Live to be 120? Possibly. Meet your greatgrandchildren? Likely. Be independent long after retirement? Almost certainly.
New vistas on aging are opening at the Health Science Center. Medical researchers are finding ways to slip the bonds of old age, and let future generations enjoy their lives as never before.
One of the most tantalizing findings involves world-renowned research into diet that holds promise for extending and improving the lives of humans. In animal experiments, scientists have successfully used a restricted diet to increase the life span of rats by 50 percent and make them highly resistant to disease.
"Is it possible to live longer than 120 years?" said Edward J. Masoro ,PhD, the Health Science Center physiologist who is a world leader in the experiments. "You can't answer yes or no. We have no recorded examples, but no one has tried to manipulate diet in humans. If we can, there's every reason to believe living more than 120 years is quite possible."
This quest for longevity and health comes at a crucial time. The United States is on the threshold of what some experts see as a potential medical crisis .
People are living longer. The average life span today is 75 years compared to 47 in 1900. The post-World War II baby boom is now a generation nearing its 50s. Sheer numbers add urgency to finding out why we age, and how to keep ourselves healthy and productive.
A record 65 million Americans will be 65 or older by the year 2030, more than twice the number of today. One out of eight Americans is over 65 today, but one out of four will be in that age group by 2030.
The statistics lead experts to predict that nursing home populations will double, the number of doctor visits will soar and health-care costs will skyrocket.
But there's reason for optimism. Medical researchers and practitioners are preparing for the changes. At the Health Science Center, nearly 100 faculty members are researching issues related to aging. Their work is supported by at least $10 million a year in grants, according to the university's Aging Research and Education Center, which coordinates research and education programs on aging at the Health Science Center.
Depending on their success, the researchers could bring profound and beneficial changes to future generations.
"We are trying to make people healthy when they are old," said Dr. Masoro's research colleague, Roger McCarter, PhD, a physiologist. "We are in a society where people are living longer and longer, but the trouble is that's exactly the age group that has the most need for medical care. We are all trying to diminish the health-care burden on the elderly, plus make their quality of life higher."
The baby boom generation, which gerontologists are calling the "New Old," presents a special challenge to tomorrow's doctors.
"This is a group of people who used good oral health, who have their teeth, who have more disposable income than any other age group, who have a high health IQ and who want to have a say in their health care. They are going to be very demanding of their doctors," said Michele Saunders, DMD, director of the South Texas Geriatric Education Center, headquartered in the Health Science Center's Dental School. The center is funded by the U.S. Public Health Service to promote geriatric education.
Robert T. Jensen, MD, a family practitioner and retired member of the university's faculty, cited a clinical anecdote to describe the high expectations of the New Old:
"A 91-year-old man goes to his physician because his right knee is killing him. The physician says to him, 'You're 91 years old. Of course your right knee is going to hurt you.' But this patient says, 'But doc, my left knee is 91, too, and it feels just fine.' "
Aging research at the Health Science Center has attracted national attention. T. Franklin Williams, MD, former director of the National Institute on Aging, the federal organization that funds aging research, headed a review panel that examined the Health Science Center's research and programs last February.
"We were very enthusiastic about the strengths in a multitude of areas," said Dr. Williams, professor emeritus of medicine at the University of Rochester in New York.
He cited the work of Dr. Masoro's team and the molecular research by Barbara Bowman, PhD, and her colleagues that examines the genetic mechanisms of aging. Dr. Williams also praised the activist roles of two organizations affiliated with the Health Science Center - the South Texas Geriatric Education Center and the Geriatric Research, Education and Clinical Center, which is headquartered at nearby Audie L. Murphy Memorial Veterans Hospital.
Dr. Williams said few institutions in the United States "have such a wide mix of parties interested in aging."
Family practice is a front line in the treatment of older Americans. David V. Espino, MD, an associate professor of family practice at the Health Science Center who is noted for his work in geriatrics, said the physician must be good at managing as well as healing.
Elderly patients often have several chronic conditions. The physician needs to select treatments with the goal of keeping the patient functioning as independently as possible.
"We need to make sure people can do their daily tasks - balance a checkbook, cook their own food, walk down the block to go shopping. When those things become impaired, that's where we have to step in. There is some social work involved in how to get that person up and running within their disability," said Dr. Espino, director of the geriatrics division in the Health Science Center's department of family practice.
"The concept is very much where pediatrics was around the turn of the century. Then there was the debate: 'Children are little adults so if you know how to take care of adults, you know how to take care of children.' As we found out, there are different diseases that strike children that we don't see in adults. The same thing is true with the elderly," he said.
Genetic researchers at the Health Science Center also are closing in on the secrets of aging, thanks in part to the work of Dr. Bowman, professor and chairman of the department of cellular and structural biology, and several faculty members in her department.
In the 1980s, geneticists worldwide needed a reliable model to test their emerging knowledge. Dr. Bowman became the first scientist to propose use of the transgenic mouse. The laboratory animal is injected with human genes and incorporates them into its own chromosomes. Researchers are able to duplicate diseases or other conditions in the mice, and then search for cures applicable to humans.
The transgenic mouse is now considered a benchmark in laboratory experiments on aging. Dr. Bowman subsequently was appointed to the National Institute on Aging's Board of Scientific Counselors in 1990.
Mice have a much shorter life span than humans, usually 28 to 32 months, so aging may be examined in quick profile. Researchers can watch genes "express," a term to describe the output and effectiveness of a gene.
"The mice just carry on as usual, and have their own genes, too, but as a valuable aside, they also are expressing the human genes," Dr. Bowman said. "If the gene overexpresses in the old age of a human, it does the same thing in a mouse."
Use of transgenic mice led Dr. Bowman to develop what she calls "designer genes." Designer genes can be constructed to mimic genes associated with tumors or diseases such as Alzheimer's.
Dr. Bowman is using the technique in her attempts to produce Alzheimer's disease in laboratory mice. The animal genes respond by expressing the protein amyloid beta, which is found in the brain of Alzheimer's sufferers. Dr. Bowman hopes the work might yield drug therapies to reduce the protein.
Bandana Chatterjee, PhD, associate director in a National Institutes of Health program project grant that supports the research, said:
"Once we understand the molecular workings of a particular gene's function and what consequences the body then faces, we can tie the pieces of information together to build a strategy to prevent debilitating effects on the body."
Research on aging at the Health Science Center derives much of its vitality from the Geriatric Research, Education and Clinical Center (GRECC) for South Texas. It is headquartered at the Audie L. Murphy Memorial Veterans Hospital. Several faculty members studying aging hold dual appointments and work under the auspices of the U.S. Department of Veterans Affairs.
The GRECC is one of 16 centers nationwide funded by the VA. It opened in1989 with the goal of running research and clinical programs on aging, and translating the research into educational and clinical uses to help the aging population.
Providing health care to the aged involves battling disabilities ranging from chronic arthritis to devastating cases of Alzheimer's disease.
At the VA hospital, GRECC staff member Michael J. Lichtenstein, MD, a Health Science Center associate professor of medicine, is 18 months into a five-year study designed to identify diseases and impairments that lead to disabilities and handicaps.
The study is called SALSA, or San Antonio Longitudinal Study of Aging, and involves city residents age 65 or older. Researchers hope to track the subjects into their 80s. The work is supported by a $1 million grant from the National Institute on Aging.
A registered nurse visits participants at home and gives them a blood test for diabetes, said Helen Hazuda, PhD, SALSA study director. They also receive a free physical examination, and a free eye exam if they have diabetes.
Dr. Lichtenstein and co-investigator Dr. David Espino, the family practitioner, hope to spot indications of future disabilities through a series of additional tests. The doctors time the subjects as they look up a number in the telephone book, put on a shirt, tie their shoelaces or open a padlocked cabinet door. They also measure the subjects' ability to stretch their arms and stand without wobbling or shaking. They have examined 300 people, and plan to add 540 more to the study.
"If we can see how different impairments lead to different disabilities," Dr. Lichtenstein said, "it may show us what can be done to help maintain a person's function and prevent a disability."
SALSA participants have an additional role in an oral health study begun in September with a five-year, $3.7 million grant from the National Institutes of Health. Directed by Dr. Michele Saunders, the study will track the relationship between oral and general health, and how disease and medical treatments affect oral health among the elderly. The work also is designed to provide a comprehensive study of oral health in Hispanic senior citizens.
A laboratory accident about a decade ago gave Health Science Center researcher Arlan Richardson, PhD, an important clue about aging.
A power outage knocked out the air conditioning in his laboratory while he was a chemistry professor at Illinois State University in the early 1980s. Dr. Richardson was working with diet-restricted rats along the line of Dr. Masoro's experiments in Texas.
The outage lasted about four hours, and his laboratory rats began to die in the heat. By the end of the day, 75 percent of the rats that ate freely had died, but only 25 percent of the diet-restricted rats had died.
"When we get old, for some reason, there is a defect in the old cells so we can't transcribe, or 'turn on,' production of what we call the heat- shock gene. This gene that normally would protect the cell from stress is not turned on, but it is turned on in rats that are diet restricted" he said.
Dr. Richardson joined the Health Science Center faculty and GRECC staff in 1990, and has pursued the mystery of failing heat-shock genes. In June, he received the prestigious Nathan W. Shock Lecture award for accomplishment in aging research.
His work holds promise for reducing the incidence of disease and finding out why older people cannot tolerate extreme heat and other environmental stress such as loss of oxygen, which often accompanies a stroke.
Dr. Richardson is midway in a four-year, $918,000 federal grant to study the heat-shock gene.
Michael S. Katz, MD, director of the GRECC, is pursuing related research. Trained in endocrinology, Dr. Katz is looking into aging for clues about diabetes.
"There are age changes in the control of glucose output in the livers of rats that may ultimately have bearing on the development of diabetes," Dr. Katz said.
Aside from being a researcher, Dr. Katz serves in several leadership roles in the field of aging. They underscore close ties between the VA hospital and the Health Science Center. At the VA, he is associate chief of staff for extended care. At the Health Science Center, Dr. Katz is a professor of medicine and chief of the division of geriatrics and gerontology in the department of medicine.
"It's very interesting that this university has a particularly rich concentration of people who are interested in aging. What also is rare is the cooperation with the VA. The doors are pretty invisible," said Meghan Gerety, MD, of the GRECC and associate professor of medicine at the Health Science Center.
Dr. Katz said the university's growing reputation for excellence in aging studies is attracting talented researchers from other prestigious institutions. He cited the recent arrivals of Robert Gregerman, MD, from Johns Hopkins Medical School in Baltimore, who is now associate director of research at the GRECC and professor of medicine; and Randy Strong, PhD, from the University of St. Louis, who has joined the GRECC and now is an associate professor in the department of cellular and structural biology.
Dr. Gregerman's research interests include abnormalities of thyroid hormones commonly seen in acutely and chronically ill elderly patients. Dr. Strong is noted for studies of cardiovascular function on a molecular level during aging.
Dealing with the immediate health care problems of the elderly also is part of the university's mission.
One innovation is the Geriatric Day Hospital that opened earlier this year under the direction of Donald Royall, MD, assistant professor of psychiatry and GRECC research staffer. The hospital, housed in the nearby Southwest Neuropsychiatric Institute, is designed for the elderly afflicted with memory or behavioral disorders.
Patients are referred to the hospital and stay during the day, but return home at night. "A day hospital keeps the family of a patient involved rather than excluded. They become part of the patient's treatment," Dr. Royall said.
In addition to offering short-term treatment, the Geriatric Day Hospital is used as a site for clinical teaching and research as part of the Health Science Center's geriatric psychiatry program.
In related work, a School of Nursing educator is researching ways to better understand and work with patients who have Alzheimer's disease.
Mary Ann Matteson, PhD, author of a highly regarded textbook on gerontological nursing, is heading a three-year study funded by the National Center for Nursing Research and the National Institute on Aging. Dr. Matteson and her colleagues are trying to correlate the cognitive levels of Alzheimer's patients to Piaget's developmental levels, which describe cognitive functions as a person matures.
"We think people with Alzheimer's disease go backwards developmentally. As people get sicker and go further into the disease, they may act like children or toddlers. Toward the end of the disease, they may become incontinent and unable to feed themselves," Dr. Matteson said.
She said her hypothesis may be difficult for nursing professionals to accept. "In gerontology, we are taught to treat our elders with respect. Now we are saying: 'You should treat them like infants and toddlers,' and some people say we are trying to take away the patient's dignity, but we're not. When we better understand how to treat them, we add to their dignity," she said.
Dr. Matteson and her colleagues are applying their theory to 71 patients in a special Alzheimer's unit at the Veterans Affairs Hospital in Kerrville, 50 miles northwest of San Antonio.
Several patients refuse to get dressed in the morning, much the way children do, Dr. Matteson said. Her colleagues use a strategy many mothers use. "If they won't put their shirt on, we help them put one sleeve on at a time, and then coax them to put the other on," she said.
Dr. Matteson said the patients become frustrated because they cannot do simple tasks. "We expect them to act like adults, but behaviorally they are only toddlers," she said.
Even if science unlocks the secret of aging, researchers say the accomplishment would be nearly worthless without learning ways to make people enjoy their extra years.
"We don't want to extend life without knowing why we are extending it," Dr. Katz said. "It reminds me of the book and movie 'Jurassic Park.' People have cloned the dinosaur, but in the ensuing chaos the theoretician asks, 'Well, you never stopped to ask why you were doing it.' "
Aging research is designed to keep older people healthy until they die. In clinical terms, this is called "compression of morbidity." It means postponing serious illness and prolonging productivity.
"I would love to live to be 200," said Dr. Chatterjee, the geneticist, "but what's the point if I am not a productive member of society?"
Researchers wistfully describe a future where more people can pursue a hobby or second career into their 80s. They talk about eliminating the agony of painful, slow deaths that wrack the elderly and compound the grief of loved ones. They talk about senior citizens living to see their greatgrandchildren grow up.
But they also see a mission of reducing America's health-care burden, and reducing the number of people who must be placed in nursing homes. Currently 1.5 million people are in nursing homes. "The looming prospect of having 4 million to 5 million people in nursing homes in the future is just staggering," Dr. Gerety said.
"Unless we figure out a way either to deal with people differently - in non-institutional ways - or reduce the morbidity that people experience in their later years, we're going to be facing an enormous bill for caring for people in long-term settings," she said.
With nearly 20 years of study completed, the Health Science Center is a nationally acknowledged leader in the quest to understand aging. The university has made the subject of aging a top priority and supports a team of researchers who are determined to meet the needs of a greying America.