Adipose-tissue fatty acid composition in recipients of long-term total parenteral nutrition (TPN)

Adipose-tissue fatty acid composition was studied in nine patients requiring long-term total parenteral nutrition (TPN). The patients received 17 ± 8% of total energy as soybean-oil emulsion (Intralipid®) and 66 ± 8% as glucose. Despite low intake of 9c−16:1, 11c−18:1, and 13c−18:1, adipose-tissue concentrations of these monounsaturated fatty acids were higher in the TPN patients than in free-living control subjects (P < 0.05) and inversely correlated with the percent energy from fat (r = −0.56, P = 0.11; r = −0.64, P = 0.06; r = −0.81, P = 0.008, respectively). This suggests that these fatty acids accumulated from endogenous synthesis from carbohydrate and thus may be markers of the percent fat in the diet. The essential fatty acids, 18:2 and 18:3n−3, positively correlated with the percent energy from fat (r = 0.79, P = 0.01; r = 0.80, P = 0.01, respectively). Linear-regression analysis suggests that normal adipose-tissue stores of 18:2 and 18:3n-3 are maintained when intravenous soybean-oil emulsion provides 11 –20% and 412%, respectively, of total energy.