Clinical and MRI characteristics and follow-up studies of insulin-derived amyloidosis

Effectiveness of management protocol for insulin balls in diabetics: a scoping review

Aim

In order to achieve good glycemic control, the prevention and management of insulin balls is important for diabetic patients during insulin therapy. However, insulin balls still occur within the clinical setting. This review evaluated the effectiveness of programs designed to manage insulin balls.

Methods

A scoping review was conducted based on the Japanese and English literature available from a systematic literature search conducted from January 1964 to March 2022. Three databases were searched: PubMed, CINAHL, and Ichushi-Web.

Results

A total of 33 articles met the inclusion criteria, which consisted of 3 for prevention management of insulin balls and 30 for management after the occurrence of insulin balls. Findings for prevention management suggested that the insulin injection technique education (avoidance of repeated injections to the same site) and providing knowledge (about insulin balls) prevented the appearance of insulin balls. As for post-occurrence management, insulin injection technique education (avoidance of injections to the insulin ball, avoidance of repeated injections to the same site, and switching the injection site) improved blood glucose control. Hypoglycemia was observed in all studies that included an assessment of hypoglycemia. None of the studies evaluated long-term effects of either preventive or post-occurrence management.

Conclusions

Providing insulin injection technique education is an effective management protocol for insulin balls. Moreover, education about hypoglycemia is important for patients with insulin balls. Further studies to investigate the long-term effects in the management of insulin balls are needed.

Determination of amyloid core regions of insulin analogues fibrils

A rapid-acting insulin lispro and long-acting insulin glargine are commonly used for the treatment of diabetes. Clinical cases have described the formation of injectable amyloidosis with these insulin analogues, but their amyloid core regions of fibrils were unknown. To reveal these regions, we have analysed the hydrolyzates of insulin fibrils and its analogues using high-performance liquid chromatography and mass spectrometry methods and found that insulin and its analogues have almost identical amyloid core regions that intersect with the predicted amyloidogenic regions. The obtained results can be used to create new insulin analogues with a low ability to form fibrils.

Abbreviations

a.a., amino acid residues; HPLC-MS, high-performance liquid chromatography/mass spectrometry; m/z, mass-to-charge ratio; TEM, transmission electron microscopy.

Insulin-derived amyloidosis without a palpable mass at the insulin injection site: A report of two cases

To date, almost all case reports of insulin-derived amyloidosis described the presence of a subcutaneous mass that was observable on physical examination. This report presents two cases of insulin-derived amyloidosis without palpable masses at insulin injection sites. In both cases, blood glucose concentrations improved, and the insulin dose could be reduced by an average of 45% after changing the insulin injection sites. The insulin absorption at the site was reduced to at most 40% of that at a normal site in one case. Magnetic resonance imaging and ultrasonography were useful to screen and differentiate insulin-derived amyloidosis without a palpable mass. This report showed that insulin-derived amyloidosis without a palpable mass can be present at the insulin injection site, and has similar clinical effects to insulin-derived amyloidosis with palpable masses.