A BERNIER-JEAN1, J LEWIS1,2,3, J CRAIG1, J HODGSON2,3, W LIM3,4, R PRINCE2,4, A TEIXEIRA-PINTO1, G WONG1
1Centre for Kidney Research, Children’s Hospital at Westmead School of Public Health, Sydney Medical School, The University of Sydney, Sydney, Australia, 2School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia, 3Medical School, University of Western Australia, Perth, Australia, 4Sir Charles Gairdner Hospital, Perth, Australia
Aim: To assess the association between the two origins of dietary protein, plant and animal, and the decline in kidney function over time in older women.
Background: Current guidelines advise against high protein intake in people with chronic kidney disease (CKD) for fear of accelerated progression in CKD. However, proteins from plant and animal origin may affect kidney function differently and have opposite effects on acid-base balance.
Methods: In a cohort of 1374 older Caucasian women (mean age 75±2.7 years-old), 999(73%) had estimated glomerular filtration rate (eGFR) measured at 5 years, and 661(48%) at 10 years, using CKD-EPI creatinine-cystatin equation. We assessed the association between plant and animal protein intake at baseline, 5 and 10 years and change in eGFR using linear mixed modelling.
Results: Mean decline of eGFR over time was 0.64 95%CI [0.56-0.72] ml/min/1.73m² per year. Higher intakes of plant protein were significantly associated with a slower decline in eGFR after adjusting for covariates such as animal protein and energy intake (P=0.008). For each 10g of plant protein, the yearly rate of eGFR decline was slower by 0.14 95%CI [0.04, 0.24] ml/min/1.73m². Animal protein intake was not associated with eGFR decline (0.03 95%CI [-0.01, 0.07] ml/min/1.73m²/year per 10g, P=0.18). Throughout 10 years, consuming the mean intake of plant protein (29g/day) was associated with a decline in eGFR of 2.5 95%CI [1.4, 3.7] ml/min/1.73m² while consuming one standard deviation above the mean (37g/day) was associated with a decline of 1.4 95%CI [-0.1, 3.1] ml/min/1.73m².
Conclusions: Older women consuming a higher plant protein intake may be protected against declining kidney function. Recommendations to reduce protein intake may need to be modified to incorporate protein origin.
Amelie is a PhD student at the Centre for Kidney Research affiliated with the University of Sydney. She completed her nephrology training in 2016 in Montreal, Canada. She is interested in lifestyle in chronic kidney disease (CKD). Her work examines the dietary patterns associated with CKD progression as well as the benefits of exercise training in people with CKD. Her thesis is currently supported by an NHMRC Post-Graduate scholarship.