Higher Body Mass Index Is a Causal Risk Factor for Skin Infections: A Mendelian Randomisation Study Using UK Biobank...

Area of Science:

• Epidemiology
• Genetics
• Infectious Diseases

Background:

• Infections are a major global cause of illness and death.
• The relationship between body mass index (BMI) and infection risk requires further causal investigation.

Purpose of the Study:

• To investigate the potential causal role of higher BMI in common bacterial, viral, and fungal infections using Mendelian randomization (MR).

Main Methods:

• Utilized UK Biobank data (over 500,000 participants) for observational and one-sample MR analyses.
• Employed two-sample MR with genome-wide association study data from UK Biobank and infection outcomes from FinnGen (over 500,000 participants).
• Assessed associations between BMI and various infections, including skin, respiratory, and urogenital types.

Main Results:

• Higher BMI showed an observational association with all infection types studied.
• One-sample MR confirmed a causal effect of higher BMI on bacterial and fungal skin infections in primary care and hospital settings.
• Two-sample MR supported the causal link between higher BMI and skin infections, showing robustness to pleiotropy.
• Potential pleiotropy may bias the estimated causal effect of BMI on some respiratory infections.

Conclusions:

• Mendelian randomization provides strong evidence that elevated BMI is a causal risk factor for bacterial and fungal skin infections.
• Weight management strategies may be effective in reducing the incidence and severity of skin infections.
• Interventions should be considered for individuals at higher risk of BMI-related skin infections.