Association between relative fat mass and cognitive function among US older men: NHANES 2011-2014

Relative fat mass (RFM) is a new metric developed to assess the entire body fat proportion in adults. The objective of this study was to examine the correlation between cognitive performance and RFM in older American males.

A total of 1,321 individuals were selected from the National Health and Nutrition Examination Survey (NHANES) that was carried out between the years 2011 and 2014. Specifically, the Consortium to Establish a Registry for Alzheimer's Disease Word Learning Test (CERAD-WL), the Animal Fluency Test (AFT), and the Digit Symbol Substitution Test (DSST) were used in order to achieve the objective of assessing cognitive function. The standardized scores of the three previously mentioned tests were averaged to create the Z-scores, a composite, generalized metric. RFM was ascertained by measuring waist circumference (WC) and height. The relationships that exist between RFM and cognitive performance were investigated using a variety of statistical methods, including multivariate linear regression, threshold effect analyses, smooth curve fitting, and subgroup analyses.

The study included 1,321 male volunteers aged 60 years or older, and comprehensive data was provided for each individual. Fully adjusted models indicated a negative correlation between RFM and CERAD-WL scores[-0.17, (-0.32,-0.01)], DSST scores[-0.83, (-1.16,-0.50)] and Z-scores[-0.03, (-0.05, -0.01)]. It was observed that the negative correlation that exists between RFM and Z-scores became more pronounced when RFM exceeded 35.78. Furthermore, subgroup analyses showed that the association between RFM and cognitive function was significantly impacted by education level, poverty-income ratio (PIR), smoking status, and drinking status.

A higher RFM was linked to lower cognitive function in older men, suggesting that management of RFM may prove advantageous in mitigating cognitive decline among older male populations.