title: Estimated glomerular filtration rate by serum cystatin C correlates with cardiometabolic parameters in patients with primary hyperparathyroidism.
abstract: OBJECTIVE
  Patients with primary hyperparathyroidism (PHPT) are at risk of chronic kidney disease (CKD). Cystatin C (Cys-C) is considered a more reliable tool to assess glomerular filtration rate (GFR) than creatinine. The study aimed to assess circulating Cys-C and its relationships with biochemical PHPT and cardiometabolic parameters.
  
  
  METHODS
  The present cross-sectional study was performed in academic endocrine units on PHPT patients (n=190) and non-hypertensive, non-diabetic, age- and sex-matched healthy controls (n=135) with no established CKD. The main outcomes were creatinine by alkaline picrate method, Cys-C by immunonephelometry and calculation of estimated GFR based on creatinine and Cys-C (eGFRcr-cys) using the CKD-EPI equation.
  
  
  RESULTS
  In PHPT patients, circulating Cys-C ranged 0.45-3.13  mg/l and correlated with creatinine, age and BMI. Mean Cys-C level was higher in PHPT patients than in controls (0.93±0.02 vs 0.78±0.14  mg/l; P=0.03). Cys-C levels in PHPT patients were predicted by age, BMI, ionized calcium, hypertension and HDL-cholesterol, the most significant determinant being ionized calcium. Cys-C positively correlated with cardiovascular disease (CVD) occurrence. Overall, 18.4% of PHPT patients with eGFRcr >60  ml/min per 1.73  m(2) (n=169) had Cys-C levels higher than the 95th percentile in controls (1.03  mg/l), consistent with a preclinical CKD, which was associated with hypertension and insulin resistance. Considering eGFRcr-cys, CKD (stages G3a, G3b, 4) was diagnosed in 13.7% of PHPT patients. Estimated GFRcr-cys, but not eGFR based on creatinine, was predicted by insulin resistance and hypertension and positively correlated with CVD.
  
  
  CONCLUSIONS
  Elevated Cys-C levels were associated with ionized calcium, cardiometabolic risk factors and CVD, and identified preclinical CKD in PHPT patients.
authors.affiliation: Diabetology and Metabolic Disease UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyEndocrine and Diabetology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyClinical Pathology LaboratoryIRCCS E. Medea, Bosisio Parini, Lecco, ItalyEndocrine and Diabetology UnitDepartment of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Ermetici
authors.affiliation: Diabetology and Metabolic Disease UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyEndocrine and Diabetology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyClinical Pathology LaboratoryIRCCS E. Medea, Bosisio Parini, Lecco, ItalyEndocrine and Diabetology UnitDepartment of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Filopanti
authors.affiliation: Diabetology and Metabolic Disease UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyEndocrine and Diabetology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyClinical Pathology LaboratoryIRCCS E. Medea, Bosisio Parini, Lecco, ItalyEndocrine and Diabetology UnitDepartment of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy.
authors.forename: Uberta
authors.initials: U
authors.lastname: Verga
authors.affiliation: Diabetology and Metabolic Disease UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyEndocrine and Diabetology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyClinical Pathology LaboratoryIRCCS E. Medea, Bosisio Parini, Lecco, ItalyEndocrine and Diabetology UnitDepartment of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Passeri
authors.affiliation: Diabetology and Metabolic Disease UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyEndocrine and Diabetology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyClinical Pathology LaboratoryIRCCS E. Medea, Bosisio Parini, Lecco, ItalyEndocrine and Diabetology UnitDepartment of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy.
authors.forename: Giorgia
authors.initials: G
authors.lastname: Dito
authors.affiliation: Diabetology and Metabolic Disease UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyEndocrine and Diabetology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyClinical Pathology LaboratoryIRCCS E. Medea, Bosisio Parini, Lecco, ItalyEndocrine and Diabetology UnitDepartment of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy.
authors.forename: Alexis Elias
authors.initials: AE
authors.lastname: Malavazos
authors.affiliation: Diabetology and Metabolic Disease UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyEndocrine and Diabetology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyClinical Pathology LaboratoryIRCCS E. Medea, Bosisio Parini, Lecco, ItalyEndocrine and Diabetology UnitDepartment of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Mapelli
authors.affiliation: Diabetology and Metabolic Disease UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyEndocrine and Diabetology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyClinical Pathology LaboratoryIRCCS E. Medea, Bosisio Parini, Lecco, ItalyEndocrine and Diabetology UnitDepartment of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy.
authors.forename: Maria Elisabetta
authors.initials: ME
authors.lastname: Raggi
authors.affiliation: Diabetology and Metabolic Disease UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyEndocrine and Diabetology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyClinical Pathology LaboratoryIRCCS E. Medea, Bosisio Parini, Lecco, ItalyEndocrine and Diabetology UnitDepartment of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Spada
authors.affiliation: Diabetology and Metabolic Disease UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyEndocrine and Diabetology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitIRCCS Policlinico San Donato, San Donato Milanese, Milan, ItalyClinical Pathology LaboratoryIRCCS E. Medea, Bosisio Parini, Lecco, ItalyEndocrine and Diabetology UnitDepartment of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Milan, ItalyEndocrinology UnitDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, Via Morandi 30, 20097 San Donato Milanese, Milan, Italy sabrina.corbetta@unimi.it.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Corbetta
mesh_terms: D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002118:Calcium / Q000097:blood*; D002318:Cardiovascular Diseases / Q000097:blood; D016022:Case-Control Studies; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D049950:Hyperparathyroidism, Primary; D006973:Hypertension / Q000097:blood*; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000097:blood*; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine; D002118:Calcium