The Association Between Sarcopenic Obesity And Cognitive Function In Middle-Aged And Elderly Adults

Objective: Defined as the coexistence of sarcopenia and obesity,sarcopenic obesity has become a major issue among older populations.Some studies suggest that sarcopenic obesity is associated with a higher risk of cognitive impairment and poorer cognitive performance.Few studies have evaluated the relationship between sarcopenic obesity and cognitive impairment in Chinese elderly.In addition,the lack of unified diagnostic criteria for sarcopenic obesity will affect the evaluation of adverse health outcomes.This study aims to assess the prevalence and the agreement of sarcopenic obesity under different definition as well as its relationship with Mild cognitive impairment(MCI)and cognitive function.Methods: Data were obtained from The Lifestyle and Healthy Aging of Chinese Square Dancer Study.Baseline measurements included body dimensions(height and waist circumference),body composition(measured by the H-Key350 body composition analyzer),and physical function(grip strength,walking speed,five times sit-to-stand test,and balance).Sarcopenia was diagnosed according to the 2019 criteria of the Asian Working Group for Sarcopenia(AWGS).Obesity was diagnosed by four different indicators:(1)body mass index(BMI)≥ 28 kg/m~2;(2)body fat percentage(BF%)≥ 35% for females and ≥ 25% for males;(3)visceral fat area(VFA)> 100 cm~2;(4)waist circumference(WC)> 80 cm for females and > 90 cm for males.Sarcopenic obesity is defined as the combination of sarcopenia with obesity.We combined AWGS criteria with four obesity-related variables to diagnose sarcopenic obesity(i.e.,AWGS+VFA,AWGS+WC,AWGS+BF%,and AWGS+BMI).Cognitive function was assessed using a battery of neuropsychological tests,including the Auditory Verbal Learning Test(AVLT),Verbal Fluency Test(VFT),Digit Symbol Substitution Test(DSST),and Trail Making Test-B(TMT-B),including memory,language,attention,executive four different cognitive function domains.The z-score was used to standardize the test results,and the overall z-score reflected overall cognitive function.MCI was diagnosed using the Petersen criteria.Based on the diagnostic criteria for sarcopenia and obesity,the subjects were divided into four groups: healthy,sarcopenia,obesity,and sarcopenic obesity.Multiple linear regression analysis and multivariate logistic regression were used to evaluate the association between the four groups and cognitive function test result and MCI.Results:(1)A total of 2451 middle-aged and elderly individuals aged 45 years and older were included in this study,with a mean age of 62.10±6.10 years.The detection rates of sarcopenic obesity using the AWGS+VFA,AWGS+WC,and AWGS+BF% diagnostic methods were 7.38%,7.83%,and 8.02%,respectively,and the consistency was good(Kappa >0.8).The detection rate using the AWGS+BMI diagnostic method was the lowest,at only1.17%,and the consistency with the other three methods was poor(Kappa < 0.4).(2)The multiple linear regression analyses showed that when VFA was used as the diagnostic criterion for obesity,the obesity,sarcopenia,and sarcopenic obesity groups were associated with worse overall cognitive function scores than the healthy group.Sarcopenic obesity was associated with lower AVLT,VFT,and DSST scores and longer TMT-B times.The obesity group was associated with lower DSST scores(P < 0.05).When WC was used as the diagnostic criterion for obesity,the results were consistent with those obtained using VFA.When BF% was used as the diagnostic criterion for obesity,the obesity and sarcopenic obesity groups were associated with worse overall cognitive function scores,and sarcopenic obesity was associated with lower AVLT,VFT,and DSST scores and longer TMT-B times.The obesity group was associated with lower DSST and VFT scores(P < 0.05).When BMI was used as the diagnostic criterion for obesity,the sarcopenia and sarcopenic obesity groups were associated with worse overall cognitive function scores,but sarcopenic obesity was only associated with lower DSST scores,and not with AVLT,VFT,or TMT-B scores(P <0.05).(3)The logistic regression models showed that when VFA was used as the diagnostic criterion for obesity,the obesity and sarcopenic obesity groups had a significantly higher risk of MCI than the healthy group(OR=1.35,95%CI: 1.02,1.78;OR=1.75,95%CI: 1.14,2.68).Using WC as the diagnostic criterion for obesity led to the same conclusion as using VFA.When BF% was used as the diagnostic criterion for obesity,sarcopenic obesity was associated with an increased risk of MCI(OR=1.94,95%CI: 1.29,2.93).Using BMI as the diagnostic criterion for obesity,there was no significant association between the obese or sarcopenic obesity groups and the risk of MCI,only the sarcopenia group was associated with an increased risk of MCI(OR=1.50,95%CI: 1.06,2.14).Conclusion: The diagnostic methods combining AWGS diagnostic criteria with WC,VFA,and BF% showed good consistency for the diagnosis of sarcopenic obesity in this middle-aged and elderly population.Sarcopenic obesity based on the above three diagnostic methods was associated with poor cognitive function and increased risk of MCI.