Abstract P145: The Effects of Phosphorus Additives on Albuminuria and Fibroblast Growth Factor-23
Background: Phosphorus-based additives are prevalent in processed foods. Their effects on cardiovascular and renal health are unknown.
Methods: We conducted a randomized, double-blind, cross-over study to examine the effects of phosphorus additives on albuminuria and fibroblast growth factor-23 (FGF-23) in adults with microalbuminuria and estimated glomerular filtration rate (eGFR) ≥ 45 ml/min/1.73m2. Participants (n=31) received unaltered beverages and breakfast bars (with or without phosphorus additives; 941 mg/d contrast in phosphorus) for 3 week periods, separated by a 2-4 week washout period. Diet was assessed by 24-hour recalls bi-weekly. Primary outcomes were albuminuria and FGF-23 assessed by two 24-hour urine collections and a single fasting blood draw at the end of each period.
Results: We included 31 participants (32% female, 90% black, 87% hypertension, 48% diabetes) with mean age, eGFR, and 24-hour urine albumin excretion of 66 years, 68 ml/min/1.73m2, and 74.4 mg/d, respectively. Mean self-reported phosphorus intake and 24-hour urine phosphorus excretion was 1113 mg/d and 687.9 mg/d at baseline. Self-reported phosphorus intake (excluding intervention products) decreased by 151 mg/d (p=0.004) during the phosphorus additive period compared to the non-phosphorus additive period as did protein intake (8.0 g/d lower, p=0.02). In unadjusted analyses, consumption of phosphorus additives increased 24-hour urine phosphorus excretion by a mean of 505 mg/d, non-significantly increased albuminuria by 14.3% (95% CI: -2.5% to 34.0%, p=0.1), but had no effect on FGF-23 (3.0%, 95% CI: -9.3% to 16.8%). After adjustment for changes in weight and self-reported dietary intake (sodium, phosphorus, and protein intake), consumption of phosphorus additives increased albuminuria by 22.5% (95% CI: 3.1% to 45.6%, p=0.02). In unadjusted analysis excluding two patients non-compliant with the intervention, consumption of phosphorus additives increased albuminuria by 17.3% (95% CI: 0.08% to 37.5%, p=0.049). Neither sensitivity analysis showed an effect on FGF-23.
Conclusion: High consumption of phosphorus-based additives may increase albuminuria. Further studies are needed to confirm this finding and determine the long-term effects on cardiovascular and renal health.
Author Disclosures: A. Chang: None. E. Miller: None. C. Anderson: None. M. Moser: None. J. Charleston: None. K. White: None. B. Henry: None. S. Oh: None. L. Appel: None. S. Juraschek: None.
This research has received full or partial funding support from the American Heart Association, National Center.
- © 2016 by American Heart Association, Inc.