title: Combining body mass index and serum potassium to urine potassium clearance ratio is an alternative method to predict primary aldosteronism.
abstract: BACKGROUND
  Though aldosterone-renin ratio (ARR) is the current routine screening method for suspicious primary aldosteronism, we hypothesized that the simple formula combining body mass index (BMI) and serum potassium to urine potassium clearance (PUKC) ratio was comparable to ARR.
  
  
  METHODS
  Records of patients who were referred to the National Taiwan University Hospital for investigation of primary aldosteronism from January 1995 through December 2007 were retrieved. Primary aldosteronism was diagnosed based on the modified 4-corners criteria, otherwise essential hypertension was diagnosed. In both groups, the PUKC/BMI ratio was determined as well as the ARR. Bland-Altman and mountain-plot analysis were used to validate the agreement between ARR and PUKC/BMI. Receiver operating characteristic (ROC) curves were used to compare the sensitivity and specificity of PUKC/BMI and ARR.
  
  
  RESULTS
  The records for urinary potassium were analyzed for 177 hypertensive patients (134 patients with primary aldosteronism). ROC curves showed comparable areas under the curves of both methods (95% CI: -0.029 to 0.183; p=0.186). Bland-Altman analysis further supported the agreement between ARR and PUKC/BMI ratio.
  
  
  CONCLUSIONS
  We found that the screening power of PUKC/BMI was as good as that of conventional ARR. With the quick and extensive availability of the PUKC/BMI method and its equivalence to ARR, this screening strategy would be a good first-line tool for massive community-based primary aldosteronism surveys.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Chin-Chi
authors.initials: CC
authors.lastname: Kuo
authors.forename: Vin-Cent
authors.initials: VC
authors.lastname: Wu
authors.forename: Ching-Wei
authors.initials: CW
authors.lastname: Tsai
authors.forename: Kuo-How
authors.initials: KH
authors.lastname: Huang
authors.forename: So-Mong
authors.initials: SM
authors.lastname: Wang
authors.forename: Bai-Chin
authors.initials: BC
authors.lastname: Li
authors.forename: Chin-Chen
authors.initials: CC
authors.lastname: Chang
authors.forename: Ching-Chu
authors.initials: CC
authors.lastname: Lu
authors.forename: Wei-Shun
authors.initials: WS
authors.lastname: Yang
authors.forename: Chia-Ter
authors.initials: CT
authors.lastname: Chao
authors.forename: I-Chieh
authors.initials: IC
authors.lastname: Tsai
authors.forename: Chun-Fu
authors.initials: CF
authors.lastname: Lai
authors.forename: Wei-Chou
authors.initials: WC
authors.lastname: Lin
authors.forename: Ming-Shou
authors.initials: MS
authors.lastname: Wu
authors.forename: Yen-Hung
authors.initials: YH
authors.lastname: Lin
authors.forename: Chien-Yu
authors.initials: CY
authors.lastname: Lin
authors.forename: Hung-Wei
authors.initials: HW
authors.lastname: Chang
authors.forename: Wei-Jei
authors.initials: WJ
authors.lastname: Wang
authors.forename: Wen-Chih
authors.initials: WC
authors.lastname: Chiang
authors.forename: Tze-Wah
authors.initials: TW
authors.lastname: Kao
authors.forename: Shih-Chieh
authors.initials: SC
authors.lastname: Chueh
authors.forename: Tzong-Shinn
authors.initials: TS
authors.lastname: Chu
authors.forename: Tun-Jun
authors.initials: TJ
authors.lastname: Tsai
authors.forename: Kwan-Dun
authors.initials: KD
authors.lastname: Wu
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood* / Q000652:urine*; D012372:ROC Curve; D012189:Retrospective Studies
chemical_list: D011188:Potassium