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.