No genetic causal association between circulating alpha-tocopherol levels and osteoarthritis, a two-sample Mendelian...

Area of Science:

• Genetics
• Nutritional Science
• Epidemiology

Background:

• The relationship between vitamin E status and osteoarthritis (OA) is debated.
• Previous epidemiological studies have yielded conflicting results regarding this association.

Purpose of the Study:

• To investigate the causal association between circulating alpha-tocopherol levels (the primary form of vitamin E) and osteoarthritis using Mendelian randomization.
• To clarify the role of vitamin E in OA development and progression.

Main Methods:

• Employed a two-sample Mendelian randomization (MR) analysis.
• Utilized genome-wide association study (GWAS) data for alpha-tocopherol levels (n=7781) and UK Biobank data for OA outcomes.
• Applied the inverse-variance weighted (IVW) method as the primary analysis, with MR-Egger for pleiotropy assessment and sensitivity analyses.

Main Results:

• No statistically significant causal relationship was found between genetically predicted alpha-tocopherol levels and clinically diagnosed OA (P=0.461).
• Similarly, no causal association was observed between alpha-tocopherol levels and self-reported OA (P=0.139).
• Sensitivity analyses and pleiotropy tests confirmed the robustness of these findings, indicating no significant heterogeneity or horizontal pleiotropy.

Conclusions:

• Genetically predicted alpha-tocopherol levels are not causally associated with the progression of osteoarthritis.
• Alpha-tocopherol may not offer beneficial effects for the management or prevention of OA.
• Further MR studies with larger GWAS datasets are warranted to confirm these results.