A daily supplement of potassium citrate may prevent painful kidney stones developing in epileptics adhering to a high-fat ketogenic diet, says a new study.
Epileptic children are sometimes recommended to eat a diet poor that is high in fat, and low in carbohydrate in order to reduce the occurrence of seizures. The diet causes ketones to accumulate in the body, and is known as ketogenic.
A side effect of the diet is the formation of kidney stones in the children. According to new findings published in Pediatrics, taking a daily potassium citrate supplement from day one of the diet may prevent the formation of these stones.
“We can confidently say this is a safe and powerful way to prevent kidney stones, and it should become part of standard therapy in all ketogenic dieters, not just those who already show elevated urine calcium levels," said senior investigator Eric Kossoff, MD.
The ketogenic diet mimics some of the effects of starvation, in which the body first uses up glucose and glycogen before burning stored body fat. In the absence of glucose, the body produces ketones, a chemical byproduct of fat that can inhibit seizures. Children who remain seizure-free for two years on the ketogenic diet often can resume normal eating and often their seizures don't return.
However, due to the build-up of calcium in the urine, kidney stones can form in about 6 per cent of children on the diet. According to the Centers for Disease Control and Prevention (CDC) 2.3 million Americans suffer from epilepsy.
Kossoff and his co-workers from John Hopkins recruited 313 children on a ketogenic diet. The children recruited into the study before 2006 received the potassium citrate supplements (2 mEq/kg per day) either after signs of hypercalciuria were identified, while all children recruited after 2006 received the supplements.
Of the 198 children overall who received the supplements, two per cent developed kidney stones, compared to 10.5 per cent of the children who did not receive the supplements.
Furthermore, the researchers found that children receiving the potassium citrate supplements were seven times less likely to develop kidney stones - 0.9 per cent compared to 6.7 per cent who were given the supplements only after testing positive for elevated levels of blood calcium.
“Oral potassium citrate is an effective preventive supplement against kidney stones in children who receive the ketogenic diet, achieving its goal of urine alkalinisation,” wrote the researchers.
“Universal supplementation is warranted,” they concluded.
Published online ahead of print, doi: 10.1542/peds.2009-0217
"Empiric Use of Potassium Citrate Reduces Kidney-Stone Incidence With the Ketogenic Diet"
Authors: M.A. McNally, P.L. Pyzik, J.E. Rubenstein, R.F. Hamdy, E.H. Kossoff