Diabetes; Nephropathy (Manifestation)

The study will investigate if treatment with Roxadustat improves kidney oxygenation in diabetic patients with nephropathy receiving treatment for renal anemia, compared to patients receiving treatment with darbepoetin alpha. Participants will be randomized to either treatment, and receive equal care for renal anemia. Kidney oxygenation will be examined before treatment start and after 24 weeks using BOLD-MRI (blood oxygen level-defendant MRI), a non-invasive method available for measurement of tissue oxygenation levels that is comparable with direct invasive measurement of partial oxygen pressure. Blood and urin samples will be collected in connection to these visits. The primary endpoint is the change in medullary and cortical R2\* (inversely proportional to the tissue oxygenation content) after 24 weeks. Secondary endpoints will be albuminuria and urinary levels of ROS (evaluated by electron paramagnetic resonance (EPR) spectroscopy with CPH spin probes).