Posted by MedPage Today on February 6, 2017.
A low blood pressure target had no effect on older patients’ physical function, neither worsening nor improving it, according to a substudy of the SPRINT trial showing no changes in gait or mobility.
Decline in gait speed was similar between adults 75 and older on intensive treatment to reach a systolic target of less than 120 mm Hg and those treated to a standard under-140 mm Hg goal (mean difference 0.0004 m/s per year, P=0.88). That finding was true across age, sex, race or ethnicity, baseline systolic blood pressure, chronic kidney disease, and cardiovascular disease history subgroups.
Intensive treatment didn’t push patients toward limited mobility either in a model accounting for competing risk of death (HR 1.06 for gait speed <0.6 m/s or self-reported trouble with walking or stairs, 95% CI 0.92-1.22), Nicholas M. Pajewski, PhD, of the Wake Forest School of Medicine in Winston-Salem, N.C., and colleagues reported online in JAMA Internal Medicine.
While some observational studies had suggested higher blood pressure might accelerate disability, the researchers concluded: “Intensive blood pressure control does not appear to have an important effect on short-term gait speed decline among older adults.”
The findings during 3 years of follow-up in the trial included 2,636 patients age 75 and older randomized to a blood pressure target as part of the SPRINT trial, all but 88 of whom had gait speed measured at baseline. At that point, 17.6% were classified as having a mobility limitation.
SPRINT showed a reduction in mortality and cardiovascular risks with treatment targeting less than 120 mm Hg systolic both overall and in those 75 and older. Previous analyses have turned up no increase in cognitive or physical decline overall in the trial and no amplification of the effect of older age on risk of syncope or falls.
Although Pajewski’s analysis showed a “modest interaction” between mobility self-reported on the Veterans RAND 12-Item Health Survey Physical Component Summary score favoring slower decline with intensive treatment in those with better physical quality of life, it was not statistically significant for those scoring at least within a standard deviation of the national average or for those scoring lower.
The researchers cautioned that “these findings should be interpreted with caution because the effect size was modest and did not reach statistical significance in either group. Further research is needed to determine whether some factors can differentiate the populations for whom intensive blood pressure treatment may slow or accelerate gait speed decline.”
They pointed to the ongoing Intensive vs Standard Ambulatory Blood Pressure Lowering to Prevent Functional Decline in the Elderly (INFINITY) trial to answer the question.
Source: MedPage Today