The great advances in the biological sciences in the last century have lead to dramatic breakthroughs in the fields of medicine and public health, thereby prolonging human life span far beyond what it had been for many millennia. The increasing age of the population, however, has also lead to a sharp rise in the incidence of chronic kidney disease (CKD).
Our kidneys are vital organs which excrete metabolic waste products; maintain the balance of acidity and minerals in the body; produce a hormone that regulates blood pressure and another that stimulates red blood cell production by the bone marrow; and they covert Vitamin D into an active form involved in calcium absorption from the gut and maintenance of bone integrity. CKD will therefore compromise all these functions, leading to various symptoms, which unfortunately may not appear until the disease has reached a fairly advanced stage. These symptoms include fatigue, loss of appetite, nausea, vomiting, altered taste sensation, breath that smells like urine; anemia; high blood pressure, shortness of breath and swelling of the legs from salt and water retention; insomnia, impairment of higher mental functions, tremors and convulsions; and abnormal heart beat or cardiac arrest from retained potassium. Untreated end-stage kidney disease is fatal unless the patient is treated with dialysis or given a kidney transplant.
The more common causes of CKD are diabetes; hypertension (high blood pressure); systemic inflammatory conditions that also involve the kidneys, such as systemic lupus erythematosis (SLE); various diseases that originate in the kidneys themselves; AIDS; hepatitis B and C; excessive use of certain pain killers; Illicit drugs like cocaine; some antibiotics; other drugs like cisplatinum for certain cancers or lithium for depression; heavy metals like lead; certain blood cancers like multiple myeloma; some parasitic diseases like malaria; and hereditary conditions like polycystic kidney disease.
In the United States and other advanced countries the increasing population age, “Western” life style and over-eating has caused a steep rise in the incidence of the “metabolic syndrome”, which includes obesity, diabetes, hypertension and high cholesterol and uric acid. Diabetes has therefore become the leading cause of end-stage kidney disease in the United States.
Treatment of CKD remains far from satisfactory, and the majority of cases ultimately progress to end-stage kidney failure requiring dialysis or kidney transplantation. More important than treatment, however, is prevention. This includes excellent control of blood sugar and cholesterol in diabetics, weight loss for the obese, good control of blood pressure and avoidance of high-salt diet in the hypertensive, smoking cessation, and avoidance of drugs injurious to the kidneys. Periodic urine testing may uncover the existence of unsuspected or early kidney disease, as the presence of protein in the urine is the hallmark of diabetic and many other kidney diseases. Once kidney disease is established, dietary protein restriction and certain drugs in the family of captopril and losartan may retard its progression.
Chronic kidney disease is much more common than most people think, and we all need to be vigilant about prevention and early detection, especially the diabetics among us. Much remains to be learned about the various mechanisms of kidney disease and therefore the discovery of more targeted preventive measures and therapies.
Asad A. Bakir, MD, FACP
3410 West Van Buren Street, Chicago, IL 60624