title: Hypercalcemia in rheumatoid arthritis: relationship with disease activity and bone metabolism.
abstract: To investigate the relationship between ionized calcium and disease activity, parameters of bone metabolism and bone mineral density (BMD) at the lumbar spine (BMD-LS) and the femoral neck (BMD-FN) measured by dual X-ray absorptiometry in rheumatoid arthritis (RA). In 146 patients with RA, the following parameters were investigated: serum levels of ionized calcium, total calcium, vitamin D metabolites 25-hydroxyvitamin D3 (25D3) and 1,25-dihydroxyvitamin D3 (1,25D3), intact parathyroid hormone (iPTH), interleukin-6, osteocalcin, erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP); renal excretion of pyridinolin (PYD)- and desoxypyridinolin (DPD)-crosslinks. A total of 30.1% of the patients were hypercalcemic (ionized calcium >1.30 mmol/l). In comparison with normocalcemic patients, those with hypercalcemia had significantly higher ESR (P<0.01) and CRP values (P<0.05) and significantly lower serum levels of both iPTH (P<0.01) and 1,25D3 (P<0.05) and a significantly lower BMD-LS (P<0.05). The results indicate that a substantial part of RA patients is hypercalcemic. Hypercalcemia is associated with high disease activity and may contribute to suppression of PTH secretion and vitamin D hormone synthesis. High levels of ionized calcium may be a reflection of disease-activity-related systemic bone loss, and could be a predictor of BMD at the lumbar spine in RA.
authors.affiliation: Department of Internal Medicine III, Division of Rheumatology/Osteology, Friedrich-Schiller University, Erlanger Allee 101, 07740 Jena, Germany. peter.oelzner@med.uni-jena.de
authors.forename: Peter
authors.initials: P
authors.lastname: Oelzner
authors.forename: Gabriele
authors.initials: G
authors.lastname: Lehmann
authors.forename: Thorsten
authors.initials: T
authors.lastname: Eidner
authors.forename: Sybille
authors.initials: S
authors.lastname: Franke
authors.forename: Andreas
authors.initials: A
authors.lastname: Müller
authors.forename: Gunter
authors.initials: G
authors.lastname: Wolf
authors.forename: Gert
authors.initials: G
authors.lastname: Hein
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000737:chemistry / Q000652:urine; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001799:Blood Sedimentation; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D002112:Calcifediol / Q000097:blood; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000097:blood; D003432:Cross-Linking Reagents / Q000737:chemistry; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D006934:Hypercalcemia / Q000097:blood / Q000503:physiopathology*; D015850:Interleukin-6 / Q000097:blood; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D012709:Serum Albumin / Q000032:analysis
chemical_list: D000596:Amino Acids; D003432:Cross-Linking Reagents; D015850:Interleukin-6; D010281:Parathyroid Hormone; D012709:Serum Albumin; D015675:Osteocalcin; C015484:pyridinoline; C036020:deoxypyridinoline; D002097:C-Reactive Protein; D002117:Calcitriol; D002112:Calcifediol; D002118:Calcium