Sex Differences in the Association Between Obesity and Cognitive Impairment in a Low-Income Elderly Population in Rural China: A Population-Based Cross-Sectional Study

Abstract

Background: Obesity is a potentially modifiable risk factor for cognitive impairment. However, sex-specific relationships between obesity and cognitive impairment in late life remain unclear.Objective: We aimed to assess sex differences in the association between various obesity parameters and cognitive impairment in a low-income elderly population in rural China.Methods: A population-based cross-sectional study was conducted to collect basic information from elderly residents aged 60 years and older from April 2014 to August 2014 in rural areas of Tianjin, China. Obesity parameters, including body mass index (BMI) and waist circumference (WC), and Mini Mental State Examination scores were measured, and the relationships between these variables were assessed.Results: A total of 1,081 residents with a mean age of 67.70 years were enrolled in this study. After adjusting for age, educational attainment, smoking status, drinking status, physical exercise participation, and the presence of diabetes and hyperlipidemia, blood pressure group; a high BMI was found to be associated with an increased prevalence of cognitive impairment in elderly women. Each 1-unit increase in BMI was associated with a 5.9% increase in the prevalence of cognitive impairment. WC was related to the prevalence of cognitive impairment in elderly men, and each 1-cm increase in WC was associated with a 4.0% decrease in the prevalence of cognitive impairment. However, there were no significant associations between WC and cognitive function in women or between BMI and cognitive impairment in men.Conclusion: A greater WC was positively associated with better cognitive function in low-income elderly men in rural China, whereas a higher BMI was associated with an increased risk of cognitive impairment in elderly women, independent of sociodemographic, lifestyle, and health-related comorbid factors. Our results suggest weight management of elderly women in rural China may have cognitive benefits. However, randomized controlled trials would be needed to confirm causality.

Associations of five obesity indicators with cognitive performance in 30,697 Taiwan Biobank participants

“…This study has two significant strengths: the availability of various obesity indicators and a much larger sample size for MMSE results in a single study (30,697 individuals) compared with previous studies [8,42]. Cognitive decline can start from age 45 [43].…”

Obesity-Induced Memory Deficits in Female Rats Are Oestrous Cycle Dependent and Linked to Impaired Brain Kynurenine Pathway Metabolism

“…A large number of epidemiological studies and animal investigations indicate that obesity causes cognitive impairment [1][2][3]30]. However, whereas various studies show that obesity-induced learning deficits exhibit sexual dimorphism [9][10][11][12], other reports show no differences in learning abilities between obese male and female individuals [30,31].…”

“…Although it is clear that obese patients show impaired brain function, it remains controversial whether the cognitive alterations associated with obesity show sexual dimorphism. Therefore, while some studies report a decrease in memory capacity in obese women but not in obese men [10, 11], other reports show better cognitive performance in obese women compared to their male counterparts [12, 13]. Discordant results have also been obtained in studies in rats and mice with either a decrease in cognitive abilities only in obese male animals [14-16] or in animals of both sexes [17, 18].…”

Physical activity and mortality in patients with dementia: 2009–2015 National Health Insurance Sharing Service data

“…However, the association between late-life dementia and BMI is multifaceted, and it could be influenced by various factors, including age, sex, and timing of BMI measurement. While both low and high BMI have been associated with an increased risk of dementia, high midlife BMI has been identified as a significant risk factor for dementia later in life [9][10][11][12]. However, previous studies have extensively investigated the role of BMI as a risk factor for dementia in the general population [13,14].…”