Table 2: SNP-by-age interaction for cross-sectional eGFR for the 12 identified variants.

For the 12 identified variants, we conducted SNP-by-age interaction analysis for cross-sectional eGFRcrea and eGFRcys in UK Biobank (excluding individuals from decline GWAS; n=351,462 for eGFRcrea, n=351,601 for eGFRcys; main age effect modelled non-linearly, main SNP effect linearly, age centered at 50 years). The interaction term (age effect and SNP effect modelled linearly) was judged at Bonferroni-corrected significance level (P<0.05/12=4.17×10⁻³). Beta-estimates are in mL/min/1.73² per year and per cross-sectional eGFR-lowering allele (which was equivalent to faster-decline allele for each SNP); significant P-values are stated in bold.

SNPID	Locus Name	EA/OA	SNP x age interaction eGFRcrea		SNP x age interaction eGFRcys
			Beta	P	Beta	P
A from GWAS/candidate search for decline (baseline-unadjusted)
rs34882080	UMOD-PDILT	a/g	−0.043	5.53×10 −22	−0.045	2.37×10 −17
rs77924615	UMOD-PDILT	g/a	−0.050	2.55×10 −29	−0.054	6.59×10 −25
rs10254101	PRKAG2	t/c	−0.009	0.0263	−0.015	9.84×10 −04
rs1028455	SPATA7	t/a	−0.014	2.19×10 −04	−0.014	1.06×10 −03
B from GWAS for declineadj, with association for decline (baseline-unadjusted)
rs1458038	FGF5	c/t	−0.013	7.11×10 −04	−0.013	3.12×10 −03
rs4930319	OVOL1	c/g	−0.015	2.55×10−05	−0.016	1.84×10−04
rs434215	TPPP	a/g	−0.028	1.02×10 −10	−0.033	5.02×10−11
rs28857283	C15ORF54	g/a	−0.010	5.09×10−03	−0.006	0.148
rs13095391	ACVR2B	a/c	0.004	0.227	0.002	0.695
C from GWAS for declineadj, without association for decline (baseline-unadjusted)
rs9998485	SHROOM3	a/g	−0.004	0.206	−0.009	0.022
rs1047891	CPS1	a/c	0.004	0.228	0.005	0.244
rs2453533	GATM	a/c	0.014	9.71×10 −05	0.002	0.722

SNPID=Variant identifier on GRCh37, Locus name=Nearest Gene, EA/OA=Effect allele / other allele, Beta and P=genetic effect and association P-value. The TPPP variant rs434215 is well-imputed in the UK Biobank (imputation quality=0.82).