KDOQI guidelines emerged in 2002, classifying CKD in 5 stages based on the presence of kidney damage or GFR below 60ml/min, irrespective of cause. This classification increased the awareness of CKD in the general population and placed the kidney in the spotlight of many health policy discussions. However, one of the concerns of this classification is that it overestimates CKD, particularly in the elderly.
When this classification is applied to the general population, more than 25 million people are estimated to have CKD in the US, with more than 40% of CKD in those over 70 years old. The question than becomes: does the lower GFR in the elderly truly reflects disease or is just a consequence of aging? Does a lower GFR in the elderly without other comorbidities lead to an increased risk of other complications, like CV disease? Is there a way to better classify those patients, taking into account their prognosis? Finally, if we compare 2 patients with an eGFR of 45ml/min and different degrees of proteinuria (below 30mg/d or 700mg/day), do they carry the same risks?
The major changes will be two:
- subdivision of CKD stage III in A (45-59 ml/min) and B (30-44 ml/min).
- addition of albuminuric categories to every CKD stage : normal-30, 30-299, 300-1,999 and greater than 2,000 mg/day.
These changes are hoped to better risk stratify patients, help guide medical care and improve global outcome. By the way, the British have published a similar guideline in 2008.
In general, I liked the new classification, especially since I truly believe that proteinuria is a helpful marker for increased risk and I don’t believe most elderly should be classified as having progressive chronic kidney disease, with subsequent renal consultation. However, I am not sure how is going to affect my daily practice. I will continue to add my ACEI for those with proteinuria… And hope the readers of this blog will discover some new intervention in the near future that would improve my patients' renal outcome… I have faith in you guys!