An analysis of the National Health and Nutrition Examination Survey data of older adults found no independent association between visceral adiposity and cognitive performance. While some correlations were initially found, these disappeared after the study authors controlled for sociodemographic factors and clinical conditions. The paper was published in Medicine.
Adiposity refers to the accumulation of body fat. It reflects the amount and distribution of fat tissue in the body. While some adiposity is normal and necessary for energy storage, insulation, and hormone regulation, excessive adiposity increases the risk of metabolic and cardiovascular diseases. Body fat is not uniform, and its health impact depends greatly on where it is located.
One specific type of adiposity is visceral adiposity. Visceral adiposity refers specifically to fat stored deep inside the abdominal cavity, surrounding organs such as the liver, pancreas, and intestines. This visceral fat is metabolically active and releases inflammatory molecules and hormones that disrupt glucose and lipid metabolism.
High visceral adiposity is strongly linked to insulin resistance, type 2 diabetes, hypertension, and heart disease, often more so than general obesity. In contrast, subcutaneous fat stored under the skin is less harmful and sometimes even protective when overall weight is stable. People may have a normal body weight yet still exhibit high visceral adiposity, a condition sometimes called “normal-weight obesity.”
Study author Long He and his colleagues note that previous studies indicated an association between excess adiposity and age-related cognitive decline in older individuals. They also note that visceral adiposity has been associated with a heightened risk of metabolic disorders. With this in mind, the authors investigated whether visceral adiposity is associated with cognitive performance in older adults.
The study authors analyzed data from the National Health and Nutrition Examination Survey (NHANES) 2011 to 2014. This is an epidemiological survey that uses a complex sampling system to obtain nationally representative data on the health and nutritional status of U.S. civilians.
To estimate visceral fat, the researchers used the Visceral Adiposity Index (VAI), a calculated score based on waist circumference, Body Mass Index (BMI), triglycerides, and HDL cholesterol. They analyzed data from 1,323 participants who were 60 years of age or older and for whom data on all cognitive assessments was available. These individuals completed the NHANES cognitive battery consisting of three tests: the CERAD Word List Learning Test, which measures immediate and delayed verbal memory; the Animal Fluency Test (AFT), which assesses semantic retrieval and executive functioning; and the Digit Symbol Substitution Test (DSST), which evaluates processing speed, attention, and working memory.
Results showed that after controlling for demographic factors and participants’ health conditions, there was no statistically significant association between participants’ VAI scores and their performance on the cognitive tests. While some of the cognitive tests showed associations with VAI scores before all demographic and clinical factors were taken into account, these associations disappeared after full adjustment.
“Age- and lifestyle-adjusted analyses showed inverse, domain‑specific links between higher VAI and cognition (most notably processing speed), but these weakened after full sociodemographic and clinical adjustment, suggesting measured sociodemographic and cardiometabolic factors largely explain the crude associations,” the study authors concluded.
The study contributes to the scientific understanding of the links between visceral adiposity and cognitive performance. However, it should be noted that visceral adiposity contributes to several of the clinical conditions the study authors controlled for (such as dyslipidemia). In doing so, the statistical models may have removed the part of the relationship between visceral adiposity and cognitive performance that acts through those factors.
The paper, “Association between visceral adiposity index and cognitive dysfunction in US participants derived from NHANES data: A cross-sectional analysis,” was authored by Long He, Cheng Xing, Xueying Yang, Shilin Wang, Boyan Tian, Jianhao Cheng, Yushan Yao, and Bowen Sui.