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by Dean Olsen
Copley News Service
As Donald Caspary has gotten older, he finds when he drives that he needs to adjust the volume of his car radio more often to offset the sound of the wind and the engine.
Caspary, 61, may not be losing his hearing, but his brain may have become less nimble in screening out background noise. It’s a common situation that requires him and many other drivers to reach for the volume knob on the radio for a better listening experience.
“Your brain used to do that for you very efficiently,” he said.
An internationally known neuroscientist at the Southern Illinois University School of Medicine, Caspary has worked with colleagues at SIU the past 25 years to discover the chemistry that takes place in the brain as hearing ability declines with age.
The changes that cause inconveniences for drivers such as Caspary also contribute to the devastating loss of hearing that affects 30 percent of Americans 65 to 74 and at least half of Americans 75 and older.
SIU is one of a handful of academic centers in the United States with a team of scientists examining hearing loss in ways that could lead to drug treatments for people as they age, and give them options beyond hearing aids.
“People don’t drop dead from hearing loss,” said Caspary, who holds the titles of “distinguished scholar” and professor of pharmacology at SIU. But he said hearing loss, which often causes people to withdraw socially, is a huge problem.
“It may be the second major malady after arthritic diseases in terms of raw numbers,” he said. “The only other one that comes close is hypertension.”
Caspary, a native of New York City, joined the medical school faculty in 1973 and has received more than $4.2 million in grant funding since then, mostly from the National Institutes of Health in Bethesda, Md.
He is part of SIU’s “auditory research group” - scientists who have received total grants of $14.5 million since 1978.
Caspary is among scientists in the group who focus on age-related hearing loss and have received $7.3 million in grants since 1978.
The scientists working with Caspary in their studies of aging include professors Tom Brozoski and Larry Hughes, associate professors Robert Helfert and Dr. Carol Bauer, assistant professor Jeremy Turner and senior researcher Lynne Ling.
The other part of the group focuses on chemically induced hearing loss.
Caspary and his fellow scientists analyze the brain tissue of laboratory rats, as well as rat brain cells while those cells are reacting to stimuli through probes connected to the brain; the animals are anesthetized and unconscious.
Over the years, the scientists have deciphered part of the complex pathway that sound takes as it flows from the outer ear to the middle-ear bones and then from the cochlea to nerve cells that fire off messages to various parts of the brain.
The researchers have begun to determine through the rat studies that aging alters the way brain chemicals help filter out background noise and allow proper processing of complex signals such as speech. The chemicals normally may keep that noise from becoming overwhelming.
As a person ages, however, the power of hearing-related nerve signals sent to the brain generally declines. The decrease can be related to a loss of hair cells in the cochlea.
The decrease also can occur when the bones of the middle ear - the structures that conduct sound from the eardrum to the cochlea - stop working as well as they used to. Even excessive earwax can reduce the sound signals transmitted to the brain.
Whatever the cause, Caspary’s research has shown that parts of the brain often respond to the decreased input with chemical changes that reduce the normal filtering and processing effect. The brain may be attempting to increase the volume to compensate for the loss of input.
A younger person’s brain can focus on a softer sound automatically, but an older person trying to compensate for less sound reaching the brain is less nimble at adjusting that biological filter. So a reduction in the filter in an older person makes all sounds louder, including background noise.
“And therefore, speech is not intelligible when it should be intelligible,” Caspary said. “They don’t hear a crisp signal. The signal is sloppy.”
It’s important to learn about how aging changes the way chemicals interact in the brain in regulating the filtering effect, he said. Eventually, he said, the brain’s “inhibitory system” could be treated with drugs to function like the brain of a young driver, who doesn’t need to adjust a car radio’s volume as often to hear the music clearly.
It could be 10 to 20 years before effective drug therapies are developed, but the pace of discovery doesn’t discourage Caspary.
“Science almost always moves in baby steps,” he said. “I personally accepted that a long, long time ago.”
One fertile area for potential drug treatments involves tinnitus, a medical condition that causes people to hear ringing in the ears or noise in the head when no external source is present.
Brozoski and Bauer, working in collaboration with Caspary and others at SIU, were the first scientists in the world to demonstrate in an animal model the brain changes that occur at the single-cell level as a result of tinnitus.
Other research from Caspary’s group has been used by pharmaceutical companies in developing patents for potential drugs to treat age-related hearing loss.
“The bottom line is that when we first proposed pharmacotherapy for age-related hearing loss, we were chuckling to ourselves,” Caspary said. “And five years later, we were being contacted by different drug companies.”
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Tips for a fulfilling life at any age
SENIORS ONLINE
More and more people 65 and older are going online. A federal study found that more than half of the people 60 and younger had access to the Internet and a third of those between the ages of 60 and 69 regularly used the Internet.
For people between the ages of 70 and 79, about 20 percent regularly went online. (CNS)
didn’t have the dental problem. In a study published in the Journal of the American Geriatrics Society, researchers indicated that root caries may be a marker of general physical decline in the elderly.
The study underscored the mouth as an integral part of the body.
Because arrhythmias can signify other possibly undiagnosed diseases in older people, researchers stress the importance of taking dental diseases seriously. (CNS)
SENIORS ONLINE
More and more people 65 and older are going online. A federal study found that more than half of the people 60 and younger had access to the Internet and a third of those between the ages of 60 and 69 regularly used the Internet.
For people between the ages of 70 and 79, about 20 percent regularly went online. (CNS)
JOBS WANTED
Half of Americans ages 50 to 70 want jobs that contribute to the greater good now and in retirement, according to a recent survey.
The vast majority of baby boomers told pollsters that, unlike their parents, they plan to work in retirement, they need continued income, and they want greater flexibility in retirement jobs.
The survey, conducted by the Princeton Survey Research Associates, found that two out of three types of work mentioned most often were jobs in education and social services. The third was retail. (CNS)
RETIRING FROM DRIVING
According to the National Highway Traffic Safety Administration, in 2002 there were 19.9 million licensed drivers age 70 and older in the United States. They accounted for 12 percent of traffic fatalities, 12 percent of all vehicle occupant fatalities and 16 percent of pedestrian fatalities.
Signs that a senior may have declining driving ability include:
-- Drives at inappropriate speeds.
-- Fails to yield to other cars or pedestrians who have the right of way.
-- Ignores street signs and traffic lights.
-- Becomes easily distracted.
-- Has one or more near accidents.
-- Gets lost repeatedly, even in familiar areas. (CNS)
TARGET MARKET
Senior Shopping Network is an online store specializing in products for those older than 50.
The online store offers more than 300 products, including such categories as bath and bed rails, blood pressure monitors, magnifying products, canes and other mobility aids, luggage, magnetic and aroma therapy, and security items.
The site has a font that can be adjusted to enlarge the lettering. The family owned business provides a note outlining the store’s product and service policies.
People can find the site at www.SeniorShoppingNetwork.com. (CNS)
PUBLIC HEALTH
The U.S. Centers for Disease Control in 1999 put fluoridation among the top 10 public health achievements of the 20th century, according to a medpagetoday.com story.
Most people in their 50s have had the benefit of fluoride for most of their lives. It’s a proven decay fighter. But dentists are reporting an increase in tooth decay with the rise in popularity of bottled water, according to the Internet story. It reported that in 2004 Americans drank nearly 6.8 billion gallons of bottled water, for a per capita consumption level of 23.8 gallons. That’s an 8.6 percent increase over the previous year.
People are turning away from tap water, which for more than two-thirds of Americans contains all of the fluoride they need to prevent tooth decay - and most bottled waters don’t have enough fluoride, the story reported.
At the same time the protective element of fluoride is being removed, children are eating more sugary snacks, according to the American Dental Association.
To coincide with the 70th anniversary of Social Security, AARP recently released a new survey that found public confidence in Social Security increased in recent years. It also found that Social Security has surpassed pensions and savings as the top source of income Americans expect to rely on in retirement. (CNS)
OSTEOPOROSIS QUIZ
Choose true or false for each statement:
1. Only women have to worry about osteoporosis.
2. Getting enough calcium when we’re young can lead to stronger bones as we get older.
3. You can usually tell when osteoporosis starts to develop.
Here are the answers:
1. False. Although women have a higher risk of developing osteoporosis, they are not alone. An estimated 2 million American men have osteoporosis.
2. True. It’s important to get enough calcium throughout our lives, but getting adequate amounts of calcium in our teens and 20s -- when our bone mass is actively developing -- can help us as we get older.
3. False. There are tests that can measure bone density; however most people do not know they have osteoporosis until they fall and break a bone. (CNS)
TAKE THE BUS
By 2030, the number of Americans who are age 65 or older will double to more than 70 million.
“As a larger percentage of Americans grow older and live longer, we need to work fast to find new ways to provide essential transportation choices,” said William Millar, president of the American Public Transportation Association. “Public transportation will be called upon to do more, and we will be prepared.”
However, a study last year by the Surface Transportation Policy Project, AARP and APTA found that the United States is ill-prepared to provide adequate transportation choices for a rapidly aging population of baby boomers.
The study found that more than half of all non-drivers age 65 and older stay home largely because transportation options are limited, particularly in rural and smaller communities.
More than 6,000 public transportation systems nationwide currently provide various forms of service for older riders, ranging from reduced fares and expanded use of low-floor vehicles to personalized travel training sessions for seniors and policies that allow drivers to deviate from fixed bus routes to better accommodate older riders. (CNS)
DAILY MULTIVITAMIN
A daily multivitamin is not an insurance policy against disease or a guarantee of longevity, according to a story in medpagetoday.com.
It may, in fact, do nothing for a healthy adult. A regular multivitamin may, however, offer some benefit to certain subgroups of populations, such as pregnant women and the elderly.
But a study in the Aug. 6 issue of the British Medical Journal found multivitamins failed to protect elderly patients from infection.
“The evidence for routine use of multivitamin and mineral supplements to reduce infections in elderly people is weak and conflicting,” according to British researchers. (CNS)
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