Galectin-3 and risk of heart failure and death in blacks and whites

Background--The association between galectin-3 and heart failure (HF) or death is well established for white, but not for black, adults. Methods and Results--Galectin-3 was measured in 1809 participants (1375 white, 434 black), enrolled in a substudy of the Atherosclerosis Risk in Communities (ARIC) observational cohort during 2004-2005. We used Cox proportional hazard models to estimate the adjusted association between galectin-3 and outcomes. Analyses were conducted overall and by race category. Median (interquartile range) galectin-3 levels were 13.4 (11.2-16.4) and 14.8 (12-17.6) ng/mL, in white and black participants, respectively. In the sample overall, galectin-3 was not independently associated with HF or death over a maximum of 7.9 years. However, in race-stratified analyses, galectin-3 was independently associated with a composite of HF or death among whites (eg, hazard ratio 2.2, 95% CI 1.2-3.9, comparing Q4 versus Q1); but not among blacks (hazard ratio of 0.8 [0.4-1.8] for Q4 versus Q1, race interaction P=0.03). Associations between galectin-3 and both outcomes analyzed individually also demonstrated similar racial differences. Furthermore, results were qualitatively similar with galectin-3 modeled as a continuous exposure. In addition, galectin-3 improved discrimination for the composite of HF or death among whites (increase in Harrell's C statistic from 0.729 to 0.735 [difference of +0.006], P=0.049), but not among blacks (0.696 to 0.695 [difference of -0.001], P=0.814). Conclusions--In contrast to whites, galectin-3 may have limited prognostic utility for predicting HF and death in blacks. While our results require replication, they could reflect racial differences in the processes by which galectin-3 mediates disease.