HAMP and diabetes mellitus: These findings were not significantly different between the thrice-weekly vs. once-monthly groups (P = 0.30 and 0.50, respectively), and were not significantly modified by age, gender, diabetes, ESA group (i.e., Monday/Tuesday darbepoetin, Wednesday/Thursday darbepoetin, and thrice-weekly epoetin-α/β), and baseline levels of 25(OH)D, hepcidin, ESA resistance index (Supplementary Fig. S1 online; Pinteraction > 0.05 for all).