Higher plasma adiponectin levels may be an independent risk factor for all-cause dementia and Alzheimer’s disease in women, according to data recently published in the Archives of Neurology.
“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,” the researchers wrote. “Our data, however, indicate that elevated adiponectin level was associated with an increased risk of dementia and Alzheimer’s disease in women.”
Participants without dementia (n=840) from the Framingham Heart Study were studied for biomarkers of glucose homeostasis (adiponectin, glucose, glycated albumin and insulin) and inflammation (high-sensitivity C-reactive protein and lipoprotein-associated phospholipase A2) between 1985 and 1988 and followed prospectively for the development of all-cause dementia or Alzheimer’s disease. Median follow-up was 13 years.
The researchers adjusted for age, education, BMI, recent change in weight, apolipoprotein E E4 allele status and plasma docosahexaenoic acid levels using sex-pooled and sex-specific multivariable Cox proportional hazards models.
During follow-up, 159 people developed dementia. The adiponectin level in women was the only risk factor associated with an increased risk for all-cause dementia (HR=1.29; 95% CI, 1.00-1.66) and Alzheimer’s disease (HR=1.33; 95% CI, 1.00-1.76).
The risk for all-cause dementia and Alzheimer’s disease was higher among women with baseline adiponectin levels more than the median compared with those whose levels were less than the median at baseline (HR=1.63; 95% CI, 1.03-2.56 for dementia and HR=1.87; 95% CI, 1.13-3.10 for Alzheimer’s disease).
“One of the main features of adiponectin is that it has been shown to play a role in the sensitization of insulin and therefore may become a therapeutic target for the treatment of type 2 diabetes,” the researchers wrote. “Surprisingly, a higher adiponectin level was found to be a predictor of all-cause and vascular mortality. In concurrence with the mortality findings, the current investigation shows that an elevated adiponectin level is also an independent predictor for all-cause dementia and Alzheimer’s disease in women.”