Urinary albumin excretion in patients with diabetes after renal transplantation

Many studies support microalbuminuria screening as the cornerstone of early detection of nephropathy in patients with diabetes mellitus (DM), but there are no studies that address its utility in the follow-up of renal transplant recipients with DM.

We retrospectively studied 104 subjects with DM who had undergone renal transplantation. Sixty three had a history of preexisting DM and 41 developed posttransplant diabetes (PTDM). We collected data on random urine albumin/creatinine (A/C) ratio, systolic blood pressure (SBP), serum creatinine concentration (Cr), and HBA1C.

Mean subject age was 58 +/- 9.8 years; 63% received cadaveric grafts while 37% received living donor grafts. Mean follow-up was 7 years (range 1.6 to 15.6). Seventy percentage developed proteinuria over time; of these 62% developed microalbuminuria (A/C ratio 30 to 300 microg albumin/mg creatinine) and 38% developed macroalbuminuria (A/C ratio >300 microg/mg). Subjects with preexisting DM were as likely to develop an elevated A/C ratio as those with PTDM. Higher A/C ratios correlated with higher SBP (P < .01), with higher HBA1C (P < .036), and with higher Cr (P < .01). Lower A/C ratios correlated with more stable Cr over time (P < .01).

Strict SBP and glycemic control are associated with a significantly lower A/C ratio in patients with DM after renal transplantation. Annual monitoring of A/C ratio in patients with DM after renal transplantation can identify candidates for stricter glycemic and blood pressure control, similar to current recommendations for all other patients with DM.