Higher protein intake is not associated with decreased kidney function in pre-diabetic older adults following a one-year intervention-a preview sub-study
Concerns about detrimental renal effects of a high-protein intake have been raised due to
an induced glomerular hyperfiltration, since this may accelerate the progression of kidney disease.
The aim of this sub-study was to assess the effect of a higher intake of protein on kidney function in
pre-diabetic men and women, aged 55 years and older. Analyses were based on baseline and one-year
data in a sub-group of 310 participants included in the PREVIEW project (PREVention of diabetes
through lifestyle Intervention and population studies in Europe and around the World). Protein
intake was estimated from four-day dietary records and 24-hour urinary urea excretion. We used
linear regression to assess the association between protein intake after one year of intervention and
kidney function markers: creatinine clearance, estimated glomerular filtration rate (eGFR), urinary
albumin/creatinine ratio (ACR), urinary urea/creatinine ratio (UCR), serum creatinine, and serum
urea before and after adjustments for potential confounders. A higher protein intake was associated
with a significant increase in UCR (p = 0.03) and serum urea (p = 0.05) after one year. There were
no associations between increased protein intake and creatinine clearance, eGFR, ACR, or serum
creatinine. We found no indication of impaired kidney function after one year with a higher protein
intake in pre-diabetic older adults