title: Normocalcemic hyperparathyroidism in patients with recurrent kidney stones: a disease entity or vitamin D deficiency?
abstract: This retrospective data analysis was undertaken to examine the biochemical differences between renal stone formers with normocalcemic hyperparathyroidism (NHPT) and those with normal parathyroid hormone (PTH) levels. Our goal was to ascertain whether 25-hydroxyvitamin D (25(OH)D) status related to PTH levels in this patient cohort. Our findings among 74 patients with NHPT indicate that stone formers with NHPT had significantly lower 25(OH)D levels compared to 192 controls (p = 0.0001) and that 25(OH)D is positively correlated with 1,25-dihydroxyvitamin D values (R = 0.736, p = 0.015). Sequential measurements (after 3 - 5 years), among 11 patients with NHPT who did not receive vitamin D (VitD) preparations, showed a significant increase in urinary calcium (3.43 ± 1.96 vs. 5.72 ± 3.95, p = 0.0426) without a significant change in PTH levels. VitD supplementation, to 3 patients resulted in significant PTH decrease (11.8 ± 1.8 vs. 9.8 ± 1.3, p = 0.003). Prospective studies are needed to confirm the role of vitamin supplementation in renal stone formers with NHPT.
authors.affiliation: Kidney Stone Clinic, Toronto Western Hospital, Division of Nephrology, University Health Network and University of Toronto, Toronto, Canada. chrysapi2001@gmail.com
authors.forename: Chrysoula
authors.initials: C
authors.lastname: Pipili
authors.forename: Nigar
authors.initials: N
authors.lastname: Sekecioglu
authors.forename: Dimitrios G
authors.initials: DG
authors.lastname: Oreopoulos
mesh_terms: D015415:Biomarkers / Q000097:blood / Q000652:urine; D002118:Calcium / Q000097:blood / Q000652:urine; D016009:Chi-Square Distribution; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood* / Q000453:epidemiology / Q000652:urine; D007669:Kidney Calculi / Q000097:blood* / Q000453:epidemiology / Q000652:urine; D008297:Male; D008875:Middle Aged; D009864:Ontario; D010281:Parathyroid Hormone / Q000097:blood*; D012008:Recurrence; D012189:Retrospective Studies; D013997:Time Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology / Q000652:urine; D014815:Vitamins / Q000627:therapeutic use
chemical_list: D015415:Biomarkers; C470125:PTH protein, human; D010281:Parathyroid Hormone; D014815:Vitamins; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium