L. Pironi et al., LIPID-PEROXIDATION AND ANTIOXIDANT STATUS IN ADULTS RECEIVING LIPID-BASED HOME PARENTERAL-NUTRITION, The American journal of clinical nutrition, 68(4), 1998, pp. 888-893
Background: Infusion of lipid emulsions rich in polyunsaturated fatty
acids (PUFAs) may increase lipid peroxidation, which is counteracted m
ainly by superoxide dismutase (SOD) (a zinc-, copper-, and manganese-d
ependent enzyme), selenium-dependent glutathione peroxidase (Se-GSHPx)
, and alpha-tocopherol. Objective: We investigated lipid peroxidation
and antioxidant status in patients receiving home parenteral nutrition
(HPN) providing variable amounts of a lipid emulsion rich in PUFAs, a
nd alpha-tocopherol, zinc, copper, and manganese as recommended by the
American Medical Association, and no selenium. Design: Serum malondia
ldehyde, plasma alpha-tocopherol, selenium, Se-GSHPx, PUFAs, and red b
lood cell Se-GSHPx and SOD were evaluated in 12 patients and in 25 hea
lthy control subjects. Malondialdehyde was also assessed in a group of
40 healthy control subjects. Results: Patients had significantly high
er concentrations of malondialdehyde and SOD and lower alpha-tocophero
l concentrations and selenium nutritional status. Linear regression an
alysis showed that malondialdehyde was associated with the daily PUFA
load (r = 0.69, P< 0.03) and with plasma alpha-tocopherol (r = -0.59,
P< 0.05), but stepwise multiple regression analysis confirmed only the
association between malondialdehyde and alpha-tocopherol; plasma alph
a-tocopherol was associated with the daily PUFA load (r = -0.65, P < 0
.04) and with the duration of HPN (r = -0.74, P < 0.92). Conclusions:
In HPN patients, the peroxidative stress due to lipid emulsions rich i
n PUFAs is counteracted primarily by alpha-tocopherol. The dosages of
alpha-tocopherol, zinc, copper, and manganese recommended by the Ameri
can Medical Association appear sufficient to sustain SOD activity but
inadequate to maintain alpha-tocopherol nutritional status. HPN formul
ations should be supplemented with selenium.