Fibrosis in Chronic Kidney Disease
Chronic kidney disease (CKD) is defined as the gradual loss of renal function. CKD patients can develop permanent kidney failure known as end-stage renal disease (ESRD). They also have a higher risk for strokes and heart attacks. A significant loss of kidney function can occur for many reasons, but research indicates that the primary causes are: diabetes, hypertension, glomerulonephritis and cystic diseases.
Fibrosis is a condition characterized by excessive extracellular matrix (ECM) accumulation. Renal fibrosis occurs regardless of the underlying disorder. It is made up of glomerulosclerosis and tubulointerstitial fibrosis and leads to renal function decline. There is no current treatment for renal fibrosis. Many efforts to block renal fibrosis that seemed promising in the laboratory have been less successful in the clinic.
The severity in kidney disease varies from Stage 1, a mild form with greater than 90% kidney function, to Stage 5 with signs of end stage renal and a GFR of less than 15% kidney function.
The prevalence of CKD is growing most rapidly in people 60 years of age and older. Between the 1988–1994 and 2003–2006 NHANES studies, the prevalence of CKD in this segment of the population jumped from 19% to 25%.
The National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) Clinical Practice Guidelines (CPGs) on CKD estimated that CKD affects 11% of the US population. Those affected are at increased risk of cardiovascular disease and kidney failure. Kidney failure represents about 1% of the prevalent cases of CKD in the United States, and the prevalence of kidney failure treated by dialysis or transplantation was projected to increase from 453,000 in 2003 to 651,000 in 2010.
Statistics are similar in Europe. At least 8-10 % of the population in Europe has some form of CKD. The population undergoing dialysis in Europe is almost double the number that underwent treatment 15 years ago. Kidney treatment is a burden for the healthcare system and, if the same trend continues, almost 3 to 5 percent of healthcare budgets will need to be spent on CKD treatments. The actual number of dialysis patients is growing steadily by about 4 to 6 percent per year.
Early Stages 1-3
Current treatments for the earlier stage of CKD involve treating the diseases that have helped to cause the CKD. The hope is that treating these conditions will slow the progression of kidney failure. Since diabetes and hypertension are responsible for an overwhelming majority of CKD, they are the focus of treatments.
- Diabetes is particularly important in CKD. In 2008, almost 50,000 people with diabetes began treatment for end-stage kidney disease and over 200,000 people with end-stage kidney disease due to diabetes were living on chronic dialysis or with a kidney transplant. Nearly one-half of patients starting dialysis each year have diabetes and most of these, about 90 percent, have type 2 diabetes. CKD patients with diabetes are treated by diet, exercise and both oral medications and injectable insulin. The emphasis is on controlling blood sugar and A1C
- Hypertension – patients are treated with angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB) to reduce blood pressure and levels of protein in the urine. A diuretic or other medication is sometimes added.
- Glomerular diseases - treatments for glomerular diseases may include immunosuppressive drugs or steroids to reduce inflammation and proteinuria. The choice of the medication depends on the specific disease.
In addition to the treatment above, stage 4 patients receive education about what their options will be when their kidneys fail.
Stage 5 patients need to be on dialysis or receive a kidney transplant in order to survive.
Costs of CKD
Management of CKD is costly. The Medicare CKD stage 5 population nearly doubled in the last 10 years, and the CKD population expanded as well. Together, they account for 16.5% of Medicare expenditures for a total of $41billion,including Part D.