3.1.1 IVs of sarcopenia
Following the clumping procedure, 690
SNPs, 157 SNPs, 176 SNPs, and 57 SNPs were shown to be closely related
(P < 5×10-8) to ASM, LH, RH, and WP,
respectively, and no LD was screened out. The MAF of the SNPs
aforementioned was at least 0.01.
There were 16 IVs of ASM which were identified as palindromic SNPs in
all COVID-19 outcomes and removed. There were 71 SNPs of ASM which were
not present in COVID-19 infection GWAS data, but only 18 of them were
substituted by their proxy SNPs. 96 SNPs of ASM were absent in COVID-19
hospitalization GWAS data while 29 of them were supplanted by their
proxy SNPs. In severe COVID-19 GWAS data, 67 SNPs of ASM cannot be
found, and 13 SNPs were replaced by proxy SNPs. No proxy SNPs for the
rest of the SNPs can be found in the outcome GWAS data. Ultimately 621
IVs of ASM on COVID-19 infection, 607 IVs of ASM on COVID-19
hospitalization and 620 IVs of ASM on severe COVID-19 were included in
the MR analysis (Supplementary Table S2 ).
As palindromic SNPs were identified, 3 IVs of LH (rs72977282, rs3959716,
rs35054365) were removed in all COVID-19 outcomes. 8 SNPs of LH were not
detected in COVID-19 infection GWAS data and 9 SNPs of LH were not found
in both COVID-19 hospitalization and severe COVID-19 GWAS data. While
only 5 SNPs (rs112485536, rs13356200, rs113315602, rs56060323,
rs8101782) were replaced by their proxy SNPs (rs67833811, rs10940168,
rs60080738, rs10507644, rs7258994), and no proxy SNPs for other SNPs can
be found. Ultimately 151 IVs of LH on COVID-19 infection and 150 IVs of
LH on both COVID-19 hospitalization and severe COVID-19 were included in
the MR analysis (Supplementary Table S3 ).
There were 8 IVs of RH which were identified as palindromic SNPs in all
COVID-19 outcomes and removed. 5 SNPs of RH failed to appear in COVID-19
infection GWAS data, and 6 SNPs of RH in both COVID-19 hospitalization
and severe COVID-19 GWAS data, respectively. But 2 SNPs of RH
(rs13356200, rs113315602) in all three types of COVID-19 GWAS data were
displaced by their proxy SNPs (rs7711053, rs60080738) and no proxy SNPs
for other SNPs can be identified. Ultimately 163 IVs of RH on COVID-19
infection, 161 IVs of RH on COVID-19 hospitalization and 165 IVs of RH
on severe COVID-19 were included in the MR analysis (SupplementaryTable S4 ).
As palindromic SNPs were identified in all COVID-19 outcomes, the IV of
WP, rs11881338, was removed. Ultimately 56 IVs of WP were included in
the MR analysis (Supplementary Table S5 ).