Improper jab site rotation, needle reuse contribute to lipohypertrophy

In patients with diabetes, lipohypertrophy (LH) is a complication of subcutaneous insulin therapy, with improper rotation of injection sites and reuse of needles being the leading causes, as reported in a study. Ultrasonography provides a reliable and objective means of detecting LH.

Important injection site complications associated with insulin therapy can influence insulin pharmacokinetics, which can, in turn, lead to glycaemic fluctuations above and below target blood glucose levels.

To assess the prevalence and risk factors of cutaneous complications of subcutaneous insulin, researchers looked at 500 patients who had been injecting insulin for ≥2 years. All patients underwent clinical examination (gel-assisted palpation), ultrasonography, and punch biopsy of skin to assess for the presence of cutaneous complications of insulin therapy.

LH was detected in 44.6 percent of patients by clinical examination, with ultrasonography diagnosing additional 13.4 percent who were missed on clinical examination. LH was strongly associated with incorrect rotation of injection sites (p<0.001) and reusage of insulin syringe for more than five times (p<0.001).

Among 100 patients who underwent skin biopsy, two showed apple green birefringence, which was confirmed to be associated with insulin via positive staining with anti-insulin antibody.

Of note, patients with insulin-derived amyloidosis had similar clinical and ultrasonographic characteristics as that of those with lipohypertrophy.

The findings indicate that insulin-derived amyloidosis may be a more common complication of subcutaneous insulin therapy than previously thought and that ultrasonography may facilitate early diagnosis of LH.