title: Renal, metabolic, and hormonal responses to proteins of different origin in normotensive, nonproteinuric type I diabetic patients.
abstract: OBJECTIVE
  Whether the differences in renal function found in vegetarian compared with omnivorous subjects are related to quantity or quality of the protein is unknown. We have studied the renal function of nine normotensive, nonproteinuric type I diabetic patients who were fed in random order for 4 weeks either an animal protein diet (APD) (protein intake 1.1 g . kg-1 . day-1) or a vegetable protein diet VPD (protein intake 0.95 g . kg-1 . day-1). The two diets were isocaloric.
  
  
  METHODS
  In a crossover study, we measured glomerular filtration rate (GFR) (inulin clearance), renal plasma flow (RPF) (p-aminohippurate clearance), plasma amino acids, growth hormone, glucagon, insulin-like growth factor I-(IGF-I), and microalbuminuria.
  
  
  RESULTS
  GFR and RPF were lower with the VPD than with the APD (89.9 +/- 4.1 vs. 105.6 +/- 5.1 ml . min-1 . 1.73 m-2, P < 0.05, and 425.7 +/- 22.2 vs. 477.8 +/- 32.2 ml . min-1 1.73m-2, P < 0.05, respectively). Renal vascular resistance (RVR) was higher with the VPD than with the APD (101 +/- 25 vs. 91 +/- 10 mmHg . min-1 . ml-1, P < 0.05). Filtration fraction (FF) remained unchanged after either diet. Fractional clearance of albumin fell with the VPD to 2.0 +/- 0.65 from 3.4 +/- 1.15 x 10-6 (P < 0.05). At the end of the APD and VPD, the plasma levels of growth hormone and glucagon did not differ significantly. Plasma levels of IGF-I were higher with the APD than with the VPD (1.1 +/- 0.6 vs. 0.9 +/- 0.13 U/ml, P < 0.05). Plasma concentrations of valine and lysine were significantly higher with the APD than with the VPD (234.6 +/- 30.3 vs. 164.5 +/- 25.4 mm1/1, P < 0.05, and 565 +/- 45.1 vs. 430 +/- 56.1 mmol/l, P < 0.05, respectively), whereas plasma valine was strongly correlated to the GFR (r = 0.832, P < 0.01). No differences were found in other amino acids.
  
  
  CONCLUSIONS
  A VPD has significantly different renal effects from an APD equal in protein intake in normotensive type I diabetic patients. This could be explained partly by differences in plasma concentrations of amino acids and IGF-I.
authors.affiliation: Renal Unit, Alexandra General Hospital, Athens, Greece.
authors.forename: P A
authors.initials: PA
authors.lastname: Kontessis
authors.forename: I
authors.initials: I
authors.lastname: Bossinakou
authors.forename: L
authors.initials: L
authors.lastname: Sarika
authors.forename: E
authors.initials: E
authors.lastname: Iliopoulou
authors.forename: A
authors.initials: A
authors.lastname: Papantoniou
authors.forename: R
authors.initials: R
authors.lastname: Trevisan
authors.forename: D
authors.initials: D
authors.lastname: Roussi
authors.forename: K
authors.initials: K
authors.lastname: Stipsanelli
authors.forename: S
authors.initials: S
authors.lastname: Grigorakis
authors.forename: A
authors.initials: A
authors.lastname: Souvatzoglou
mesh_terms: D000328:Adult; D000419:Albuminuria; D000596:Amino Acids / Q000097:blood*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000503:physiopathology* / Q000652:urine; D014676:Diet, Vegetarian; D004044:Dietary Proteins; D002149:Energy Intake; D005260:Female; D005919:Glomerular Filtration Rate; D005934:Glucagon / Q000097:blood / Q000378:metabolism; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism; D006728:Hormones / Q000097:blood / Q000378:metabolism*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011897:Random Allocation; D012079:Renal Circulation; D014675:Vegetables
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D004044:Dietary Proteins; D006728:Hormones; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D005934:Glucagon