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

Aim: 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). The relationship of CPPs with factors known to underlie the CKD-MBD pathophysiology is not well known.The aim of this study is to examine 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. Serum CPP Fetuin-A was measured and analyzed in relation to clinical parameters. Results: Estimated glomerular filtration rates (eGFR) were 103 ± 11 and 75 ± 24 mL/min per 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.