A case of minimal change nephrotic syndrome with hypothyroidism deterioration

Kidney disease and thyroid dysfunction: the chicken or egg problem

Patients with non-dialysis-dependant chronic kidney disease (NDD-CKD) and dialysis-dependant chronic kidney disease (DD-CKD) frequently also suffer from thyroid disorders, especially hypothyroidism which is found two to five times more often among them compared to the general population. Emerging research has illustrated the potential prognostic implications of this association as NDD-CKD and DD-CKD patients with hypothyroidism have been shown to have higher mortality rates, and treatment of subclinical hypothyroidism in NDD-CKD patients has been reported to attenuate the decline of glomerular filtration rate over time. This review illustrates the bidirectional, multi-layered interplay between the kidneys and the thyroid gland explaining how pathologies in one organ will affect the other and vice versa. Additionally, it outlines the impact of thyroid disorders on routine parameters of kidney function (especially serum creatinine and serum cystatin C) that nephrologists should be aware of in their clinical practice. Lastly, it summarizes the emerging evidence from clinical studies on how treatment of subclinical hypothyroidism in NDD-CKD and DD-CKD patients may potentially have beneficial effects on kidney function as well as mortality. While most of the research in this area has been performed on adult patients, we specifically discuss what is currently known about thyroid dysfunctions in paediatric CKD patients as well and provide management suggestions. The evidence accumulated so far clearly indicates that further, prospective studies with meticulous methodology are warranted to refine our understanding of thyroid disorders in paediatric and adult CKD patients and establish optimal treatment pathways.

Nephrotic Syndrome as a Cause of Transient Clinical Hypothyroidism

Nephrotic syndrome may trigger the onset of hypothyroidism, promoting massive urinary protein losses including thyroxine (T4) and triiodothyronine (T3) along with their binding proteins. At an early stage, a clinical and biochemical euthyroid state is expected. However, in patients with prolonged and severe proteinuria, especially with concomitant low thyroid reserve, urinary losses of free and protein-bound thyroid hormones are sufficiently pronounced to induce a subclinical or overt hypothyroidism. Despite its high prevalence in clinical practice, the literature lacks case reports of newly diagnosed clinical hypothyroidism due to NS in adults, making this condition under-recognized. We report a case of a 23-year-old man with previous normal thyroid function who developed overt hypothyroidism due to a severe nephrotic syndrome, requiring supplementation with levothyroxine (LT). After the patient had undergone bilateral nephrectomy, treatment with LT was discontinued and thyroid function normalized.

Bidirectional Interaction of Thyroid-Kidney Organs in Disease States

Purpose

Thyroid hormones play an important role in growth, development, and physiology of the kidney. The kidney plays a key role in the metabolism, degradation, and excretion of thyroid hormones and its metabolites. The aim of this study is to investigate the prevalence of disease states of thyroid-kidney organs and detecting the correlation between thyroid and kidney function abnormalities.

Materials and Methods

In this retrospective study, a total of forty-five patients with thyroid and kidney dysfunction were investigated. Clinical features, laboratory data at initial presentation, management, and outcomes were collected. The paper has been written based on searching PubMed and Google Scholar to identify potentially relevant articles or abstracts. Median, percentage, mean ± standard deviation (SD), and the two-tailed t-test were used for statistical analyses. The correlation between variables was assessed by Pearson's, Spearman's correlation tests and regression analyses.

Results

The mean ± SD of age of study patients was 48.2 ± 22.93 years (ranging from 1 to 90 years). There was no correlation between serum thyroid-stimulating hormone, free thyroxine levels with estimated glomerular filtration rate, and proteinuria. No association between antimicrosomal antibodies with estimated glomerular filtration rate was seen. Cardiovascular disease was the most common complication of overt hypothyroidism in kidney dysfunction patients.

Conclusion

The present study showed more prevalence of primary hypothyroidism in comparison with other thyroid dysfunctions in patients with kidney dysfunction. Reduced mean values of thyroid function profiles after treatment suggest that this thyroid disease should be considered and ameliorated with thyroid hormone replacement therapy in patients with kidney disease.

Changes in the thyroid hormone profiles in children with nephrotic syndrome

Purpose

We compared thyroid hormone profiles in children with nephrotic syndrome (NS) during the nephrotic phase and after remission.

Methods

This study included 31 pediatric NS patients. The thyroid hormone profiles included serum levels of triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), and free T4.

Results

Of the 31 patients, 16 (51.6%) showed abnormal thyroid hormone profiles: 6 had overt hypothyroidism, 8 had subclinical hypothyroidism, and 2 had low T3 syndrome. The mean serum T3, T4, and free T4 levels in the nephrotic phase and after remission were 82.37±23.64 and 117.88±29.49 ng/dL, 5.47±1.14 and 7.91±1.56 µg/dL, and 1.02±0.26 and 1.38±0.23 ng/dL, respectively; the levels were significantly lower in the NS nephrotic phase (P=0.0007, P<0.0001, and P=0.0002). The mean serum TSH levels during the nephrotic phase and after remission were 8.05±3.53 and 4.08±2.05 µIU/ mL, respectively; they were significantly higher in the nephrotic phase (P=0.0005). The urinary protein/ creatinine ratio during the nephrotic phase was significantly correlated with serum T3, T4, and free T4 levels (r=-0.5995, P=0.0032; r=-0.5797, P=0.0047; r=-0.5513, P=0.0078) as well as with TSH levels (r=0.5022, P=0.0172). A significant correlation was found between serum albumin and serum T3 levels during the nephrotic phase (r=0.5385, P=0.0018) but not between serum albumin and T4, TSH, or free T4 levels. These significant correlations all disappeared after remission.

Conclusion

Abnormal thyroid hormone profile findings were observed in 51.6% of pediatric patients with NS. Thyroid hormone levels normalized after remission, regardless of levothyroxine therapy.