title: Significance of serum magnesium as an independent correlative factor on the parathyroid hormone level in uremic patients.
abstract: BACKGROUND
  PTH is a critical factor in mineral homeostasis, and chronic kidney disease mineral and bone metabolism disorder is a very important problem in patients with renal failure. Abnormal levels of PTH, serum phosphate, and calcium influence chronic kidney disease mineral and bone metabolism disorder, but there is little information about the influence of magnesium (Mg) on PTH.
  
  
  OBJECTIVE
  The aim of this study was to elucidate the correlation between magnesium and PTH levels in uremic patients just prior to beginning hemodialysis (HD) for the first time.
  
  
  METHODS
  We enrolled 1231 patients in nine Japanese facilities who had begun HD for end-stage renal disease. We investigated their serum Mg levels and the correlation between intact PTH (iPTH) and the serum Mg levels and other clinical parameters and medications.
  
  
  RESULTS
  The mean serum Mg was 2.2 ± 0.5 mg/dL, and hypermagnesemia was found in 663 patients (53.9%). Divided into two groups according to median iPTH level, the serum Mg levels were significantly higher in patients with low iPTH (2.3 ± 0.5 vs 2.1 ± 0.5, P < .01). Furthermore, divided into two groups according to the Mg level, iPTH levels were lower in patients with high Mg than in patients with normal serum Mg levels (277.9 ± 195.9 pg/mL vs 321.9 ± 203.7 pg/mL, P < .01). In the multiple regression analysis according to the effect of iPTH level, the serum Mg level was an independent variable after adjustment for other factors.
  
  
  CONCLUSIONS
  A high serum level of Mg is frequent in uremic patients with end-stage renal disease just prior to beginning HD. In the present set of patients, there was a significant correlation between the serum Mg and iPTH levels. Furthermore, the serum Mg level was an independent factor apart from the other factors regulating iPTH. These results suggest that serum Mg may be one of the factors regulating the serum PTH level in uremic patients.
authors.affiliation: Division of Nephrology (M.O., S.N., T.Sa., T.Shig.), Department of Internal Medicine, Wakayama Medical University, Kimiidera Wakayama City, Wakayama, 641-8509, Japan; and Japan Study Group of Assessing Initiation of Renal Replacement Therapy (F.K., R.A., Y.K., T.Shin., D.I., N.J., T.Y., M.I.), Wakayama, 641-8509, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Ohya
authors.forename: Shigeo
authors.initials: S
authors.lastname: Negi
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Sakaguchi
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Koiwa
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Ando
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Toshio
authors.initials: T
authors.lastname: Shinoda
authors.forename: Daijo
authors.initials: D
authors.lastname: Inaguma
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Joki
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Yamaka
authors.forename: Masato
authors.initials: M
authors.lastname: Ikeda
authors.forename: Takashi
authors.initials: T
authors.lastname: Shigematsu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D008274:Magnesium / Q000097:blood*; D008297:Male; D008659:Metabolic Diseases / Q000378:metabolism*; D008875:Middle Aged; D015999:Multivariate Analysis; D010281:Parathyroid Hormone / Q000097:blood*; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000378:metabolism* / Q000628:therapy; D014511:Uremia / Q000378:metabolism* / Q000628:therapy; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone; D008274:Magnesium