Genetic background influences cardiac phenotype in murine chronic kidney disease

BACKGROUND: Levels of fibroblast growth factor 23 (FGF23) increase early in chronic kidney disease (CKD) and are independently associated with left ventricular hypertrophy (LVH), heart failure and death. Experimental models of CKD with elevated FGF23 and LVH are needed. We hypothesized that slow rates of CKD progression in the Col4a3 knockout (Col4a3(KO)) mouse model of CKD would promote development of LVH by prolonging exposure to elevated FGF23. METHODS: We studied congenic Col4a3(KO) and wild-type (WT) mice with either 75% 129X1/SvJ (129Sv) or 94% C57Bl6/J (B6) genomes. RESULTS: B6-Col4a3(KO) lived longer than 129Sv-Col4a3(KO) mice (21.4 ± 0.6 versus 11.4 ± 0.4 weeks; P