The obesity paradox in intracerebral hemorrhage: a systematic review and meta-analysis.

Background: Intracerebral hemorrhage (ICH) has a mortality rate which can reach 30-40%. Compared with other diseases, obesity is often associated with lower mortality; this is referred to as the 'obesity paradox'. Herein, we aimed to summarize the studies of the relations between obesity and mortality after ICH. Method: For this systematic review and meta-analysis (PROSPERO registry CRD42023426835), we conducted searches for relevant articles in both PubMed and Embase. Non-English language literature, irrelevant literature, and non-human trials were excluded. All included publications were then qualitatively described and summarized. Articles for which quantitative analyses were possible were evaluated using Cochrane's Review Manager. Results: Ten studies were included. Qualitative analysis revealed that each of the 10 studies showed varying degrees of a protective effect of obesity, which was statistically significant in 8 of them. Six studies were included in the quantitative meta-analysis, which showed that obesity was significantly associated with lower short-term (0.69 [0.67, 0.73], p<0.00001) and long-term (0.62 [0.53, 0.73], p<0.00001) mortality. (Data identified as (OR [95%CI], p)). Conclusion: Obesity is likely associated with lower post-ICH mortality, reflecting the obesity paradox in this disease. These findings support the need for large-scale trials using standardized obesity classification methods. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023426835, identifier CRD42023426835.