Background: The interactions between kidney and thyroid functions have been known for many
years; oxidative damage has been proposed as one of the possible mechanism involved in the
nephrotic syndrome (NS). This study was done to find out the thyroid function of nephrotic children
during nephrosis and to compare any significant changes of thyroid function status during nephrosis
and remission in relation to oxidative stress markers. Patients and Methods:The study included
60 patients with steroid responsive NS (SRNS) and 30 children with matched age and sex as control.
Cases were divided into three groups as follow, Group A: Include 35 patients with SRNS in relapse.
Group B: Include 25 patients with SRNS in remission for periods ranging from 3 to 9 months, and
not receiving steroid therapy. Group C: Include 30 children with matched age and sex as control.
Methods: A thorough history and examinations, total serum thyroxine and triiodothyronine (TT4
and TT3) as well as serum free T4 (FT4), thyroid-stimulating hormone (TSH), and assessment of
malondialdehyde (MDA) and total antioxidant capacity (TAC) levels as an oxidative stress markers
were measured in all studied groups. Results:Serum TSH was significantly higher in patients with
SRNS in relapse in comparison with patients with SRNS in remission and with control group (P < 0.001
in both), we found a significant decrease in TT4 and FT4 and TT3 and FT3 (FT3) concentrations in
patients with SRNS in relapse in comparison with both cases with SRNS in remission and control
group (P < 0.001 in both). MDA levels were significantly elevated, while TAC level was significantly
decreased in patients with SRNS in relapse in comparison with patients with SRNS in remission and
with control group (P < 0.001 in both). There was a positive correlation between serum TSH and
plasma MDA and a negative correlation with FT4. Conclusions:The development of hypothyroidism
in children with SRNS is associated with alteration in oxidant and antioxidant status. The biochemical
hypothyroid state in relapse phase is temporary and improves with remission.