title: Hypercalciuria May Persist After Successful Parathyroid Surgery and It Is Associated With Parathyroid Hyperplasia.
abstract: BACKGROUND
  Hypercalciuria is frequently found in primary hyperparathyroidism (1HPT) and, although it generally normalizes after successful parathyroidectomy, may persist in some patients. The factors associated with persistent calcium renal leak (cRL) have not been clarified.
  
  
  OBJECTIVE
  The purpose of this study was to determine the prevalence of cRL in our 1HPT population and investigate cRL-related factors.
  
  
  METHODS
  This was a retrospective longitudinal study.
  
  
  METHODS
  The study was conducted in an outpatient setting.
  
  
  METHODS
  The participants were 95 patients with 1HPT successfully operated on who had a normal estimated glomerular filtration rate.
  
  
  METHODS
  The biochemical parameters of calcium metabolism and bone mineral density (BMD) measured by dual-X-ray absorptiometry before and 24 months after surgery were assessed. All histological findings were recorded.
  
  
  RESULTS
  The prevalence of hypercalciuria before and after surgery was 74% and 32%, respectively. Before, surgery patients with cRL showed lower calcium and higher phosphate levels than those without cRL (10.9 ± 0.6 vs 11.4 ± 0.8 mg/dL [2.7 ± 0.2 vs 2.8 ± 0.2 mmol/L], P = .01 and 2.6 ± 0.5 vs 2.4 ± 0.4 mg/dL [0.84 ± 0.2 vs 0.77 ± 0.1 mmol/L], P = .04, respectively), whereas 24-h calciuria levels and the prevalence of 1HPT complications (osteoporosis, renal stones, and hypertension) were comparable. After surgery, serum calcium, phosphate, and PTH levels were comparable between patients with and without cRL. The prevalence of the histological finding of parathyroid hyperplasia was higher in patients with cRL (50%) than in patients without cRL (22%) (P = .01). The presence of cRL was independently associated with presurgery hypercalciuria (odds ratio, 4.71; 95% confidence interval, 1.18-18.8; P = .03) and parathyroid hyperplasia (odds ratio, 3.52; 95% confidence interval, 1.31-9.43; P = .01). Only patients without cRL had improved BMD at the spine (P = .04), total femur (P = .01), and femoral neck (P = .01).
  
  
  CONCLUSIONS
  cRL is present in 30% of patients with 1HPT after successful surgery, and it is associated with parathyroid hyperplasia before surgery and the lack of improvement in BMD after surgery.
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Palmieri
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Eller-Vainicher
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Cairoli
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Morelli
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Volha V
authors.initials: VV
authors.lastname: Zhukouskaya
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Uberta
authors.initials: U
authors.lastname: Verga
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Filopanti
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Vicentini
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Ferrero
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Spada
authors.affiliation: Unit of Endocrinology and Metabolic Diseases (S.P., C.E.-V., E.C., V.M., A.S., I.C.), Endocrine Surgery Unit (L.V.), and Division of Pathology (S.F.), Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, 20122 Milan, Italy; and Department of Clinical Sciences and Community Health (S.P., E.C., V.M., V.V.Z., U.V., M.F., A.S.) and Department of Biomedical, Surgical and Dental Sciences (S.F.), University of Milan, 20122 Milan, Italy.
authors.forename: Iacopo
authors.initials: I
authors.lastname: Chiodini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D053565:Hypercalciuria / Q000453:epidemiology*; D049950:Hyperparathyroidism, Primary / Q000453:epidemiology* / Q000601:surgery*; D006965:Hyperplasia / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000473:pathology* / Q000601:surgery; D016105:Parathyroidectomy / Q000706:statistics & numerical data*; D011184:Postoperative Period; D015995:Prevalence; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult