Hypothyroidism and acute kidney injury: an unusual association

An Interesting Case of Hypothyroidism Associated Acute Kidney Injury

Muscle involvement is common in hypothyroidism. However, hypothyroidism as a causal factor for severe rhabdomyolysis and acute kidney injury (AKI) is rarely reported. We report a case of a 56-year-old Arab male who presented with unexplained acute worsening of chronic kidney disease. The patient was detected to have hypothyroidism and rhabdomyolysis on laboratory investigations. However, thyroxine replacement led to partial recovery of renal function. CPK also improved with vigorous hydration and thyroxine replacement. Although this is a rare association, in the absence of other causes of rhabdomyolysis, hypothyroidism should be suspected in patients presenting with AKI and high creatinine phospho-kinase.

Endocrinological disorders in acute kidney injury: an often overlooked field of clinical research

Acute kidney injury (AKI) is a common comorbidity, affecting approximately one in five hospitalized adults. The kidney is the site for the production, metabolism or excretion of most hormones, including the production of erythropoietin (EPO), the active form of vitamin D, renin, thrombopoietin, and the excretion of insulin, catecholamines, gastrin and many other hormones. Therefore, it is reasonable to say that AKI can have a considerable impact on the endocrine system. Although the effects of AKI on various parameters, including cardiovascular parameters, serum electrolytes and acid-base disorders, neuro-humoral mechanisms and neurological outcomes have been extensively studied, the endocrinological consequences of AKI are understudied. Thyroid dysfunction, mainly euthyroid sick syndrome, hypo/hyperglycemia, bone mineral disorders, changes in EPO and atrial natriuretic peptide (ANP) levels are commonly found in AKI. EPO, thyroxine and ANP administration have been evaluated as potential tools to prevent or treat AKI with varying success, while the effects of AKI on some key hormones, including cortisol and insulin, have never been studied. Aim of this narrative review is to illustrate what is known and what is not known about the endocrinological outcomes of AKI. Few clinical trials are ongoing: however, there is a clear need for large-scale randomized controlled trials investigating the endocrinological consequences of AKI.

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.

Paradoxical effects of thyroid function on glomerular filtration rate estimated from serum creatinine or standardized cystatin C in patients with Japanese Graves' disease

BACKGROUND

Estimated glomerular filtration rate (eGFR) is clinically valuable for evaluating renal function. Recently, serum cystatin C (sCysC) measurement has been standardized and has demonstrated utility as a novel indicator of renal function. Thyroid hormone is known to affect serum creatinine (sCr) and sCysC, however, the clinical significance of post-treatment renal function evaluation is yet to be completely elucidated. This study examined the effects of thyroid hormones on eGFR by sCr (eGFRCr), and standardized sCysC (eGFRCysC) in patients with Japanese Graves' disease (GD).

METHODS

Serum samples were obtained from 113 outpatients with GD. Following pharmacotherapy, 41 of the 113 outpatients with GD achieved remission. Renal function was evaluated by eGFRCr and eGFRCysC. Reference method used Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations.

RESULTS

eGFRCr levels significantly increased whereas eGFRCysC levels significantly decreased with elevated FT3 and FT4 levels in patients with GD. In the remission group, eGFRCr levels significantly decreased and eGFRCysC levels significantly increased. No significant differences between eGFRCr and eGFRCysC levels were observed. Furthermore, CKD-EPI equations show a similar trend and eGFRCr-CysC levels were no significant differences regardless of before and after treatment.

CONCLUSIONS

Renal function evaluation by eGFRCr and eGFRCysC had clinical utility in post-treatment euthyroidism.