Thyroid Function in Patients with Nephrotic Syndrome and Normal Renal Function

Abstract

Alterations of thyroid hormone indices have been described in patients with nephrotic syndrome. However, the majority of these patients also had either diabetes mellitus or significant renal failure, conditions known to alter thyroid hormone indices. To evaluate the changes in serum thyroid hormone indices due to nephrotic syndrome per se, we studied 15 nondiabetic patients with untreated nephrotic syndrome who had normal glomerular filtration rates (108 ± 5.3 ml/min). The serum levels of total thyroxine (TT4) were decreased in 7 of 15 patients with a mean of 5.7 ± 0.66 μg/dl (normal: 8.0 ± 0.14 μg/dl; p < 0.01). Serum levels of thyroxine-binding globulin were reduced in 2 of 6 patients and triiodothyronine (T3) uptake ratio values were elevated in 3 of 15 patients. Free T4 levels by radioimmunoassay and equilibrium dialysis were either normal or elevated. Both the basal serum thyroid-stimulating hormone (TSH) levels and the peak TSH response to thyrotropin-releasing hormone (TRH) were within the normal range. Serum levels of total T3 (TT3) were reduced in 8 of 15 patients (101 ± 12; normal 147 ± 2.8 ng/dl; p < 0.01) but those of total reverse T3 (TrT3) were normal. Free rT3 levels were elevated in 7 of the 10 patients studied. Patients with reduced serum levels of TT4 also had low TT3 values. The TT3/TT4 ratios were normal in these patients. There were direct and significant (p < 0.01) correlations between the total serum levels of both TT4 and TT3 and those of serum albumin. These data indicate that: (1) nephrotic syndrome per se is associated with alterations in thyroid hormone indices; (2) the normal free T4 levels, the normal TSH response to TRH and the normal TT3/TT4 ratios suggest that the production rates of T4 and T3 are not impaired; (3) the reduced serum levels of TT4 and TT3 in these patients may be due to decreased binding to and/or concentration of serum carrier proteins, and (4) as in acute and chronic renal failure, patients with nephrotic syndrome with normal renal function have normal total and increased free rT3 values in association with reduced TT3 levels. Since these three groups of patients have elevated blood levels of parathyroid hormone, it is tempting to speculate that excess parathyroid hormone may affect rT3 metabolism.

Prevalence of thyroid hormone abnormalities in stage 5 chronic kidney disease: a tertiary care center study of Nepal

“…On the other hand, kidney is involved in the metabolism and elimination of TH and is an important target organ for TH actions. 8,9 The present study was carried out to estimate the prevalence of thyroid hormone abnormalities in stage 5 CKD patients. In our study, there was significant reduction in the level of fT3 and fT4 in stage 5 CKD patients as compared to the healthy control group.…”

The Thyroid and the Kidney: A Complex Interplay in Health and Disease

“…Thyroid hormonal changes depend on the degree of albuminuria and serum albumin concentration (82). However, free T3 and T4 levels remain in the normal range probably due to a compensatory mechanism of the thyroid gland to urinary losses (5).…”

“A Study of Thyroid Function Abnormalities in Patients with Chronic Kidney Disease”

“…In spite of diverse etiologies, CKD is the final common pathway of irreversible loss of nephrons finally resulting in alteration of -milieu interior‖ affecting every system in the body including thyroid hormonal system.The functions of thyroid and kidney are interrelated [3][4][5][6] . The thyroid hormones are essential for growth and development of the kidney and for maintaining electrolyte and water homeostasis.So excretion of iodine is reduced in advanced renal failure.…”