Association between sarcopenia and intervertebral disc degeneration: A bidirectional two-sample Mendelian...

Area of Science:

• Gerontology
• Orthopedics
• Genetics

Background:

• Sarcopenia (SP) and Intervertebral Disc Degeneration (IVDD) are prevalent age-related conditions impacting health.
• Evidence suggests a link between SP and IVDD, but causality remains unclear.

Purpose of the Study:

• To determine the causal relationship between SP and IVDD using Mendelian randomization (MR).

Main Methods:

• Utilized genome-wide association study (GWAS) data for SP (muscle lean mass, grip strength, walking speed) and IVDD.
• Employed Inverse-Variance Weighted (IVW) as the primary MR analysis method, supported by MR-Egger, MR-PRESSO, and leave-one-out analyses for robustness.
• Assessed instrumental variable strength, heterogeneity, and horizontal pleiotropy to ensure reliable causal inference.

Main Results:

• Appendicular lean mass (ALM) showed a protective causal effect against IVDD (OR=0.89).
• Left and right-hand grip strength indicated a causal risk for IVDD development (OR=1.52 and OR=1.50, respectively).
• Intervertebral Disc Degeneration (IVDD) was causally associated with reduced walking speed (OR=0.99).

Conclusions:

• Appendicular lean mass (ALM) may protect against Intervertebral Disc Degeneration (IVDD).
• Grip strength is identified as a potential risk factor for IVDD.
• Intervertebral Disc Degeneration (IVDD) is linked to decreased walking speed, highlighting potential therapeutic targets.