Abstract: PO0538
Circadian Changes in Serum Phosphate Among Patients with ESKD on Hemodialysis
Session Information
- Bone and Mineral Metabolism: Clinical
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Bone and Mineral Metabolism
- 402 Bone and Mineral Metabolism: Clinical
Authors
- Ginsberg, Charles, University of California San Diego, La Jolla, California, United States
- Miller, Lindsay M., University of California San Diego, La Jolla, California, United States
- Ofsthun, Norma J., Fresenius Medical Care North America, Waltham, Massachusetts, United States
- Dalrymple, Lorien S., Fresenius Medical Care North America, Waltham, Massachusetts, United States
- Ix, Joachim H., University of California San Diego, La Jolla, California, United States
Background
Serum phosphate concentrations are known to have a circadian rhythm in healthy adults and in CKD, with a nadir in the late morning and a peak in the afternoon. Circadian changes in serum phosphate concentrations among persons on chronic hemodialysis may have important treatment implications, as serum phosphate concentrations are a therapeutic target in these patients.
Methods
We assessed serum phosphate concentrations in 118,440 persons with ESKD treated with in-center hemodialysis at Fresenius Kidney Care centers across the United States in July 2017. We used linear regression to assess the relationship between time of day and serum phosphate concentrations. We assessed unadjusted models and models adjusting for age, sex, race, region, weight, diabetes and use and dose of vitamin D analogs, calcimimetics and phosphate binders.
Results
The cohort had mean age 63 ± 13 years, 44% were female, 53% were white and 33% were black. The mean serum phosphate concentration was 5.3 ± 1.5mg/dl. In both the unadjusted and fully adjusted models, serum phosphate concentrations varied over the day with a peak at 6:00 pm and a nadir at 10:00 am (p<0.001). In the unadjusted model the difference from peak to nadir was 0.6mg/dl. This difference was attenuated in the fully adjusted model to 0.2 mg/dl (Figure).
Conclusion
In a large and diverse cohort of adults with ESKD treated with hemodialysis, serum phosphate concentrations varied depending on the time of day in which serum phosphate levels were measured. Thus, the target serum phosphate range for patients treated with hemodialysis should account for when serum phosphate is being measured.
Funding
- NIDDK Support –