Serum lipoproteins in home total parenteral nutrition patients

Patients maintained in our home total parenteral nutrition (HTPN) program receive very small amounts of cholesterol in their solutions. Because of the severe intestinal insufficiency which is characteristic of this group, they do not absorb significant amounts of cholesterol or bile salts from their intestines. We investigated the serum lipoproteins in nine patients maintained on HTPN for 36 +/- 4 (mean +/- SEM) months. Fat emulsions were given twice a week as a source of essential fatty acids. Mean serum cholesterol 110 +/- 6.5 mg/dl, LDL-cholesterol 75 +/- 6 mg/dl, and HDL-cholesterol 29 +/- 1 mg/dl, were at or below the 5th percentile compared with age- and sex-matched Lipid Research Clinic controls. HDL-cholesterol to serum cholesterol ratio was in the normal range (0.25 +/- 0.30). The mean serum cholesterol did not rise, but the mean serum triglyceride rose significantly from 72 +/- 4 to 104 +/- 16 mg/dl (p less than 0.05) immediately after completion of TPN infusions with fat emulsions. There was a negative correlation between the length of HTPN therapy and the total serum cholesterol (r = 0.43, p less than 0.05). Thus, HTPN patients have markedly depressed concentrations of total serum cholesterol, LDL-cholesterol, and HDL-cholesterol, but the ratio of HDL cholesterol to total serum cholesterol is in the normal range.