Meta-Analysis of the Association Between Body Mass Index and All-cause Mortality in Patients with Cardiogenic Shock

Background: the correlation between BMI and in-hospital mortality of patients with cardiogenic shock is still controversial. We hope to explore whether there is an "obesity paradox" in patients with cardiogenic shock through meta-analysis. Methods: PubMed, EMbase and Cochrane databases were searched by computer to include clinical studies related to BMI all-cause mortality of patients with cardiogenic shock. The search time was from the establishment of the database to July 2020. After screening documents, extracting data and evaluating quality according to the inclusion and exclusion criteria, two evaluators used RevMan5.3 statistical software provided by Cochrane Collaboration Network for Meta-analysis. Results: There was no significant difference in all-cause mortality (OR=0.86, 95% CI 0.71-1.06, P =0. 16) between the obese and the non-obese patients with cardiogenic shock. In subgroup analysis, in the American population, developed countries and retrospective studies, the all-cause mortality in the obesity group of patients with cardiogenic shock is lower than that of the non-obese group (OR=0.86, 95% CI 0.71-1.06, P =0. 16; OR=0.71,95%CI0.65-0.77, P＜ 0.00001; OR=0.71，95%CI0.66-0.76, P＜ 0.00001). Conclusion: For patients with cardiogenic shock, there is an "obesity paradox", there is no significant difference in all-cause mortality between obese group and non-obese group. In the subgroup analysis, it was found that the in-hospital all-cause mortality rate of patients with cardiogenic shock in obese group was lower than that in non-obese group according to the country, economic development level and research type. The exact cause of this phenomenon requires more clinical trials and meta-analysis in the future.