(HealthDay News) – There seems to be no significant correlation between glucose intolerance and insulin resistance with brain β-amyloid burden or Alzheimer’s disease (AD) pathology, according to a study published online July 29 in JAMA Neurology.

Madhav Thambisetty, MD, PhD, from the National Institute on Aging in Baltimore, and colleagues conducted a prospective study among a cohort of community-dwelling subjects to examine the correlation between serial measures of glucose intolerance and insulin resistance and in vivo brain β-amyloid burden, assessed with carbon 11 labeled Pittsburgh Compound B (11C-PiB) and AD pathology at autopsy. Participants included 197 subjects from the Baltimore Longitudinal Study of Aging who had two or more oral glucose tolerance tests (OGTTs) during life and a complete brain autopsy after death, and 53 living subjects with two or more OGTTs who underwent 11C-PiB positron emission tomography.

During a mean follow-up of 22.1 years, the researchers found no significant correlations between measures of brain AD pathology or 11C-PiB β-amyloid load with glucose tolerance or insulin resistance (mean of 6.4 OGTTs). AD pathology scores were similar for the 30 subjects with diabetes mellitus who received medications.

“In this prospective cohort with multiple assessments of glucose intolerance and insulin resistance, measures of glucose and insulin homeostasis are not associated with AD pathology and likely play little role in AD pathogenesis,” the authors write.

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