Bone density, muscle strength the focus of major hormone and exercise study

June 22nd, 2018

 

A photo of Kathy Jankowski
Kathy Jankowski, PhD, a CU College of Nursing professor, is leading the DAMES study on the impact of DHEA and exercise on bone density and muscle strength among older women.

University of Colorado researchers have launched a four-year study to see how boosting naturally declining levels of the hormone DHEA in older women might improve bone density and muscle strength. If you’re between the ages of 60 and 85, a healthy nonsmoker, and aren’t big on exercise but would like to make it a habit, you might be just the person they’re looking for.

The National Institute on Aging-funded study, called DAMES (for DHEA Augmentation of Musculoskeletal Adaptions to Exercise in Women Study,” will involve 180 women. They’ll take 50-milligram DHEA-supplement pills or a placebo once a day for nine months. Some will work out three times a week at the Exercise Research Laboratory in the Anschutz Medical Campus’s Leprino Building; some will stick to their current routines. Would-be exercisers randomly placed in the non-workout group needn’t fret: at the end of the nine months, they’ll have the option to do the same nine-month exercise program anyway.

Exercise alone is medicine, said Dr. Rebecca Boxer, a University of Colorado School of Medicine geriatrician who sees patients at the UCHealth Lone Tree Medical Center Senior’s Clinic. Boxer is co-investigator on the DAMES research team. She’ll review study candidates to help make sure they fit the mold and that the study will be safe for them. Exercise in general is particularly important for older adults, she said.

“You know the old saying, ‘If you don’t use it, you lose it?’ For older adults, we find that people who exercise have the best chance to sustain their physical function as well as cognitive function,” Boxer said.

Amp it up

The DAMES study, led by Catherine Jankowski, a CU College of Nursing professor, seeks to understand whether adding DHEA to exercise can improve bone density and muscle strength in older women with low bone density.

A woman demonstrates weight-training exercises on a weight machine in a gymnasium
Jankowski demonstrates one of the weight-training exercises many DAMES participants will do during the three-times-a-week, nine-month exercise program at the Exercise Research Laboratory in UCHealth’s Leprino Building on the Anschutz Medical Campus.

Jankowski has been interested in the potential of DHEA supplements to improve the well-being of older adults since arriving at CU in 2000. She and others including mentor Wendy Kohrt, PhD, CU’s director of research for geriatric medicine, published a 2006 study linking DHEA with improved bone density, particularly among women. The study also included a smaller follow-up, in which a few participants both in the DHEA group and the placebo group did supervised, high-intensity weight training for another six months. Jankowski and colleagues found that those taking DHEA had greater muscle size and ended up stronger than those exercising on the placebo. DHEA seemed to serve, as Boxer put it, “as an amplification of exercise.” This effect was also noted by researchers elsewhere.

It made intuitive sense, Jankowski said. The body converts DHEA produced by the adrenal gland into estrogen and testosterone and has mild anabolic properties (that is, builds bone and muscle). But without the demands of exercise, would those properties come into play to the same degree?

“If there’s no stimulus to develop more bone or more muscle, why would DHEA work?” Jankowski asked. “It seems to me there has to be a mechanical stimulus to go with it.”

Into the architecture

The DAMES study aims to prove or disprove that hypothesis. The small doses reflect the aim of lifting DHEA levels back to what they were when the women were younger. Among the criteria for participation include low bone density (technically, osteopenia), which will be established during the screening process. Among the tests along the way – they include occasional blood samples and a hair sample, among others – will be a quantitative CT (QCT) scan to determine not only bone density, but also bone architecture.

The scan itself is done in a standard CT scanner. Dana Carpenter, PhD, a University of Colorado Denver mechanical engineering professor, will then use a mechanical and structural engineering tool called finite element analysis to determine the internal structure – the tiny struts, bridges and pillars – of participants’ bones at the beginning and at the end of the six-month trial. It’s this architecture, combined with bone density that will determine what really matters: how robust and fracture-resistant the bones of aging women are. QCT has been used in studies of astronauts after spaceflight and other bone-density analysis work; this will be the first time it comes into play in DHEA research, Jankowski said.

A photo of a woman jumping.
In addition to weight training, the program includes jumping, bounding and stair climbing.

Boxer said she’s waiting for the science to show clear benefit of DHEA supplements before she recommends it to her UCHealth patients in Lone Tree.

“I still think we have a lot to learn about how women may benefit in terms of muscle and bone,” she said.

It will be the early 2020s before the results are in, but if Jankowski’s suspicions hold up under the weight of scientific rigor, they could have a big impact. DHEA could – with or without exercise, depending on the results – become a standard supplement for women who want to enhance bone density and fend off fractures as they age. Which should be about every woman.

For more information or to participate in the DAMES study contact Sarah Roberts at 720-848-6476 or email DAMES@ucdenver.edu