Walking speed and hypertension in older adults

Walking speed is emerging as an important measure of frailty in older adults. It’s easy to measure, reproducible and associated with survival. Walking speed might also help identify older adults who need treatment for high blood pressure, according to an observational study from the USA. In a nationally representative cohort of 2 340 adults aged ≥65 years, systolic blood pressure of ≥140 mmHg predicted mortality in faster walkers (hazard ratio 1.35 (95% CI 1.03 - 1.77)) but not in slower walkers (hazard ratio 1.12 (0.87 - 1.45)). High blood pressure seemed protective in the small subset of adults who failed to complete the short walking test.

Doctors disagree about how to manage blood pressure in older adults, says a linked comment (doi:10.1001/archinternmed.2012.2642). Many are reluctant to accept that high blood pressure isn’t always a bad sign. It may be a bad sign for those lucky enough to be well and physically fit (the kind of adults recruited to trials of antihypertensive drugs). But the direct association between blood pressure and mortality breaks down, or even reverses, in older adults who are unable to walk 1.8 miles/hour for 20 feet (0.8 m/s for 6 m), which is the defining threshold used in this study.

The new data reinforce walking speed as a useful measure of frailty, says the comment, and remind us that there is no such thing as an average older person when it comes to blood pressure. Guidelines for treatment based on age alone will miss the mark and risk over-treating frail adults who may need their high blood pressure to perfuse vital organs, including the heart.

Odden MC, et al. Arch Intern Med 2012

[http://dx.doi.org/10.1001/archinternmed.2012.2555]