, University of Ulm, Ulm, Germany.
authors.forename: W
authors.initials: W
authors.lastname: König
authors.affiliation: Medical Clinic V (Nephrology, Hypertensiology, Endocrinology, Diabetology, Rheumatology) Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany.|Mannheim Institute of Public Health, Social and Preventive Medicine, Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany.
authors.forename: T B
authors.initials: TB
authors.lastname: Grammer
authors.affiliation: Medical Clinic V (Nephrology, Hypertensiology, Endocrinology, Diabetology, Rheumatology) Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany.|Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria.|Synlab Academy, Synlab Laboratory Services GmbH, Mannheim, Germany.
authors.forename: W
authors.initials: W
authors.lastname: März
mesh_terms: D000368:Aged; D018798:Anemia, Iron-Deficiency / Q000097:blood* / Q000188:drug therapy; D015992:Body Mass Index; D017023:Coronary Angiography; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000188:drug therapy; D012307:Risk Factors; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy / Q000453:epidemiology*
chemical_list: D006454:Hemoglobins; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D
keywords: 1,25-Dihydroxyvitamin D; 25-Hydroxyvitamin D; Anemia subtypes; Coronary angiography; Hemoglobin