Weighing the Risk: A Scoping Review on the relationship between Obesity and Glioma

Abstract This review examines the relationship between obesity and glioma, as a comprehensive analysis has been lacking. A search of Cochrane, ProQuest, PubMed, and Google Scholar from 2004 to 2024 yielded 26 relevant studies out of 461. The evidence on high BMI or waist circumference as risk factors is mixed, varying by age, gender, and tumour grade. Notably, high BMI combined with high waist circumference poses a greater risk in women, with a stronger linear association observed in females. Low BMI paired with high waist circumference may increase risk more than high BMI with high WC. Lifestyle factors might influence glioma risk more than BMI alone. Early-life elevated BMI (ages 18–21) shows a stronger link to glioma, and height is also a recognised risk factor. While some studies associate higher BMI with poorer survival outcomes, others suggest overweight individuals may have a survival advantage over normal or underweight patients. Obesity’s impact on prognosis is more significant in MGMT-methylated gliomas. Overall, further research is needed to clarify these complex relationships.