Hypothyroidism is primarily thought to exert profibrotic phenotype associated with increases in the LV TGF-β1 and procollagen-I mRNAs and protein,164 induced LV hypertrophy with fibrotic lesions, and upregulated α-SMA expression; all these changes were reversed by euthyroid state. Here, TGFB1 is linked to hypothyroidism.