Urinary creatinine excretion is an indicator of physical performance and function

Muscle mass is essential for performing physical activity, and low muscle mass (sarcopenia) has been found to have a strong association with all-cause mortality in patients with type 2 diabetes (T2D).1 However, muscle mass is not routinely assessed in clinical practice and low muscle mass can easily go unnoticed in obese patients (sarcopenic obesity), which was emphasized in previous DIALECT findings.2 The current definition of sarcopenia requires presence of either low muscle mass, low muscle strength or poor physical performance rather than low muscle mass alone.3 Two methods for estimating muscle mass independent of kidney function in clinical practice are the 24 h urinary creatinine excretion rate (CER) and bioelectric impedance analysis (BIA), but their association with physical performance and function is unclear.4 In this study we investigate whether CER or BIA-derived predicted muscle mass also indicate physical performance and function in patients with T2D, in order to indirectly screen patients on sarcopenia.