Kidney Function After Cure of Primary Aldosteronism (PA): What All Patients and Their Nephrologists Need to Know

Primary aldosteronism (PA), a condition where the adrenal glands overproduce the hormone aldosterone, affects millions of people worldwide, often causing high blood pressure and low potassium levels. While these symptoms are well-known, the impact of PA on kidney health is a critical concern for patients and their healthcare providers. Adrenal surgery, specifically adrenalectomy (particularly the best operations, MBSA), is a common and effective treatment for PA, especially when caused by a benign adrenal adenoma. This procedure can normalize hormone levels and alleviate symptoms, but it also raises important questions about its effects on kidney function. Drawing on insights from medical research, this blog post explores how curing PA affects the kidneys, offering practical guidance for patients and nephrologists in an accessible, engaging way.

What Is Primary Aldosteronism and How Does It Affect the Kidneys?

Primary aldosteronism occurs when the adrenal glands, located just above the kidneys, produce too much aldosterone. This hormone helps regulate sodium and potassium levels, which in turn control blood pressure and fluid balance in the body. However, excessive aldosterone can harm the kidneys over time. It causes the kidneys to work harder than normal, a state called glomerular hyperfiltration, which can lead to inflammation, scarring, and a gradual decline in kidney function. Over time, this damage may contribute to chronic kidney disease (CKD), where the kidneys lose their ability to filter waste effectively.

For many patients, an adrenalectomy offers a cure by removing the adrenal gland tumor(s) responsible for excess aldosterone production. This surgery can normalize blood pressure, restore potassium levels, and reduce the strain on the kidneys. Research has shown that an adrenalectomy effectively resolves the hormonal imbalances caused by PA, leading to significant health improvements. However, the procedure also reveals important insights about kidney function that patients and their doctors need to understand.

The Benefits: Protecting Your Kidneys from Further Harm

One of the most significant advantages of curing PA through adrenalectomy is its potential to protect the kidneys from long-term damage. Excess aldosterone puts the kidneys under constant stress, leading to scarring (glomerular fibrosis) and reduced function over time. By removing the source of excess aldosterone, the adrenalectomy halts this harmful process, potentially preserving kidney function for years to come.

Studies have shown that patients who undergo an adrenalectomy often see normalization of aldosterone levels and improvements in related symptoms, such as high blood pressure and low potassium, and reduced risk of early death. This reduction in aldosterone-related stress can prevent further kidney damage, particularly for patients in the early stages of kidney dysfunction. For those diagnosed with PA, this is a powerful reason to consider surgery, as it can safeguard kidney health and improve overall quality of life.

For patients, this means that adrenalectomy can be a kidney-saving intervention. Nephrologists, who specialize in kidney care, can emphasize this benefit when discussing treatment options, highlighting how surgery addresses the root cause of PA and protects against further renal deterioration.

The Challenge: Unmasking Hidden Kidney Issues

While adrenalectomy offers clear benefits, it can also uncover underlying kidney problems that were previously hidden by PA. Before surgery, high aldosterone levels can artificially boost the kidneys’ filtration rate (estimated glomerular filtration rate, or eGFR), making kidney function appear better than it is. After adrenalectomy, as aldosterone levels normalize, the kidneys return to their true baseline function, which may reveal a lower eGFR than expected. This drop can indicate pre-existing CKD that was masked by the effects of PA.

Research notes that many patients experience a temporary decline in eGFR after adrenalectomy. This isn’t a sign of new kidney damage but rather a reflection of the kidneys’ actual condition once the artificial boost from aldosterone is removed. For most patients, this decline stabilizes over time, but for those with severe pre-existing kidney issues, the drop may be more pronounced or persistent. Understanding this possibility is crucial for setting realistic expectations before surgery.

For patients, this means that a drop in eGFR post-surgery doesn’t mean the kidneys are worsening. Instead, it may reveal a pre-existing condition that needs monitoring. Nephrologists should track eGFR closely in the months following surgery to ensure the kidneys stabilize and to determine if additional care is needed to manage CKD.

Risk Factors for Kidney Function Changes

Certain factors can increase the likelihood of a noticeable eGFR drop after adrenalectomy. Research highlights several key risk factors, including a longer history of hypertension, the presence of diabetes mellitus, and low potassium levels before treatment. These conditions can exacerbate kidney stress over time, making a post-surgical eGFR decline more likely.

For example, long-standing high blood pressure, a hallmark of PA, can damage blood vessels in the kidneys, contributing to CKD. Similarly, diabetes can harm kidney function, and when combined with PA, it increases the risk of renal complications. Low potassium levels, another common feature of PA, can also signal more severe aldosterone effects, which may correlate with a higher chance of eGFR decline after surgery.

Patients with these risk factors should be aware that their kidney function may change post-surgery, but this doesn’t mean the procedure is harmful. Nephrologists can use this information to identify high-risk patients and tailor their care, such as scheduling more frequent eGFR tests or adjusting medications that affect kidney function, like angiotensin II receptor blockers (ARBs) or angiotensin-converting enzyme inhibitors (ACEIs).

The Long-Term Picture: What to Expect

While adrenalectomy can protect the kidneys from further aldosterone-related damage, the long-term impact on kidney function is still an area of active research. Some patients, especially those with advanced kidney dysfunction before surgery, may experience a sustained eGFR decline. However, this doesn’t necessarily mean the surgery caused harm. In many cases, the procedure prevents further deterioration, offering a better long-term outcome than leaving PA untreated.

The challenge lies in predicting long-term kidney prognosis. Studies suggest that while eGFR may drop initially, it often stabilizes within a year. However, for patients with severe kidney damage, ongoing monitoring is essential to manage CKD and prevent progression to kidney failure. Nephrologists can help by developing individualized care plans, which may include lifestyle changes, blood pressure control, and medications to support kidney health.

Practical Steps for Patients and Nephrologists

For patients considering adrenalectomy for PA, here are key takeaways:

1. Understand the Benefits: Adrenalectomy can stop aldosterone-related kidney damage, potentially preserving function and preventing CKD progression.
2. Be Prepared for eGFR Changes: A drop in eGFR after surgery is common and often reflects the kidneys’ true state, not new damage. Discuss this with your doctor to set realistic expectations.
3. Know Your Risk Factors: If you have a long history of hypertension, diabetes, or low potassium levels, you may be at higher risk for an eGFR decline. Share your medical history with your nephrologist for personalized care.
4. Stay Proactive: Regular follow-up appointments and eGFR monitoring are crucial, especially in the first year after surgery, to track kidney function and address any concerns.

For nephrologists, these steps can guide patient care:

1. Monitor eGFR Closely: Schedule regular eGFR tests post-surgery to track changes and ensure stabilization.
2. Assess Risk Factors: Evaluate patients for hypertension duration, diabetes, and pre-treatment potassium levels to identify those at risk for eGFR decline.
3. Educate Patients: Explain that an eGFR drop may reveal underlying CKD, not new damage, and emphasize the protective benefits of surgery.
4. Tailor Treatment: Adjust medications like ARBs or ACEIs as needed, and consider additional kidney-protective strategies for high-risk patients.

Conclusion

Adrenalectomy for primary aldosteronism is a life-changing treatment that can halt the damaging effects of excess aldosterone on the kidneys, offering hope for long-term renal health. However, it may also unmask underlying chronic kidney disease, leading to a temporary or sustained drop in eGFR. By understanding the risk factors—such as long-term hypertension, diabetes, and low potassium levels—patients and nephrologists can work together to monitor and manage kidney function effectively. With insights from ongoing medical research, this knowledge empowers patients to make informed decisions and nephrologists to provide targeted care, ensuring the best possible outcomes for kidney health after curing PA.

Dr. Tobias Carling, of the Carling Adrenal Center, is one of the world's leading experts in adrenal gland surgery. Dr. Carling performs more adrenal operations than any other surgeon in America. Dr. Carling left Yale University in 2020 to open the Carling Adrenal Center in Tampa, Florida.

To discuss the details of your case with Dr. Carling and become his patient, fill out the new patient form and he will be in touch with you shortly.

Additional Resources: 

• Learn more about the Carling Adrenal Center
• Learn more about Dr. Tobias Carling
• Learn more about our sister surgeons at the Norman Parathyroid Center, and Clayman Thyroid Center.
• Learn more about the Hospital for Endocrine Surgery