AIMS: To investigate the effects of a single dose of 1.2 mg liraglutide, a once-daily glucagon-like peptide-1 (GLP-1) receptor agonist, on key renal parameters in patients with type 2 diabetes.

METHODS: The study was a placebo-controlled, double-blind, cross-over in 11 male patients with type 2 diabetes. Measurements included (51) Cr-EDTA plasma clearance estimated glomerular filtration rate (GFR) and MRI-based renal blood flow (RBF), tissue perfusion and - oxygenation.

RESULTS: Liraglutide had no effect on GFR (95% CI -6.8 to 3.6 ml/min/1.73 m(2) ) or RBF (95% CI -39 to 30 ml/min) and did not change local renal blood perfusion or oxygenation. The fractional excretion of lithium increased 14% (p = 0.01) and sodium clearance tended to increase (p = 0.06). Liraglutide increased diastolic and systolic blood pressure (3 and 6 mm Hg) and heart rate (3 min(-1) ) (all p < 0.05). Angiotensin II concentration decreased 21% (p = 0.02), but there were no effects on other renin-angiotensin system components, atrial natriuretic peptides (ANP), methanephrines or the excretion of catecholamines.

CONCLUSIONS: Short-term liraglutide treatment did not affect renal hemodynamics but decreased the proximal tubular sodium reabsorption. Blood pressure increased as opposed to long-term treatment. Catecholamine levels were unchanged and the results did not support a GLP-1-ANP axis. Angiotensin II levels decreased, which may contribute to renal protection by GLP-1 receptor agonists.