(HealthDay News) – Diabetes mellitus (DM) is associated with worse cognitive function and greater cognitive decline among older adults, according to a study published online June 18 in the Archives of Neurology.
To investigate the correlation between prevalent and incident DM and the risk of cognitive decline, Kristine Yaffe, MD, from the University of California in San Francisco, and colleagues conducted a prospective cohort study involving 3,069 elderly adults (mean age, 74.2 years) participating in the Health, Aging, and Body Composition Study. At baseline and selected intervals during a ten-year period, participants completed the Modified Mini-Mental State Examination (3MS) and Digit Symbol Substitution Test (DSST). Glycosylated hemoglobin was measured at baseline and years 4, 6, and 10.
The researchers found that, at baseline, 717 participants (23.4%) had DM, and an additional 159 participants developed DM during follow-up. Compared with participants without DM, those with existing DM had significantly lower baseline test scores (3MS: 88.8 vs. 90.9; DSST: 32.5 vs. 36.3). A similar pattern existed for nine-year decline. The baseline and nine-year decline scores of participants with incident DM tended to fall between the other groups but were not significantly different from the group without DM. Glycosylated hemoglobin levels were associated with significantly lower average mean cognitive scores, even after adjustment for other variables among participants with existing DM.
“This study supports the hypothesis that older adults with DM have reduced cognitive function and that poor glycemic control may contribute to this association,” the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.