Methods of treating individuals with a glucose metabolism disorder such as diabetes, hyperglycemia, hyperinsulinemia or obesity by administering human FAM3D (family with sequence similarity 3, member D) are provided. Specifically a method of treating hyperglycemia resulting in a reduction of plasma glucose is provided. Additionally, a method of treating hyperinsulinemia resulting in a reduction of plasma glucose is provided. In addition, a method of treating glucose intolerance resulting in an increased glucose tolerance is provided. Pharmaceutical compositions are provided.