Decades of type 1 diabetes linked to mild drop in cognition

June 5, 2018, Joslin Diabetes Center
Credit: CC0 Public Domain

People who live with type 1 diabetes for very long duration show signs of mild decreases in cognitive abilities, primarily in memory, compared to those who don't have the disease, Joslin Diabetes Center researchers have shown.

The study compared Joslin 50-year Medalists, who have lived successfully with type 1 for at least that long, with other people of similar age with type 2 diabetes or without diabetes, says Gail Musen, Ph.D., an assistant investigator in Joslin's Research Division. The work is the first to evaluate whether cognitive function is changing in an aging group of people who have successfully managed their type 1 diabetes, a very complex associated with many complications, for from 50 to more than 80 years.

The mild cognitive declines don't appear in clinical signs for these Medalists, who remain in the normal range of function for people their age, emphasizes Musen, who is lead author on the paper about the work published in Diabetes Care.

Joslin investigators also examined how various measures of cognitive health among these Medalists might correspond to common diabetes complications. Most strikingly, "the memory changes are associated with cardiovascular disease," says Hillary Keenan, Ph.D., a former principal investigator on the Medalist study and corresponding author on the paper.

The scientists tested and compared cognition in 82 Medalists, 31 age-matched individuals with type 2 diabetes and 30 age-matched non-diabetic controls. Their investigation included standard tests for memory, psychomotor speed and executive function (higher cognitive processes involved in decision-making).

The memory tests required participants to recall a list of words immediately after presentation as well as after a 30-minute delay. Performance was significantly but not dramatically lower in people with either form of diabetes than in people lacking the disease. While this has been known for people with type 2 diabetes, the changes in memory in aging people with type 1 diabetes had not been clearly established.

In the psychomotor test, the researchers looked at how quickly and well subjects inserted small key-shaped pegs into similarly shaped slots that have been rotated to require fine motor dexterity. Medalists on average performed slightly worse than those without diabetes. This diminished performance was associated with proliferative diabetic retinopathy, an advanced form of eye disease. (However, it didn't reflect poorer vision, since Medalists wore their corrective lenses.)

The executive-function test scored how quickly and accurately participants put scrambled letters and numbers into a given order. Here the Joslin team also saw a tendency of slightly worse results among Medalists than their peers without diabetes.

"Overall, nobody among the Medalists needs to worry; this is a very healthy group that's showing minimal signs of cognitive decline," Musen stresses. "However, these small deficits may be avoidable with self-care behaviors that help minimize diabetes complications."

Previous research on the Medalists has consistently found that moderate physical exercise is linked to a reduction in cardiovascular disease. The latest findings provide yet another incentive for people with type 1 diabetes to pursue physical exercise, in addition to following general guidelines for healthcare and diabetes management, says Keenan.

With the incidence of type 1 diabetes on the rise, Joslin continues to examine the long-term effects of the disease on cognition and other complications, says George King, MD, Joslin's Chief Scientific Officer and Director of Research Division. "We want to further study this population, to better understand these processes and find therapies to protect against them," he says. "Since both eye and cardiovascular diseases in diabetic patients are treatable, we are very hopeful the cognitive decline in type 1 diabetes is also preventable."

Explore further: Medalist study underlines importance of glucose control in adults with Type 1 diabetes

Related Stories

Medalist study underlines importance of glucose control in adults with Type 1 diabetes

July 27, 2017
"People are living longer with type 1 diabetes, and the onset of complications is taking longer," says Hillary Keenan, Ph.D., a Joslin Diabetes Center Assistant Investigator and co-Principal Investigator on the Joslin 50-Year ...

Eye and heart complications are tightly linked in type 1 diabetes

January 31, 2018
In people with type 1 diabetes, high levels of blood glucose eventually can harm blood vessels in the eye, kidney, heart and other organs—but the damage may be inflicted by different biological mechanisms in different organs. ...

Glycemic extremes in T1DM impact cognitive skills in kids

April 6, 2018
(HealthDay)—Type 1 diabetes is associated with cognitive dysfunction in children, according to a review published online March 23 in the Journal of Diabetes Investigation.

Study shows some may be protected from diabetic eye disease

June 11, 2012
Researchers at Joslin Diabetes Center, supported by JDRF, have completed a study of 158 people who have lived with type 1 diabetes (T1D) for 50 years or more with eye examinations at Joslin over many decades of follow-up, ...

Suggests a novel treatment approach that may protect against diabetic kidney disease

April 24, 2017
More than 660,000 people in the United States suffer from end-stage kidney disease, which can only be treated by dialysis or kidney transplantation. Almost half of these patients develop the condition as a complication of ...

Recommended for you

A novel insulin accelerant

October 17, 2018
Insulin levels rise after eating a meal, signaling uptake of circulating glucose by skeletal muscle. In individuals with diabetes this process is often impaired—a condition known as insulin resistance.

Fat tissue may play a crucial role in the progression of diabetes, challenging long established notions

October 12, 2018
A new study by Australian researchers, out today, is challenging what we know about the causes of diabetes. The new research points to fat tissue as a source of disease, and widens our understanding beyond the traditional ...

Does breastfeeding hormone protect against type 2 diabetes?

October 12, 2018
(HealthDay)—The hormone prolactin—most commonly associated with breastfeeding—may play a role in reducing the risk of type 2 diabetes, a new study suggests.

Planned intermittent fasting may help reverse type 2 diabetes, suggest doctors

October 10, 2018
Planned intermittent fasting may help to reverse type 2 diabetes, suggest doctors writing in the journal BMJ Case Reports after three patients in their care, who did this, were able to cut out the need for insulin treatment ...

Markers of dairy fat consumption linked to lower risk of type two diabetes

October 10, 2018
Higher levels of biomarkers of dairy fat consumption are associated with a lower risk of developing type 2 diabetes, according to new research published today in PLOS Medicine. The study, in more than 60,000 adults, was undertaken ...

New discovery restores insulin cell function in type 2 diabetes

October 8, 2018
By blocking a protein, VDAC1, in the insulin-producing beta cells, it is possible to restore their normal function in case of type 2 diabetes. In preclinical experiments, the researchers behind a new study have also shown ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.