Increased adiposity negatively affects cognitive function of adults: JAMA

Canada: A team of researchers led by Sonia S. Anand conducted a new study that found that after controlling for cardiovascular risk factors and vascular brain damage, obesity was linked to worse cognitive scores. The findings of this study, published in the Journal of American Medical Association, suggest that strategies to prevent or reduce adiposity may preserve cognitive function.

Other cardiovascular risk factors are increased by excess adipose tissue, which may be linked to vascular brain damage and cognitive impairment. The extent to which the volume and distribution of adipose tissue, independent of its relationship with cardiovascular risk factors, may be related with worse cognitive scores is not well understood. As a result, the purpose of this study was to look into the impact of obesity on vascular brain damage and cognitive scores.

This cross-sectional study included 9189 participants from the Canadian Alliance for Healthy Hearts and Minds (CAHHM) and Prospective Urban Rural Epidemiological–Mind (PURE-MIND) cohort studies. 9166 of the individuals had bioelectrical impedance analysis to determine their body fat (BF) percentage, and 6773 had magnetic resonance imaging to determine vascular brain damage and determine the amount of visceral adipose tissue (VAT). CAHHM participants were enrolled between January 1, 2014, and December 31, 2018, whereas PURE-MIND participants were enrolled between January 1, 2010, and December 31, 2018. CAHHM and PURE-MIND are both population-based cohorts with many sites. CAHHM participants are Canadians, whereas PURE-MIND participants are either Canadians or Poles. The data was analysed between May 3 and November 24, 2021. The Digital Symbol Substitution Test and the Montreal Cognitive Assessment were used to test cognitive function. A DSST score of less than 1 SD below the mean was considered reduced cognition. The INTERHEART Risk Score was used to determine cardiovascular risk.

The key findings of this study are as follow:

1. A total of 9189 people took part in the research. Body adiposity as defined by BF % was substantially linked with visceral adipose tissue.

2. With the fourth quartile IHRS at 13.8 and VAT at 13.3, cardiovascular risk factors increased with rising BF % and with VAT. Increases in BF percentage (fourth quartile value: 8.6%) and VAT (fourth quartile value: 7.2%) were associated with an increase in vascular brain damage.

3. With rising BF %, cognitive scores were lower, with a fourth quartile score of 70.9 for BF and a fourth quartile score of 72.8 for VAT. The DSST score decreased by 0.8 points for every 1-SD rise in BF percentage (9.2%) or VAT (0.8 points for BF percentage and 0.8 points for VAT).

4. The population attributable risk for a lower DSST score was 20.5 percent for a greater BF percentage and 19.6 percent for VAT. The Montreal Cognitive Assessment scores were not linked to a higher BF % or VAT.

In conclusion, excess adiposity was revealed to be a risk factor for worse cognitive scores in this cross-sectional investigation, which was independent of cardiovascular risk factors, educational level, and MRI-detected vascular brain damage. Adults' cognitive function may be preserved by strategies to prevent or minimize obesity.

Reference:

Anand SS, Friedrich MG, Lee DS, et al. Evaluation of Adiposity and Cognitive Function in Adults. JAMA Netw Open. 2022;5(2):e2146324. doi:10.1001/jamanetworkopen.2021.46324