Association Between Autoimmune Diseases and Sarcopenia: A Two-Sample Mendelian Randomization Study

Figures & data

Figure 1 The study design and workflow of the present MR study.

Abbreviations: GWAS, genome-wide association study; SLE, systemic lupus erythematosus; RA, rheumatoid arthritis; MS, multiple sclerosis; IBD, inflammatory bowel disease; T1D, type 1 diabetes; IVs, instrumental variables; MR, Mendelian randomization; SNP, single-nucleotide polymorphism.

Figure 2 MR analysis of associations between autoimmune diseases and appendicular lean mass in discovery samples.

Abbreviations: SLE, systemic lupus erythematosus; RA, rheumatoid arthritis; MS, multiple sclerosis; IBD, inflammatory bowel disease; T1D, type 1 diabetes; OAD, overall autoimmune disease; nSNP, number of single-nucleotide polymorphisms; MR, Mendelian randomization; IVW, inverse-variance-weighted; MR-RAPS, MR-robust adjusted profile score; OR, odds ratio; CI, confidence interval.

Table 1 Results of MR Analysis in Replication Samples

Exposure	Outcome	nSNP	MR Method	OR (95% CI)	P-value
RA	ALM	3	IVW	0.966 (0.951–0.982)	<0.0001
		3	Weighted median	0.969 (0.963–0.974)	<0.0001
		3	MR-RAPS	0.967 (0.953–0.980)	<0.0001
IBD	ALM	5	IVW	1.020 (0.998–1.044)	0.0808
		5	Weighted median	1.011 (0.999–1.023)	0.0690
		5	MR-RAPS	1.015 (0.998–1.032)	0.0807
T1D	ALM	3	IVW	0.975 (0.940–1.012)	0.1795
		3	Weighted median	0.993 (0.976–1.011)	0.4717
		3	MR-RAPS	0.985 (0.960–1.012)	0.2718
RA	Low grip strength	3	IVW	1.067 (1.043–1.090)	<0.0001
		3	Weighted median	1.068 (1.043–1.093)	<0.0001
		3	MR-RAPS	1.067 (1.042–1.091)	<0.0001

Abbreviations: RA, rheumatoid arthritis; ALM, appendicular lean mass; IBD, inflammatory bowel disease; T1D, type 1 diabetes; MR, Mendelian randomization; nSNP, number of single-nucleotide polymorphisms; IVW, inverse-variance weighted; MR-RAPS, MR-robust adjusted profile score; OR, odds ratio; CI, confidence interval.

Figure 3 MR analysis of associations between autoimmune diseases and low grip strength in discovery samples.

Abbreviations: SLE, systemic lupus erythematosus; RA, rheumatoid arthritis; MS, multiple sclerosis; IBD, inflammatory bowel disease; T1D, type 1 diabetes; OAD, overall autoimmune disease; nSNP, number of single-nucleotide polymorphisms; MR, Mendelian randomization; IVW, inverse-variance-weighted; MR-RAPS, MR-robust adjusted profile score; OR, odds ratio; CI, confidence interval.

Figure 4 MR analysis of associations between autoimmune diseases and walking pace in discovery samples.

Abbreviations: SLE, systemic lupus erythematosus; RA, rheumatoid arthritis; MS, multiple sclerosis; IBD, inflammatory bowel disease; T1D, type 1 diabetes; OAD, overall autoimmune disease; nSNP, number of single-nucleotide polymorphisms; MR, Mendelian randomization; IVW, inverse-variance-weighted; MR-RAPS, MR-robust adjusted profile score; OR, odds ratio; CI, confidence interval.