IntroductionCardiac biomarkers soluble ST2 (sST2) and galectin-3 may reflect cardiac inflammation and fibrosis. It is plausible that these mechanisms may also contribute to the progression of kidney disease. We examined associations of sST2 and galectin-3 with kidney function decline in participants with chronic kidney disease (CKD).MethodsThis was a pooled analysis of 2 longitudinal cohorts of participants with CKD: the Clinical Phenotyping and Resource Biobank (C-PROBE) study and the Seattle Kidney Study (SKS). We measured circulating concentrations of sST2 and galectin-3 at baseline. Our primary outcome was progression to estimated glomerular filtration rate (eGFR) <15 ml/min per 1.73 m2 or end-stage renal disease (ESRD). We used competing risk Cox regression models to study the association of sST2 and galectin-3 with CKD progression, adjusting for demographics, kidney function, and comorbidity.ResultsAmong the 841 participants in the pooled cohort, baseline eGFR was 51 ± 27 ml/min per 1.73 m2 and median urine albumin-to-creatinine ratio (UACR) was 141 (interquartile range = 15−736) mg/g. Participants with higher sST2 and galectin-3 were more likely to be older, to have heart failure and diabetes, and to have lower eGFR. Adjusting for demographics, kidney function, and comorbidity, every doubling of sST2 was not associated with progression to eGFR <15 ml/min per 1.73 m2 or ESRD (adjusted hazard ratio 1.02, 95% confidence interval = 0.76−1.38). Every doubling of galectin-3 was significantly associated with a 38% (adjusted hazard ratio = 1.35, 95% confidence interval = 1.01−1.80) increased risk of progression to eGFR <15 ml/min per 1.73 m2 or ESRD.ConclusionHigher concentrations of the cardiac biomarker galectin-3 may be associated with progression of CKD, highlighting potential novel mechanisms that may contribute to the progression of kidney disease.