Systolic BP Predicts Diabetic Nephropathy Progression

Findings provide strong support for aggressive BP reduction for people with nephropathy from type 2 diabetes.

Dr. George L. Bakris, of Rush Medical College, Chicago, colleagues used a Cox proportional hazards regression model to examine the effects of baseline systolic blood pressure, diastolic blood pressure, and pulse pressure on renal outcomes in patients with established nephropathy and hypertension associated with type 2 diabetes. Included were 1513 patients enrolled in the Reduction of Endpoints in NIDDM (non-insulin dependent diabetes mellitus) with the Angiotensin II Antagonist Losartan (RENAAL) study.

The main outcome measures were doubling of serum creatinine, end-stage renal disease (ESRD), or death. The team also examined the effects of the angiotensin receptor blocker losartan potassium on composite and renal outcomes.

Compared with patients with baseline systolic blood pressure below 130 mm Hg, those with a baseline systolic blood pressure between 140 and 159 mm Hg had a 38% increased risk of ESRD (p < 0.01). The risk more than doubled in patients with systolic blood pressure levels at least 160 mm Hg (p < 0.001).

Multivariate analysis demonstrated that the risk for ESRD or death increased by 6.7% for every 10-mm Hg rise in baseline systolic blood pressure (p = 0.007). After adjusting for urinary albumin-creatinine ratio, serum creatinine, serum albumin, hemoglobin A1c, and hemoglobin, every 10-mm Hg rise in diastolic blood pressure decreased the risk by 10.9% (p = 0.01).

“Those randomized to the losartan group with a baseline pulse pressure above 90 mm Hg had a 53.5% risk reduction for ESRD alone (p = 0.003) and a 35.5% risk reduction for ESRD or death (p = 0.02) compared with the placebo group,” Dr. Bakris and colleagues report.

The findings provide strong support for aggressive BP reduction for people with nephropathy from type 2 diabetes. Arch Intern Med 2003;163:1555-1565.