Classification of chronic kidney disease in the elderly: pitfalls and errors.

The average glomerular filtration rate (GFR) is lower in the elderly than in the young and is usually a consequence of biological ageing, the rate of which varies between individuals. In some subjects, the decline is aggravated by concomitant vascular disease. The prevalence of significant kidney disease in the elderly has been overestimated - largely by rendering a diagnosis of chronic kidney disease by reference to estimates of GFR which are found in the young. A stable low GFR in the elderly, provided it is physiologically sufficient to meet homeostatic demands, is not a disease per se and seldom progresses to true kidney failure. However, it can be a risk factor for acute kidney injury drug misdosing, and possibly cardiovascular disease, so it should be noted.