The causal relationship between bacterial pneumonia and diabetes: a two-sample mendelian randomization study

Area of Science:

• Genetics
• Epidemiology
• Public Health

Background:

• Observational studies indicate a high prevalence of bacterial pneumonia in diabetic patients, correlating with increased mortality.
• A direct causal link between bacterial pneumonia and diabetes has not been previously established.

Purpose of the Study:

• To investigate the potential bidirectional causal relationship between bacterial pneumonia and different types of diabetes using Mendelian randomization.
• To explore the genetic correlation between bacterial pneumonia and gestational diabetes mellitus (GDM), type 1 diabetes mellitus (T1DM), and other diabetes types.

Main Methods:

• A bidirectional two-sample Mendelian randomization (MR) study was conducted using genome-wide significant single-nucleotide polymorphisms (SNPs) as instrumental variables.
• Inverse variance weighted (IVW), MR-Egger, and weighted median methods were employed to analyze the association.
• Sensitivity analyses including heterogeneity, pleiotropy, MR-PRESSO, and leave-one-out tests were performed to ensure result reliability.

Main Results:

• Bacterial pneumonia was found to significantly increase the incidence of GDM (OR=1.150) and T1DM (OR=1.277).
• Reverse MR analysis indicated that GDM is associated with an elevated risk of bacterial pneumonia (OR=1.112).
• No significant association was observed between bacterial pneumonia and T1DM or other diabetes types in the reverse analysis.

Conclusions:

• The study provides robust evidence for a bidirectional causal association between bacterial pneumonia and GDM.
• A potential causal link between bacterial pneumonia and T1DM is suggested, warranting further investigation.