March 1, 2005
View Full PaperThe Effect of a Lower Target Blood Pressure on the Progression of Kidney Disease: Long-Term Follow-up of the Modification of Diet in Renal Disease Study
Key Result
A low target blood pressure significantly reduced the risk of kidney failure compared to a usual target blood pressure (HR 0.68; 95% CI 0.57-0.82; P<0.001).
Study Design
Type
RCT (n=840)
Multicenter
Yes
Structured PICO
Does a low target blood pressure reduce kidney failure and all-cause mortality in persons with predominantly nondiabetic kidney disease?
P
Population
840 persons with predominantly nondiabetic kidney disease and a glomerular filtration rate of 13 to 55 mL/min per 1.73 m2
I
Intervention
A low target blood pressure (mean arterial pressure < 92 mm Hg)
C
Comparator
A usual target blood pressure (mean arterial pressure < 107 mm Hg)
O
Outcome
Kidney failure (defined as initiation of dialysis or kidney transplantation) and a composite outcome of kidney failure or all-cause mortality ascertained through 31 December 2000hard clinical
Long-term follow-up demonstrates that targeting a lower blood pressure (MAP < 92 mm Hg) significantly reduces the risk of kidney failure and all-cause mortality in patients with nondiabetic chronic kidney disease.
Main Result
Effect estimate: HR 0.68 (95% CI 0.57-0.82)
p-value: p=<0.001
Limitations
- The exact mechanism underlying the benefit of a low target blood pressure is unknown.
Abstract
BACKGROUND: Hypertension is a risk factor for progression of chronic kidney disease. The optimal blood pressure to slow progression is unknown. OBJECTIVE: To evaluate the effects of a low target blood pressure on kidney failure and all-cause mortality. DESIGN: Long-term follow-up of the Modification of Diet in Renal Disease Study, a randomized, controlled trial conducted from 1989 to 1993. SETTING: 15 outpatient nephrology practices. PARTICIPANTS: 840 persons with predominantly nondiabetic kidney disease and a glomerular filtration rate of 13 to 55 mL/min per 1.73 m2. INTERVENTION: A low target blood pressure (mean arterial pressure < 92 mm Hg) or a usual target blood pressure (mean arterial pressure < 107 mm Hg). MEASUREMENTS: After the randomized trial was completed, kidney failure (defined as initiation of dialysis or kidney transplantation) and a composite outcome of kidney failure or all-cause mortality were ascertained through 31 December 2000. RESULTS: Kidney failure occurred in 554 participants (66%), and the composite outcome occurred in 624 participants (74%). After Cox proportional hazards modeling and intention-to-treat analysis, the adjusted hazard ratios were 0.68 (95% CI, 0.57 to 0.82; P < 0.001) for kidney failure and 0.77 (CI, 0.65 to 0.91; P = 0.0024) for the composite outcome in the low target blood pressure group compared with the usual target blood pressure group. Evidence was insufficient to conclude that the benefit of a low target blood pressure differed according to the cause of kidney disease, baseline glomerular filtration rate, or degree of proteinuria. LIMITATIONS: The exact mechanism underlying the benefit of a low target blood pressure is unknown. CONCLUSIONS: Assignment to a low target blood pressure slowed the progression of nondiabetic kidney disease in patients with a moderately to severely decreased glomerular filtration rate.