OCT 15, 2020 3:08 PM PDT

Gene Variants Influence Aging and Mobility in the Elderly

WRITTEN BY: Carmen Leitch

Small changes in a gene that is involved in controlling the levels of the neurotransmitter dopamine could influence how mobile elderly adults can be. A study reported in the Journal of The American Geriatric Society suggested that low levels of dopamine may be contributing to the slow, unsteady gait seen in some elderly people. Dopamine levels are also known to be low in the brain of Parkinson’s disease patients.

Image credit: Pixabay/edparanoid

"Most people think about dopamine's role in mobility in the context of Parkinson's disease, but not in normal aging," said the senior study author Caterina Rosano, M.D., M.P.H., a professor of epidemiology at the University of Pittsburgh Graduate School of Public Health. "We were curious to see if a genetic predisposition to produce more or less dopamine was related to mobility in individuals who had some level of frailty, yet did not have dementia, parkinsonism, or any other neurological condition."

Dopamine can be released by cells in several places in the brain, and several genetic elements are involved in dopamine signaling, but in this work, the researchers focused on a gene called COMT. The COMT gene makes an enzyme that breaks dopamine down, which keeps dopamine levels under control.

The study analyzed differences in the COMT gene in over 500 adults over age 65 that did not have any history or indication of Parkinson’s disease. The researchers noted how frail each participant was and their gait; frailty is commonly seen in aging individuals experiencing a decline in physical and physiological function and an increased risk of poor health outcomes. They hypothesized that frail people are more susceptible to changes in dopamine levels brought on by COMT.

"We found that in older, frail adults, those who have a high-dopamine genotype are more likely to maintain a faster gait and may be more resilient to mobility disablement as they age," said Rosano. The research showed that frail individuals with a COMT genotype linked to high dopamine levels were ten percent faster when they walked than people with a COMT genotype connected to low dopamine levels.

"This ten percent difference may seem small, but it could make a big difference for a person walking across a busy street while negotiating traffic," said Rosano. "This difference is even more striking when you consider just how many complex genes influence walking."

The scientists are continuing this research; they want to measure how much dopamine is needed to provide more resilience to seniors with a slowing gait, who are losing mobility. It may one day be possible to supplement these levels to stave off the functional decline.

"There are a lot of individuals living in the community who have dopamine levels toward the lower end of normal who don't have Parkinson's disease or psychiatric conditions," said Rosano. "If we give dopamine to these people, could we make them more resilient? That's what we don't know yet."

Rosano suggested that seniors should try to stay as active as possible in ways that they enjoy.

"I love to see grandparents walking around holding hands with their grandchildren because they have to look where they are going, where the child is going, keep an eye on the surroundings and pay attention to what the grandchild is saying, all at the same time," said Rosano. "They get an amazing multi-sensory rehab, and it's fantastic."

Sources: AAAS/Eurekalert! via University of Pittsburgh, Journal of American Geriatric Society

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
AUG 17, 2020
Genetics & Genomics
Woolly Rhinos Weren't Hunted to Extinction
AUG 17, 2020
Woolly Rhinos Weren't Hunted to Extinction
It's been hypothesized that animals like the woolly mammoth, woolly rhinoceros and cave lion began to disappear at t ...
AUG 24, 2020
Genetics & Genomics
Towards a Cure for Latent Herpes 1 Infections
AUG 24, 2020
Towards a Cure for Latent Herpes 1 Infections
Herpes simplex virus 1 (HSV-1) causes what's popularly known as cold sores, and is transmitted mostly through oral-t ...
AUG 28, 2020
Genetics & Genomics
'Jumping' Genes Can Regulate Gene Expression in Human Neurons
AUG 28, 2020
'Jumping' Genes Can Regulate Gene Expression in Human Neurons
Even though genes that code for protein have been an intense focus of biomedical research for decades, the human genome ...
SEP 06, 2020
Genetics & Genomics
Climate Change Caused a Mastodon Migration
SEP 06, 2020
Climate Change Caused a Mastodon Migration
Around 11,000 years ago, megafauna of the earth began to go extinct. Mastodons were some of the largest land animals liv ...
OCT 04, 2020
Cardiology
The Genetics of Body Fat May Shape Health Risks
OCT 04, 2020
The Genetics of Body Fat May Shape Health Risks
The work may help explain why men and women are at risk for different diseases and often respond to different treatments ...
OCT 11, 2020
Genetics & Genomics
Using Terahertz Waves to Control Gene Expression
OCT 11, 2020
Using Terahertz Waves to Control Gene Expression
Terahertz waves sit in the far infrared/microwave portion of the electromagnetic spectrum, and can be generated by power ...
Loading Comments...