Older women with diabetes or impaired fasting glucose tend to have worse cognitive function than those with normal blood sugar, and are at greater risk of cognitive decline over time.
Dr. Yaffe’s group analyzed data from the prospective Multiple Outcomes of Raloxifene Evaluation trial, which included 7027 postmenopausal, "relatively high-functioning community-dwelling women" (mean age 66.3 years). A total of 267 were classified as diabetic and 297 as having impaired fasting glucose.
At baseline, those with diabetes on average had the lowest age-adjusted cognitive scores, but scores of those with impaired fasting glucose were also significantly lower than the scores of women with normal glucose (p < 0.001).
Over the ensuing 4 years, diabetic women also experienced significantly greater cognitive decline, with z-scores of -1.00 compared with -0.05 for those with normal glucose levels and 0.11 with impaired fasting glucose (p = 0.001). The findings remained highly significant after adjusting for education, depression, ethnicity and body mass index.
Clinical evaluations for dementia revealed that 24 (12.1%) of diabetics and 22 (10.1%) of those with impaired fasting glucose had dementia, mild cognitive impairment or a Short Blessed Score > 6. In comparison, 273 (5.9%) of those with normal glucose levels were so impaired.
Dr. Yaffe’s group suggests that diabetic complications, such as renal disease and ischemic heart disease, neuronal damage, or cerebrovascular atherosclerotic disease could be the cause of the impaired cognitive performance.
"Interventions aimed at early diagnosis and treatment of abnormal glucose metabolism and their effects on prevention of cognitive impairment need to be undertaken," they conclude.
FACT: People with at least three signs of what’s known as metabolic syndrome are at increased risk of dying from coronary heart disease and cardiovascular disease, according to a study in the Aug. 24 issue of Circulation. Metabolic syndrome is characterized by unhealthy traits such as excessive belly fat, high cholesterol and other blood-fat disorders, insulin resistance and/or glucose intolerance, and either a high normal blood pressure or hypertension. The syndrome is usually linked to obesity, physical inactivity, and genetic factors.