Table 5.

Mediation of association between protein–PC1 and proteins and general cognitive fluid ability by MRI brain variables in LBC1936: grey matter volume, normal-appearing white matter volume, white matter hyperintensity volume, perivascular spaces, general fractional anisotropy and general mean diffusivity.

Protein	Total beta	Total SE	Total P	Sum IDE beta	Sum IDE SE	Sum IDE P	% attn	c′
EDA2R	−0.162	0.041	<0.001	−0.059	0.015	<0.001	36.42	−0.103
PVR	−0.173	0.041	<0.001	−0.038	0.014	0.006	21.97	−0.135
EFNA4	−0.136	0.042	0.001	−0.028	0.014	0.049	20.59	−0.108
DDR1	−0.136	0.041	0.001	−0.014	0.014	0.308	10.29	−0.122
RSPO1	−0.136	0.041	0.001	−0.027	0.014	0.055	19.85	−0.109
SKR3	−0.125	0.042	0.003	−0.038	0.015	0.01	30.40	−0.087
TNFRSF12A	−0.117	0.041	0.005	−0.032	0.015	0.027	27.35	−0.085
VWC2	−0.129	0.041	0.001	−0.012	0.013	0.342	9.30	−0.117
Siglec-9	−0.141	0.041	0.001	−0.018	0.014	0.187	12.77	−0.123
SCARB2	−0.136	0.042	0.001	−0.024	0.015	0.104	17.65	−0.112
LAYN	−0.126	0.042	0.003	−0.025	0.014	0.074	19.84	−0.101
UNC5C	−0.101	0.041	0.014	−0.01	0.014	0.438	9.90	−0.091
CLM-6	−0.118	0.041	0.004	−0.031	0.015	0.033	26.27	−0.087
CPM	−0.109	0.041	0.008	−0.014	0.013	0.299	12.84	−0.095
MSR1	−0.109	0.04	0.006	−0.039	0.015	0.007	35.78	−0.070
Protein–PC1	−0.111	0.041	0.007	−0.006	0.013	0.646	5.41	−0.105
N2DL-2	−0.109	0.041	0.008	−0.018	0.014	0.218	16.51	−0.091
GFR-alpha-1	−0.107	0.042	0.01	−0.036	0.014	0.01	33.64	−0.071
SIGLEC1	−0.112	0.041	0.007	−0.021	0.014	0.12	18.75	−0.091
CDH6	−0.088	0.041	0.032	0.002	0.014	0.862	−2.27	−0.090
THY1	−0.104	0.041	0.012	−0.021	0.014	0.121	20.19	−0.083
SCARA5	−0.098	0.041	0.018	−0.005	0.014	0.718	5.10	−0.093
PLXNB1	−0.081	0.041	0.050	−0.006	0.014	0.636	7.41	−0.075

Corrected for age and sex. Total effect sizes (total betas) differ from those in Table 3 as the mediation analysis included fewer individuals. Significant mediations (FDR corrected) are indicated in bold.

IDE indirect effect, % attn percentage attenuated.