title: Letter: Variations in plasma urea and creatinine.
mesh_terms: D000328:Adult; D003404:Creatinine / Q000097:blood*; D004032:Diet; D004044:Dietary Proteins; D004435:Eating; D005215:Fasting; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D014508:Urea / Q000097:blood*
chemical_list: D004044:Dietary Proteins; D014508:Urea; D003404:Creatinine