Eder M, Darmann E, Haller MC, et al. - Given that renal loss of potassium (K⁺) and magnesium (Mg²⁺) in salt losing tubulopathies (SLT) results in a significantly decreased Quality of Life (QoL) as well as higher risks of cardiac arrhythmia, and the function of K⁺ as the ideal marker of potassium homeostasis in SLT is questioned based on certain findings, so researchers sought to define surrogate endpoints for future treatment trials in SLT in terms of their usefulness to ascertain QoL as well as essential clinical results. In this hypothesis-generating study, 11 patients with SLTs were examined. The biochemical, clinical and cardiological parameters as well as their link with QoL were evaluated among participants. The findings of this prospective cross-sectional study revealed hyperaldosteronism, K⁺ and Mg²⁺ as the most crucial parameters of QoL, and refuted the suitability of transtubular potassium gradient as a marker for hyperaldosteronism or QoL. QoL as well as aldosterone, K⁺ and Mg²⁺ should be evaluated in future confirmatory studies in SLT.