The use of thiazolidinediones (peroxisome proliferator-activated receptor-gamma; PPAR-χ agonists) and both rosiglitazone [21] and pioglitazone [22] led to more HF hospitalizations than the use of a placebo [21,23] according to a randomized clinical trial, because PPAR-χ agonists may enhance renal sodium retention [24], which results in worsening HF. This evidence concerns the gene PPARG and hydrops fetalis.