BACKGROUND: Acute kidney injury develops in 20-50% of patients with sepsis and septic shock (1), the risk being increased in patients with type 2 diabetes (2). To which extent, if any, changes in renal haemodynamics during sepsis contribute to the pathogenesis of AKI, remains controversial. The aim of this study was to measure renal plasma flow (RPF) and glomerular filtration rate (GFR) in healthy volunteers and persons with type 2 diabetes, respectively, using an intravenous injection of Escherichia coli endotoxin as a model of systemic inflammation during early sepsis. METHODS: After ethical approval, a thorough physical examination and informed consent, RPF and GFR were measured with DTPA renography in 16 healthy men and 16 men with type 2 diabetes at baseline as well as 1.5 hours and 6.5 hours after endotoxin injection (0.3 ng/kg). Noninvasive blood pressure and heart rate were measured every 15 minutes. Filtration fraction (FF) was calculated as GFR / RPF. Repeated measurements analysis of RPF, GFR and FF were performed using SAS Mixed Models with the model TIME GROUP TIME*GROUP and SUBJECT as a random factor. Significant changes from baseline were analysed post hoc with paired t-tests. RESULTS: Data are presented in the Figure “Renal Haemodynamics” and Table 1. A mixed model analysis showed no interaction between time and group (healthy vs. diabetics). Time, but not group, had a significant effect on RPF (P<0.001), GFR (P<0.01) and FF (P<0.05). Mean arterial pressure and heart rate were unchanged. A systemic inflammatory response with leucocytosis, temperature rise and malaise was seen but resolved within 6 hours. CONCLUSION: RPF, GFR and FF are reversible reduced during early systemic inflammation triggered by an injection of Escherichia coli endotoxin. The presence of type 2 diabetes did not affect these changes. The results suggest a role for renal haemodynamic alterations in sepsis-induced acute kidney injury. In contrast, the significance of these changes for the increased risk in diabetic patients of developing acute kidney injury during sepsis is less clear.