Lipid peroxidation and antioxidant status in adults receiving lipid-based home parenteral nutrition.
BACKGROUND
Infusion of lipid emulsions rich in polyunsaturated fatty acids (PUFAs) may increase lipid peroxidation, which is counteracted mainly by superoxide dismutase (SOD) (a zinc-, copper-, and manganese-dependent 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, and alpha-tocopherol, zinc, copper, and manganese as recommended by the American Medical Association, and no selenium.


METHODS
Serum malondialdehyde, plasma alpha-tocopherol, selenium, Se-GSHPx, PUFAs, and red blood cell Se-GSHPx and SOD were evaluated in 12 patients and in 25 healthy control subjects. Malondialdehyde was also assessed in a group of 40 healthy control subjects.


RESULTS
Patients had significantly higher concentrations of malondialdehyde and SOD and lower alpha-tocopherol concentrations and selenium nutritional status. Linear regression analysis 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 alpha-tocopherol was associated with the daily PUFA load (r=-0.65, P< 0.04) and with the duration of HPN (r=-0.74, P< 0.02).


CONCLUSIONS
In HPN patients, the peroxidative stress due to lipid emulsions rich in PUFAs is counteracted primarily by alpha-tocopherol. The dosages of alpha-tocopherol, zinc, copper, and manganese recommended by the American Medical Association appear sufficient to sustain SOD activity but inadequate to maintain alpha-tocopherol nutritional status. HPN formulations should be supplemented with selenium.
Pironi
L
L
Department of Internal Medicine and Gastroenterology, Saint Orsola-Malpighi Hospital, University of Bologna, Italy. Pironi@med.unibo.it
Ruggeri
E
E
Zolezzi
C
C
Savarino
L
L
Incasa
E
E
Belluzzi
A
A
Munarini
A
A
Piazzi
S
S
Tolomelli
M
M
Pizzoferrato
A
A
Miglioli
M
M
D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D005217:Fat Emulsions, Intravenous / Q000008:administration & dosage*; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D016331:Parenteral Nutrition, Home; D012044:Regression Analysis; D012643:Selenium / Q000097:blood; D013482:Superoxide Dismutase / Q000097:blood; D014810:Vitamin E / Q000097:blood
D000975:Antioxidants; D005217:Fat Emulsions, Intravenous; D005231:Fatty Acids, Unsaturated; D014810:Vitamin E; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D012643:Selenium