The relationship between inflammatory bowel disease and sarcopenia-related traits: a bidirectional two-sample...

Area of Science:

• Genetics
• Gastroenterology
• Musculoskeletal Health

Background:

• Observational studies suggest a link between inflammatory bowel disease (IBD) and sarcopenia.
• The causal nature of this association remains undetermined.

Purpose of the Study:

• To investigate the bidirectional causal relationship between IBD and sarcopenia using a two-sample Mendelian randomization (MR) approach.

Main Methods:

• Utilized genetic instrumental variables (IVs) for IBD, ulcerative colitis (UC), Crohn's disease (CD), low hand grip strength (LHGS), and appendicular lean mass (ALM).
• Employed a two-sample bidirectional MR analysis with inverse variance weighting and other MR methods.
• Conducted heterogeneity, pleiotropy, leave-one-out, and multivariate MR analyses to ensure result robustness.

Main Results:

• Genetically predicted UC and CD were causally associated with reduced ALM (low muscle mass).
• Higher LHGS (stronger grip strength) was associated with reduced risk of IBD and CD.
• Increased ALM was found to reduce the risk of IBD, UC, and CD.

Conclusions:

• This MR study provides evidence for a bidirectional causal relationship between IBD and sarcopenia.
• UC and CD are causally linked to decreased muscle mass, while improved muscle strength and mass may protect against IBD.