Many clinical studies have indicated that there is a close relationship between obesity and pneumonia, but the causal relationship between them has not been reported. Body mass index (BMI), waist-to-hip ratio (WHR) and waist-to-hip ratio adjusted for BMI (WHRadjBMI), which are closely related to obesity. Single nucleotide polymorphisms (SNPs) associated with them were used as instrumental variables for MR analysis. Inverse variance weighted (IVW), weighted median, MR-Egger, simple mode and weighted mode were used to analyze the causal effect. The result of IVW showed a potential causal relationship between BMI and pneumonia (P = 0.006, OR = 1.22, 95 % CI = 1.06-1.40), but no causal relationship between WHR and pneumonia (P = 0.351, OR = 0.93, 95 % CI = 0.79-1.09). The result of MR Egger showed a potential causal relationship between WHR and pneumonia (P = 0.020, OR = 1.87, 95 % CI = 1.11-3.16). The result of IVW showed that WHRadjBMI had no causal effect on pneumonia (P = 0.708, OR = 1.03, 95 % CI = 0.87-1.22). The study showed that obesity increased the risk of pneumonia, which may help to further explore the pathogenesis of pneumonia.

Mei Yang, Haizong Hu, Lijun Chen, Hongxia Yu, Xiaochao Du, Qixin Wang. Causality between Obesity and Pneumonia: A Two-Sample Mendelian Randomization Analysis. Academic Journal of Medicine & Health Sciences (2025), Vol. 6, Issue 9: 21-27. https://doi.org/10.25236/AJMHS.2025.060904.

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