title: Effect of urine urea nitrogen and protein intake adjusted by using the estimated urine creatinine excretion rate on the antiproteinuric effect of angiotensin II type I receptor blockers.
abstract: OBJECTIVE
  The aim of this study was to determine the role of protein intake on proteinuria in chronic kidney disease (CKD), as it is presently not conclusive.
  
  
  METHODS
  This is a subanalysis of data from an open-label, case-controlled, randomized clinical trial on education about low-salt diets (NCT01552954). We estimated the urine excretion rate of parameters in a day, adjusted by using the equation for estimating urine creatinine excretion, and analyzed the effect of urine urea nitrogen (UUN), as well as estimating protein intake on the level of albuminuria in hypertensive patients with chronic kidney disease.
  
  
  RESULTS
  Among 174 participants from whom complete 24-h urine specimens were collected, the estimates from the Tanaka equation resulted in the highest accuracy for the urinary excretion rate of creatinine, sodium, albumin, and UUN. Among 227 participants, the baseline value of estimated urine albumin excretion (eUalb) was positively correlated with the estimated UUN (eUUN) or protein intake according to eUUN (P = 0.012 and P = 0.038, respectively). We were able to calculate the ratios of eUalb and eUUN in 221 participants and grouped them according to the ratio of eUUN during 16-wk trial period. The proportion of patients that achieved a decrement of eUalb ≥25% during 16 wk with an angiotensin II type I receptor blocker (ARB) medication was 80% (24 of 30) in group 1, with eUUN ratio ≤-25%; 82.2% (111 of 135) in group 2, with eUUN ratio between -25% and 25%; and 66.1% (37 and 56) in group 3, with eUUN ratio ≥25% (P = 0.048). The probability of a decrease in albuminuria with ARB treatment was lower in patients with an increase of eUUN or protein intake during the 16 wk of ARB treatment, as observed in multiple logistic regression analysis as well.
  
  
  CONCLUSIONS
  The estimated urine urea excretion rate showed a positive association with the level of albuminuria in hypertensive patients with chronic kidney disease. The increase of eUUN excretion ameliorated the antiproteinuric effect of ARB.
authors: Department of Internal Medicine, Seoul National University Bundang Hospital, Seong-Nam, South Korea.
authors: Ho Jun
authors: HJ
authors: Chin
authors: Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea.
authors: Dong Ki
authors: DK
authors: Kim
authors: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, South Korea.
authors: Jung Hwan
authors: JH
authors: Park
authors: Department of Internal Medicine, Dongguk University Ilsan Hospital, Goyang, South Korea.
authors: Sung Joon
authors: SJ
authors: Shin
authors: Department of Internal Medicine, Kyung Hee University Medical Center, Seoul, South Korea.
authors: Sang Ho
authors: SH
authors: Lee
authors: Department of Internal Medicine, Seoul St Mary's Hospital, Seoul, South Korea.
authors: Bum Soon
authors: BS
authors: Choi
authors: Research Institute of Salt and Health, Seoul, South Korea.
authors: Suhnggwon
authors: S
authors: Kim
authors: Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, South Korea. Electronic address: cslimjy@snu.ac.kr.
authors: Chun Soo
authors: CS
authors: Lim
mesh_terms: D000328:Adult; D000368:Aged; D000418:Albumins / Q000378:metabolism; D000419:Albuminuria / Q000209:etiology / Q000517:prevention & control* / Q000652:urine; D000804:Angiotensin II / Q000378:metabolism; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology*; D003404:Creatinine / Q000652:urine*; D004032:Diet; D004044:Dietary Proteins / Q000009:adverse effects / Q000652:urine; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy; D008297:Male; D055641:Mathematical Concepts; D008875:Middle Aged; D008954:Models, Biological; D009584:Nitrogen / Q000652:urine*; D011507:Proteinuria; D044139:Receptor, Angiotensin, Type 2 / Q000378:metabolism; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000188:drug therapy / Q000652:urine; D012964:Sodium / Q000652:urine; D014508:Urea / Q000652:urine*; D055815:Young Adult
chemical_list: D000418:Albumins; D047228:Angiotensin II Type 1 Receptor Blockers; D004044:Dietary Proteins; D044139:Receptor, Angiotensin, Type 2; D000804:Angiotensin II; D014508:Urea; D012964:Sodium; D003404:Creatinine; D009584:Nitrogen
keywords: Albuminuria; Chronic kidney disease; Protein intake; Urine urea nitrogen