Protein from plant, as opposed to animal, sources may be preferred in chronic kidney disease (CKD), due to lower bioavailability of phosphate and lower nonvolatile acid load.
Observational cross-sectional study.
Setting & Participants
2938 participants with chronic kidney disease and information on dietary intake at the baseline visit in the Chronic Renal Insufficiency Cohort Study.
Percentage of total protein from plant sources (% plant protein) was determined by scoring individual food items from the National Cancer Institute Diet History Questionnaire (DHQ).
Metabolic parameters, including serum phosphate, bicarbonate (HCO3), potassium, and albumin, plasma fibroblast growth factor 23 (FGF23), and parathyroid hormone (PTH), and hemoglobin.
We modeled the association between % plant protein and metabolic parameters using linear regression. Models were adjusted for age, sex, race, diabetes, body mass index, eGFR, income, smoking, total energy intake, total protein intake, 24 hour urinary sodium, use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers and use of diuretics.
Higher % plant protein was associated with lower FGF23 (p=0.05) and higher HCO3 (p=0.01), but not with serum phosphate or PTH (p=0.9 and 0.5, respectively). Higher % plant protein was not associated with higher serum potassium (p=0.2), lower serum albumin (p=0.2) or lower hemoglobin (p=0.3). The associations of % plant protein with FGF23 and HCO3 did not differ by diabetes status, sex, race, CKD stage (2/3 vs. 4/5) or total protein intake (≤ 0.8 g/kg/d vs. >0.8 g/kg/d) (p-interaction > 0.10 for each).
Cross-sectional study; Determination of % plant protein using the DHQ has not been validated.
Consumption of a higher percentage of protein from plant sources may lower FGF23 and raise HCO3 in patients with CKD.