Differences in clinicopathological characteristics between lipohypertrophy and localized insulin-derived amyloidosis: A scoping review

Insulin is used as a therapeutic agent in patients with diabetes, and cutaneous lipohypertrophy (LH) and localized insulin-derived amyloidosis (LIDA) are well-known adverse effects associated with insulin injections. The clinical implications, management, assessment methods, and pathological differentiation of LH and LIDA have been recently updated. This review was to update our knowledge of the pathological differentiation, effects of insulin absorption, hypoglycemic events, and recent assessment methods for LH and LIDA. A scoping review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta Analyses extension for Scoping Reviews guidelines. Original studies and case reports in English were also included. PubMed and Scopus databases were searched for keywords to identify papers published up to January 2022. A total of 113 studies were identified through a database search, and 31 were eligible for inclusion in this scoping review. In the 31 studies included in this review, patients with type 2 diabetes had high frequencies of LH and LIDA. LH outcome parameters were assessed using pathological findings and imaging. LIDA is mainly determined by pathological methods, such as hematoxylin and eosin and Congo red staining. Several in vitro and in vivo LIDA models of LIDA have been developed. These results suggest that pathological analysis is required to identify LH and LIDA. It is important to consider LIDA, as it likely influences insulin adsorption and glycemic control. Although several studies have evaluated the LIDA process, little is known about the mechanisms underlying the development of adverse effects associated with insulin injections.