title: Influence of parathyroidectomy on mortality in hemodialysis patients: a prospective observational study.
abstract: BACKGROUND
  In hemodialysis patients, the relationships between serum PTH and phosphorus levels and mortality are debated because both high and low turnover bone diseases increase the risk of vascular calcifications. Furthermore, the prevalence of hypoparathyroidism is increasing, and there is a fear that this state is associated with an increase in bone fractures.
  
  
  METHODS
  We performed a cross-sectional study to determine the prevalence and the causes of hypoparathyroidism (defined as basal and post-hypocalcemic-challenge serum PTH levels < 55 pg/mL) in 97 patients undergoing chronic hemodialysis treatment in our unit. We then prospectively observed patients with low PTH levels (< 55 pg/mL, n = 26) and those with hyperparathyroidism defined as a PTH levels > 200 pg/mL (n = 25) during eight years for all causes of mortality and bone fractures. Kaplan-Meyer survival curves were adjusted for age and sex.
  
  
  RESULTS
  Hypoparathyroidism was present in 30% of our patients. The main causes of hypoparathyroidism were parathyroidectomy (77%) and aluminium and iron overload. Survival did not differ between patients with hypoparathyroidism and hyperparathyroidism and between patients with serum phosphorus < or > 2 mmol/L. Parathyroidectomy was associated with better survival (p < 0.01). Similarly, incidence of bone fractures did not differ for the two groups.
  
  
  CONCLUSIONS
  Parathyroidectomy is the main cause of hypoparathyroidism in hemodialysis patients and is associated with a lower mortality risk. This result suggests that a more aggressive treatment of secondary hyperparathyroidism could decrease mortality in this high-risk population.
authors.affiliation: Centre de Néphrologie et de Transplantation Rénale, Hôpital de la Conception, Marseille, France. bdussol@ap-hm.fr
authors.forename: Bertrand
authors.initials: B
authors.lastname: Dussol
authors.forename: Pascal
authors.initials: P
authors.lastname: Morand
authors.forename: Catherine
authors.initials: C
authors.lastname: Martinat
authors.forename: Elise
authors.initials: E
authors.lastname: Lombard
authors.forename: Henri
authors.initials: H
authors.lastname: Portugal
authors.forename: Philippe
authors.initials: P
authors.lastname: Brunet
authors.forename: Yvon
authors.initials: Y
authors.lastname: Berland
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007011:Hypoparathyroidism / Q000097:blood / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D016105:Parathyroidectomy; D015995:Prevalence; D011446:Prospective Studies; D006435:Renal Dialysis / Q000401:mortality*
chemical_list: D010281:Parathyroid Hormone