Since myocardial fibrosis is a prominent feature in LVH induced by insulin resistance, we tested the hypothesis that the interaction between ENPP1 rs1974201 and rs9402349 polymorphisms and the tissue inhibitor of metalloproteinases (TIMP-1)--a pro-fibrotic protein which inhibits extracellular matrix degradation--is implicated in concentric LVH and diastolic dysfunction in a cohort of 223 dialysis patients.