'Frail' seniors more at risk of death from hypertension
Not all senior adults are alike -- especially when it comes to high blood pressure. Those who are classified as "extremely frail" are more likely to die from the disease.
That's the conclusion of a study recently published in the Journal of the American Medical Association's Archives of Internal Medicine. The researchers found that lower blood pressure protected healthier, robust older adults but the same may not be true for their more frail counterparts.
Lead author Michelle Odden, a public health epidemiologist at Oregon State University, said blood pressure rises naturally as people age.
"As we age, our blood vessels lose elasticity and becomes stiff," she said. "Higher blood pressure could be a compensatory mechanism to overcome this loss of vascular elasticity and keep fresh blood pumping to the brain and heart."
The issue is in defining frailty.
Vive le différence
"We're just starting to understand the concept of frailty," Odden told Feeling Fit. "It's an emerging area, and we don't know exactly what causes frailty."
Odden's study used walking speed as a measure of frailty. Participants were asked to walk a distance of about 20 feet at their normal rate. Those who walked less than 0.8 meters per second were defined as slower walkers. Those who walked faster than 0.8 meters per second were in the second group of more robust adults, who also had a lower prevalence of diabetes, coronary heart disease, stroke and heart failure.
The third group included those who were not able to complete the walking test for various reasons, including inability to walk 20 feet.
Among the faster walkers, those with high blood pressure had a 35 percent greater risk of dying compared with those with normal blood pressure.
In contrast, there was no association between high blood pressure and mortality in the slow walking group. Strikingly, those who were unable to complete the walking test had the opposite results -- those with higher blood pressure had a 62 percent lower mortality rate.
Odden said the mortality differences between the fast walkers and slow walkers or noncompleters can be explained simply -- everyone ages differently.
"Not all older adults are the same," she explained. "There's great diversity in their physiologic age. There's a big difference between a 75-year-old who's playing tennis every day and one who's in a nursing home."
"In geriatrics, really old starts at 85," said Port Charlotte internist Dr. Mario Carbonell. "The elderly start at 65 and that's the young elderly -- they're very functional. Those 75 to 84 are fine if they're in good shape. After 85, some authors consider them frail by definition -- although that's not necessarily true."
One size does not fit all
The treatment for high blood pressure is a little bit more complicated in older adults, Carbonell added. With a condition called pseudohypertension, a thickened artery prevents a blood pressure cuff from taking an accurate reading, making the pressure appear high when it isn't. There is also a hypertension-fueled lacunar stroke in the brain's cerebrum, causing movement disorders similar to Parkinson's, and is difficult to diagnose.
Because of these diverse physiological conditions of older adults, "How hypertension is treated within this age group has been a subject of controversy for many years," Odden said. "I think our study highlights the heterogeneity of older adults. I think it's really very important that in research and in clinical practice that we consider factors beyond simply just your age when making treatment decisions."
Since this is one of the first studies to examine walking speed, mortality and blood pressure, Odden cautioned against people making health decisions based on these early findings.
"Any sort of decision regarding medication use should be done in consultation with a physician," she said. "Our study supports treating high blood pressure in healthy, active older adults. But in frail older adults, with multiple chronic health conditions, we need to take a closer look at what sorts of effects high blood pressure could serve and whether having a higher blood pressure could be protective."
Carbonell said that, in many cases, frailty can be delayed or warded off completely through lifestyle changes, such as a healthier diet and mild exercise if the patient is capable of it.
"Although it can be quite difficult for older folks to do exercise, they can do some," Carbonell said. "They can walk. They can do chair yoga if they can't walk around. Exercise is probably the best thing you can do for yourself, as long as you're healthy. You start low and you go slow."
The key to exercising is to start earlier in life, to not wait until the body begins to deteriorate to the point where it's difficult.
"I know a fellow who's in his early 90s and does 200 pushups every day," Carbonell said. "I can't do that. But he's been doing it since he was 19. And he said, 'The day I don't do it will be the last day I ever can.' This guy's sharp as a tack."
Carbonell recommends early treatment of hypertension, since the damage caused by the disease is progressive.
"Obviously the longer you're around, the more this can progress," he said. "Certainly if it's uncontrolled in the elderly, they have a higher incidence of mortality and morbidity with strokes, heart attacks and organ damage. It's an accelerant -- like putting gas on a fire."
Odden wants her research to raise the question of just how hypertension is treated.
"I hope that our study will promote the further exploration of both blood pressure and medication use in frail older adults, because this population has really been underrepresented in clinical trials. Older adults are a really complex group, and they have unique needs and considerations.
"I think we're just beginning to understand how to quantify that in a way that's meaningful and can improve outcomes in older adults."