My dad has cystic kidney disease. Can diet changes help him?

Question

Hello doctor,

My father is 53 and has autosomal dominant cystic kidney disease. His recent ultrasound shows multiple cysts, the largest 4.8 cm, and his creatinine has risen to 2.1 mg/dL.

BP is persistently high despite Telmisartan 40 mg daily. So we have a few doubts -

Should we consider Tolvaptan therapy now to slow kidney damage, or wait until eGFR declines further?
Also, would getting an MRI of the abdomen help monitor cyst growth better than an ultrasound?
Lastly, have any specific diet modifications or fluid restrictions been proven to slow progression in such cases?

Kindly help.

Answer 1

Hello,

Welcome to icliniq.com.

I read your query and can understand your concern.

Your father has autosomal dominant polycystic kidney disease (ADPKD), which is a condition where multiple cysts develop in the kidneys over time and gradually impair kidney function.

A creatinine of 2.1 mg/dL indicates a moderate reduction in kidney function, and given his persistent hypertension despite telmisartan, this shows that the disease is progressing and needs close monitoring.

Tolvaptan is currently the only approved disease-modifying therapy shown to slow cyst growth and preserve kidney function. It is usually considered in patients at risk of rapid progression. It can be assessed based on kidney size, cyst burden, age at diagnosis, family history, and the rate of decline in kidney function.

Since his creatinine is already elevated, it would be reasonable to start Tolvaptan therapy now rather than waiting for further decline, if he does not have any contraindications and is willing to undergo regular monitoring for possible side effects, especially liver toxicity.

Ultrasound is often sufficient for routine follow-up, but MRI (magnetic resonance imaging) or CT (computed tomography) provides a more accurate assessment of total kidney volume, which is an important predictor of disease progression.

If Tolvaptan therapy is being considered, an MRI of the abdomen would be useful to document baseline kidney size and cyst burden.

Lifestyle and dietary measures are also very important, which include -

A low salt diet helps with blood pressure control and reduces further kidney damage.
Adequate hydration with liberal water intake has been suggested to reduce vasopressin activity, which may slow cyst growth. Unlike many other kidney diseases, fluid restriction is not recommended in polycystic kidney disease unless advised for another reason.
Avoiding smoking, maintaining a healthy weight, limiting excessive protein intake, and controlling blood pressure with appropriate medications are also essential in slowing progression.

Regular follow-up with a nephrologist will be important to guide the timing of Tolvaptan initiation and to monitor kidney function, blood pressure, and liver safety during treatment.

I hope this helps. Always feel free to reach out to me at any time. I am always here to help.

Thank you and take care.

Regards.