Structural changes indicating diabetic nephropathy can occur very rapidly even with intensive glycemic control, and more research is needed to improve prevention of nephropathy after kidney transplantation, according to study findings published in Diabetes Care.
Improved glycemic control can reduce the occurrence of early diabetic nephropathy, but there is limited evidence whether intensive glycemic control decreases the risk for severe renal outcomes. Diabetic nephropathy in renal allografts has been reported in patients with diabetes prior to transplant and with new-onset diabetes after transplantation. Researchers conducted a prospective study to investigate the effect of pretransplant diabetes on occurrence of diabetic nephropathy up to 5 years after kidney transplantation. They also studied the contribution of posttransplant glycemic control in a cohort of 953 renal allograft recipients with 3458 protocol-specified renal allograft biopsy specimens.
Pretransplant diabetes was present in 164 (17.2%) recipients, with type 2 diabetes being the primary type (n = 146; 89%). Despite intensive glycemic control (average glycated hemoglobin between 6.90% and 7.10% at years 1, 2, and 5), mesangial matrix expansion reached a cumulative incidence of 47.7% in patients with pretransplant diabetes vs 27.1% in patients without diabetes (hazard ratio, 1.55; 95% CI, 1.07-2.26; P =.005). Mesangial matrix expansion, however, was not speciﬁc to diabetic nephropathy and was independently associated with increasing age. Diabetic nephropathy development was also independent of posttransplant glycated hemoglobin levels.
These data suggest that mechanisms other than glycemic control “also underlie the rapid development of mesangial matrix expansion in patients with diabetes,” wrote the researchers, and that preventing diabetic nephropathy “requires more than pursuing low levels of glycated hemoglobin.”
Coemans M, Van Loon E, Lerut E, et al. Occurrence of diabetic nephropathy after renal transplantation despite intensive glycemic control: an observational cohort study [published online February 14, 2019]. Diabetes Care. doi:10.2337/dc18-1936