The reversibility of kidney damage depends on the type of kidney damage that has occurred, how long the kidneys have been damaged, and a person’s actions to optimize their health. Maintaining kidney function is critical, as options such as dialysis and transplant can be life-saving but offer lower quality of life than maintaining one’s own kidney function. Excitingly, new research is opening the possibility that acute kidney injury and chronic kidney disease may be more reversible than previously believed.
Acute Kidney Injury (AKI)
Acute kidney injury (AKI) is a type of kidney damage in which kidney function declines quickly usually as the result of specific damage such as injury, dehydration, or drug overdose. AKI can cause long-term kidney failure but in many cases is reversible at least to an extent. The reversibility of AKI depends on the cause of kidney damage and its treatment, as well as the health of the person both before and following the injury. Factors known to contribute to the likelihood of recovery include age, cardiovascular disease risk factors, blood pressure, and the health of the kidneys prior to the injury. For these reasons, it is wise to optimize kidney health through proper nutrition and lifestyle support to decrease the likelihood of kidney failure throughout life.
Chronic Kidney Disease (CKD)
Chronic kidney disease (CKD) was previously considered to not be reversible but emerging evidence is beginning to change this outlook. For decades, there have been case reports in the medical literature of people who regain kidney function. More common was the understanding that CKD sometimes paused its progression. The African American Study of Kidney Disease and Hypotension demonstrated that many people with CKD have prolonged periods of non-progression of kidney decline, indicating that decline in kidney function is not necessarily continuously progressive(1).
The reason CKD is often considered non-reversible is that nephrons, the cells that filter blood in the kidney, cannot be regenerated after birth. We are born with all the nephrons we will ever have. However, regeneration or repair of other areas of the kidney is possible including the epithelium, parenchyma, and vasculature. Some physicians believe that the repair of these structures may improve overall kidney health and halt GFR decline or even restore kidney function(2).
A New Understanding of CKD Reversal
In recent years the idea that CKD may be reversible, known as CKD regression, has become more prevalent as evidence builds that some people can regain kidney function after a diagnosis of CKD. A 2021 Canadian study of over 81,000 CKD patients (eGFR of 15 – 60) found that 14.3% had regression of CKD (kidney function improvement) compared to 14.6% who had progression of CKD (kidney function decline) over five years(3). Patients who experienced improved kidney function were more likely to have their kidney function either stabilize or continue to improve versus the likelihood of their kidney function once again worsening. The authors hypothesized that risk factor modification may be one reason that kidney function improved in some patients.
A 2015 Italian study of over 1,400 CKD patients found that 27% of patients experienced regression of CKD over two years of follow-up(4). Regression of CKD was predicted by lower proteinuria (less protein in the urine), lower systolic blood pressure, higher body mass index, and absence of autosomal dominant polycystic kidney disease.
Blood pressure control appears to be a particularly important factor in studies where patients halted or reversed their CKD. A study of people with nephritis showed that blood pressure treatment led to the halting of CKD progression and a subset of the patients regained estimated glomerular filtration rate (eGFR) and thus have not required treatment for end-stage renal disease (ESRD)(5). Full remission of proteinuria and stabilization of kidney function was observed in a small number of patients in a long-term follow-up study of diabetic patients with nephropathy(6). These results further support the potential for CKD regression in CKD patients with or without diabetes(2). The importance of the vascular system in reversing kidney decline is cited by some physicians who postulate that sections of the kidney can regain function by blood capillary lengthening or branching(2).
Defining CKD Regression
The new optimism around the reversal or regression of CKD is highlighted by recent efforts to define a medical definition for CKD regression. Previously, CKD was thought of only as a disease that progressed eventually to kidney failure or death. Given recent improvements in kidney care and the prognosis of patients, there is a movement in 2022 among medical professionals to officially define CKD regression as an improvement of 25% or greater in eGFR(7). This movement indicates that there is growing evidence that CKD can be reversible cases and highlights the need for additional studies on strategies to reverse CKD.
The Role of Pharmaceutical Drug Therapies in Kidney Health
Pharmaceutical drug therapies can have positive or negative impacts on kidney function. The kidneys play a key role in removing drugs from the body and some drugs can increase the workload on kidneys and even cause kidney damage when used in excess. No drugs are currently approved to reverse or stop reverse kidney damage. However, some drugs have shown great promise in slowing kidney function decline including blood pressure medications and a new class of medications called SGLT2 inhibitors. It is beneficial to consult a physician about both prescription and over-the-counter medications to ensure kidney health.
Optimizing Kidney Health
Regardless of whether your case of kidney disease can be reversed, halted, or merely slowed, there are several steps to help optimize kidney health:
- Optimize nutrition to support kidney health and provide the nutrients needed by the kidneys.
- Become educated on what constitutes a kidney-healthy diet.
- Ensure adequate hydration to support the kidneys.
- Maintain an active lifestyle and a healthy weight.
- Check your blood pressure regularly and pursue lifestyle modification or therapeutics if needed to maintain appropriate blood pressure.
- Perform regular blood tests to determine your current eGFR and track changes in kidney function over time.
- Consult a physician to review your medications and supplements to ensure they are appropriate for maximizing kidney health.
1. Li, L. et al. Longitudinal progression trajectory of GFR among patients with CKD. American Journal of Kidney Diseases 59, (2012).
2. Yang, H. C. & Fogo, A. B. Mechanisms of Disease Reversal in Focal and Segmental Glomerulosclerosis. Advances in Chronic Kidney Disease vol. 21 Preprint at https://doi.org/10.1053/j.ackd.2014.04.001 (2014).
3. Liu, P. et al. Progression and Regression of Chronic Kidney Disease by Age among Adults in a Population-Based Cohort in Alberta, Canada. JAMA Netw Open (2021) doi:10.1001/jamanetworkopen.2021.12828.
4. Borrelli, S. et al. Epidemiology of CKD regression in patients under nephrology care. PLoS One 10, (2015).
5. Ruggenenti, P. et al. In chronic nephropathies prolonged ACE inhibition can induce remission: dynamics of time-dependent changes in GFR. Investigators of the GISEN Group. Gruppo Italiano Studi Epidemiologici in Nefrologia. J Am Soc Nephrol 10, (1999).
6. Wilmer, W. A. et al. Remission of nephrotic syndrome in type 1 diabetes: Long-term follow-up of patients in the captopril study. American Journal of Kidney Diseases 34, (1999).
7. Taal, M. W. Defining improvement in chronic kidney disease: regression and remission. Curr Opin Nephrol Hypertens 31, 517–521 (2022).