Dietary Protein Intake and Change in Estimated GFR in the Cardiovascular Health Study
Jeannette M. Beasley Nutrition Available online 14 December 2013
Objective
With aging, kidney function declines, as evidenced by reduced glomerular filtration rate. It is controversial whether or not high protein intake accelerates the kidney function decline.
Research Methods & Procedures
We examined whether dietary protein is associated with change in kidney function (mean follow-up 6.4 (SD=1.4, range = 2.5 to 7.9) years in the Cardiovascular Health Study (n =3,623). We estimated protein intake using a food frequency questionnaire (FFQ) and estimated glomerular filtration rate (eGFR) from cystatin C. Associations between protein intake and kidney function were determined by linear and logistic regression models.
Results
Average protein intake was 19% of energy intake (SD=5%). Twenty-seven percent (n=963) of study participants had rapid decline in kidney function, as defined by (ΔeGFRcysC > 3 mL/min per 1.73 m2). Protein intake (characterized as g/day and % energy/day), was not associated with change in eGFR (P>0.05 for all comparisons). There were also no significant associations when protein intake was separated by source (animal and vegetable).
Conclusion
These data suggest that higher protein intake does not have a major impact on kidney function decline among elderly men and women.