title: Low-grade albuminuria and the risks of hypertension and blood pressure progression.
abstract: BACKGROUND
  It has been postulated that glomerular hyperfiltration and endothelial dysfunction are early features of essential hypertension that may antedate blood pressure elevation. Microalbuminuria, a marker of glomerular hyperfiltration and endothelial dysfunction, has been described in individuals with established hypertension, but its role as a biomarker of preclinical stages of this disease has not been investigated prospectively.
  
  
  RESULTS
  We examined the association between urinary albumin excretion and the risks of hypertension and blood pressure progression in 1499 nonhypertensive individuals (58% women) without diabetes. During a mean follow-up of 2.9 years, 230 participants (15%) developed hypertension and 499 (33%) progressed to a higher blood pressure category (defined by the sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure). In multivariable logistic regressions that adjusted for known risk factors, the urine albumin-creatinine ratio (UACR) was a significant predictor of incident hypertension (adjusted OR 1.20, 95% CI 1.01 to 1.44, per 1-SD increment in log UACR). Compared with those in the lowest UACR quartile, participants in the highest quartile (men: >6.66 mg/g; women: >15.24 mg/g) had an approximately 2-fold risk of developing hypertension (adjusted OR 1.93, P=0.006) and 1.5-fold risk of blood pressure progression (adjusted OR 1.45, P=0.03).
  
  
  CONCLUSIONS
  Urinary albumin excretion predicts blood pressure progression in nondiabetic, nonhypertensive individuals incrementally over established risk factors and at levels well below the conventional threshold for microalbuminuria. UACR may be a useful biomarker for identifying individuals most likely to develop hypertension.
authors.affiliation: Framingham Heart Study, Framingham, Mass 01702-5827, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Wang
authors.forename: Jane C
authors.initials: JC
authors.lastname: Evans
authors.forename: James B
authors.initials: JB
authors.lastname: Meigs
authors.forename: Nader
authors.initials: N
authors.lastname: Rifai
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Fox
authors.forename: Ralph B
authors.initials: RB
authors.lastname: D'Agostino
authors.forename: Daniel
authors.initials: D
authors.lastname: Levy
authors.forename: Ramachandran S
authors.initials: RS
authors.lastname: Vasan
mesh_terms: D000419:Albuminuria / Q000453:epidemiology* / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology*; D015331:Cohort Studies; D018450:Disease Progression; D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000453:epidemiology* / Q000503:physiopathology; D015994:Incidence; D007678:Kidney Glomerulus / Q000098:blood supply / Q000503:physiopathology*; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D012306:Risk