Purpose of review: Elevated circulating levels of growth hormone (GH) and/or increased expression of the GH receptor in the kidney are associated with the development of nephropathy in type1 diabetes and acromegaly. Conditions of GH excess are characterized by hyperfiltration, glomerular hypertrophy, glomerulosclerosis and albuminuria, whereas states of decreased GH secretion or action are protected against glomerulopathy. The direct role of GH's action on glomerular cells, particularly podocytes, has been the focus of recent studies. In this review, the emerging role of GH on the biological function of podocytes and its implications in the pathogenesis of diabetic and chronic kidney disease will be discussed.
Recent findings: Elevated GH levels impair glomerular permselectivity by altering the expression of podocyte slit-diaphragm proteins. GH stimulates the epithelial-mesenchymal transition of podocytes and decreases podocyte count. GH also induces the expression of prosclerotic molecules transforming growth factor beta, and TGFBIp.
Summary: Our understanding of the cellular and molecular effects of GH in the pathogenesis of renal complications of diabetes and acromegaly has significantly progressed in recent years. These observations open up new possibilities in the prevention and treatment of diabetic nephropathy.