To the editor

We read with great interest the results of the study by Wawrzeńczyk et al,1 who showed that individuals hospitalized due to decompensation of chronic heart failure (CHF) face a greater nutritional risk, with a significant decrease in skeletal muscle mass (SMM) by 2.5 kg and in skeletal muscle index, by 0.8 kg/m2, compared with controls. Notably, patients with an SMM of 45.5% or greater (expressed as percentage of fat-free mass) experienced a significant 9-fold increase in the odds of death.1

Sodium-glucose cotransporter 2 (SGLT-2) inhibitors, primarily developed as a drug class for patients with type 2 diabetes mellitus (T2DM), have now been established as a treatment option in individuals with CHF, according to the most recent guidelines. They have been shown to significantly decrease the risk for hospitalization due to decompensation of CHF.2 In the acute setting, they have been proven to decrease the risk for a combined end point of worsening heart failure (HF), rehospitalization for HF or death at 60 days, despite the fact that they do not improve symptoms, diuretic response, and levels of N-terminal pro–B-type natriuretic peptide or shorten the length of hospital stay.3 Therefore, there is a vivid and ongoing discussion on whether SGLT-2 inhibitors should be continued or started in individuals with acute HF or decompensation of CHF.

SGLT-2 inhibitors decrease body weight, mainly due to net caloric loss in the context of glucosuria. They have been also shown to decrease total fat mass when administered in patients with T2DM receiving insulin treatment.4 A numerical but statistically insignificant decrease in SMM was demonstrated.4 There is an ongoing randomized controlled trial that will assess the effect of long-term treatment with SGLT-2 inhibitors on SMM in elderly patients with T2DM.5

Therefore, since more than half of patients included in the study by Wawrzeńczyk et al1 had a previous diagnosis of T2DM, it would be of great interest to know how many of them were taking SGLT-2 inhibitors prior to enrollment and if there was a difference in SMM between individuals treated with SGLT-2 inhibitors and those that were not. The latter analysis will provide some useful insights into the mechanisms of action of SGLT-2 inhibitors.