PITTSBURGH —What precisely is the relationship between cognitive decline in patients with both diabetes and obesity?

Researchers from the VA Pittsburgh Healthcare System and the University of Pittsburgh sought to investigate the potential mechanisms leading to those results. To do that, they conducted a population-based study of older adults, with results published in the Journal of the American Geriatrics Society.1

The 10-year population-based cohort study involved 478 adults, 65 and older, and researchers tested participants’ fasting blood for markers of glycemia (glucose and hemoglobin A1c [HbA1c]), insulin resistance (IR) (insulin and homeostatic model assessment of IR), obesity (resistin, adiponectin, and glucagon-like peptide-1), and inflammation (C-reactive protein).

Those indicators were used as predictors of the slope of decline in global cognition, adjusting for age, sex, education, APOE*4 genotype, depressive symptoms, waist-hip ratio (WHR) and systolic blood pressure.

After multivariable regression analyses, in the entire sample, the study determined that HbA1c was significantly associated with cognitive decline. After stratifying by median WHR, HbA1c remained associated with cognitive decline in those with higher WHR, although no metabolic indices were associated with cognitive decline in those with lower WHR. Cross-validated WHR-stratified CART analyses selected no predictors in participants older than 87 to 88 years old, however.

The study determined that faster cognitive decline was associated, in lower WHR participants younger than 87 years, with adiponectin of 11 or greater; and in higher WHR participants younger than 88 years, with HbA1c of 6.2% or greater.

“Our population-based data suggest that, in individuals younger than 88 years with central obesity, even modest degrees of hyperglycemia might independently predispose to faster cognitive decline,” the authors conclude. “In contrast, among those younger than 87 years without central obesity, adiponectin may be a novel independent risk factor for cognitive decline.”

  1. Ganguli M, Beer JC, Zmuda JM, et al. Aging, Diabetes, Obesity, and Cognitive Decline: A Population-Based Study [published online ahead of print, 2020 Feb 4]. J Am Geriatr Soc. 2020;10.1111/jgs.16321. doi:10.1111/jgs.16321