Role of obesity-related anthropometric indicators on cognitive function in obese older adults: A systematic review and meta-analysis

Abstract

Objectives

The association between obesity and cognitive function in older adults remains inconsistent due to the use of various anthropometric indicators, such as body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR). More conclusive evidence is warranted. The aim of this study was to systematically summarize and synthesize the association between specific obesity-related anthropometric indicators (BMI, WC, and WHR) and cognitive function in obese older adults. Higher BMI, WC, or WHR is linked to cognitive decline in this population.

Study design

Systematic review and meta-analysis.

Methods

A comprehensive literature search was carried out using PubMed, CINAHL, Scopus, Embase, and the Cochrane Library (from their inception to October 2023). Studies investigating the association between obesity indicators, including BMI, WC, WHR, and cognitive performance in older adults were included. The weighted mean difference (WMD), Odds Ratio, and 95 % confidence interval (CI) were used to estimate the pooled effect size. A random-effects model was employed as the main method. Subgroup analyses and the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach were assessed (registered number: CRD42023461770).

Results

Thirty-three eligible studies, involving 83,251 participants, were included. Obese older adults, as assessed by WC, had lower Mini-Mental State Examination (MMSE) scores than non-obese counterparts (WMD −0.84, 95 % CI −1.64 to −0.05, very low certainty). Those measured by WHR had a 31 % higher risk of cognitive impairment (OR 1.31, 95 % CI 1.12 to 1.53, moderate certainty). Subgroup analysis revealed a lower Montreal Cognitive Assessment (MoCA) score in obese group classified by WHO criteria compared to controls (WMD -1.67, 95 % CI -2.94 to −0.39).

Conclusion

This review suggests an association between obesity, as measured by WHR and WC, and poorer cognitive performance in older adults. WHR is moderately recommended for identifying cognitive impairment-related obesity, while WC recommendations are limited by very low evidence certainty.