The latest finding from the large, long-running Health, Aging, and Body Composition (Health ABC) Study adds to the evidence that preventing or controlling diabetes helps prevent age-related cognitive decline.
The study involves 3,069 older adults (70+), of whom 717 (23%) had diabetes at the beginning of the study in 1997. Over the course of the study, a further 159 developed diabetes. Those with diabetes at the beginning had lower cognitive scores, and showed faster decline. Those who developed diabetes showed a rate of decline that was between that faster rate and the slower rate of those who never developed diabetes.
Among those with diabetes, those who had higher levels of a blood marker called glycosylated hemoglobin had greater cognitive impairment. Higher levels of this blood marker reflect poorer control of blood sugar.
In other words, both duration and severity of diabetes are important factors in determining rate of cognitive decline in old age.