title: The Impact of Hypoparathyroidism Treatment on the Kidney in Children: Long-Term Retrospective Follow-Up Study.
abstract: BACKGROUND
  Adults with hypoparathyroidism have significant rates of nephrocalcinosis and impaired renal function. Little is known about the impact of hypoparathyroidism treatment on renal function in children.
  
  
  OBJECTIVE
  To determine the prevalence and predictors for renal abnormalities (nephrocalcinosis and decreased estimated glomerular filtration rate [eGFR]) in children with treated hypoparathyroidism.
  
  
  METHODS
  A retrospective chart review of patients with permanent hypoparathyroidism at the Hospital for Sick Children, Toronto, between 1996 and 2013.
  
  
  METHODS
  Data of 29 patients (15 males) followed for at least 1 year with documented hypoparathyroidism were analyzed. Mean duration of follow up was 7.4 ± 5 years.
  
  
  METHODS
  The presence or absence of nephrocalcinosis as detected on ultrasound and eGFR were evaluated.
  
  
  RESULTS
  Time-weighted average serum measurements were calculated for all biochemical variables. Mean total and ionized serum calcium were 8.9 ± 0.8 and 4.6 ± 0.5 mg/dL, respectively. Nephrocalcinosis was observed in 38% of the subjects, with the most significant predictors being the degree of relative hypercalcemia and hyperphosphatemia (R(2) = 0.47, P < .01). Although all patients had an eGFR greater than 60, in 45% of the children, the eGRF was between 60 and 90 mL/min per 1.73 m(2). Higher calcium concentrations (r = -0.42, P = .02) and a greater proportion of time with relative hypercalcemia (r = -0.41, P = .03) were associated with lower eGFR.
  
  
  CONCLUSIONS
  Our results establish that children with hypoparathyroidism treated with calcitriol and calcium supplements are at risk for nephrocalcinosis and decreased eGFR. Because hypoparathyroidism is most commonly a life-long condition, careful monitoring and management of calcium abnormalities has important future implications.
authors: Division of Endocrinology (I.L., E.S., J.H.), Division of Nephrology (C.L.); and Division of General Radiology and Body Imaging (A.D.), Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada M5G 1X8.
authors: Isaac
authors: I
authors: Levy
authors: Division of Endocrinology (I.L., E.S., J.H.), Division of Nephrology (C.L.); and Division of General Radiology and Body Imaging (A.D.), Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada M5G 1X8.
authors: Christoph
authors: C
authors: Licht
authors: Division of Endocrinology (I.L., E.S., J.H.), Division of Nephrology (C.L.); and Division of General Radiology and Body Imaging (A.D.), Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada M5G 1X8.
authors: Alan
authors: A
authors: Daneman
authors: Division of Endocrinology (I.L., E.S., J.H.), Division of Nephrology (C.L.); and Division of General Radiology and Body Imaging (A.D.), Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada M5G 1X8.
authors: Etienne
authors: E
authors: Sochett
authors: Division of Endocrinology (I.L., E.S., J.H.), Division of Nephrology (C.L.); and Division of General Radiology and Body Imaging (A.D.), Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada M5G 1X8.
authors: Jennifer
authors: J
authors: Harrington
mesh_terms: D000293:Adolescent; D002117:Calcitriol / Q000009:adverse effects / Q000627:therapeutic use; D002118:Calcium / Q000097:blood / Q000652:urine; D002120:Calcium Channel Agonists / Q000009:adverse effects / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D006934:Hypercalcemia / Q000139:chemically induced / Q000378:metabolism; D007011:Hypoparathyroidism / Q000188:drug therapy* / Q000453:epidemiology / Q000473:pathology*; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000473:pathology*; D007674:Kidney Diseases / Q000209:etiology / Q000503:physiopathology; D008297:Male; D009397:Nephrocalcinosis / Q000000981:diagnostic imaging / Q000209:etiology; D010710:Phosphates / Q000097:blood; D015995:Prevalence; D012189:Retrospective Studies; D014463:Ultrasonography
chemical_list: D002120:Calcium Channel Agonists; D010710:Phosphates; D002117:Calcitriol; D002118:Calcium