Study Links Dietary Potassium Intake With Blood Potassium Concentration in CKD Patients

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“The relationship between dietary potassium intake and the blood potassium concentration in patients with CKD is incompletely understood”; says Ewout J.Hoorn, MD, PhD, a professor of Nephrology at The Erasmus Medical Center in The Netherlands, where this study was conducted.  

‍Potassium is a mineral, it is found in the foods that you eat.  It is also an electrolyte. Electrolytes conduct electrical impulses throughout your body, and play a key role in a lot of your body functions necessary for you to stay healthy.  These functions include:

. blood pressure

. normal water balance

. muscle contractions

. nerve impulses

. digestion

. heart rhythm

. pH balance

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Your body does not not produce potassium, it comes from the food in your diet. Consuming too much, as well as not enough potassium can both lead to some serious health issues. Low level of potassium is called hypokalemia. Too much potassium is called hyperkalemia. Healthy kidneys are able to maintain a normal potassium level in your body because they filter out the extra potassium into your urine. However, in Chronic Kidney Disease, (CKD), the kidneys have become damaged over time until they no longer are able to properly do their job of filtering extra waste and fluid out of the blood and into urine so that it can pass from the body.  This can cause potassium to build to high and unsafe levels, hyperkalemia. Hyperkalemia can be life threatening; its symptoms may include heart palpitations, shortness of breath, chest pain, nausea and vomiting. Potassium is easily removed during dialysis (artificial filtering), though people with CKD are usually told to follow a diet that is low in potassium to avoid a build up to dangerous levels in between dialysis treatments.  But is maintaining a low potassium diet also having negative consequences to the health of the kidneys as some data has suggested? If so, do the benefits of sticking to a low potassium diet to avoid hyperkalemia outweigh the negative effects to the kidneys a low potassium diet could cause? Dr Hoorn asserted that the relationship between the potassium consumed in food to the concentration of potassium in the blood was not completely understood in patients with CKD, and, for that reason the study he conducted used that as their starting point. 

Dr. Hoorn wanted to increase the potassium levels of patients with chronic kidney disease from low to normal ranges for a short period of time.  The study involved 191 patients with advanced chronic kidney disease. They were given a potassium supplement to be taken three times per day. The total daily dose was 40 mmol potassium and 40 mmol chloride. They were also to continue with their regular diet. After two weeks the patients were seen for a follow up appointment.  

The results of the study data showed that there is a relationship between potassium ingested and blood potassium levels. Dr. Hoorn said that, “our data shows that, in patients with CKD, there is a relationship between dietary potassium intake and the blood potassium concentration which, on average, increased by 0.4 mmol/L.”  Dr. Hoorn went on to say, “Despite this rise, only a minority of the patients (11%) developed hyperkalemia.  This is remarkable as the patients had advanced CKD and the majority used renin-angiotensin inhibitors, commonly used renoprotective drugs, which often contribute to hyperkalemia.” Now Dr Hoorn must look at effects of long term potassium supplements in patients with CKD, and has started to do so in clinical trials.  Dr Hoorn said in an interview conducted by Healio, “The next relevant question is what the long-term effects of potassium supplementation are on kidney function, blood pressure, and cardiovascular complications.  This will be addressed by our ongoing double-blind randomized clinical trial in which we treat patients with CKD with placebo, potassium chloride or potassium citrate supplementation for 2 years.”  Hoorn says the results are expected in the coming years. 

If the study shows positive results, health care providers may have to re-assess the standard dietary guidelines now given to patients with advanced chronic kidney disease.  Instead of avoiding foods that are rich in potassium, and maintaining a low potassium diet, this could perhaps lead to a diet in which CKD patients could enjoy eating high potassium foods such as bananas and avocados, in order to have an adequate or normal level of potassium intake.

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Dr. Hoorn said, “The implication would be to recommend adequate dietary potassium intake in patients with CKD.”         

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References

Healio

Effects of Short-Term Potassium Chloride Supplementation in Patients with CKD

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About the Author

Monica McCarthy has bachelors in Political Science and Criminal Justice from Central Washington University.  A majority of her career was spent as a political consultant.   She currently works at KidneyLuv as a staff writer.

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Patient Education Disclaimer

This material is for informational purposes only. It does not replace the advice or counsel of a doctor or health care professional. KidneyLuv makes every effort to provide information that is accurate and timely, but makes no guarantee in this regard. You should consult with, and rely only on the advice of, your physician or health care professional.

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