24-hour ambulatory systolic blood pressure was positively correlated with urinary albumin (r=0.44, P<0.01) and NAG excretion (r=0.32, P<0.05), whereas office blood pressure only correlated with albumin.
Cross-Sectional (n=42)
Does 24-hour ambulatory blood pressure measurement improve correlation with urinary markers of renal damage compared to office blood pressure in untreated patients with essential hypertension?
Ambulatory blood pressure monitoring correlates better than office blood pressure with early markers of hypertensive renal damage (urinary NAG), suggesting it is more reliable for identifying at-risk patients.
p-value: p=<0.01
Ambulatory blood pressure (ABP) correlates better than office blood pressure with hypertensive changes in the heart and vasculature. Using the 24-hour urinary excretions of albumin and N-acetyl-beta-D-glucosaminidase (NAG) as markers, we examined the relationship between office and ABP and target-organ changes in the kidney in 42 untreated patients with essential hypertension. Mean urinary albumin excretion was 23.2 +/- 34.3 mg/day and mean urinary NAG excretion was 45.1 +/- 22.9 nmol/hr/mg creatinine. Urinary albumin excretion was positively correlated with both office and mean 24-hour systolic blood pressure (r = 0.31, P less than 0.05; and r = 0.44, P less than 0.01, respectively). Urinary NAG excretion was positively correlated with 24-hour ambulatory systolic, diastolic, and mean blood pressure (r = 0.32, P less than 0.05; r = 0.32, P less than 0.05; and r = 0.39, P less than 0.05, respectively), but not with office blood pressure. Thus, urinary albumin and NAG excretions are positively correlated with blood pressure and may be useful markers of renal involvement in patients with essential hypertension. Additionally, ABP may be more reliable than office blood pressure in identifying those patients at risk for hypertensive target-organ changes in the kidney.
Opsahl et al. (1988) conducted a cross-sectional in essential hypertension (n=42). 24-hour ambulatory blood pressure vs. Office blood pressure was evaluated on Correlation with 24-hour urinary excretions of albumin and N-acetyl-beta-D-glucosaminidase (NAG) (p=<0.01). 24-hour ambulatory systolic blood pressure was positively correlated with urinary albumin (r=0.44, P<0.01) and NAG excretion (r=0.32, P<0.05), whereas office blood pressure only correlated with albumin.