FGF21 and cardiac hypertrophy: To determine if FGF21 elevation could induce concentric cardiac hypertrophy in the absence of confounding effects on body weight, adult wildtype BALB/cJ mice were injected intravenously (i.v.)twice daily with 40 μg/kg of recombinant FGF21 protein or isotonic saline for five days, followed by echocardiography and tissue collection on the sixth day.