The method of treating diabetes-related vascular complications includes the treatment of diabetic patients with α-lipoic acid (LA) in order to mitigate the negative impact of diabetes-related vascular dysfunctions upon vascular homeostasis. The treatment method includes the step of administering to the patient an initial dosage of α-lipoic acid believed to be therapeutically effective. The patient's response is then monitored by measuring α-lipoic acid-responsive biomarkers and by performing assays from blood and tissue taken from the patient.