Diabetes, obesity associated with cognitive decline in older adults
Sustained blood sugar elevations were linked to an increased risk for cognitive decline in older adults, according to results of a population-based study published in Journal of the American Geriatrics Society. Researchers also found that the hormone adiponectin was likely a risk factor for cognitive decline in older adults without abdominal obesity.
“In people aged 87 to 88 years or older, there does not seem to be anything related to diabetes or obesity that is associated with the rate of cognitive decline, so all bets seem to be off in the tenth and late ninth decades of life,” Mary Ganguli, MD, MPH, of the department of psychiatry at the University of Pittsburgh School of Medicine, told Healio Psychiatry. “Below that age, it matters whether people have abdominal obesity.”
According to the researchers, diabetes is a consistent risk factor for cognitive decline and dementia whether measured in midlife or later life. Prior research has suggested that diabetes, high BP and high BMI should be examined together to determine their contributions to adverse cognitive outcomes.
To investigate potential mechanisms related to the association of diabetes and obesity with cognitive decline, Ganguli and colleagues conducted a 10-year prospective population-based study of 478 individuals aged 65 years or older. They assayed fasting blood markers of glycemia, insulin resistance, obesity and inflammation and modeled these indices as predictors of the slope of decline in global cognition. In multivariable regression analyses of the entire sample and stratified by sex-specific median waist-hip ratio (WHR), they adjusted for sex, education, age, APOE-4 genotype, WHR, depressive symptoms and systolic BP. They then analyzed the same variable using WHR-stratified machine-learning.
The multivariable regression analyses of the entire sample revealed that HbA1c was significantly associated with cognitive decline, and it remained associated with cognitive decline in those with higher WHR after stratifying by median WHR. Metabolic indices were not associated with cognitive decline in those with lower WHR. Among individuals aged younger than 88 years with central obesity, the researchers noted that even small amounts of hyperglycemia might independently predispose to faster cognitive decline. Among those aged younger than 87 years without central obesity, they found that adiponectin may be a novel independent risk factor for cognitive decline.
“Clinicians need to pay more attention to abdominal obesity and be concerned about prediabetes in those individuals," Ganguli said. "In those who don't have abdominal obesity, we should perhaps pay more attention to unexplained weight loss. I'd like to see the adiponectin relationship be investigated further before saying adiponectin should be measured in the clinical setting.” – by Joe Gramigna
Disclosures: The authors report no relevant financial disclosures.