It’s one of the biggest conundrums nephrologists face – how to prevent or treat chronic hyperkalemia by managing diet in patients with chronic kidney disease.
Hyperkalemia is the medical term that describes potassium levels in a patient’s blood that are higher than normal. Hence, the traditional recommendation for managing these with patients is to keep them off foods high in potassium.
The problem, as pointed out by Kamyar Kalantar-Zadeh, MD, MPH, PhD, chief of nephrology, hypertension, and kidney transplantation at the University of California Irvine School of Medicine, is that potassium is critical to the normal functioning of cells, and ensures the proper functioning of nerves and muscles, including the heart. “So potassium is extremely important,” he told MedPage Today, “And it has been shown to lower blood pressure, lower the risk of stroke and heart disease, and increase longevity.”
According to the National Kidney Foundation, a normal amount of potassium in the typical healthy American’s diet is 3,500 to 4,500 mg per day, while a potassium-restricted diet will usually be 2,000 mg per day. Foods that are high in potassium and likely to be targeted for restriction include many fruits and vegetables including such mainstays as bananas, avocados, and oranges.
“Everything that is healthy has potassium in it,” said Kalantar-Zadeh. “It is the quintessential component of fresh fruit and vegetables.”
Heart-healthy diets are therefore loaded with potassium, he continued. “So it is heartbreaking to have to tell a patient, or hear my dietitian tell patients, that they have to eliminate or limit foods like bananas, or avocados, or fruits and nuts – all of those things that are heart healthy.”
So, restricting diet can present patients and caregivers with therapeutic tradeoffs and associated challenges.
For example, a recent article in Kidney Medicine noted that low-potassium diets can adversely affect patients’ acid-base balance and intestinal microbiota, and result in nutritional deficiencies that reduce health-related quality of life.
The authors also wrote that patient adherence to these dietary restrictions can be problematic since it requires individualized dietary regimens and access to skilled dietitians and regular counseling – something that may not be too common in regular clinical practice. Furthermore, the article stated, there are a number of patient-reported barriers to adherence that are associated with diet restriction, including “a lack of appetite, craving salty foods, being too tired to cook, finding the diet bland and tasteless, difficulty tracking nutrient intake, feeling deprived, and lack of motivation to eat the right foods.”
Kalantar-Zadeh emphasized that while kidney disease has a close relationship with hyperkalemia, in many cases a patient’s condition can be managed before he or she develops chronic hyperkalemia. That does entail a close look at diet, but restriction does not have to mean elimination, he said.
In an article in Nutrients that Kalantar-Zadeh co-authored, he and his colleagues emphasized that careful control of the dietary potassium load is an important aspect of the management of chronic kidney disease and heart failure patients with, or at risk of hyperkalemia.