Existing Knowledge Gaps in Risk Factors and Consequences of Lipohypertrophy in People Using Continuous Subcutaneous Insulin Infusion Therapy: A Systematic Review and Meta-analysis

Background: Lipohypertrophy is a common skin complication in individuals with insulin-treated diabetes, but this condition in those using insulin pumps (continuous subcutaneous insulin infusion, CSII) remains poorly understood. This study aimed to identify and summarize scientific evidence regarding the risk factors and clinical consequences of lipohypertrophy in people using CSII. Methods: Medical databases (MEDLINE/PubMed, Embase, CENTRAL) were searched to identify relevant studies published in English from 1990 to March 19, 2024. If possible, extracted data were cumulated in meta-analyses. This systematic review was registered on PROSPERO (CRD42024554127). Results: Nine studies reporting risk factors for lipohypertrophy or its consequences in people treated with CSII were identified. In the included studies, only individual risk factors were reported, which in most cases prevented the conduct of a meta-analysis. Meta-analyses could be performed for two factors, that is, improper cannula site rotation and male sex. The odds of developing lipohypertrophy were higher in individuals incorrectly rotating (prevalence odds ratio, pOR = 2.59 [1.39; 4.83]), whereas gender had no impact on the prevalence of lipohypertrophy (pOR = 1.13 [0.62; 2.06]). Due to the limitations of the available data, it was not possible to draw conclusions about the clinical consequences of lipohypertrophy in people on CSII. Conclusions: This systematic review demonstrated that studies on the risk factors and clinical consequences of lipohypertrophy in CSII users are limited and that the currently published data are insufficient to draw definitive conclusions. There is a need for more comprehensive and well-designed clinical studies to better understand this issue in CSII users.