[Kidney aging: a predictable and partly avoidable fragility].

The 9th World Kidney Day, on 13 March 2014, was devoted to the topic of renal aging. The proportion of older people in the general population is increasing steadily worldwide, with the most rapid growth in developing countries. This demographic upheaval is a consequence of socioeconomic development and increasing life expectancy. Chronic kidney disease is an important public health problem characterized by poor health outcomes and very high healthcare costs. Chronic kidney disease is a major risk multiplier in patients with diabetes, hypertension, heart disease and stroke, all of which are key causes of death and disability among older people. The prevalence of chronic kidney disease is higher in the elderly, in whom it contributes to the effects of aging. The decrease in renal function with age also compounds the effects of renal disease, whether primary or secondary to systemic or urinary tract disorders. This physiological reduction in functional capacity affects the glomerular filtration rate and renal tubular functions, including water and salt regulation and also the elimination of many drugs. The aging kidney is much more sensitive to toxic insults, especially those due to nonsteroidal antiinflammatory drugs and iodinated contrast agents. Prevention of renal deterioration in the elderly is based on monitoring renal function, adapting medications, and maintaining a regular supply of water and salt.