Thyroid Dysfunction in Children with Idiopathic Nephrotic Syndrome Attending a Paediatric Hospital in Qazvin, Iran

Abstract

Objectives: Nephrotic syndrome is a glomerular disease characterised by a loss of albumin and high-molecular-weight proteins such as thyroxine-binding globulin and thyroid hormones, potentially resulting in subclinical or even overt hypothyroidism. This study aimed to compare thyroid hormone levels between nephrotic children and healthy controls as well as between nephrotic children in the active phase of the disease and those in remission. Methods: This case-control study was conducted between March 2016 and 2018 at a paediatric hospital in Qazvin, Iran. A total of 73 nephrotic children comprised the case group—including 49 with active disease and 24 in remission—while the control group included 74 healthy children. Thyroid function was assessed according to levels of thyroid-stimulating hormone (TSH), free triiodothyronine (T3), free thyroxine (T4), total T4, total T3 and anti-thyroid peroxidase. Results: All of the controls had normal total T4 levels. Elevated TSH levels were more frequent in nephrotic children compared to controls (34.2% versus 10.8%; P = 0.001). A significantly lower number of patients with active disease were euthyroid compared to those in remission (51% versus 95.8%; P = 0.001). Moreover, 7 (9.5%) of patients in the active and no patient in remission phase had abnormal total T4 levels (P <0.001), while 14.3% and 0% had highly elevated TSH levels (P = 0.002). Conclusion: Due to the prevalence of subclinical and even overt hypothyroidism, thyroid screening tests may be required for nephrotic children. However, further research is needed to confirm these findings.
 Keywords: Nephrotic Syndrome; Children; Albuminuria; Proteinuria; Hypothyroidism; Iran.

Hypothyroidism Among Children and Adolescents With Nephrotic Syndrome in Mulago National Referral Hospital, Kampala, Uganda; a Cross-sectional Study

“…These ndings of hypoalbuminemia being associated with hypothyroidism are similar to the ndings in a case-control study by Saffari et al which was conducted at a paediatric hospital in Qazvin, Iran. (20). The researchers reported a negative correlation between serum albumin and TSH levels in serum.…”

Overt Hypothyroidism and Severe Growth Retardation in a Preschool Girl with Poorly Controlled Nephrotic Syndrome: Case Report and Literature Review

“…It is impossible to precisely determine the incidence of hypothyroidism in children with NS [ 9 ]. 34.7–46.9% nephrotic children may develop subclinical hypothyroidism [ 2 , 4 ]. It has historically been linked to steroid-resistant NS; however, new evidence suggests that subclinical hypothyroidism can occur even in steroid-sensitive NS (SSNS) [ 10 ].…”

“…Patients with subclinical hypothyroidism have an increased risk of cardiovascular morbidity and mortality due to high serum cholesterol levels and other cardiac risk factors. TH assessment is strongly recommended for NS patients with elevated serum cholesterol [ 2 ]. Weight gain, hypercholesterolemia, delayed growth, delayed puberty, and depression can all occur because of hypothyroidism and may be mistakenly attributed to NS or the effect of steroid treatment.…”

“…NS is frequently associated with other pathologies, such as systemic diseases. Nephrotic children may also rarely develop thyroid hormone dysfunction due to urinary excretion of thyroid-binding globulin, transthyretin, and thyroid hormones [ 2 ]. Thyroid hormones are essential for normal growth [ 3 ], however, thyroid function tests are not generally performed in children with NS.…”

Re: Thyroid Dysfunction in Children with Idiopathic Nephrotic Syndrome Attending a Paediatric Hospital in Qazvin, Iran

“…Furthermore, 9.5% of patients in the active and no patient in the remission stage had abnormal free thyroxine levels (P <0.001), while 14.3% and 0% had highly increased TSH levels, respectively (P = 0.002). 1 In patients with NS, the rates of subclinical hypothyroidism (34.7%) and overt hypothyroidism (14.3%) were significantly higher compared to controls (4.2%; 0% respectively; P = 0.001). Based on the reported prevalence of subclinical (34.7%) and even overt hypothyroidism (14.3%), Saffari et al recommended that thyroid screening tests might be needed for patients with NS.…”