Differences in urinary albumin excretion rate between normotensive and hypertensive, white and nonwhite subjects
Eighty-one normotensive and 61 hypertensive white and nonwhite subjects were studied cross-sectionally to determine the prevalence and determinants of elevated urinary albumin levels. Twenty-four-hour urinary albumin excretion was determined by radioimmunoassay. The prevalence of elevated urinary albumin level (greater than or equal to 15 mg/24 h) was significantly greater in hypertensive than in normotensive subjects (31.1% and 8.6%). Among hypertensive subjects, a much greater proportion of whites than nonwhites had urinary albumin levels of 15 mg/24 h or greater (39.5% and 17.4%). The independent association of blood pressure with urinary albumin level was affirmed by logistic regression analyses for white normotensive and hypertensive subjects combined, and for hypertensive subjects alone. Furthermore, among hypertensive subjects, whites were five times as likely as nonwhites to have elevated urinary albumin levels. Thus, blood pressure and ethnicity were the important determinants of urinary albumin excretion among hypertensive subjects.