title: Associations of proteinuria, fluid volume imbalance, and body mass index with circadian ambulatory blood pressure in chronic kidney disease patients.
abstract: OBJECTIVE
  Obesity and hypervolemic status are the main causes of hypertension in patients with chronic kidney disease (CKD). However, it is difficult to differentiate between them. We aimed to assess the associations of body mass index (BMI) and total body water (TBW) with ambulatory blood pressure (ABP).
  
  
  METHODS
  Body composition by bioelectrical impedance analysis (BIA) and 24-h ABP were measured in 40 patients with CKD. TBW was assessed using corrected TBWBIA adjusted for body surface area (cTBWBIA) and the TBWBIA/TBWWatson ratio obtained using an anthropometric formula (Watson).
  
  
  RESULTS
  Elevated ABP (average 24-h BP ≥ 135/85 mmHg) was noted in 23 patients, who were more likely to have a higher cTBWBIA and TBWBIA/TBWWatson ratio than patients without elevated BP. Patients with nocturnal non-dipping (<10% drop in BP during sleep) were more likely to have a higher TBWBIA/TBWWatson ratio. Proteinuria and the TBWBIA/TBWWatson ratio were significant independent factors for 24-h ABP. BMI had a positive correlation with the cTBWBIA, TBWBIA/TBWWatson ratio and furosemide use.
  
  
  CONCLUSIONS
  Hypertension is dependent on proteinuria and fluid volume imbalance. The TBWBIA/TBWWatson ratio can serve as an indicator of fluid volume-dependent hypertension. BMI is affected by TBW, in which case BMI can become less involved with 24-h ABP.
authors.affiliation: Department of Nephrology, Toho University School of Medicine, Tokyo, Japan. ys-0084@med.toho–u.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ohashi
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Otani
authors.forename: Reibin
authors.initials: R
authors.lastname: Tai
authors.forename: Takayuki
authors.initials: T
authors.lastname: Okada
authors.forename: Kentarou
authors.initials: K
authors.lastname: Tanaka
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Ken
authors.initials: K
authors.lastname: Sakai
authors.forename: Atsushi
authors.initials: A
authors.lastname: Aikawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D002940:Circadian Rhythm / Q000502:physiology*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000503:physiopathology; D011507:Proteinuria / Q000150:complications / Q000503:physiopathology*; D012044:Regression Analysis; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology / Q000503:physiopathology*; D012189:Retrospective Studies; D014882:Water-Electrolyte Balance / Q000502:physiology*