High Adiponectin Levels May Increase Dementia Risk in Women
Women with elevated plasma adiponectin levels may have an increased risk of developing both all-cause dementia and Alzheimer’s disease, researchers reported in the January 2 online issue of Archives of Neurology.
Thomas M. van Himbergen, PhD, a postdoctoral associate at the Lipid Metabolism Laboratory at Tufts University in Boston, and colleagues examined biomarkers for glucose homeostasis (ie, adiponectin, glucose, glycated albumin, and insulin levels) and inflammation (ie, high-sensitivity C-reactive protein and lipoprotein-associated phospholipase A2 levels) in a prospective cohort study that included 840 dementia-free participants in the Framingham Heart Study. The participants, 541 of whom were women, had a median age of 76, and the researchers measured subjects’ sera for biomarkers at the 19th biennial examination (1985 to 1988).
During the mean 13-year follow-up period for development of Alzheimer’s disease and all-cause dementia, 159 cases of dementia were identified, including 125 cases of Alzheimer’s disease. To evaluate which biomarkers may contribute to disease development, the researchers used sex-pooled and sex-specific Multivariable Cox Proportional Hazards models to control for other dementia risk factors such as age, education, APOE e4 allele status, plasma docosahexaenoic acid levels, weight change, and BMI.
Plasma insulin, glucose, and glycated albumin levels as well as the inflammatory marker lipoprotein-associated phospholipase A2 were not linked with Alzheimer’s disease or all-cause dementia. Although high-sensitivity C-reactive protein initially seemed to be associated with a lower risk of Alzheimer’s disease and dementia, adjustment for the APOE e4 allele and other factors revealed that the association was not significant. The investigators identified adiponectin as the only factor associated with a higher risk of all-cause dementia and Alzheimer’s disease in women.
Furthermore, women with baseline adiponectin levels greater than the sex-specific median showed a higher risk of all-cause dementia, compared to women with adiponectin values less than the median, even after adjustment for other risk factors.
“It is well established that insulin signaling is dysfunctional in the brains of patients with Alzheimer’s disease, and since adiponectin enhances insulin sensitivity, one would also expect beneficial actions protecting against cognitive decline,” Dr. van Himbergen’s group noted. “Our data, however, indicated that elevated adiponectin level was associated with an increased risk of dementia and Alzheimer’s disease in women.”
van Himbergen TM, Beiser AS, Ai M, et al. Biomarkers for insulin resistance and inflammation and the risk for all-cause dementia and Alzheimer disease. Arch Neurol. 2012 Jan 2; [Epub ahead of print].