Abstract
BACKGROUND: The relationship between childhood obesity and cardiovascular and cerebrovascular diseases (CCVD) remains ambiguous. This study aims to explore the causal relationship between childhood obesity and CCVD utilizing the two-sample Mendelian randomization (MR) method. Furthermore, the study investigates the prognostic implications of obesity on CCVD, utilizing insights derived from the Global Burden of Disease (GBD) study 2021. METHODS: This study utilized pooled data on childhood obesity from the genome-wide association study (GWAS) available in the IEU Open GWAS database, alongside data on 20 types of CCVD from the GWAS in the 2024 Finngen database for analysis. The inverse variance weighted (IVW) method was served as the primary analysis method, while MR-Egger regression, weighted median, simple mode and weighted mode were employed as supplementary analyses to explore the causal relationship between childhood obesity and CCVD in adulthood. Cochran’s Q test, MR-Egger intercept test, and leave-one-out test were performed to access the robustness of the results. Simultaneously, summary data on childhood obesity from GWAS in the EGG database were utilized to replicate the analysis to verify the robustness of the results. Additionally, the latest data from the 2021 GBD study were employed to analyze the prognostic correlation between obesity and CCVD. RESULTS: IVW analysis finds positive causal relationship between childhood obesity and risk of coronary atherosclerosis, cardiovascular diseases, hard cardiovascular diseases, ischemic heart disease, angina pectoris, unstable angina pectoris, myocardial infarction, heart failure, major coronary heart disease event, cardiac arrhythmias, atrial fibrillation and flutter, coronary revascularization (ANGIO or CABG), coronary angioplasty, coronary artery bypass grafting, stroke, and embolic stroke (all P < 0.05). These causal relationships remained significant after correcting for the false discovery rate (all P < 0.05). Steiger directional test confirmed that the direction of the effect of childhood obesity on CCVD was correct (all P < 0.001). No causal relationship was identified between childhood obesity and cardiac arrest, stroke (excluding SAH), subarachnoid haemorrhage, and intracerebral haemorrhage (all P>0.05). MR-Egger intercept test and leave-one-out test suggested that the research results are robust. The replication analysis corroborated the consistent findings, thereby further confirming the robustness of the results. The findings of GBD study showed that obesity was an important risk factor for deaths and DALYs in patients with CCVD. CONCLUSION: This study revealed the positive causal relationship between childhood obesity and various CCVD. Obesity was identified as a risk factor for contributing to adverse prognostic outcomes in CCVD patients. This highlights the need for clinicians to prioritize evidence-based strategies in the management of childhood obesity to prevent the onset and adverse progression of CCVD in adulthood. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-025-25315-2.