Prevention of total parenteral nutrition-induced cholestasis by low non-protein energy supply: an animal experiment and clinical study.

30 cecum-ligated rats were divided into 3 groups: group OS fed with stock diet; group HTPN (high-energy total parenteral nutrition) infused with 260 kcal/kg/d of non-protein energy (NPE), which was isoenergetic to the first group; and group LTPN (low-energy total parenteral nutrition) infused with 160 kcal/kg/d. All rats received approximately 1.4 g/kg/d of nitrogen. Positive nitrogen balances were obtained in all 3 groups, although the values were lower in group LTPN. Serum albumin remained normal. Total bilirubin, lipoprotein-X, alkaline phosphatase (AKP), gamma-glutamyl trans-peptidase (gamma-GT) and glutamic-pyruvic transminase (GPT) were significantly lower in group LTPN than in group HTPN. Histological examination with both light and electron microscopy revealed more severe bile stasis in the canaliculi in group HTPN than in group LTPN. In a separate clinical study, lasting more than 4 weeks, two groups of surgical patients received isonitrogenous TPN regimes containing different amounts of energy (40 kcal/kg/d and 30 kcal/kg/d, respectively). 40% of the NPE was infused as fat. The patients were matched for age, clinical condition and nutritional support technique. There were no differences between the groups in nitrogen balance or serum albumin. However serum AKP and gamma-GT increased in the HTPN group after 2 weeks of nutritional support, whilst in the LTPN group the increase did not occur until the fourth week. Our results suggest that TPN-induced cholestasis can be prevented or delayed by reducing the intake of NPE.