Relationship of Different Sourced Protein Intake, Quantity of Plasma Amino Acid with Chronic Kidney Disease

The association of protein from different food sources and different plasma amino acids with risk of chronic kidney disease (CKD) is unclear.

We aimed to investigate longitudinal relationships of dietary protein intake from different sources and quantity of plasma amino acids with new-onset CKD in the general population.

Participants (mean age: 56 y) without CKD at baseline were included in the UK Biobank. A total of 176,980 were included in the analysis for protein intakes and 99,061 participants were included in the analysis for plasma amino acids. Information on dietary protein was collected based on a 24-h dietary recall from the previous day. Plasma amino acid concentrations were measured by a high-throughput nuclear magnetic resonance (NMR)-based metabolic biomarker profiling platform. The study outcome was new-onset CKD.

During a median follow-up of 12 y (beginning between 2006 and 2010 and ending in 2021), 3542 participants (2,128,626 person-year) developed new-onset CKD. Higher intakes of dairy-derived and fish-derived protein were associated with lower incidence of CKD [per standard deviation, SD increment, adjusted hazard ratio, HR (95% confidence interval, 95% CI): 0.95 (0.91, 0.98) and 0.95 (0.92, 0.99), respectively], but protein intake from other foods was not (P-trend > 0.1). Moreover, incident CKD was lower among those with higher plasma histidine (per SD increment; adjusted HR = 0.90; 95% CI: 0.86, 0.95), tyrosine (0.90; 0.87, 0.94), isoleucine (0.89; 0.85, 0.92), leucine (0.89; 0.85, 0.93), and valine (0.89; 0.85, 0.93).

The protein intake from dairy and fish, as well as the concentration of plasma histidine, tyrosine, isoleucine, leucine, and valine, was inversely associated with new-onset CKD.