Pharmaceutical dosage forms for oral administration to a patient for the treatment of diabetes, comprising insulin and a delivery agent that facilitates insulin transport in a therapeutically effective amount to the bloodstream and that result in a lower incidence of vascular diseases associated with the repeated administration of insulin are disclosed. Also disclosed is a method of attenuating the undesirable incidence of diseases associated with chronic dosing of insulin is provided whereby the oral administration to a patient of insulin along with a suitable delivery agent that facilitates the absorption of insulin from the gastrointestinal tract of the patient in a therapeutically effective amount, for treatment of diabetes.