Causal association between 3 adiposity indices and 5 infectious diseases: A Mendelian randomization study

Area of Science:

• Genetics
• Epidemiology
• Public Health

Background:

• Inconsistent findings exist regarding the link between adiposity and infection risk.
• Adiposity indices like body mass index (BMI), waist circumference (WC), and hip circumference (HC) are commonly used measures.
• Understanding the causal relationship is crucial for public health interventions.

Purpose of the Study:

• To investigate the causal associations between different adiposity indices (BMI, WC, HC) and the risk of various infections.
• To determine if WC is a more effective predictor of infectious disease risk compared to BMI and HC.

Main Methods:

• Mendelian randomization (MR) analysis was employed, including univariate and multivariable approaches (MVMR).
• Data were sourced from large biobanks (UK Biobanks, FinnGen) and consortia.
• Inverse-variance weighted (IVW) and other MR methods were used to ensure result robustness, with Bonferroni correction for significance.

Main Results:

• Multivariable MR analysis revealed a significant, independent causal association between WC and increased risk of sepsis susceptibility (OR=1.95), sepsis mortality (OR=3.23), cholecystitis (OR=1.87), and skin/subcutaneous tissue infections (SSTI) (OR=1.74).
• No significant causal links were found between BMI or HC and the studied infections.
• No evidence of pleiotropy or reverse causality was detected.

Conclusions:

• Waist circumference (WC) is a significant independent predictor of several infectious diseases, including sepsis and cholecystitis.
• Controlling WC may be a viable strategy for reducing the risk of these infections.
• Further prospective studies are needed to explore dynamic adiposity measures and diverse infections across populations.