Researchers led by the University of California San Diego School of Medicine have reported that obesity alone is not associated with cognitive decline among Latinos, after they examined data from more than 6,000 participants enrolled in the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA). Participants were ethnically diverse, including Central Americans, Cubans, Dominicans, Mexicans, Puerto Ricans and South Americans, residing in one of four US cities: San Diego, New York City, Miami and Chicago.
For SOL-INCA, participants completed a range of cognitive exams at two time points, seven years apart on average. Additionally, they underwent clinical testing to assess obesity and cardiometabolic abnormality, defined as having two or more of the following conditions: hypertension, hyperglycaemia, high triglycerides and low "good" cholesterol (high-density lipoprotein).
After accounting for factors such as age, gender, education and depressive symptoms, the researchers found that obesity alone did not predict how well someone performed on cognitive testing seven years later nor the extent of cognitive decline across that time period.
Instead, said first author, Dr Ariana M Stickel, a postdoctoral scholar in the Department of Neurosciences at UC San Diego School of Medicine, cardiometabolic abnormality was more strongly associated with cognitive function and decline. Individuals with obesity and cardiometabolic abnormality had much lower performance results on testing and greater cognitive decline than obese peers who did not present with cardiometabolic abnormality.
"These data clearly suggest that individuals with obesity take a big hit to their cognition when other risk factors, such as diabetes and high cholesterol, are present," said Stickel. "Obesity/fat stigma tends to put a hyper-focus on a number on the scale, sometimes at the expense of other health goals. If maintaining a specific weight is difficult, preventing or managing cardiometabolic abnormalities is just as important, if not more important from a cognitive health standpoint."
Stickel said developing new strategies for improving cardiometabolic health are essential, regardless of whether someone has obesity. The findings, ‘Central Obesity, Cardiometabolic Risk, and Cognitive Change in the Study of Latinos: Investigation of Neurocognitive Aging’, were published in the Journal of Alzheimer's Disease.
Moving forward, the authors want to investigate the relationships between obesity, cardiometabolic risk and cognition in a more dynamic way.
"Weight can fluctuate in later life, and we sometimes see sharp declines in weight in Alzheimer's disease. However, this pattern has yet to be well-characterized in a diverse Latino cohort," said senior author, Dr Hector M González, professor in the Department of Neurosciences at UC San Diego School of Medicine.
In the published study, González and colleagues looked at individuals 50 to 86 years of age, but they were unable to assess age-of-onset or duration of obesity and/or cardiometabolic abnormality.
"Unfortunately, obesity and subsequent cardiometabolic abnormalities are seen at younger ages, and Latinos have the highest rates of childhood obesity in the United States. It is unclear if and how this impacts cognition, job performance and the workforce as a whole," added González. "Health care workers and researchers need to invest more time into developing culturally appropriate interventions to tackle obesity and cardiometabolic abnormalities among Latinos of all ages."