New York, Jun 7 (IANS): People suffering from Type 1 diabetes for a very long time may have mild decreases in cognitive abilities -- primarily in memory -- as compared to those who don't have the disease, a new study suggested.

According to the researchers of the study, published in the journal Diabetes Care, the memory changes are associated with cardiovascular disease.

The study compared cognition in 82 participants aged 50 years -- who have lived successfully with Type 1 diabetes for a long period -- with other people of similar age with Type 2 diabetes or without diabetes.

Their research included standard tests for memory, psychomotor speed and executive function (higher cognitive processes involved in decision-making).

The mild cognitive declines don't appear in clinical signs for these participants, who remain in the normal range of function for people their age, said lead author Gail Musen from the Joslin Diabetes Centre in Boston.

The researchers also examined how various measures of cognitive health among these participants might correspond to common diabetes complications.

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 without the disease, the researcher said.

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, they added.

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.

Participants on average performed slightly worse than those without diabetes, the researcher said.

This diminished performance was associated with proliferative diabetic retinopathy, an advanced form of eye disease. However, it didn't reflect poorer vision, since the participants wore their corrective lenses, they added.

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