Subclinical non-autoimmune hypothyroidism in children with steroid resistant nephrotic syndrome

Abstract

Subclinical non-autoimmune hypothyroidism is present in a significant proportion of children with SRNS despite partial or complete remission. Thyroid profile should be evaluated routinely in this subset of patients.

Autoimmune Hypothyroidism and Nephrotic Syndrome

“…In addition, other factors that are frequently present in patients with the nephrotic syndrome, such as hypoalbuminemia, increased serum free fatty acid concentrations, and furosemide administration, can also affect thyroid function tests. [9][10][11][12] Urinary losses of thyroxine (T4)-binding globulin (TBG) and other thyroid hormone-binding proteins (transthyretin and albumin) and the T4 bound to them result in a low total T4 concentrations in approximately 50 percent of nephrotic patients with a relatively normal glomerular filtration rate (GFR). [9][10][11][12] Serum triiodothyronine (T3) concentrations may also be low due also to decreased binding.…”

“…There is often a good correlation between the serum T4 and T3 and the serum albumin concentration. [9][10][11][12] Serum reverse T3 (rT3) concentrations are also low. Similar mechanism also seen in patient with metabolic syndrome associated with thyroid dysfunction.…”

A study on thyroid function test in children with nephrotic syndrome

“…They found an overt hypothyroidism with low FT 4 (normal values: 0.7-2.0 ng/mL) and elevated serum TSH above reference values (0.45-mIU/L). 15 Hypothyroidism should be actively sought for in patients with nephrotic syndrome as it is a treatable complication which increases morbidity in children. Given the urinary losses of multiple proteins in addition to albumin, it is important to monitor all children with nephrosis for secondary metabolic complications and to treat these complications at the earliest.…”

Should all nephrotics with thyroid dysfunction be treated with levothyroxine?

“…Guo et al did not mention estimated GFR (eGFR) of the patients in their study, which may confound their results [1]. Finally, decrease in thyroid hormones and increase in TSH is transient in patients with SSNS, and they return to normal on remission; however, this may be persistent in patients with congenital NS and those with SRNS due to massive prolonged proteinuria [3]. We studied thyroid functions in 20 children with SRNS (14 in complete remission and six in partial remission) and found six of them to have nonautoimmune subclinical hypothyroidism [3].…”

“…Finally, decrease in thyroid hormones and increase in TSH is transient in patients with SSNS, and they return to normal on remission; however, this may be persistent in patients with congenital NS and those with SRNS due to massive prolonged proteinuria [3]. We studied thyroid functions in 20 children with SRNS (14 in complete remission and six in partial remission) and found six of them to have nonautoimmune subclinical hypothyroidism [3]. Four of six children with grade 2-3 subclinical hypothyroidism received thyroid hormone replacement therapy, and levels of TSH normalized in all patients on therapy.…”