Albumin-to-creatinine ratio predicts change in ambulatory blood pressure in normotensive persons: a 7.5-year prospective study.
BACKGROUND
The relationship between urinary albumin excretion and blood pressure (BP) has been found to be positive in hypertensive and normotensive subjects. It is not known, in a normotensive and nondiabetic sample, whether elevated urinary albumin levels predict future increases in BP.


METHODS
In this prospective study, we followed a cohort of 108 individuals who were initially free of hypertension and diabetes for an average of 7.7 years. Urinary albumin excretion was determined at baseline by radioimmunoassay in a 24-h collection. Ambulatory BP monitoring was used to assess BP at baseline and at 7.5-year follow-up. Regression models were used to evaluate the relationship of baseline urinary albumin-to-creatinine ratio to baseline BP and average rate of change in BP before and after controlling for several potential confounding variables.


RESULTS
Baseline albumin-to-creatinine ratio was not associated with baseline ambulatory BP, but was positively associated with change in ambulatory BP. Before and after controlling for sex, race/ethnicity, age, body mass index at baseline, and change in body mass index, urinary albumin-to-creatinine ratio was found to be a significant independent predictor of change in awake and sleep systolic and diastolic BPs (all P < .05). It also independently predicted hypertension status at follow-up.


CONCLUSIONS
In healthy normotensive individuals, the urinary albumin-to-creatinine ratio predicts change in ambulatory BPs 7.5 years later. This finding suggests that urinary albumin excretion may be an important marker for processes that increase BP over time.
Gerber
Linda M
LM
Department of Public Health, Weill Medical College of Cornell University, New York, New York 10021, USA. lig2002@med.cornell.edu
Schwartz
Joseph E
JE
Pickering
Thomas G
TG
D000328:Adult; D000418:Albumins / Q000378:metabolism*; D000419:Albuminuria / Q000652:urine; D015415:Biomarkers / Q000652:urine; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm / Q000502:physiology*; D003404:Creatinine / Q000652:urine*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012016:Reference Values; D012307:Risk Factors; D013997:Time Factors
D000418:Albumins; D015415:Biomarkers; D003404:Creatinine