title: D-xylose absorption and disposition in patients with moderately impaired renal function.
abstract: D-Xylose kinetics were studied after oral and intravenous administration to 10 patients with impaired renal function, three of whom were being evaluated for intestinal malabsorption. The 0.32 +/- 0.06 L/kg (mean +/- SD) distribution volume of D-xylose in patients with uncomplicated renal impairment was larger than the value of 0.23 +/- 0.04 L/kg that we reported previously for normal subjects (P less than 0.01). Renal clearance was also reduced, averaging 87% of glomerular filtration rate estimated from creatinine clearance, so that the elimination-phase half-life was prolonged to 138 +/- 39 minutes from 75 +/- 11 minutes in normal individuals (P less than 0.01). The 25 gm oral D-xylose dose was 77.4% +/- 14.8% absorbed in the patients with uncomplicated renal impairment, similar to the 69.4% +/- 13.6% absorption reported in normal individuals. However, the absorption half-life was prolonged from 31 +/- 12 minutes in normal subjects to a value of 62 +/- 23 minutes (P less than 0.02). Of the usual clinical indexes of D-xylose absorption, the serum concentration measured 1 hour after the oral dose was best correlated with the extent of D-xylose absorption (r = 0.76; P less than 0.01), and the standard lower normal limit of 0.2 mg/ml was satisfactory.
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007408:Intestinal Absorption; D007674:Kidney Diseases / Q000150:complications / Q000378:metabolism*; D007700:Kinetics; D008286:Malabsorption Syndromes / Q000150:complications / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D008954:Models, Biological; D014994:Xylose / Q000378:metabolism*
chemical_list: D014994:Xylose