Endocrine Disorders in Nephrotic Syndrome-A Comprehensive Review

Abstract

Nephrotic syndrome is a clinical syndrome characterized by massive proteinuria, called nephrotic range proteinuria (over 3.5 g per day in adults or 40 mg/m² per hour in children), hypoalbuminemia, oncotic edema, and hyperlipidemia, with an increasing incidence over several years. Nephrotic syndrome carries severe morbidity and mortality risk. The main pathophysiological event in nephrotic syndrome is increased glomerular permeability due to immunological, paraneoplastic, genetic, or infective triggers. Because of the marked increase in the glomerular permeability to macromolecules and the associated urinary loss of albumins and hormone-binding proteins, many metabolic and endocrine abnormalities are present. Some of them are well known, such as overt or subclinical hypothyroidism, growth hormone depletion, lack of testosterone, vitamin D, and calcium deficiency. The exact prevalence of these disorders is unknown because of the complexity of the human endocrine system and the differences in their prevalence. This review aims to comprehensively analyze all potential endocrine and hormonal complications of nephrotic syndrome and, vice versa, possible kidney complications of endocrine diseases that might remain unrecognized in everyday clinical practice.

Keywords: adrenal gland; endocrine gland; gonadal axis; hypophysis; nephrotic syndrome; pancreas; parathyroid gland; pathophysiology; thyroid gland.

Figure 1

A review of pituitary gland hormones’ effects on kidneys. Created in BioRender.com. Abbreviations: adrenocorticotropic hormone (ACTH), growth hormone (GH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), prolactin (PRL), antidiuretic hormone (ADH), thyrotropin-releasing hormone (TRH), gonadotropin-releasing hormone (GnRH), growth-hormone-releasing hormone (GnRH), corticotropin-releasing hormone (CRH), prolactin-releasing hormone (PRH), and interstitial fibrosis and tubular atrophy (IFTA).

Figure 2

Bidirectional interplay of the thyroid gland and kidneys in healthy and NS patients. Abbreviations: Na, sodium; K, potassium; Ca, calcium; RAAS, renin–angiotensin–aldosterone system; TPO, thyroid peroxidase.