The Mayo Clinic study, led by Rosebud Robert, found the rates of diabetes among 329 individuals with mild cognitive impairment and 1,640 participants without mild cognitive impairment were similar.

However cognitive impairment was associated with a greater likelihood of developing diabetes before 65 years of age. The researchers suggest complications of diabetes mellitus may play a role in cognitive impairment.

"Severe diabetes mellitus is more likely to be associated with chronic hyperglycemia or high blood glucose, which, in turn, increases the likelihood of cerebral microvascular disease and may contribute to neuronal damage, brain atrophy and cognitive impairment," the study authors said in a statement.

Individuals with the eye disease diabetic retinopathy were twice as likely to have mild cognitive impairment.

The findings are published in Archives of Neurology.