Brødsgaard and colleagues report associations between lower resting oxygen saturation and several neuropathy phenotypes in type 1 and type 2 diabetes. Three issues may sharpen their interpretation. Fingertip pulse oximetry may be influenced by neuropathy-related changes in peripheral perfusion, potentially making the exposure partly dependent on the phenotype being studied. The proposed differences between diabetes types require formal interaction testing rather than comparison of separate stratum-specific significance. Finally, discordance between continuous and dichotomous SpO₂ analyses argues for direct assessment of the exposure-response shape. Addressing these issues could clarify whether resting SpO₂ reflects systemic hypoxaemia, a peripheral perfusion-sensitive phenotype, or both.