Higher levels of fibroblast growth factor 23 (FGF23) are associated with a higher risk of respiratory infection among older adults independent of renal function.
In a study of 55 elderly individuals (mean age 80 years) living in long-term care facilities, Anna Jovanovich, MD, and colleagues at the University of Colorado Denver found that approximately each 5 mg/mL increment in FGF23 was associated with a significant 5-fold increased odds of respiratory infection in a fully adjusted model.
“Our study is the first to report a link between higher FGF23 levels and increased risk of infection in a non-dialysis population,” Dr Jovanovich told Renal & Urology News. “This observational study cannot prove causation but it adds to the existing literature that FGF23 may be involved in immune function.”
The investigators noted that FGF23 inhibits conversion of 25-hydroxyvitamin D to 1,25-hydroxyvitamin D, the active form of vitamin D that acts on immune cell vitamin D receptors to produce bactericidal cathelicidins. Higher levels of FGF23 have been linked with increased risk of infection among hemodialysis patients.