Endocrine Abstracts

Introduction: Insulin neuritis is a rare form of presentation of diabetic neuropathy, usually associated with the sudden intensification of glucose control in individuals with long standing uncontrolled diabetes mellitus.

Objectives: To report a case of insulin neuritis in a young male, few weeks after diagnosis and insulin therapy initiation.

Clinical case: Male, 22 years old, previous history of excess weight until he was 19 years old, moment at which he began an intensive exercise regimen and lost 30 kg in the following 3 years. The general practitioner detected fasting hyperglycemia (404 mg/dl and 22.4 mmol/l) in routine analysis and he referenced the patient to urgent care of a diabetologist. He did not present with ketoacidosis, although he had ketonuria. He was positive for anti-GAD antibodies (31 IU/ml) and his C-peptide was 0.43 ng/ml. He initiated treatment with intensive insulin therapy in the endocrinology ward and was released with good glycemic control. Two months after discharge he presented with intense neuropathic burning-like pain, in both feet, and reduced leg muscle strength resulting in impairment of gait. Other causes of neuropathy were excluded. The electromyography was suggestive of diabetic neuropathy. Pain was controlled with pregabalin, tramadol, and amytriptiline, with clinical improvement. An overlooked previous episode of fasting hyperglycemia 3 years before was confirmed in the review of the clinical file of the patient.

Conclusion: Insulin neuritis is a variant of diabetic neuropathy that occurs with the fast resolution of hyperglycemia in patients with long standing unsatisfactory glucose control. This case occurred in a young individual with long-standing previously undiagnosed latent autoimmune diabetes, as suggested by the development of insulin neuritis. As such it is a rare presentation for this variant of diabetic neuropathy.