EpistemisInsulin lipodystrophy
Specialty: Endocrine and metabolic.
Why it occurs
- Repetitive microtrauma at the insulin injection site (lack of rotation of the cutaneous injection areas)
- Direct local lipogenic effect of high local concentrations of insulin (lipohypertrophy, characterized by hyperplasia and hypertrophy of local adipocytes due to sustained stimulation of insulin receptors)
- Local immunological reaction of type IV delayed hypersensitivity to impurities or components of the insulin preparation (lipoatrophy, characterized by the circumscribed loss of subcutaneous adipose tissue, more common with old animal insulins but still rarely present with analogues)
- Systematic reuse of insulin injection needles (causes deformation of the needle tip with microstructural tissue tearing and release of inflammatory mediators)
Initial workup
Detailed physical examination through systematic palpation and marking of the usual injection areas to delimit indurated or depressed areas; high-resolution soft tissue ultrasound of the affected sites to confirm and quantify the thickness of lipohypertrophic plaques (demonstration of homogeneous hyperechoic areas in the subcutaneous cellular tissue) or areas of lipid atrophy; and continuous glucose monitoring for 14 days to correlate glycemic variability with injection sites.
red flags
Presence of extensive indurated deformed areas of fatty tissue that are associated with unexplained and recurrent episodes of severe neuroglycopenic hypoglycemia alternating with extreme hyperglycemia that is difficult to control and great unexplained glycemic variability, due to the erratic and unpredictable absorption of insulin injected into the dystrophic tissue.
Standard management
- Insulin aspart or lispro — use of highly purified recombinant insulin analogues administered strictly by rotating injection sites in peripheral healthy tissue to avoid local accumulation
- 1% hydrocortisone cream — in selected cases of active autoimmune lipoatrophy, injecting or applying in a very localized manner to mitigate the inflammatory reaction mediated by immune complexes, although strict monitoring is required due to the risk of inducing more local atrophy
- Change to continuous insulin infusion systems (insulin pump to limit the number of daily microtraumas from multiple injections).
Educational guidance for study. It is NOT a prescription recommendation. The actual choice depends on the cause, the patient, and current guidelines.
- Area
- Endocrine and metabolic
- Listed causes
- 4
- Treatment options
- 3