The impact of pancreas transplantation on diabetic complications: A systematic review.

Background: Pancreas Transplantation (PT) provides optimal treatment for patients with severe complicated Type 1 Diabetes Mellitus (T1DM). Restoration of beta-cell mass allows return to euglycaemia and insulin independence. We aimed to examine its impact on the secondary complications associated with severe T1DM including diabetic eye disease, neuropathy and cardiovascular disease.

Methods: A database search using MedLINE to identify publications to April 2023 was conducted. Searches were performed using MeSH terms 'Pancreas Transplantation' AND 'Diabetes Mellitus, Type 1' 'Diabetic Retinopathy' OR 'Heart Disease' OR 'Cardiovascular Diseases' OR 'Peripheral Vascular Disease' OR "Amputation' OR 'Neuropathy."

Results: All articles were retrospective with 51.1 % (n = 23) case control studies and 48.9 % (n = 22) cohort studies. 82.2 % (n = 37) examined simultaneous pancreas and kidney (SPK) transplantation and 17.8 % (n = 8) analysed pancreas transplant alone (PTA). Heterogenous outcomes metrics were employed. 15 studies examined diabetic retinopathy (DR) with 53.3 % (n = 8) demonstrated improvements after PT, while the remainder (n = 7) exhibited stabilisation. 16 studies assessed neuropathy and 87.5 % (n = 14) demonstrated beneficial effects of PT on nerve conduction studies, vibration perception threshold or corneal confocal microscopy. There was a positive effect on cardiovascular disease by reduction in the incidence of cardiac events, improvement in metabolic profile and increased left ventricular ejection fraction. 14 studies examined cardiovascular disease (71.4 % (n = 10) improvement; 14.2 % (n = 2) stabilisation; 14.2 % (n = 2) progression).

Conclusion: SPK and PTA have beneficial effects in ameliorating or stabilising diabetes complications. Future work should seek to reduce heterogeneity of outcome metrics assessing T1DM complication profile to facilitate robust comparison of beta-cell replacement interventions.