With over 50 million individuals worldwide having chronic kidney disease (CKD), a well recognized risk factor for cardiovascular disease, CKD is emerging as a worldwide public health problem.1 As countries develop and industrialize, diseases related to infections, crowding, and poor nutrition recede, and chronic disease associated with affluence, aging, overnutrition, medical interventions, drugs, addictions, and other exposures becomes prominent. While diseases of westernized societies are the main focus of this chapter, globalization has contributed to an increasing rate of noncommunicable chronic disease worldwide. In 2003 it was estimated that 60% of deaths worldwide would be due to noncommunicable diseases, with 16 million deaths resulting from cardiovascular disease and 1 million deaths from diabetes.2 Thus, the information in this chapter pertains to an ever widening circle of communities. With ischemic heart disease and cerebrovascular disease now listed as the number one and two causes of death worldwide, it is very probable that renal disease related to vascular disease will become more prevalent. In addition the increase in the prevalence of diabetes virtually assures that chronic kidney disease will continue to be a major cause of morbidity and mortality.
Rates of most renal diseases and of end-stage renal disease (ESRD) in westernized societies rise with age, and increased longevity enhances the expression of both. More males than females are affected by many renal diseases, and more males enter ESRD treatment programs. Some groups recently absorbed into industrialized societies, such as U.S. blacks, North American Indians, Hispanics and Mexican Americans, urban South African blacks, Australian aborigines, Pacific Islanders, and New Zealand Maoris, have especially high rates of renal disease, in part from conditions such as hypertension and diabetes that were rare in their forebears. ESRD treatment programs themselves have produced a whole new set of clinical, economic, and sociological perspectives and concerns.
Renal and urinary tract diseases are frequently asymptomatic for most of their course, and diagnosis is frequently dependent on laboratory and radiologic studies. Clinical renal disease may be manifested by blood, protein, or white blood cells in the urine, often with hypertension. Heavy protein excretion, decreased levels of serum albumin, hyperlipidemia, and edema characterize the “nephrotic syndrome.” Excretory renal function can be normal or impaired and can remain stable or progress to renal failure. Renal impairment generates, and is exacerbated by, hypertension. ESRD defines a situation of chronic irreversible renal failure in which prolonged survival is not possible without dialysis or renal transplantation.
Specific diseases are diagnosed by history and clinical findings, biochemical, serological, imaging, and urodynamic studies, and sometimes by biopsy of the kidneys, bladder, or prostate. Kidney biopsy specimens are examined by light, immunofluorescent, and electron microscopy to aid in diagnosis and prognosis. The serum creatinine level provides an approximate measure of renal insufficiency, although it varies with muscle mass and diet, underestimates renal insufficiency in the elderly, is relatively insensitive to loss of the first 50% of renal function, ...