Masked Hypertension Linked to Low GFR, Elevated Urine Protein
ATLANTA—Increased urine protein is associated with an increased risk of white coat, masked, and sustained hypertension in patients with chronic kidney disease (CKD), a study reported at the American Society of Nephrology's Kidney Week 2013 meeting.
As part of the Chronic Renal Insufficiency Cohort (CRIC) study, Paul E. Drawz, MD, and colleagues at the University of Minnesota in Minneapolis, studied 1,439 patients who had 24-hour ambulatory blood pressure (ABP) monitoring. The purpose of the study was to determine whether elevated proteinuria and low estimated glomerular filtration rate (eGFR) were associated with an increased risk of white-coat hypertension (HTN), masked HTN, or sustained HTN in patients with CKD.
They found that 52.7% of subjects had controlled BP, 5.5% had white-coat HTN, 24.5% had masked HTN, and 17.2% had sustained HTN. Each doubling of urine protein/creatinine ratio was associated with a 33%, 26%, and 49% increased odds of white-coat, masked, and sustained HTN, respectively. In addition, each 10 unit decrease in eGFR was associated with an 11% increased risk of masked HTN.
White-coat HTN was defined as a clinic BP of 140/90 mm Hg or greater as well as a daytime ABP less than 135/85 mm Hg. Masked HTN was defined as a clinic BP less than 140/90 mm Hg and a daytime ABP of 135/85 mm Hg or greater. SH was defined as a clinic BP of 140/90 mm Hg or greater and a daytime ABP of greater than 135/85 mm Hg or greater.
“ABP may be particularly important in patients with CKD in order to better characterize their BP control, especially among those with proteinuria,” the authors noted.