No gain or loss of gait speed with strict BP control in elderly SPRINT participants

Effect of intensive blood pressure control on gait speed and mobility limitation in adults 75 years or older: a randomized clinical trial

News - Feb. 16, 2017

Background

The SPRINT data suggested that targeting a systolic blood pressure (SBP) <120 mmHg confers benefit on CV morbidity and mortality in hypertensive adults of 50 years and older without type 2 diabetes and stroke [1]. The benefit was also seen in those of 75 years and older and exploratory analyses suggested the same effect in those with frailty or slow gait speed [2]. It is important to evaluate the balance between this benefit and other health consequences of intensive BP control.

Gait speed is a well-established measure of physical functioning, predictive of adverse health outcomes and mortality [3,4]. Observational evidence suggests that gait speed decline is faster in older adults with high BP [5]. Lower SBP has, however, also been connected to greater limitations on daily activities and greater probability of worsening disability [6].

This study compared the trajectory of gait speed decline and incident mobility limitation in the intensive- and standard treatment groups in SPRINT [1,7], within the subgroup of participants aged at least 75 years at the time of randomisation (n=2636). An earlier report on this subgroup [2] reported

a higher frequency of aspirin use (820 [62.3%] vs 765 [58.0%]) and higher prevalence of frailty, as assessed by a 37-item frailty index (440 [33.4%] vs 375 [28.4%]) in the intensive-treatment group as statistically significant treatment group differences at baseline.

Main results

Overall mean gait speed at baseline was 0.91 m/s, with a mean annual change of -0.026 (95%CI: -0.028 to -0.023) m/s.
Both treatment groups showed a similar trajectory of gait speed; the decline in mean gait speed was the same for those randomised to intensive or standard treatment (mean difference: 0.004 m/s per year, 95%CI: -0.005 to 0.005 m/s per year, P=0.88).
Change in gait speed were not significantly different between subgroups defined by age, sex, race or ethnicity, baseline SBP, chronic kidney disease, or history of CVD.
Assessment of mobility status was based on self-report. Overall, the mean transition rate from no mobility limitation to mobility limitation was 12.5 per 100 person-years.
No significant effect of intensive treatment on transitioning to mobility limitation (HR: 0.92, 95%CI: 0.91-1.22) or transitioning into a limitation-free state (HR: 0.92, 95%CI: 0.77-1.10).

Conclusion

These data of individuals aged 75 years and older, enrolled in the SPRINT trial, show no differences in gait speed decline between those receiving intensive BP-lowering therapy vs. standard therapy. Nor were differences seen between the groups in mobility limitations, based on self-reports.

References

Show references

Find this article online at JAMA Intern med.