A hormone found in body fat may contribute towards increased risk of dementia and Alzheimer's disease (AD) in women, a new study has suggested. AD is the most common form of dementia. According to the authors, the data suggest an association between insulin resistance and inflammation, hallmarks for type 2 diabetes, and development of dementia.
"An additional potential factor that may contribute to the onset of AD and all-cause dementia is adiponectin," the authors said. "Adiponectin is a hormone derived from visceral fat, which sensitizes the body to insulin, has anti-inflammatory properties, and plays a role in the metabolism of glucose and lipids."
The 840 patients (541 women, median age of 76 years) were followed-up for an average of 13 years and evaluated for signs of the development of AD and all-cause dementia.
During that time, 159 patients developed dementia, including 125 cases of AD. After adjustment for other dementia risk factors (age, apoE genotype, low plasma docosahexaenoic acid, weight change) only adiponectin in women was associated with an increased risk of all-cause dementia and AD.
"It is well established that insulin signaling is dysfunctional in the brains of patients with AD, and since adiponectin enhances insulin sensitivity, one would also expect beneficial actions protecting against cognitive decline," the authors wrote.
"Our data, however, indicate that elevated adiponectin level was associated with an increased risk of dementia and AD in women."
The authors including Thomas M. van Himbergen, Ph.D., from the Lipid Metabolism Laboratory, Human Nutrition Research Center on Aging, Tufts University, Boston, and colleagues said that 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 T2D (type 2 diabetes). "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 AD in women," the authors added. The study has been published Online First by the Archives of Neurology, one of the JAMA/Archives journals.