Decoding Proteinuria: A Window into Kidney Health in IgAN

IgA nephropathy (IgAN) is an autoimmune disorder that causes irregular kidney inflammation due to an abnormal abundance of the antibody immunoglobulin A. This inflammation causes serious kidney damage and often leads to eventual kidney failure.

IgAN is difficult to diagnose, requiring a kidney biopsy for accurate identification. Many IgAN patients present no symptoms, though bloody or cola-colored urine is often a telltale sign of kidney disease.

Another common symptom of IgAN is proteinuria, which is the presence of excess protein in the urine. Proteinuria is also associated with a number of other conditions, including diabetes, hypertension, and heart disease, but it serves as a key indicator of kidney disease.

However, if proteinuria is a sign of IgAN, the amount of protein in the urine may serve as a predictor of long-term kidney health.

What Proteinuria Indicates About Future Kidney Function

In 2024, a study published in the American Journal of Kidney Diseases showed that protein levels in IgAN patients’ urine can be a clear indicator of their kidneys’ long-term health.

The study focused on 1,530 patients with IgAN who underwent treatment at Peking University First Hospital in China, measuring their levels of proteinuria over time. After a median follow-up period of about 43.5 months, 254 of those patients experienced severe kidney damage.

The likelihood of developing major kidney issues doubled for patients with 0.3 to 0.5 grams of proteinuria per day, and those with 0.5 to 1.0 grams per day saw a probability four times higher than patients with less than 0.3 grams per day. Moreover, patients with levels between 1.0 and 2.0 grams saw a risk 8.5 times higher than average, while those with more than 2.0 grams per day were an astounding 38 times more likely to develop severe kidney issues.

This study was conducted only at the Peking University First Hospital, so additional trials may be necessary to confirm its findings. But it showcases a clear correlation between levels of proteinuria and severity of kidney damage, at least on a smaller scale.

Steps to Achieving Optimal Kidney Health

Maintaining pristine kidney health may not be possible for everyone. Some are predisposed to kidney issues due to genetic factors. However, those without a family history of kidney disease may be able to reduce their risk of disorders like IgAN by following best practices for ideal kidney health. These include:

Eating a Healthy Diet: Processed foods high in sodium can be harmful not just to the kidneys, but for the body as a whole. It is best to stick to whole foods like fruits, vegetables, and unprocessed meats.

Getting Exercise: Regular exercise can lead to improved muscular fitness, better blood pressure control, and other metabolic benefits. However, patients should always consult with a health care professional before starting a new workout regimen.

Staying Hydrated: Regularly drinking water is an essential part of maintaining a healthy lifestyle. Better hydration leads to better filtration of potentially harmful toxins, resulting in overall better function for the kidneys and the body as a whole.

References:

Tang , T., Chen, P., Si, F.-L., Lv, J.-C., Shi, S.-F., Zhou, X.-J., Liu, L.-J., & Zhang, H. (2024, August). Time-varying proteinuria and progression of IGA nephropathy: A cohort study. American journal of kidney diseases : the official journal of the National Kidney Foundation. https://pubmed.ncbi.nlm.nih.gov/38364955/

Alison, A. (2023, March 3). 8 ways to care for your kidneys. Massachusetts General Hospital. https://www.massgeneral.org/news/article/8-ways-to-care-for-your-kidneys