title: [Etiology analysis of 628 patients with refractory hypertension].
abstract: OBJECTIVE
  To analyze the etiology of 628 patients with refractory hypertension and to observe the disease distribution with respect to gender and different age groups.
  
  
  METHODS
  In this study, clinical data of 628 refractory hypertensives who hospitalized in our hospital from September 1997 to December 2005 were retrospectively analyzed.
  
  
  RESULTS
  (1) There were 80.1% (503/628) patients with essential hypertension, 18.9% (119/628) with secondary hypertension (SH) while diagnosis was not clear in 1.0% (6/628) patients. Renovascular hypertension (33.6%) and obstructive sleep apnea syndrome (23.5%) were the major causes of SH. The highest prevalence rate of endocrine hypertension was primary aldosteronism (13.5%). (2) There were significantly more male patients than female patients with essential hypertension, SH, renal hypertension, obstructive sleep apnea syndrome, primary aldosteronism while the incidence of pheochromocytoma in female was significantly higher than that in male patients (all P < 0.05). The incidence of renovascular hypertension was similar between male and female patients. (3) SH occurred more often in young patients (33.1%) than in aged patients (13.8%, P < 0.05).
  
  
  CONCLUSIONS
  Our data from this patient cohort showed that SH, especially renovascular hypertension and obstructive sleep apnea syndrome are major causes for refractory hypertension in young patients and primary aldosteronism was the commonest reason of endocrine hypertension in youth and middle-aged patients with refractory hypertension.
authors.affiliation: Department of Hypertension, People's Hospital of Xinjiang Uygur Autonomous Region, The Center of Diagnosis, Treatment and Research of Hypertension of Xinjiang Uygur Autonomous Region, Urumuqi 830001, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Nan-Fang
authors.initials: NF
authors.lastname: Li
authors.forename: Ke-Ming
authors.initials: KM
authors.lastname: Zhou
authors.forename: Xin-Ling
authors.initials: XL
authors.lastname: Wang
authors.forename: Fei-Ya
authors.initials: FY
authors.lastname: Zu
authors.forename: De-Lian
authors.initials: DL
authors.lastname: Zhang
authors.forename: Gui-Juan
authors.initials: GJ
authors.lastname: Chang
authors.forename: Yan-Min
authors.initials: YM
authors.lastname: Zhang
authors.forename: Guli
authors.initials: G
authors.lastname: Nuer
authors.forename: Meng-Hui
authors.initials: MH
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000150:complications; D006973:Hypertension / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D017678:Sex Distribution; D020181:Sleep Apnea, Obstructive / Q000150:complications; D055815:Young Adult