Cardiac Autonomic Neuropathy in Diabetes

CASE PRESENTATION — A 26year-old woman with “brittle” type 1 diabetes and severe CAN experienced sudden cardiac death. She had a 16-year history of poor diabetes control presenting with wide blood glucose fluctuations, recurrent episodes of severe hypoglycemia, and hypoglycemia unawareness. Over time she developed persistent orthostatic hypotension with daily falls in systolic blood pressure ranging from 30–60 mmHg. These episodes had significant impact on her daily activities and required intermittent therapy with the -1 agonist midodrine. Other complications included severe gastroparesis, refractory diarrhea, and painful diabetic peripheral neuropathy. Her last clinical examination revealed resting tachycardia with a fixed rate of 115 bpm, supine blood pressure of 110/78 mmHg, which dropped to 70/48 mmHg while standing, symmetrical absent pinprick and temperature discrimination in stocking distribution, and left Charcot joint. Her last pertinent laboratory findings were A1C 8.7%, creatinine 1.9 mg/dl, microalbumin/creatinine 496 mg/g, and hemoglobin 10.8 g/dl.