Living longer with Type 2 diabetes raises dementia risk later, study finds

April 27 (UPI) -- People 70 years old and older diagnosed with Type 2 diabetes over 10 years earlier are more than twice as likely to develop dementia than those who do not have the blood-sugar disorder, a JAMA analysis found.

In addition, those age 70-plus diagnosed with Type 2 diabetes between six and 10 years earlier have s nearly 50% higher risk for dementia, the data showed.

Those diagnosed with the blood-sugar disorder five years earlier or less have an 11% higher risk for dementia, the researchers said.

The findings indicate that the longer people live with Type 2 diabetes, the greater the likelihood they will develop dementia.

"Younger age of diabetes carries risk for neurocognitive outcomes, [and] this risk is even higher when diabetes is accompanied by [heart] disease," study co-author Archana Singh-Manoux told UPI in an email.

"From a prevention perspective it is important to encourage lifestyle changes in those with diabetes to improve cardiovascular health," said Singh-Manoux, a research professor in epidemiology at the National Institute of Health and Medical Research in Paris.

More than 30 million people in the United States have Type 2 diabetes, a chronic condition that affects the way the body regulates, processes and uses sugar as a fuel, the Centers for Disease Control and Prevention estimates.

Risk for the disease increases with age, and the excess levels of sugar circulating in the bloodstream it causes can lead to complications, such as circulatory, nervous and immune system disorders, as well as heart disease, stroke and dementia, according to the agency.

About 6 million people nationwide have some form of dementia and, like Type 2 diabetes, the risk for the condition increases with age, the Alzheimer's Association says.

For this study, Singh-Manoux and her colleagues analyzed health data on more than 10,000 adults and tracked them for period an average of more than 30 years.

Among the study participants, more than 1,700 were diagnosed with Type 2 diabetes, and nearly 650 developed dementia over the course of the study, the researchers said.

Rates of dementia were 8.9 per 1,000 person-years -- or average number of years each participant spent in the study -- in participants without diabetes at age 70.

These rates rose to 10 per 1,000 person-years for participants with diabetes onset up to five years earlier, 13 for six to 10 years earlier and just over 18 for more than 10 years earlier, the researchers said.

"We show younger age of onset of diabetes to be particularly salient [and] this implies that the longer one lives with diabetes the greater the risk for dementia," Singh-Manoux said.