1. In this secondary subgroup analysis of the Systolic Blood Pressure Intervention Trial (SPRINT), intensive blood pressure control (SBP<120mmHg) in adults over the age of 75 years was not associated with any significant difference in gait speed change or loss of mobility.
2. Evaluation of functional status, which was the purpose of this study, is an important endpoint when measuring outcomes in the elderly, since that may be more clinically meaningful compared to just mortality outcomes.
Evidence Rating Level: 2 (Good)
Study Rundown: Management of hypertension is important in reducing cardiovascular mortality. However, in the elderly, there is concern that side effects from anti-hypertensive medications may worsen mobility and increase falls. Conversely, reduction in cardiovascular disease through blood pressure management may help maintain mobility. The Systolic Blood Pressure Intervention Trial (SPRINT) recently demonstrated mortality benefit for intensive blood pressure control in adults 75 years and older. Gait speed, a marker of overall physical function and mortality, and self-reported mobility data were available for participants of the SPRINT trial, which allowed for evaluation of the relationship between intense blood pressure control and mobility change.
For patients in the intensive blood pressure control group (SBP<120mmHg) of the SPRINT trial, there was no observed difference in change in gait speed or self-reported mobility. These observations provided reassurance that elderly adults did not suffer significant functional decline with anti-hypertensive therapy. As this was a secondary analysis, bias is present in the analysis. Additionally, differences in mobility or gait speed may have been present if patient follow-up was longer (since the study was stopped early).
Click to read the study, published in JAMA Internal Medicine
Relevant Reading: Blood Pressure Trajectory, Gait Speed, and Outcomes: The Health, Aging, and Body Composition Study
In-Depth [randomized controlled trial]: This study is a subgroup analysis of the SPRINT study which randomized people to intensive blood pressure control (SBP<120mmHg) or standard therapy (<140mmHg). Patients were excluded if they were on anti-hypertensive medications for other indications, had a history of diabetes, stroke, dementia, or orthostatic hypotension. Gait speed was measured with timed 4-meter walk performed at enrollment and then annually. Self-reported mobility was assessed with isolated questions from the Veterans RAND 12-Item Health Survey (VR-12) which inquired about difficulty with stair climbing and walking. Of the 2,636 adults 75 years of age or older in the SPRINT study, 99.7% had data on mobility. Gait speed loss between intensive and control groups did not differ significantly (mean difference, 0.0004 m/s per year; 95%CI, −0.005 to 0.005; P = .88). There was an interaction between gait speed loss and VP-12 score on subjective mobility, however these changes did not meet statistical signicance.
Image: PD
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