Impact of abdominal fat distribution on sepsis: A comparison with traditional anthropometric indices in the UK Biobank study

AIM: This study aims to examine the dose-response relationship between visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (ASAT), and sepsis and sepsis-related mortality. Additionally, we seek to determine whether VAT or ASAT offers better prognostic value for above outcomes compared to traditional measures such as waist circumference (WC) and body mass index (BMI), using data from the UK Biobank. MATERIALS AND METHODS: In this secondary analysis of the UK Biobank, 25,083 participants with available abdominal MRI data were included. Cox proportional hazards regression was used to examine the association between VAT and ASAT, both as tertiles and continuous variables, and the incidence of sepsis as well as sepsis-related mortality. RESULTS: Over a median follow-up of 14.1 years (interquartile range: 13.4-14.9 years), 305 cases of incident sepsis (0.86 per 1000 person-years) and 90 sepsis-related deaths (0.25 per 1000 person-years) were identified. Both VAT and ASAT showed a linear relationship with sepsis risk, with hazard ratios (HR) of 1.29 (95% CI: 1.12-1.47) for VAT and 1.22 (95% CI: 1.07-1.40) for ASAT per standard deviation increase. After further adjusting for BMI or WC, the association with ASAT was eliminated, while VAT remained significant. Only VAT was positively associated with sepsis-related mortality, although this association was nullified after adjusting for BMI or WC. VAT was a more important predictor of sepsis risk than BMI or WC, and its inclusion improved the predictive model already adjusted for BMI or WC. In contrast, ASAT did not provide any additional predictive value for either sepsis risk or sepsis-related mortality compared to BMI and WC. CONCLUSIONS: VAT is independently associated with sepsis risk and improves its prediction beyond traditional measures like BMI and WC. However, VAT does not enhance the prediction of sepsis-related mortality, with BMI and WC performing better in this context.