title: Plasma 25-hydroxyvitamin D and not 1,25-dihydroxyvitamin D is associated with parathyroid adenoma secretion in primary hyperparathyroidism: a cross-sectional study.
abstract: BACKGROUND
  Primary hyperparathyroidism (PHPT) is associated with reduced plasma 25-hydroxyvitamin D (P-25OHD) and usually increased plasma 1alpha,25-dihydroxyvitamin D (P-1,25(OH)2D). Parathyroid tissue expresses the vitamin D receptor and it is thought that circulating 1,25(OH)2D participate in the regulation of parathyroid cell proliferation, differentiation and secretion.
  
  
  OBJECTIVE
  To investigate the relations between circulating levels of 1,25(OH)2D and 25OHD respectively and parathyroid adenoma weight (AW), plasma-parathyroid hormone (P-PTH) and PTH secretion expressed as P-PTH/AW.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  One hundred and seventy-one consecutive hypercalcaemic caucasian patients aged 19-87 years (median 63, 84% females) with surgically proven parathyroid adenoma.
  
  
  RESULTS
  A weak positive correlation was found between P-25OHD and P-1,25(OH)2D (r=0.24, P<0.005). AW depended on sex and body mass index. Following adjustment, it was correlated positively to P-PTH, calcium (Ca) and alkaline phosphatase (AP) and inversely to plasma phosphate in a multiple regression model. AW was not associated with vitamin D metabolites. Preoperative P-PTH correlated positively to plasma levels of Ca and AP, but inversely to phosphate and 25OHD (P<0.001) levels. P-PTH was not associated with P-1,25(OH)2D (P=0.65). The P-PTH:AW ratio correlated inversely to P-25OHD (P<0.05), but showed no relations to plasma levels of Ca, phosphate or 1,25(OH)2D (P=0.22).
  
  
  CONCLUSIONS
  In this material, low levels of 25OHD were related to higher levels of P-PTH and higher PTH:AW ratios in patients with PHPT suggesting that vitamin D deficiency increase PTH secretion activity. Neither PTH secretion nor AW was associated with circulating levels of 1,25(OH)2D.
authors.affiliation: Aarhus Bone and Mineral Research Group, Department of Endocrinology, Aarhus University Hospital, Denmark. bmoos@as.aaa.dk
authors.forename: B
authors.initials: B
authors.lastname: Moosgaard
authors.forename: P
authors.initials: P
authors.lastname: Vestergaard
authors.forename: L
authors.initials: L
authors.lastname: Heickendorff
authors.forename: F
authors.initials: F
authors.lastname: Melsen
authors.forename: P
authors.initials: P
authors.lastname: Christiansen
authors.forename: L
authors.initials: L
authors.lastname: Mosekilde
mesh_terms: D000236:Adenoma / Q000097:blood* / Q000150:complications / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000097:blood* / Q000209:etiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D010280:Parathyroid Glands / Q000378:metabolism / Q000473:pathology; D010281:Parathyroid Hormone / Q000097:blood / Q000378:metabolism; D010282:Parathyroid Neoplasms / Q000097:blood* / Q000150:complications / Q000473:pathology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D014808:Vitamin D Deficiency / Q000097:blood / Q000473:pathology
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D; C104450:25-hydroxyvitamin D