Researchers have found that people diagnosed with diabetes in their 50s are significantly more likely than others to suffer mental decline by their 70s.
The study, published Monday in the Annals of Internal Medicine, started in 1990. Scientists examined 13,351 black and white adults, aged 48 to 67, for diabetes and prediabetes using self-reported physician diagnoses and glucose control tests. They also administered widely used tests of memory, reasoning, problem solving and planning.
About 13 percent had diabetes at the start. The researchers followed them with five periodic examinations over the following 20 years. By that time, 5,987 participants were still enrolled.
After adjusting for numerous health and behavioral factors, and for the large attrition in the study, the researchers found people with diabetes suffered a 30 percent larger decline in mental acuity than those without the disease.
Diabetes can impair blood circulation, and the authors suggest that the association of diabetes with thinking and memory problems may be the result of damage to small blood vessels in the brain.
People may think cognitive decline with age is inevitable, but its not, said the senior author, Elizabeth Selvin, an associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health. Factors like diabetes are potentially modifiable. If we can better control diabetes we can stave off cognitive decline and future dementia.