WASHINGTON, Jan. 2 (Xinhua) -- A hormone derived from visceral fat called adiponectin may play a role as a risk factor for development of all-cause dementia and Alzheimer's disease (AD) in women, according to a study published on Monday in online issue of the Archives of Neurology.

Thomas van Himbergen, from Human Nutrition Research Center on Aging at Tufts University, and colleagues measured levels of glucose, insulin, and glycated albumin, as well as C reactive protein, lipoprotein associated phospholipase A2, and adiponectin in the plasma of patients at the 19th biennial examination (1985 -- 1988) of the Framingham Heart Study.

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, 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 write. "Our data, however, indicate that elevated adiponectin level was associated with an increased risk of dementia and AD in women."