Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, February 7, 1995 TAG: 9502070075
SECTION: EXTRA PAGE: 1 EDITION: METRO
SOURCE: SANDRA JACOBS KNIGHT-RIDDER/TRIBUNE
DATELINE: LENGTH: Long
Researchers are closing in on ways to make us age more gracefully.
The results - perhaps just a few years away - won't help us live longer. But we may live better.
``People have become ambivalent about extending life,'' says Dr. Carl Eisdorfer, director of the University of Miami Center for Adult Development and Aging. ``If we can enhance the [human] organism to increase ``quality'' of life, that's what everyone is concerned about.''
At UM and at research centers around the country, millions of dollars are being directed at one of the big questions of aging: If certain chemicals decline in our bodies as we age, might replenishing them make us feel younger?
More is at stake than personal vanity and morning creaks. If scientists can help build muscle and strengthen bones, aging people may be able to stay independent and out of nursing homes longer - at great savings in personal dignity and public dollars.
There is reason for optimism, though doctors still are not certain exactly how some of the most promising agents work and what all their side effects may be.
Early this month, a San Diego doctor drew headlines with a compound known as DHEA that seemed to make aging adults just plain feel better. The 30 men and women in Dr. Samuel S.C. Yen's study reported they had less joint pain, improved sleep and a better ability to move around and cope with stress.
``Amazing, so far,'' says Dr. Bernard Roos, director of geriatric research at the Veterans Administration Medical Center in Miami. ``A low dose of DHEA had an incredibly dramatic effect on well-being.''
DHEA stands for dehydroepiandrosterone. Made in the adrenal gland, it is a component of sex hormones. It increases dramatically during puberty, then gradually declines. By age 70, you have 10 percent of the DHEA you had as a 25-year-old.
Yen set out to restore DHEA to youthful levels. After six months of a daily dose, the patients - ranging in age from 40 to 70 - taking DHEA reported a distinctly improved sense of physical and psychological well-being. Patients on placebos did not report the same improvements.
But the answer to the question you really want to know is: No, the study showed no change in libido.
Roos worked with Yen in California years ago, testing much larger doses of DHEA than were used in the recent study. The results of the new study are doubly significant, says Roos, because the smaller dose diminishes the risk of side effects.
In this study, patients on DHEA showed increased levels of a substance called insulin-like growth factor, or IGF-1, which helps to regulate cell metabolism and is believed to help keep young muscles firm. Its decline may be related to the frailty of old age.
Yen has two follow-up studies under way - one to examine the impact of DHEA on immunity, the other to measure whether DHEA strengthens muscles and bones.
``Our result is sufficiently strong to imply it will be beneficial to the aging population,'' says Yen, whose study was published in the Journal of Clinical Endocrinology and Metabolism``'' last summer.
Even more attention has been focused on another hormone that also stimulates IGF-1: Human Growth Hormone, or HGH, which triggers childhood growth.
When scientists first learned that HGH levels drop as people age, they didn't think the revelation meant much for understanding aging.
``We thought, `Who needs growth hormone after you're grown?''' says Dr. S. Mitchell Harman, an endocrinologist at the National Institute on Aging.
But researchers realized that when adults with pituitary problems were treated with hormones believed necessary for a healthy adult - sex hormones, for instance - the patients still didn't feel at their best. They had soft muscles and thin bones, and generally were weak and flabby. Something was still missing.
At the time, there wasn't much Human Growth Hormone around to test - it was available only from human cadavers. But once HGH could be made by inserting genes into cells grown in the lab, they tried that and, ``Voila,'' Harman says. ``Bones, muscles, energy, libido improved.''
That was a dramatic finding. It prompted scientists to ask themselves: If HGH helps strengthen bones and muscles and decrease fat in young adults, might its decline in old people be a cause of aging?
The first key study, published in the prestigious New England Journal of Medicine in 1990, suggested that diminished growth hormone in men over 60 was partly responsible for the decrease in muscle, increase in fat and thinning of skin that occur in old age.
While researchers kept an eye out for side effects - carpal tunnel syndrome and possibly hypertension and diabetes - the study at the Medical College of Wisconsin inspired great enthusiasm and further research.
Today, a large, ongoing federal study is under way to measure the effect of HGH on aging - alone and in combination with sex hormones.
HGH has been a popular - and controversial - drug to aid growth in children who are deficient in the hormone. As with any drug that has received FDA approval for safe dosages, doctors can legally prescribe it for purposes other than that for which it was approved.
In the United States, most doctors and researchers are wary - and then some - about using HGH for anti-aging until more research is done.
Harman describes use of HGH in clinics like the one Baxas runs as ``unconscionable.''
``We don't know risk-benefit ratios. We don't know the optimal doses. They may be doing more harm than good.''
But the government's interest in learning how to decrease mid-section fat and add muscle as we age is strong, and more than cosmetic. The big question for society is how these hormones might reduce frailty - the reason elderly people become dependent on others. An elderly person who can carry groceries and climb stairs is likely to stay independent longer. And now that we're living longer thanks to advances in fighting disease, the prospect of the whole baby boom too frail to fix a meal is a daunting one.
Think of an 80-year-old woman who trips on her stairs, suffering a broken hip from which she never really recovers. She ends up in a nursing home - unable to walk, her health and spirits in gradual decline. After five years, genes and old age conspire to give her a stroke, which quickly brings death.
But what if that broken hip could have been prevented, by giving her surer footing or sturdier bones? She still might suffer the stroke at age 85, but her five prior years could have been lived at home in relative good health.
``If we're all old and in a rest home, it is going to be expensive to support us,'' says Yen.
But even the most optimistic researchers agree that aging is too complex for one magic bullet - one single compound such as DHEA - to hold all the answers.
Among the theories of how the body ages are those that say we have a finite capacity to produce certain elements of life, similar to the way a woman's body stops producing hormones that trigger menstruation. Another theory suggests that over time, the body's own chemicals to get rid of cell waste are overwhelmed by the task, or go awry.
Any anti-aging drug, if successful, likely would address only one small piece of a complex process.
Even if current research on DHEA goes without a hitch, it will be at least another year or two before it is ready for government scrutiny, says Yen. Then FDA approval could take years.
For HGH, Harman says, the risks and benefits probably will be known within two or three years, but it could take another five to 10 years to determine the best doses.
While research on anti-aging is under way, doctors emphasize that we already know the best defense against dwindling muscles and crumbling bones: healthy foods and regular exercise. Exercise even raises DHEA levels, Roos says.
``Good diet and exercise,'' says Yen, ``is universally good for everyone.''
by CNB