Intensive monitoring for post-transplant diabetes mellitus and treatment with dipeptidyl peptidase-4 inhibitor therapy

Aim: Current monitoring practices fail to diagnose patients with post-transplant hyperglycaemia and tend to delay initiation of treatment, which potentially results in adverse graft and morbidity outcomes. This real-world study set out to assess the impact on insulin resistance indices of a new clinical pathway for diagnosis and treatment of hyperglycaemia following renal transplantation. Methods: A hundred and forty-seven adult renal transplant recipients, without pre-existing diabetes, from a single centre were included. Patients transplanted between January 2008 to September 2015 formed the historical cohort. Patients transplanted between October 2015 and February 2018 were subject to a new clinical pathway - if they had fasting blood sugar levels more than 7 mmol/L or random blood glucose levels more than 11.1 mmol/L, they had early introduction of oral therapy, using the DPP-4 inhibitor linagliptin. Results: In the historical cohort, 19.8% were diagnosed with PTDM, compared to 46.3% in the protocol cohort. Amongst patients with PTDM, there was a significant difference in HOMA-IR (p = 0.02) between the historical cohort (median HOMA-IR 3.33) and the protocol cohort (median HOMA-IR 2.21). There was a significant difference at each time point (0,1,2-h measurements) of blood glucose levels form oral glucose tolerance testing between patients with and without PTDM in the historical cohort (p < 0.001), but no difference between patients in the protocol cohort. Conclusion: Detection of PTDM was higher with the new clinical pathway. Early treatment of hyperglycaemia resulted in better insulin resistance scores. Larger prospective controlled studies focussing on early detection and management of PTDM with linagliptin are warranted.