Oxidative stress and antioxidant enzyme values in lymphomonocytes after an oral unsaturated fat load test in familial hypercholesterolemic subjects.

Oxidative stress (OS) has been observed in conditions affecting the cardiovascular system. Familial hypercholesterolemia (FH) is associated with an increased risk of premature coronary heart disease. In the postprandial state, circulating lipids and lipoproteins can modulate OS status. Our aim was to study the response of lymphomonocyte OS status and reactive oxygen species by-products after an oral unsaturated fat load test (OFLT) in those with FH and to compare this response with that obtained in normolipidemic, normoglycemic subjects. We studied 12 patients with FH and 20 healthy controls. In both groups, lymphomonocyte, oxidized/reduced glutathione ratio, and malondialdehyde were determined at baseline and at 2, 4, 6, and 8 hours after an OFLT. Fasting urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine and isoprostane were measured using standard procedures. In both groups, oxidized/reduced glutathione ratio and malondialdehyde significantly decreased in the postprandial state after the OFLT. Both parameters were significantly higher in the FH group at baseline and during all the postprandial points, but the reduction from the baseline levels was significantly higher in the FH group than in the control group. Urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine was significantly increased in the FH group compared with the healthy control group, indicating a higher fasting OS status. We conclude that subjects with FH exhibited OS levels that were higher than in controls before and after an OFLT, but the improvement in the OS status after the unsaturated fat load was significantly higher in subjects with FH.