Daily variability in serum levels of calciprotein particles and their association with mineral metabolism parameters: A cross‐sectional pilot study

Background Calciprotein particles (CPPs), colloidal protein-mineral nanoparticles composed of solid-phase calcium phosphate and serum protein fetuin-A found in blood, are emerging as a novel component of chronic kidney disease-mineral and bone disorder (CKD-MBD). In this study, we examined daily variations in CPPs as well as their association with mineral metabolism parameters in normal individuals and early-stage CKD patients. Methods Twenty subjects (10 healthy adults, 10 diabetic patients) were enrolled. We measured serum CPP Fetuin-A and analyzed related clinical parameters. Results Estimated glomerular filtration rates (eGFR) were 103 ± 11 and 75 ± 24 mL/min/1.73 m2 in healthy adults and diabetic patients, respectively. Serum CPP Fetuin-A (g/L) were elevated at postprandial 2 h in diabetic patients. Furthermore, serum CPP Fetuin-A were inversely correlated with eGFR and serum 1,25-dihydroxyvitamin D3 and magnesium levels and were positively correlated with serum fibroblast growth factor-23. Conclusions These findings indicated that serum CPP Fetuin-A were affected by food intake and may contribute to the pathophysiology of mineral metabolism in subjects with normal and moderately impaired renal function.