Insulin-Induced Severe Lipohypertrophy

A 75-year-old lady with history of type 2 diabetes mellitus for more than 10 years complicated by nephropathy and peripheral neuropathy presented to the endocrine clinic for diabetes care. Her outpatient diabetic regimen included Aspart, 30 units every morning, Glargine, 50 units every morning, Dapagliflozin 10 mg daily, and Dulaglutide 0.75 mg weekly. On presentation A1c was noted to be 8.1% (4.2 – 5.6%). On examination, she was noted to have two painless, indurated, well demarcated and easily palpable areas of hyperpigmentation bilaterally surrounding her umbilicus, the left lesion is covered with shiny skin, larger in size and measuring 5 x 5 cm (Figure A, labeled as 1 and 2). What is the diagnosis? Answer Given the history and physical exam findings, the lesions were felt to be secondary to lipohypertrophy, she did endorse only injecting insulin at these two sites for many years and mainly over the left-side as she is right-handed. Following the appointment, insulin Aspart was adjusted to 20 units with meals plus moderate correction scale. Additionally, Dulaglutide was discontinued and Tirzepatide was initiated. The patient was provided education on avoiding the affected sites when injecting insulin as well as proper site rotation. Subsequently, over the next couple months her insulin requirement decreased to Glargine, 25 units every morning with only sliding scale Aspart. She remained on Farxiga, 10 mg daily and Tirzepatide. At 6-month follow up, A1c had decreased to 7.0% (Figure B). On physical exam, the areas of lipohypertrophy had decreased significantly in size (Figure C). Lipohypertrophy has been associated with increased risk of hypoglycemia, glycemic variability and decreased insulin absorption in areas of lipohypertrophy[1Gentile S. et al.Lipohypertrophy in Elderly Insulin-Treated Patients With Type 2 Diabetes.Diabetes Ther. 2021; 12: 107-119Crossref PubMed Scopus (11) Google Scholar]. This case emphasizes the importance of a routine physical examination, particularly abdominal inspection, when evaluating patients with diabetes on insulin as well as patient education on proper insulin administration and rotation of sites[2Blanco M. et al.Prevalence and risk factors of lipohypertrophy in insulin-injecting patients with diabetes.Diabetes Metab. 2013; 39: 445-453Crossref PubMed Scopus (197) Google Scholar]. Patient education should include avoidance of lipohypertrophy sites, proper site rotation, use of a new needle with each injection, and routine self-inspection of injection sites[3Al Ajlouni M. et al.Prevalence of lipohypertrophy and associated risk factors in insulin-treated patients with type 2 diabetes mellitus.Int J Endocrinol Metab. 2015; 13e20776Crossref Scopus (37) Google Scholar].