Sex-specific differences in serum phosphate persist in patients with CKD

Phosphate plays a critical role in numerous metabolic processes, and sex-specific differences have been identified in its concentrations in the general population. However, such differences have not been investigated in the context of CKD, in which additional factors may exert a more pronounced impact on these levels.

This retrospective study was conducted in an outpatient nephrology clinic and included data from 632 patients with CKD stages 1-5.

Serum phosphate was negatively associated with age (r = -0.08; p = 0.04) and estimated glomerular filtration rate (eGFR) (r = -0.23; p < 0.001). Women had significantly higher serum phosphate levels than men (3.6 mg/dL vs. 3.3 mg/dL; p = 0.01), an association confirmed in multivariate analysis. No significant sex differences were observed in serum calcium, parathyroid hormone (PTH), 25-hydroxyvitamin D, or the use of vitamin D supplements, calcium salts, or calcitriol.

Even in the presence of CKD, women have higher serum phosphate (P) levels than men. This sex difference should be considered in the management of CKD-mineral and bone disorder (CKD-MBD).