title: Association of serum intact parathyroid hormone with lower estimated glomerular filtration rate.
abstract: OBJECTIVE
  The prevalence of mineral metabolism abnormalities is almost universal in stage 5 chronic kidney disease (CKD), but the presence of abnormalities in milder CKD is not well characterized.
  
  
  METHODS
  Data on adults > or =20 yr of age from the National Health and Nutrition Examination Survey 2003-2004 (N = 3949) were analyzed to determine the association between moderate declines in estimated GFR (eGFR), calculated using the Modfication of Diet in Renal Disease formula, and serum intact parathyroid hormone (iPTH) > or = 70 pg/ml.
  
  
  RESULTS
  The geometric mean iPTH level was 39.3 pg/ml. The age-standardized prevalence of elevated iPTH was 8.2%, 19.3%, and 38.3% for participants with eGFR > or = 60, 45 to 59, and 30 to 44 ml/min/1.73 m(2), respectively (P-trend < 0.001). After adjustment for age; race/ethnicity; sex; menopausal status; education; income; cigarette smoking; alcohol consumption; body mass index; hypertension; diabetes mellitus; vitamin D supplement use; total calorie and calcium intake; and serum calcium, phosphorus, and 25-hydroxyvitamin D levels-and compared with their counterparts with an eGFR > or = 60 ml/min/1.73 m(2)-the prevalence ratios of elevated iPTH were 2.30 and 4.69 for participants with an eGFR of 45 to 59 and 30 to 44 ml/min/1.73 m(2), respectively (P-trend < 0.001). Serum phosphorus > or = 4.2 mg/dl and 25-hydroxyvitamin D < 17.6 ng/ml were more common at lower eGFR levels. No association was present between lower eGFR and serum calcium < 9.4 mg/dl.
  
  
  CONCLUSIONS
  This study indicates that elevated iPTH levels are common among patients with moderate CKD.
authors.affiliation: Department of Community and Preventive Medicine, Mount Sinai School of Medicine, 1 Gustave L Levy Place, New York, NY 10016, USA. paul.muntner@mssm.edu
authors.forename: Paul
authors.initials: P
authors.lastname: Muntner
authors.forename: Tiffany M
authors.initials: TM
authors.lastname: Jones
authors.forename: Amanda D
authors.initials: AD
authors.lastname: Hyre
authors.forename: Michal L
authors.initials: ML
authors.lastname: Melamed
authors.forename: Arnold
authors.initials: A
authors.lastname: Alper
authors.forename: Paolo
authors.initials: P
authors.lastname: Raggi
authors.forename: Mary B
authors.initials: MB
authors.lastname: Leonard
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002118:Calcium / Q000097:blood; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006306:Health Surveys; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000097:blood / Q000175:diagnosis* / Q000208:ethnology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009749:Nutrition Surveys; D010281:Parathyroid Hormone / Q000097:blood*; D010758:Phosphorus / Q000097:blood; D012720:Severity of Illness Index; D014481:United States / Q000453:epidemiology; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone; D010758:Phosphorus; D002118:Calcium