Antioxidant status in experimental hyperthyroidism: effect of vitamin E supplementation.

Free radical-mediated oxidative stress has been implicated in the genesis and exacerbation of degenerative diseases. In view of the role of oxidative processes in hyperthyroidism, in this study, we investigated the antioxidant status of erythrocytes in experimental hyperthyroidism and the effect of vitamin E supplementation on defense systems. Our findings of significantly increased T4 and T3 and undetectable TSH values in thyroxine administered rats confirmed the establishment of hyperthyroidism. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione (GSH) values were found to be significantly increased in hyperthyroid rats in comparison to the control group. Vitamin E supplementation to hyperthyroid rats induced a significant decrease in GSH-Px activity and a significant increase in GSH level. These findings show that hyperthyroidism increases the components of the antioxidant system in the erythrocytes. Furthermore, vitamin E supplementation reduces the burden of oxidative stress in hyperthyroidism.

Growth and IGF-1 levels of children with familial Mediterranean fever on colchicine treatment.

OBJECTIVE: To evaluate growth process and insulin like growth factor-1 (IGF-1) levels in children with familial Mediterranean fever (FMF). METHODS: This prospective study group consisted of 51 children with FMF under colchicine therapy (20 boys, 31 girls) and 42 healthy children (22 boys, 20 girls). All children were prepubertal. Bone ages and IGF-1 levels were determined in all cases. Height velocity (HV), height standard deviation score (SDS), target height and target height SDS were calculated. RESULTS: There was no statistical difference in age, HSDS, target height SDS and bone ages between healthy and diseased subjects. HV of children with FMF did not differ significantly from the control group. There was no statistical difference in age, HSDS, target height SDS and bone ages between healthy and FMF subjects. HV of children with FMF did not differ significantly from the control group. There was no significant correlation between disease duration, number of attacks, erythrocyte sedimentation rate and HV, HSDS and IGF-1 levels of FMF patients. There was positive correlation between cumulative colchicine dose and HV (r = 0.29). CONCLUSION: Growth and IGF-1 levels of children with FMF do not differ from their healthy peers. However, there was positive correlation between HV and cumulative colchicine dose. This study suggests that colchicine not only has no adverse influence on growth, but more by suppressing disease activity and inflammation it has an enhancing role.

The effect of iron supplementation on GSH levels, GSH-Px, and SOD activities of erythrocytes in L-thyroxine administration.

Our aim was to study the effect of iron supplementation on the following aspects of erythrocyte metabolism in experimental hyperthyroidism: glutathione (GSH) levels, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) activities. Hyperthyroidism induced by L-thyroxine administrations significantly raised erythrocyte GSH, GSH-Px and SOD levels of the rats (P < 0.001). Likewise, we observed that iron supplementation induced significant rises in erythrocyte GSH, GSH-Px and SOD levels (P < 0.001) as compared with the control group. The erythrocyte GSH, GSH-Px and SOD levels of hyperthyroidism-induced iron-supplemented animals were significantly higher when compared with either the iron-supplemented group (P < 0.001) or the only L-thyroxine-administered hyperthyroid group (P < 0.001, P < 0.05, P < 0.01, respectively). The results of this study show that L-thyroxine administration and/or iron supplementation increases GSH, GSH-Px and SOD levels of erythrocytes.

Evaluation of growth hormone secretion and insulin-like growth factor-1 in prepubertal children with thalassemia.

Growth retardation is a clinical feature of patients with thalassemia major, and endocrine studies have frequently revealed the presence of normal growth hormone (GH) secretion. The present study was undertaken in 14 prepubertal thalassemic children (9 males and 5 females), aged 2(2/12) to 10(3/12) years, with the aim of evaluating GH response to i.v. arginine, oral L-dopa stimulation and insulin-like growth factor-1 (IGF-1) levels. Eleven patients had peak serum GH levels less than 7 ng/ml and two patients had peak serum GH levels of 7-10 ng/ml with arginine. Similarly, 10 patients had peak levels less than 7 ng/ml and one patient had a peak level of 7-10 ng/ml with L-dopa. Thus, nine of the patients had GH deficiency and two had partial GH deficiency. Three patients had elevated basal GH values. The serum IGF-1 levels in the patients were not statistically different from the levels in the controls, but three patients had low IGF-1 values. These findings suggest a defect in the regulatory mechanisms of GH secretion.

Effect of treatment on growth in congenital adrenal hyperplasia.

In 22 patients with congenital adrenal hyperplasia (CAH), the effect of treatment on growth was evaluated retrospectively. The degree of control with treatment had generally been assessed by measurements of serum 17-hydroxyprogesterone (17-OHP) and/or urinary pregnanetriol levels. In 20 patients, there were no significant differences in both height SDS for bone age (-2.05 +/- 1.89 vs -1.85 +/- 1.30) and height SDS for chronological age (CA) (0.23 +/- 1.94 vs -0.36 +/- 1.81) in a mean uninterrupted treatment period of 5.80 +/- 3.58 years. Further analysis in salt-losers and nonsalt-losers separately showed that height SDS for bone age had decreased in the salt-losers and had increased in the nonsalt-losers. Six patients had signs of early puberty. In 22 patients, there was a negative correlation between the prednisolone dose on one hand and height velocity SDS for CA and bone age velocity on the other. It was also found that the mean serum levels of 17-OHP did not always reflect the degree of long term control measured by auxological parameters. These findings indicate that our treatment in the patients did not result in a significant improvement in height prognosis. We can conclude that growth prognosis in CAH patients can be improved by relying on auxological parameters rather than serum 17-OHP and urinary pregnanetriol levels for monitoring control. Special attention should be paid to salt-losers in this respect.