Premium
A high protein diet at the upper end of the Acceptable Macronutrient Distribution Range (AMDR) leads to kidney glomerular damage in normal female Sprague‐Dawley rats
Author(s) -
Wakefield Andrew P.,
House James D.,
Ogborn Malcolm R.,
Weiler Hope A.,
Aukema Harold M.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a100
Subject(s) - glomerulosclerosis , medicine , renal function , endocrinology , creatinine , kidney , proteinuria , albumin
In setting the AMDR for protein at 10–35% of daily energy, the Institute of Medicine acknowledged a lack of data regarding the safety of long‐term intakes. The current study assessed the impact of chronic (17 months) protein consumption at the upper end of the AMDR on renal function and histology. Using plant and animal whole protein sources, female Sprague‐Dawley rats (70 days old; n=8–11 at 4, 8, 12, or 17 mo.) were randomized to either a normal (NP; 15% of energy) or high protein (HP; 35% of energy) diet. Egg albumin and skim milk replaced carbohydrates in the HP diet. Diets were balanced for energy, fat, vitamins and minerals, and offered ad libitum . Renal function was analyzed by urinary protein levels and serum creatinine. Glomerular hypertrophy, glomerulosclerosis and tubulointerstitial fibrosis were assessed on formalin fixed kidneys sections. Rats consuming the HP compared to NP diet had ~15% higher kidney weights (P = <0.0001) and 2–8 times higher proteinuria (P = <0.0001). Consistent with this, HP compared to NP rats had ~23% larger glomeruli (P = 0.0017) and ~29% more glomerulosclerosis (P = 0.0003). Serum creatinine and tubulointerstitial fibrosis levels were not different between groups. These data in normal female rats suggest that protein intakes at the upper end of the AMDR are detrimental to kidney health in the long term. Further studies in other animal models and in humans are warranted. Funded by CIHR.