title: The impact of obesity on the presentation of primary hyperparathyroidism.
abstract: BACKGROUND
  Obesity has been associated with elevated serum PTH (sPTH) in the general population. Obesity may also alter the clinical presentation in patients with primary hyperparathyroidism (PHPT).
  
  
  OBJECTIVE
  The objectives of the study were to compare the clinical presentation of obese (OB) vs nonobese (NO) PHPT patients and to assess the impact of obesity on the presentation of PHPT independent of serum calcium and PTH.
  
  
  METHODS
  Consecutive PHPT patients who underwent parathyroidectomy between 2003 and 2012 by a single surgical group participated in the study.
  
  
  METHODS
  The study was conducted at an academic medical center.
  
  
  METHODS
  Cross-sectional review of records of preoperative demographic, historical, laboratory, and densitometry findings and intraoperative pathological findings were compared in OB vs NO patients.
  
  
  METHODS
  The prevalence of nephrolithiasis and osteoporosis was measured.
  
  
  RESULTS
  Two hundred forty-seven PHPT patients were included in this analysis. Fifty percent were OB and 79% were women. Mean body mass index was 25.3 ± 3.3 and 36.0 ± 5.2 kg/m(2) in the NO and OB groups, respectively. Age, gender, and race distribution was similar between the two groups. Serum calcium was similar between the groups (11.0 ± 0.7 mg/dL in NO vs 11.1 ± 0.9 mg/dL in OB, P = .13), whereas sPTH was higher in OB (151 ± 70 vs 136 ± 69 pg/mL, P = .03). The OB group exhibited higher prevalence of hypercalciuria (urine calcium > 400 mg per 24 h) (41% vs 23% in NO, P = .01) and nephrolithiasis (36% vs 21% in NO, P = .03). Despite higher sPTH, OB patients showed higher bone mineral density and a lower rate of osteoporosis (21% vs 35%, P = .05). Differences in the prevalence of hypercalciuria and osteoporosis between the groups persisted after adjustment for age, race, estimated glomerular filtration rate, gender, sPTH, and calcium.
  
  
  CONCLUSIONS
  In PHPT patients, obesity is a risk factor for hypercalciuria and nephrolithiasis and is protective against osteoporosis. The impact of parathyroidectomy on the clinical features of obese PHPT patients merits further evaluation.
authors.affiliation: The Charles and Jane Pak Center for Mineral Metabolism and Clinical Research (H.T., J.S.G., N.M.M.), Departments of Internal Medicine (H.T., B.A.-H., N.M.M.), Clinical Sciences (B.A.-H.), and Surgery (F.E.N., J.I.R., S.L.W., S.A.H.), University of Texas Southwestern Medical Center, Dallas, Texas 75390-8885.
authors.forename: Hien
authors.initials: H
authors.lastname: Tran
authors.forename: Jacob S
authors.initials: JS
authors.lastname: Grange
authors.forename: Beverley
authors.initials: B
authors.lastname: Adams-Huet
authors.forename: Fiemu E
authors.initials: FE
authors.lastname: Nwariaku
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Rabaglia
authors.forename: Stacey L
authors.initials: SL
authors.lastname: Woodruff
authors.forename: Shelby A
authors.initials: SA
authors.lastname: Holt
authors.forename: Naim M
authors.initials: NM
authors.lastname: Maalouf
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D053040:Nephrolithiasis / Q000453:epidemiology / Q000209:etiology; D009765:Obesity / Q000097:blood / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D010024:Osteoporosis / Q000453:epidemiology / Q000209:etiology; D010281:Parathyroid Hormone / Q000097:blood; D016105:Parathyroidectomy; D015995:Prevalence; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D010281:Parathyroid Hormone; D002118:Calcium