SERUM TOTAL ANTIOXIDANT ACTIVITY IN RELATIVE HYPOCHOLESTEROLEMIA AND HYPERCHOLESTEROLEMIA

Individuals with low serum cholesterol experience greater than expecte d age-adjusted mortality from non-atherosclerotic diseases, including cancer, respiratory and digestive illnesses, but the basis for these a ssociations remains unclear. The current investigation considered the hypothesis that hypocholesterolemia is associated with reduced antioxi dant reserve. Serum total antioxidant activity as well as concentratio ns of vitamin E, vitamin C, and thiols were compared in two groups of 24 subjects distinct in both mean low density lipoprotein (LDL) choles terol (2.3 v. 4.9 mM) and mean total cholesterol (4.3 v. 7.0 mM). The low and high cholesterol groups were equivalent in gender mix, age, we ight, and serum total protein. Results reveal that compared with the h igh group, the low cholesterol group had decreased total serum antioxi dant activity (p <.05). Thiol concentrations were also lower in the lo w cholesterol group (p <.05). Group differences in serum total antioxi dant activity and thiol concentration were larger among men than women . The two groups did not differ in vitamin C. Low cholesterol was asso ciated with reduced absolute vitamin E levels, although the tocopherol : cholesterol ratio was the same in low and high cholesterol individua ls. These data indicate that hypocholesterolemia may be associated wit h low serum antioxidant reserve, possibly increasing susceptibility to oxidative stress.