**3. Risk factors**

It is estimated that by 2030,more than 2,000,000 Americans will need dialysis or transplantation. Who are these patients? What risk factors do they have?

Low birth weight individuals with a decreased number of nephrons, the elderly population losing 1 ml/min/year after the age of 30 and Americans of African descent with hypertension, are several groups of individuals at risk.About one half of patients starting dialysis in America have diabetes mellitus, with hypertension the second largest group. Autoimmune disorders, infections, kidney stones, cystic kidneys and toxins/medications round out the list. Microalbuminuria may indicate systemic endothelial dysfunction and may be associated with a prothrombotic state. Insulin resistance is mediated in part by aldosterone; blocking the receptor attenuates cardiovascular and renal injury.

The risk factors can be classified as those that increase the risk of development of kidney disease and those that increase the risk of adverse outcomes associated with CKD. The factors which increase the risk for CKD are further classified into susceptibility and initiation factors; whereas factors which effect adverse outcomes are classified as progression factors and end stage factors. The association between variables and disease may be due to chance, a non-causal relation or may signify a true risk factor.
