Progression of chronic kidney disease: the role of blood pressure control, proteinuria, and angiotensin-converting enzyme inhibition: a patient-level meta-analysis.

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors reduce blood pressure and urine protein excretion and slow the progression of chronic kidney disease.

PURPOSE

To determine the levels of blood pressure and urine protein excretion associated with the lowest risk for progression of chronic kidney disease during antihypertensive therapy with and without ACE inhibitors.

DATA SOURCES

11 randomized, controlled trials comparing the efficacy of antihypertensive regimens with or without ACE inhibitors for patients with predominantly nondiabetic kidney disease.

STUDY SELECTION

MEDLINE database search for English-language studies published between 1977 and 1999.

DATA EXTRACTION

Data on 1860 nondiabetic patients were pooled in a patient-level meta-analysis. Progression of kidney disease was defined as a doubling of baseline serum creatinine level or onset of kidney failure. Multivariable regression analysis was performed to assess the association of systolic and diastolic blood pressure and urine protein excretion with kidney disease progression at 22 610 patient visits.

DATA SYNTHESIS

Mean duration of follow-up was 2.2 years. Kidney disease progression was documented in 311 patients. Systolic blood pressure of 110 to 129 mm Hg and urine protein excretion less than 2.0 g/d were associated with the lowest risk for kidney disease progression. Angiotensin-converting enzyme inhibitors remained beneficial after adjustment for blood pressure and urine protein excretion (relative risk, 0.67 [95% CI, 0.53 to 0.84]). The increased risk for kidney progression at higher systolic blood pressure levels was greater in patients with urine protein excretion greater than 1.0 g/d (P < 0.006).

CONCLUSION

Although reverse causation cannot be excluded with certainty, a systolic blood pressure goal between 110 and 129 mm Hg may be beneficial in patients with urine protein excretion greater than 1.0 g/d. Systolic blood pressure less than 110 mm Hg may be associated with a higher risk for kidney disease progression.