Chronic kidney disease (CKD) is caused by a progressive deterioration of kidney function due to loss of functional units in the kidneys. The functional units, termed nephrons, are made up of the glomerulus and the tubules. The main site of filtration is called the glomerulus, which is made up of an arteriole that curls around itself to create a ball-like structure. The glomerulus is held together by the mesangial matrix, while the surface of the endothelial cells of the arteriole is covered by the foot-processes of the podocytes and the specialized glomerular basement membrane (GBM). The GBM and the slit diaphragms of the interdigitating foot-process of the podocytes make up the filtration barrier. After filtration, the filtrate moves into the tubules (proximal tubules, loop of Henle and distal tubules), where various molecules are reabsorbed or secreted into urine; after this process, urine enters the collecting ducts. Throughout life, nephrons are lost due to injuries and aging. While the loss of nephrons is irreversible, humans are born with a large reservoir of nephrons and a large proportion can be lost before symptoms appear. As the kidney is the main site of excretion of waste products, a reduced kidney function will have widespread effects throughout the body. As an example, patients with CKD are at markedly increased risk of cardiovascular events.
How many have CKD?
Large-scale, nationally representative screening programs undertaken in the 2000s in Australia, Norway, and the US showed that more than 10% of the adult population have CKD. In the western world, diabetes is the leading cause of CKD, followed by hypertension. With the increase in lifestyle diseases such as diabetes and hypertension and the increased life-expectancy, CKD is projected to become an increasing problem worldwide. In 2017, there were 697.5 million cases of CKD globally and approximately 1.2 million people died from CKD.
How is CKD treated?
If detected early, it is possible to pharmacologically halt or slow the progression of CKD. However, due to the reservoir of nephrons, patients are usually diagnosed when CKD is already advanced. Patients that reach end-stage kidney disease require dialysis or kidney transplantation. The main classes of treatments for CKD are drugs regulating blood-pressure or treating the underlying disease drivers (e.g. GLP-1 agonists and SGLT2 inhibitors in diabetes, which have a positive effect on kidney health).
How is CKD diagnosed?
Patients are diagnosed with CKD if the concentration of creatinine in blood and/or proteins or albumin in urine is above a certain threshold. Since serum creatinine only rises after the loss of many nephrons and not all patients present with proteinuria or albuminuria, better diagnostic tools are needed to identify patients at risk of developing CKD.
Please don't hesitate to contact us if you have any questions or other inquiries.