Plasma selenium content, platelet glutathione peroxidase and superoxide dismutase activity of residents in Kashin-Beck disease affected area in China.

The activity of platelet glutathione peroxidase, of platelet and erythrocyte superoxide dismutase and the concentration of plasma selenium and vitamin E were measured in two groups of residents in the Kashin-Beck disease affected area and in three from a non-affected area. Average plasma selenium levels and platelet glutathione peroxidase activity were significantly lower in the endemic area than in the non-endemic area, indicating that the residents in the endemic area are indeed in a low selenium status. There existed a significantly positive correlation, r = 0.94, n = 78, p less than 0.001, between platelet glutathione peroxidase activity and plasma selenium concentration over a range from 2 to 79 micrograms/L (mean values 5 to 66 micrograms/L). Platelet glutathione peroxidase also correlated well with plasma selenium in each group of residents with varying plasma selenium levels, demonstrating that determination of glutathione peroxidase activity in platelets can be used as an indicator for assessing low selenium status in humans. No significant difference of vitamin E levels was observed between the residents in the endemic and non-endemic areas. There were no statistically significant differences in the activity of superoxide dismutase between each two groups studied, showing that superoxide dismutase does not undergo a compensatory increase in the residents of low selenium status.