Chronic Kidney Disease: Overview and Risk Factors

The condition termed "chronic kidney disease" (CKD) is a progressive syndrome of renal insufficiency and failure in which the kidneys lose their ability to filter blood, concentrate the urine, excrete wastes, and maintain electrolyte balance. Formerly called chronic renal failure, CKD is an important public health issue that has been increasing in incidence and prevalence worldwide and consumes disproportionate healthcare resources in the United States. CKD is also a major independent risk factor for cardiovascular mortality.

About 75% of CKD cases are due to diabetes mellitus and/or hypertension. Other common etiologies include glomerulonephritis, renal cystic disease, congenital urologic disorders, urinary obstruction, multiple myeloma, amyloidosis, analgesic abuse, and atheroemboli.

While biochemical and hormonal abnormalities occur early, few symptoms occur until about 75% of kidney function has been lost. Initial presentation includes fluid retention, hypertension, anemia, and electrolyte disturbances. As kidney function is further compromised, overt signs of uremia occur: shortness of breath, nausea, vomiting, anorexia, weight loss, encephalopathy, asterixis, pruritis, and pericarditis.

Risk Factors

African Americans have a significantly higher rate of CKD than other racial groups. This is partly due to higher rates of hypertension in this group. Other factors associated with increased risk include:

• Older age.
• Family history.
• Urinary tract disorders that may increase the risk of kidney damage: urinary tract infections, urolithiasis, urinary tract obstruction.
• Systemic medical disorders that may increase the risk of kidney damage: diabetes mellitus, hypertension, autoimmune disorders (eg, systemic lupus erythematosus), systemic infections.
• Nephrotoxic medications (eg, nonsteroidal anti-inflammatory drugs, contrast dye).
• Tobacco smoking.