Data from a trial involving 7027 postmenopausalwomen showed that olderwomen with diabetes or prediabeteshave worse mental function than womenwith normal blood sugar levels and are atgreater risk for mental decline over time.The participants were "relatively high-functioningcommunity-dwelling women"with an average age of 66.3 years. Theresearchers reported their findings inNeurology (August 24, 2004). The studyinvolved 267 participants who were classifiedas diabetic and 297 as having"impaired fasting glucose," meaning thatthey had high blood glucose levels butwere not yet diabetic.
At the beginning of the 4-year study,the diabetic group had the lowest age-adjustedcognitive scores on average,but the scores of those with impairedfasting glucose also were dramaticallylower, compared with the scores ofwomen with normal glucose. As thestudy progressed, the diabetic womenshowed a significantly higher decline inmental powers than the other 2 groups,despite controlling for education, depression,and ethnicity.
The assessments showed that 24 ofthe diabetic participants (12%) and 22 ofthose with impaired fasting glucose (10%)had dementia or milder cognitive impairment.Only 6% of those with normal glucoselevels were affected in this way.