Causal Association Between Diabetes, Body Mass Index and Lichen Sclerosus: A Bidirectional Two-Sample Mendelian Randomization Analysis

Figures & data

Figure 1 Workflow of Mendelian randomization study in this study.

Table 1 Details of GWAS Used for Exposures and Outcomes.

Variables	Sample size	Case	Control	No. SNPs	Participates	Year Of Release	PMID/Source
T1D	25,063	9358	15,705	1,27,83,129	European	2020	32,005,708
T2D	6,59,316	62,892	5,96,424	50,30,727	European	2018	30,054,458
BMI	681275	NA	NA	2336260	European	2018	30,124,842
Lichen sclerosus	323,887	1984	321903	2,01,69,015	European	2022	FinnGen biobank(R8)

Table 2 The Causal Effect of (A) T1D, (B) T2D, and (C) BMI on Lichen Sclerosus.

Exposures	Outcomes	Methods	No. SNPs	OR (95% CI)	P-value
T1D	Lichen sclerosus	IVW	29	0.97(0.91–1.04)	0.4294
		MR Egger		1.02(0.92–1.12)	0.766
		Weighted median		1.00(0.95–1.05)	0.9596
T2D		IVW	122	0.88(0.78–0.99)	0.031
		MR Egger		0.71(0.54–0.94)	0.0195
		Weighted median		0.81(0.69–0.94)	0.0049
T2D(After removing outliers)		IVW	112	0.91(0.82–1.00)	0.0511
		MR Egger		0.77(0.61–0.94)	0.0247
		Weighted median		0.81(0.69–0.95)	0.0082
BMI		IVW	436	0.92(0.73–1.15)	0.4554
		MR Egger		1.04(0.58–1.86)	0.895
		Weighted median		0.97(0.69–1.36)	0.8591

Figure 2 Scatter plots visualizing the Mendelian randomization (MR) estimates of the different exposures ((A): Type 1 diabetes; (B): Type 2 diabetes; (C): Body mass index) with the outcome (lichen sclerosus). Inverse-variance weighted (IVW), MR-Egger, and weighted median methods were the main estimators of the analysis.

Table 3 The Causal Effect of LS on (A) T1D, (B) T2D, and (C) BMI.

Exposures	Outcomes	Methods	No. SNPs	OR (95% CI)	p-value
LS	D1M	IVW	4	0.74(0.27–2.05)	0.5639
		MR Egger		4.77(0.25–92.58)	0.4102
		Weighted median		1.56(1.26–1.93)	0.000031
	D2M	IVW	8	0.97(0.92–1.03)	0.3979
		MR Egger		1.10(0.82–1.47)	0.5632
		Weighted median		0.97(0.92–1.03)	0.3182
	BMI	IVW	6	0.99(0.96–1.01)	0.3144
		MR Egger		1.10(0.94–1.29)	0.2821
		Weighted median		1.01(0.99–1.02)	0.471

Figure 3 Scatter plots visualizing the Mendelian randomization (MR) estimates of the exposure (lichen sclerosus) with different outcomes ((A): Type 1 diabetes; (B): Type 2 diabetes; (C): Body mass index).