No Causal Association Between Inguinal Hernia and Aortic Aneurysm Using Mendelian Randomization Analysis.

Area of Science:

• Genetics
• Epidemiology
• Cardiovascular Research

Background:

• Aortic aneurysm (AA) is a significant health concern, particularly in aging populations.
• Previous observational studies suggested a potential association between inguinal hernia and AA.
• The underlying causal relationship requires robust investigation.

Purpose of the Study:

• To investigate the potential causal association between inguinal hernia and the risk of developing aortic aneurysm.
• To differentiate between inguinal hernia and aortic aneurysm (AA), abdominal aortic aneurysm (AAA), and thoracic aortic aneurysm (TAA).
• To compare genetic evidence with existing observational data.

Main Methods:

• Utilized summary statistics from large-scale genome-wide association studies (GWAS) for inguinal hernia (UK Biobank) and AA (FinnGen).
• Employed Mendelian Randomization (MR) methods, including MR-Egger, weighted median, and inverse variance weighting.
• Compared MR findings with previously published observational estimates.

Main Results:

• No convincing causal effect was found between genetically predicted inguinal hernia and the risk of AA (OR = 1.05, 95% CI = 0.85-1.31, P = .65).
• Analysis showed no significant causal link for abdominal aortic aneurysm (AAA) (OR = 1.15, 95% CI = 0.92-1.46, P = .22) or thoracic aortic aneurysm (TAA) (OR = 1.05, 95% CI = 0.85-1.30, P = .67).
• Results contrasted with prior observational studies suggesting a common causal pathway.

Conclusions:

• The genetic evidence does not support a causal relationship between inguinal hernia and aortic aneurysm.
• This finding challenges previous observational data and highlights the need for further research.
• Understanding the complex interplay of risk factors in aneurysm development remains crucial.