FGF21 and diabetes mellitus: Studies have shown that OH and SCH are closely related to a variety of metabolic disorders including obesity, hypertension, dyslipoproteinemia, insulin resistance/diabetes mellitus, and cardiovascular diseases.[15,16,23,24] Many metabolic regulators and adipokines/hepatokines including leptin, adiponectin, resistin, and FGF21 were found to be altered with thyroid dysfunction.[25]