Objective. Obesity is one of the modifiable risk factors for dementia. Insulin resistance, the abundance of advanced glycated end-products, and inflammation are some of the mechanisms associated with the lower cognitive performance observed in obesity. This study aims to evaluate the cognitive function of subjects with distinct degrees of obesity, comparing class I and II obesity (OBI/II) to class III obesity (OBIII), and to investigate metabolic markers that can distinguish OBIII from OBI/II. Study Design. This is a cross-sectional study, in which 45 females with BMI varying from 32.8 to 51.9 kg/m² completed a set of 4 cognitive tests (verbal paired-associate test, stroop color, digit span, and Toulouse–Pieron cancellation test) and their plasma metabolites, enzymes, and hormones related to glycemia, dyslipidemia, and liver function, as well as the biomarkers of iron status, were concomitantly analyzed. Results. OBIII showed lower scores in the verbal paired-associate test compared to OBI/II. In other cognitive tests, both groups showed similar performance. OBIII presented a lower iron status compared to OBI/II based on total iron binding capacity, degree of transferrin saturation, hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin. The levels of indicators for glycemia, liver function, and lipid metabolism were similar in both groups. Analysis of plasma metabolites showed that OBIII had lower levels of pyroglutamic acid, myoinositol, and aspartic acid and higher levels of D-ribose than OBI/II. Conclusion. Iron is an essential micronutrient for several metabolic pathways. Thus, iron dyshomeostasis observed in severe obesity may aggravate the cognitive impairment by altering metabolic homeostasis and enhancing oxidative stress. These findings can contribute to searching for biomarkers that indicate cognitive performance in the population with obesity.

中文翻译：

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与低度肥胖相比，女性重度肥胖可导致更差的记忆功能和铁失衡

目标。肥胖是痴呆症的可改变风险因素之一。胰岛素抵抗、大量晚期糖化终产物和炎症是与肥胖症中观察到的较低认知能力相关的一些机制。本研究旨在评估不同程度肥胖受试者的认知功能，将 I 级和 II 级肥胖 (OBI/II) 与 III 级肥胖 (OBIII) 进行比较，并研究可以区分 OBIII 和 OBI/II 的代谢标志物。学习规划。这是一项横断面研究，其中 45 名 BMI 介于 32.8 和 51.9 kg/m ^{2之间的女性}完成了一组 4 项认知测试（口头配对测试、stroop 颜色、数字跨度和 Toulouse-Pieron 取消测试）及其与血糖、血脂异常和肝功能相关的血浆代谢物、酶和激素，以及同时分析了铁状态的生物标志物。结果. 与 OBI/II 相比，OBIII 在口头配对关联测试中的得分较低。在其他认知测试中，两组都表现出相似的表现。根据总铁结合力、转铁蛋白饱和度、血红蛋白、平均红细胞体积和平均红细胞血红蛋白，OBIII 与 OBI/II 相比呈现出较低的铁状态。两组的血糖、肝功能和脂质代谢指标水平相似。血浆代谢物分析表明，与 OBI/II 相比，OBIII 的焦谷氨酸、肌醇和天冬氨酸水平较低，D-核糖水平较高。结论. 铁是多种代谢途径必不可少的微量营养素。因此，在严重肥胖中观察到的铁稳态失调可能会通过改变代谢稳态和增强氧化应激来加重认知障碍。这些发现有助于寻找指示肥胖人群认知能力的生物标志物。