Zinc, copper and antioxidant enzyme activities in healthy elderly Tunisian subjects.

Trace elements like zinc and copper play an important role in maintaining metabolic homeostasis in elderly subjects and is therefore expected to have a crucial effect on antioxidant mechanism. The objective of the present study was to investigate age-related variations of zinc, copper and antioxidant enzyme activities (superoxide dismutase: SOD, glutathione peroxidase: GPx and catalase: CAT) taking into account gender differences in a Tunisian elderly population. A group of 100 healthy elderly subjects (55-85 years old) were then separated in three sub-groups according to age intervals. A control group of 100 adults aged between 30 and 45 years was considered. The obtained results confirmed the decrease of plasma zinc level with age increase in both men and women. Moreover, prevalence of zinc deficiency increased with age: normal zinc concentration was obtained in about 60% of adults and only in 35% of the elderly subjects over 75 years old. No significant variation was obtained for copper concentration. GPx and SOD activities were lower in aged subjects in comparison to adults. Zinc and antioxidant enzyme activities were found to be negatively correlated to age. However, an investigation on a large size sample with various health and well-controlled dietary statuses should be conducted for a better understanding of the zinc or copper metabolism and their effect on oxidant stress during aging.