#715 Adiponectin / leptin ratio as an index to determine the risk of metabolic and rejection complications in patients after kidney transplantation
Authors: Graňák Karol , Vnučák Matej , Beliančinová Monika , Kleinova Patricia , Blichová Tímea , Dedinska Ivana 
Published: May 2024

Abstract

Background and Aims
Adipose tissue, as an endocrine and paracrine organ, produces several hormones that are involved in the regulation of metabolic and inflammatory processes or immune system activity. While leptin is the main pro-inflammatory marker of adipose tissue, adiponectin is characterized by its anti-inflammatory effects. The adiponectin / leptin (A/L) ratio had been shown to correlate better with the occurrence of cardiometabolic risk factors than hormone concentrations alone. Results in the general population suggest that an A/L ratio &gt; 1 can be considered normal, an A/L ratio of 0.5-1 indicates a moderate increase, and an A/L ration &lt; 0.5 a high increase in cardiometabolic risk. The first aim of our study was to determine the risk of developing post-transplant diabetes mellitus (PTDM), prediabetes and other metabolic risk factors in relation to the A/L ratio in patients after kidney transplantation (KT). The second aim was to determine the risk of developing acute graft rejection in relation to the A/L ratio in patients after KT.

Method
A total of 104 patients were included in our prospective analysis after applying inclusion and exclusion criteria. Pre-transplantation and subsequently at 3, 6 and 12 months after KT, we recorded baseline characteristics of donors and recipients, including parameters characterizing graft function, metabolic (lipid profile, indices of glucose metabolism) and anthropometric parameters. At the same time, we examined serum adipocytokine concentrations (adiponectin, leptin) and calculated the A/L ratio. In the third month after KT, all patients underwent protocol graft biopsy and donor specific antibody (DSA) testing by Luminex method.

Results
We found that during the follow-up period, there was a significant increase in the A/L ratio in the control group (p = 0.0013) and, on the other hand, a significant decrease in the group who developed PTDM (p = 0.0003). Comparing the different subgroups divided on the A/L ratio one year after KT, we found that patients with an A/L &lt; 0.5 were significantly longer in the dialysis program, had higher body mass index (BMI), waist circumference, worse graft function, and a higher prevalence of prediabetes and PTDM compared with those whose A/L ratio was &gt; 1. Using logistic regression in multivariate analysis, we identified age at the time of KT [OR 1.0709, (p = 0.0337)], triglycerides level at 1 year after KT [OR 2.7735, (p = 0.446)] and A/L ratio &lt; 0.5 [OR 3.1724, (p = 0.014)] as independent risk factors for the development of prediabetes and PTDM 1 year after KT. At the same time, after adjusting for differences in baseline donor and recipient characteristics, we identified the subgroup with an A/L ratio &lt; 0.5 pre-transplant [HR 1.6126, (p = 0.0133)] and 3 months after KT [HR 1.3150, (p = 0.0172)] as an independent risk factor for the development of acute graft rejection. In the subsequent specification of the rejection episode, we found that A/L ratio &lt; 0.5 pre-transplant [HR 2.2353, (p = 0.0357)] and 3 months after KT [HR 3.0954, (p = 0.0237)] is and independent risk factor for the occurrence of acute humoral rejection with DSA positivity.

Conclusion
In our study, we found that an A/L ratio &lt; 0.5 is an independent risk factor for the development of prediabetes, PTDM 1 year after KT and acute humoral graft rejection with de novo DSA production in the third month after KT. This is the first study to investigate the correlation of the A/L ratio with the risk of developing metabolic and immunological complications in patients after KT.