Supplementary Material for: Coexisting Obesity and Malnutrition and its Impact on Stroke and Brain structure: Insights from UK Biobank study

Background: The dual burden of malnutrition, characterized by the coexistence of malnutrition and obesity, represents a growing concern in global health. This study examines the association of combined effects of obesity and malnutrition with the risk of stroke and brain structure.
Methods: Data from the UK Biobank, a large-scale population-based cohort study, were analyzed. Patients were stratified into nourished nonobese, malnourished nonobese, nourished obese, and malnourished obese. Malnutrition risk using objective scores, including the controlling nutritional status score (CONUT), nutritional risk index (NRI), and prognostic nutritional index (PNI). Obesity was defined as BMI ≥30. Cox proportional hazard models were used to assess the association between combined obesity and nutritional status and incident stroke. Kaplan-Meier curves for incident stroke were constructed. Linear regression models were used to evaluate the associations between combined obesity and nutritional status and brain structure.
Results: A total of 409,694 participants were included in the analysis. Among them, 37930 participants had imaging data. Kaplan-Meier curves illustrated a higher incidence of stroke in the malnourished obese group. Malnourished obese was found to increase the risk of stroke (HRCONUT 1.27, 95%CI [1.09 - 1.48]; HRNRI 2.61, 95%CI [2.03 - 3.36]; HRPNI 7.9, 95%CI [1.11 - 56.07]) , ischemic stroke (HRCONUT 1.29, 95%CI [1.08 - 1.54]; HRNRI 2.8, 95%CI [2.09 - 3.76]; HRPNI 8.43, 95%CI [1.19 - 59.83]) and hemorrhagic stroke (HRNRI 2.53, 95%CI [1.57 - 4.09]). Brain imaging analysis revealed associations between malnourished obese and certain structural parameters. Cerebral white matter hyperintensities may be associated with the occurrence of stroke.
Conclusion: Malnourished obese is associated with the risk of stroke and brain structure parameters. Further research is needed to better understand the underlying mechanisms and develop targeted interventions for individuals with combined effects of obesity and malnutrition.

背景：以营养不良与肥胖共存为特征的营养不良双重负担，已成为全球健康领域日益关注的问题。本研究旨在探讨肥胖与营养不良的联合效应与中风风险及脑结构之间的关联。
方法：本研究分析了英国生物银行（UK Biobank）——一项大规模人群队列研究——的数据。研究对象被分为营养良好非肥胖组、营养不良非肥胖组、营养良好肥胖组及营养不良肥胖组。营养不良风险采用客观评分评估，包括控制营养状况评分（controlling nutritional status score，CONUT）、营养风险指数（nutritional risk index，NRI）及预后营养指数（prognostic nutritional index，PNI）。肥胖定义为BMI≥30。采用Cox比例风险模型评估肥胖与营养状况联合状态与新发中风之间的关联，并绘制新发中风的Kaplan-Meier曲线。采用线性回归模型评估肥胖与营养状况联合状态与脑结构之间的关联。
结果：共纳入409,694名参与者进行分析，其中37,930名参与者具有影像学数据。Kaplan-Meier曲线显示，营养不良肥胖组的中风发生率更高。研究发现，营养不良肥胖状态会增加中风风险（CONUT评分对应的风险比HR为1.27，95%置信区间CI为[1.09-1.48]；NRI对应的HR为2.61，95%CI为[2.03-3.36]；PNI对应的HR为7.9，95%CI为[1.11-56.07]）、缺血性中风风险（CONUT对应的HR为1.29，95%CI为[1.08-1.54]；NRI对应的HR为2.8，95%CI为[2.09-3.76]；PNI对应的HR为8.43，95%CI为[1.19-59.83]）及出血性中风风险（NRI对应的HR为2.53，95%CI为[1.57-4.09]）。脑影像学分析显示，营养不良肥胖状态与某些脑结构参数存在关联；脑白质高信号可能与中风的发生相关。
结论：营养不良肥胖状态与中风风险及脑结构参数相关。未来需开展进一步研究，以深入理解其潜在机制，并为受肥胖与营养不良联合效应影响的个体制定针对性干预措施。