Patients with chronic kidney dysfunction frequently develop thickening of the heart muscle, so-called left ventricular hypertrophy. This is particularly pronounced in patients who are in the late stage of renal dysfunction, that is to say those requiring renal replacement therapy such as haemodialysis. The danger of this cardiac hypertrophy lies in the considerable associated increase in risk of acute cardiovascular disease, such as sudden cardiac death, for example. Haemodialysis patients have a number of risk factors for developing this form of cardiac hypertrophy. One of those is elevated levels of the protein Fibroblast Growth Factor 23 (FGF23), and these levels increase as kidney function deteriorates. However, FGF23 can be influenced by drugs in various ways. That is the finding of a recent study led by Katharina Dörr from the Division of Nephrology and Dialysis at MedUni Vienna’s Department of Medicine III.