Wendy Kohrt, PhD, combines a background in exercise science with a focus on geriatrics to lead a research group dedicated to preventing disease and maintaining functional independence in old age. Dr. Kohrt is director of research in the division of geriatric medicine and the Center on Aging at the University of Colorado School of Medicine.
Her current research focus is divided into two subject areas: how bones react to exercise and where women store fat.
In the most recent studies of how to optimize the bone-building effects of exercise, young women and older women and men were evaluated on the protocol of taking ibuprofen (e.g., a non-steroidal inflammatory drug, or NSAID) before or after each exercise session during a nine-month exercise training program. Younger women benefited from taking ibuprofen after exercise (through increased bone density), but taking ibuprofen before or after exercise impaired the bone-building effect of exercise in older adults.
An under-studied factor that may influence how the skeleton responds to exercise is the loss of calcium through sweat. Serum calcium decreases during intense exercise, possibly because of dermal calcium loss, and this triggers an increase in parathyroid hormone and a mobilization of calcium from bone. Dr. Kohrt’s team has observed these responses to exercise in both competitive young athletes and in older women during vigorous exercise. The long-term goal of this research is to determine whether calcium supplementation before exercise can minimize the disruption in calcium homeostasis.
The other side of the Kohrt lab is quite different. In this area, the focus is on understanding why women seem to be protected from abdominal fat accumulation until menopause. Before menopause, women tend to accumulate excess fat in hips and thighs, which has benign, or potentially beneficial, effects on health. However, after menopause women accumulate fat in the abdominal region, where it is linked to greater risk for cardiovascular disease and diabetes.
“Our first aim is to look at whether suppressing ovarian function causes weight gain by decreasing metabolic rate,” Dr. Kohrt says. Subjects spend the night in a metabolic chamber, which measures energy expenditure over 24 hours. She speculates that “the lack of estrogen suppresses metabolic rate and if you don’t decrease how much food you eat or increase how much you exercise, you will gain weight.”
“Studying menopause is extremely challenging,” Dr. Kohrt explains. “Menopause is a process not an event.” Some metabolic changes begin three to five years before women actually become post-menopausal.
Nevertheless, a few labs nationally are conducting this research. In fact, Dr. Kohrt and Dr. Robert Schwartz, director of the Center on Aging, arrived at the university at the same time (1999), and together they built the research program. “There was zero research in the physiology of aging” at the time, Dr. Kohrt recalls. “We were given a lot of support to build our research group. Grant support has grown exponentially.” The department in 2012 has a total of $13,750,000 (direct costs) in active multi-year grants; of that, $2,615,000 (direct costs) is active in the current year.
The research at the Center on Aging fits a niche that sits in the middle of the research spectrum—clinical intervention studies that are mechanistically driven. “We take cellular research in animals and challenge that from a human perspective,” Dr. Kohrt says. “Translational research is critical to understand if what is done at the basic level applies on the human level. We are one of the few groups in the country that is doing this kind of intervention research in older adults.”
University of Colorado students benefit from the interdisciplinary efforts on the Anschutz Medical Campus, which includes the College of Nursing and schools of medicine, pharmacy, dental medicine, public health and graduate studies. The College of Nursing has recently expanded its nurse practitioner and clinical specialist programs to include a substantial gerontological component.