title: Prevalence of secondary hyperparathyroidism in patients with stage 3 and 4 chronic kidney disease seen in internal medicine.
abstract: OBJECTIVE
  Despite the high prevalence of chronic kidney disease in the elderly population, few data are available on the frequency of secondary hyperparathyroidism in the Spanish population affected by this problem. We undertook a study on this issue in patients attending the internal medicine departments in our area.
  
  
  METHODS
  An observational, cross-sectional survey performed at internal medicine departments on 415 patients with stage 3 and 4 chronic kidney disease. Clinical history and risk factors were collected using a standardized protocol. Serum creatinine, phosphate, calcium, intact parathormone (PTH) and 25-hydroxy-cholecalciferol (25-OH-vitD) levels were measured in all patients.
  
  
  RESULTS
  Among stage 3 patients, 62.9% had PTH levels ≥70pg/mL and 32.7% levels ≥110pg/mL. Median PTH level in stage 4 patients was 120pg/mL (p <0.001), and 77.9% of these patients had PTH ≥70pg/mL (p <0.001) and 54.1% ≥110pg/mL (p=0.015). Adequate 25-hydroxy-cholecalciferol levels were found in only 7.2% of stage 3 patients and 4.1% of stage 4 patients. Only 7.2% of stage 3 patients had hyperphosphatemia, as compared to 25.4% of stage 4 patients (p <0.001).
  
  
  CONCLUSIONS
  Hyperparathyroidism is a common complication of stage 3 and 4 chronic kidney disease which is not associated to detectable changes in serum calcium and phosphate levels. It is therefore advisable to measure PTH levels in all patients with decreased glomerular filtration rate.
authors.affiliation: Servicio de Medicina Interna, Hospital Infanta Cristina, Badajoz, España.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Bureo
authors.affiliation: Sección de Medicina Interna, Hospital de Zafra, Badajoz, España.
authors.forename: Jose Carlos
authors.initials: JC
authors.lastname: Arévalo
authors.affiliation: Servicio de Medicina Interna, Hospital San Pedro de Alcántara, Cáceres, España.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Antón
authors.affiliation: Servicio de Medicina Interna, Hospital Infanta Cristina, Badajoz, España.
authors.forename: Gaspar
authors.initials: G
authors.lastname: Adrados
authors.affiliation: Servicio de Medicina Interna, Hospital Tierra de Barros, Almendralejo, Badajoz, España.
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Jiménez Morales
authors.affiliation: Servicio de Medicina Interna, Hospital Infanta Cristina, Badajoz, España. Electronic address: nrrobles@yahoo.es.
authors.forename: Nicolás Roberto
authors.initials: NR
authors.lastname: Robles
mesh_terms: D000368:Aged; D002117:Calcitriol / Q000097:blood / Q000172:deficiency; D002118:Calcium / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006748:Hospital Departments; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D007388:Internal Medicine; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D015995:Prevalence; D051436:Renal Insufficiency, Chronic / Q000150:complications*; D012307:Risk Factors; D012720:Severity of Illness Index; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires
chemical_list: D010281:Parathyroid Hormone; D010758:Phosphorus; D002117:Calcitriol; D002118:Calcium
keywords: Anciano; Chronic kidney disease; Elderly; Hiperparatiroidismo; Hyperparathyroidism; Insuficiencia renal crónica