| Popis: |
Introduction: Insulin resistance occurs most commonly in association with obesity but may result from multiple causes, e.g. medications, lipodystrophy, or antibodies to insulin or insulin receptors. We review a case of an unusual presentation of insulin resistance. We highlight challenges of diagnostic testing and treatment when there are cost limitations. Clinical Case:A 41 year old Hispanic male with T2DM and a history of well-controlled BPD on quetiapine only presents for management of diabetes. His current treatment is metformin and a TDD of 170 U human insulin; A1C is 12.2%. He was diagnosed at age 32 via routine lab tests. At diagnosis BW was 96.4 kg, BMI 29, BP 100/70, CHOL 152, TG 247, HDL 35, LDL 68. Physical exam was unremarkable without acanthosis or lipodystrophy. Anti-GAD, anti-islet cell antibodies, insulin and C-peptide levels were ordered, but not obtained due to cost. He was managed with lifestyle modification for 2 years with maintenance of A1C 11%, with no change in BW. Glargine 5 U was added, and glyburide was changed to glipizide. Glargine was increased to 40 U without changes in glycemia. At age 37 glipizide was stopped, and he could not afford glargine. He was switched to 70/30 human insulin. Insulin dosages were progressively increased to 220 U a day with no change in glycemia. Liraglutide was tried but not continued due to cost, and quetiapine was switched to trazodone without improvement in A1C. LFTs, CBC, HIV, Hepatitis C and B have been negative. The patient has had multiple visits for education with documented adequate disease understanding and performance of injections. Nonadherence was suspected; for its evaluation, the patient was observed in clinic self-injecting 30 U of regular insulin (brought from home); fasting was confirmed for 3hrs post-injection. BG was 327mg/dL pre-injection and 326mg/dL 3hrs post-injection. Insulin antibodies were requested but not obtained due to cost. Insulin receptor antibodies are not commercially available in the US. Potential empiric strategies, e.g. the NIH protocol for insulin type B resistance (rituximab + dexamethasone + cyclophosphamide) was considered but cost is a limitation. We discussed steroids or methotrexate for possible antibody mediated insulin resistance versus a trial of thiazolidinedione, which has been reported to decrease severe insulin resistance in patients with lipodystrophy. The patient opted to initially try a thiazolidinedione. Conclusion:Although poor adherence has not been excluded, the patient appears to have no response to high doses of injected human insulin, suggesting extreme insulin resistance. Cost limitations preclude optimal diagnostic evaluation. Empiric treatment with low cost options potentially may provide diagnostic information as well as efficacious treatment. |
