A novel hypothesis linking low-grade ketonaemia to cardio-renal benefits with sodium-glucose cotransporter-2 inhibitors

The cardio-renal benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors are well established. In 2016, we postulated that these benefits are attributable, in part, to the occurrence of chronic low-grade ketonaemia and a shift in myocardial and renal fuel metabolism away from fat oxidation, which is energy inefficient, towards ketone oxidation, which is more energy efficient. This shift improves myocardial and renal function and can potentially translate into lower rates of progression to heart failure and end-stage kidney disease in patients with and without diabetes. There is now evidence that, in addition to being an efficient fuel substrate, ketones also have antiinflammatory and antioxidative benefits on the heart and the kidney. In addition, ketones have positive effects on mitochondrial biogenesis and function, and on erythropoiesis, and thereby are potentially able to further ameliorate the proinflammatory and hypoxic milieu in those with heart and kidney failure, independent of hyperglycaemia. In the present review, we propose a novel hypothesis to link the pleiotropic effects of low-grade ketonaemia to the cardio-renal benefits seen with SGLT2 inhibitors.