The impact of body mass index and gender on the development of infectious complications in polytrauma patients

Abstract

Purpose: The aim was to test the impact of body mass index (BMI) and gender on infectious complications after polytrauma. Methods: A total of 651 patients were included in this retrospective study, with an Injury Severity Score (ISS) ≥16 and age ≥16 years. The sample was subdivided into three groups: BMI <25 kg/m2, BMI 25–30 kg/m2, and BMI >30 kg/m2, and a female and a male group. Infectious complications were observed for 31 days after admission. Data are given as mean ± standard errors of the means. Analysis of variance, Kruskal–Wallis test, χ2 tests, and Pearson’s correlation were used for the analyses and the significance level was set at P < 0.05. Results: The overall infection rates were 31.0 % in the BMI <25 kg/m2 group, 29.0 % in the BMI 25–30 kg/m2 group, and 24.5 % in the BMI >30 kg/m2 group (P = 0.519). The female patients developed significantly fewer infectious complications than the male patients (26.8 vs. 73.2 %; P < 0.001). The incidence of death was significantly decreased according to the BMI group (8.8 vs. 7.2 vs. 1.5 %; P < 0.0001) and the female population had a significantly lower mortality rate (4.1 vs. 13.4 %; P < 0.0001). Pearson’s correlations between the Abbreviated Injury Scale (AIS) score and the corresponding infectious foci were not significant. Conclusion: Higher BMI seems to be protective against polytrauma-associated death but not polytrauma-associated infections, and female gender protects against both polytrauma-associated infections and death. Understanding gender-specific immunomodulation could improve the outcome of polytrauma patients.