Age-dependent variations of the plasma peroxides and total antioxidants in women with obesity and hypothyroidism.

The concentrations of peroxides, total antioxidants and free sulfhydryl (SH) groups in the plasma of normal persons vary depending on age and sex. The most significant differences for peroxides were found between young and old people over 60 years in both sexes. For the SH groups, significant differences were observed only between young and older women, while in men, similar differences were found only for total antioxidants. In women, the association of obesity with hypothyroidism induces a significant increase of peroxides even at the age of 35 years. This significant increase goes in parallel with a increase of uric acid and a decrease of the total antioxidants. Considering the inclusion of uric acid and of free SH groups among the natural antioxidants, the changes observed in obesity associated with hypothyroidism may suggest a tendency of an adaptation of the organism since hypothyroidism favors the peroxidation of lipids. Up to a certain age, varying according to the individuals, the rise of lipid peroxides is compensated by the increase of certain antioxidants, especially of uric acid.