BOSTON—Higher levels of fibroblast growth factor 23 (FGF23) are associated with an elevated risk of respiratory infection among older adults, independent of renal function, researchers reported at the National Kidney Foundation 2016 Spring Clinical Meetings.

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.”

Continue Reading

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.

The study cohort was composed of participants in a randomized controlled trial evaluating the effect of high versus standard dose vitamin D on infection.