title: Is longitudinal pulse pressure a better predictor of 24-hour urinary albumin excretion than other indices of blood pressure?
abstract: The strong relationship between urinary albumin excretion (UAE) and pulse pressure (PP) in cross-sectional studies suggests that pressure pulsatility may contribute to renal microvascular injury. The longitudinal relationships between UAE and the various indices of blood pressure (BP) are not well studied. We compared the associations of UAE with the longitudinal exposure to PP and systolic, diastolic, and mean BPs. UAE was measured from 24-hour urine collections in 450 community-dwelling subjects (age: 57+/-15 years, 53% women, all with UAE <200 microg/min). For each subject, longitudinal indices of BP were estimated by dividing the area under the curve of serial measurements of BP (median: 5) during 1 to 22 years preceding UAE measurement by the number of follow-up years. Median (interquartile range) UAE was 4.7 microg/min (3.3 to 7.8 microg/min) in women and 5.2 microg/min (3.7 to 9.8 microg/min) in men. In women, UAE was not related to longitudinal indices of BP. In men, in multivariable-adjusted models that included either longitudinal systolic and diastolic BPs or longitudinal PP and mean BP, UAE was independently associated with systolic (standardized regression coefficient [beta]=0.227; P=0.03) but not with diastolic (beta=-0.049; P=0.59) BP and with PP (beta=0.216; P=0.01) but not with mean BP (beta=0.032; P=0.72). Comparisons of these 2 models and stepwise regression analyses both indicated that, of the 4 longitudinal indices of BP, PP was the strongest predictor of UAE in men. The pulsatile component of BP confers the highest risk for BP-induced renal microvascular injury. Future studies should examine whether PP reduction provides additional renoprotection beyond that attained by conventional BP goals alone.
authors.affiliation: MedStar Research Institute, National Institute on Aging, National Institutes of Health, Baltimore, Md, USA.
authors.forename: S Morteza
authors.initials: SM
authors.lastname: Farasat
authors.forename: Carolina
authors.initials: C
authors.lastname: Valdes
authors.forename: Veena
authors.initials: V
authors.lastname: Shetty
authors.forename: Denis C
authors.initials: DC
authors.lastname: Muller
authors.forename: Josephine M
authors.initials: JM
authors.lastname: Egan
authors.forename: E Jeffrey
authors.initials: EJ
authors.lastname: Metter
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.forename: Samer S
authors.initials: SS
authors.lastname: Najjar
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000175:diagnosis*; D000704:Analysis of Variance; D015415:Biomarkers / Q000652:urine; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000379:methods; D011237:Predictive Value of Tests; D011336:Probability; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013997:Time Factors; D016482:Urinalysis
chemical_list: D015415:Biomarkers