GDF15 and cardiovascular disorder: While this approach reduces the heterogeneity of participants, caution should be exercised in generalising our data to broader ICU populations, particularly given the importance of GDF-15 in cardiovascular disease.5 Only 8/20 patients were able to complete the MRC score for diagnosis of ICUAW; however, all patients were found to have definite evidence of visible muscle wasting and functional muscle weakness, and within the criteria set out by Stevens et al,19 the diagnosis was made by the clinical team.