Liver dysfunction and energy source: results of a randomized clinical trial

Controversy still exists regarding the role of the carbohydrate:fat ratio on liver function abnormalities associated with the administration of total parenteral nutrition (TPN). We designed a prospective clinical trail comparing standard carbohydrate-based TPN (8.5% amino acids, 50% dextrose, 7.5% of total calories from lipids) with an isocaloric lipid-based TPN (8.5% amino acids, 30% dextrose, 40% of total calories from lipids) in 43 patients exclusively receiving TPN > or = 2 weeks. Energy needs were calculated as basal energy expenditure x 1.5. The mean daily calorie intake for patients who obtained carbohydrate-based TPN (CHO) was 2227 kcal, whereas the lipid-based TPN (LIP-CHO) group achieved a mean of 2310 kcal. Patients with preexisting liver disease were excluded. There was no significant difference in age or diagnosis between the groups. We monitored total bilirubin, direct bilirubin, alkaline phosphatase, gamma-glutamyl transferase, lactic dehydrogenase, serum glutamic oxaloacetic transaminase, and serum glutamic pyruvic transaminase. Initial liver-associated tests did not vary significantly between groups. Group mean values after 2 weeks of TPN were significantly different for total bilirubin (1.5 mg/dL in the CHO group compared with 0.7 in the LIP-CHO group, p < .05) and direct bilirubin (0.8 mg/dL in the CHO group compared with 0.3 mg/dL in the mixed substrate group, p < .05). Differences in mean values between groups were also noted for serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, and lactic dehydrogenase. In conclusion, this prospective trial reveals that the use of a balanced energy source TPN solution prevents the abnormalities in liver-associated tests commonly associated with TPN.(ABSTRACT TRUNCATED AT 250 WORDS)