Researchers seeking ways to help older adults preserve their mobility

"People are in nursing homes for two reasons, either they can't think or they can't walk," said Stephen Kritchevsky, Ph.D., director of the Sticht Center on Aging at Wake Forest Baptist Medical Center. North Carolina. "We're working very hard on the thinking part, and the walking part is equally important.

"The older people who report the highest life satisfaction, and who also seem to live longer, are those with intact and robust social networks. The ability to walk is fundamental to maintaining one's social contacts and remaining independent. Mobility is critical to quality of life in addition to physical health."

Kritchevsky is among the Wake Forest Baptist researchers collaborating with colleagues across the country to find ways to keep older adults on their feet.

Backed by a $5.3 million National Institutes of Health (NIH) grant, Wake Forest Baptist and five other institutions are launching a multi-site study to determine if reducing the chronic, low-grade inflammation that is common in the elderly can help avert mobility problems. "The levels of inflammation we are studying are way below the levels that you can observe when there's an acute infection," said Marco Pahor, M.D., director of the Institute on Aging at the University of Florida and co-principal investigator of the study with Walter T. Ambrosius, Ph.D., professor and chair of biostatistical sciences at Wake Forest Baptist. "We are talking about inflammation that's associated with aging, not disease."

The researchers will enlist 300 older adults who either have or are at risk for mobility limitations and see whether omega-3 fish oil and the blood pressure drug losartan -- both of which have proven effective in lessening inflammation -- can improve their physical function and help prevent mobility loss.

Wake Forest Baptist is the data coordinating center for the study -- responsible for overall data management, monitoring and communication among all sites and general oversight of the project -- and also a field site. The other participating institutions, in addition to the University of Florida, are Tufts University, Northwestern University, the University of Pittsburgh and the University of Vermont.

"This is looking at reducing inflammation in the hopes that we might be able to design a larger study that would target inflammation in order to preserve the ability of people to walk," Ambrosius said. "But the ultimate goal is to develop therapies that can preserve people's ability to walk unassisted and live independently."

Kritchevsky said the inflammation project has essentially the "same infrastructure" as a 2014 study that was the first to demonstrate that exercise can help prevent mobility loss in older adults.

In that NIH-funded trial, which included 1,635 sedentary men and women ages 70 to 89, the participants who followed a structured, moderate-intensity exercise program for an average of 2.6 years were 18 percent less likely to suffer mobility disability than those who took part in a program of health education workshops and stretching exercises.

That study also was led by Pahor and coordinated by Wake Forest Baptist. It was conducted at eight field sites: five that are involved in the current inflammation study -- Wake Forest Baptist, Florida, Tufts, Northwestern and Pittsburgh -- plus Stanford, Yale and Louisiana State universities.

Taking yet another approach to promoting mobility in seniors is Denise Houston, Ph.D., associate professor of geriatrics and gerontology at Wake Forest Baptist. Her focus is on vitamin D, which is essential to bone strength and can have positive effects on other parts of the anatomy, including muscle.

Most of the vitamin D the body needs is produced through exposure to sunlight, but it also can be obtained by consuming fatty fish such as salmon, tuna and mackerel; "fortified" products such as milk, juices and cereals; and supplements.

"Unfortunately, for a variety of reasons a lot of older adults have inadequate intakes of vitamin D," Houston said. "The current recommendations for vitamin D are based on bone health, and we're trying to see if those numbers are the same or need to be adjusted for muscle health." In a 2012 study that examined data from more than 2,000 older adults, Houston found that over a six-year period those who had low vitamin D levels were 30 percent more likely to develop mobility limitations and 90 percent more likely to develop mobility disability than those with higher levels. In a 2015 study of 68 homebound seniors with low vitamin D levels, she found that those who received a monthly vitamin D supplement with a Meals on Wheels delivery reported half as many falls as their counterparts who received a placebo.

In an NIH-supported clinical trial currently under way at Wake Forest Baptist, Houston is testing vitamin D's effects on muscle function in older adults. The study will eventually include 200 people ages 65 to 89 with low-normal vitamin D levels and some difficulty performing tasks such as getting in and out of a chair or walking up stairs. Half the participants get a year's supply of vitamin D pills to be taken once daily while the others receive placebo pills. All participants are tested for vitamin D levels, muscle qualities and physical capabilities at three intervals over a 12-month period.

"What we're trying to find out in this study is how vitamin D affects risk factors for falls such as balance and muscle strength," Houston said, "and whether increasing vitamin D levels in people at risk for mobility problems can improve their balance, muscle strength and function, leading to better mobility and a lower risk of falling."