To join the resveratrol study, participants were first given a fasting glucose tolerance test to obtain a baseline level, and then retested two hours after eating. During digestion, the blood sugar level increases, but the pancreas produces insulin to lower it. A high sugar level after two hours reveals glucose intolerance (pre-diabetes) or diabetes if the level is very high.
"The number of people with glucose intolerance (pre-diabetes) was much higher than expected," says Turner. "I was surprised by how many people didn't know they were pre-diabetic, and these are individuals who already get the best medical care."
Five (4 percent) of 128 participants had impaired fasting glucose levels while three others (2 percent) had findings consistent with type 2 diabetes mellitus. Of the 125 subjects who completed the two-hour test, 38 (30 percent) demonstrated glucose intolerance while 16 (13 percent) had results consistent with diabetes. Thus, the overall prevalence of impaired glucose tolerance or diabetes at two hours was 43 percent - or almost half of the individuals recruited to the study.
Turner asks, "How does glucose intolerance or diabetes lead to AD? Does the inflammationassociated with AD trigger glucose intolerance? Or do both events create a vicious cycle of Alzheimer's and glucose intolerance?"