Fibroblast Growth Factor-23 and Hypophosphatemia in Chronic Obstructive Pulmonary Disease Patients

Impaired serum phosphate levels may contribute to respiratory muscle weakness that further negatively impacts Chronic Obstructive Pulmonary Disease (COPD) patients. Recently, Fibroblast Growth Factor 23 (FGF-23) has been shown to play an important role in the regulation of body phosphate. The current study includes 2 groups: 70 COPD patients and 34 control subjects. Blood samples were taken for a panel of routine lab tests. FGF-23 was measured using a commercially available ELISA kit. Plasma FGF-23 levels were significantly higher in the patient group compared to the control group (P=0.000). Tubular maximum absorption of phosphate was significantly reduced in COPD patients compared to the control group (P=0.04). Plasma FGF-23 negatively correlated with FEV1 and serum albumin. Elevated plasma FGF-23 levels found in COPD patients correlated with disease severity and may represent an additional factor causing low serum phosphate.