The Dietary Approach to the Treatment of the Rare Genetic Tubulopathies Gitelman's and Bartter's Syndromes

Abstract

Gitelman's (GS) and Bartter's (BS) syndromes are rare, inherited autosomal recessive tubulopathies characterized by hypokalemia, metabolic alkalosis, renal sodium, chloride, and potassium and magnesium-wasting. While the treatment based on potassium, sodium, chloride, and magnesium supplementation in addition to other pharmacologic options are widely established, recommendations about the dietary approach to GS and BS still remain generic. In this review we focus on the dietary strategies to increase sodium, potassium, and magnesium intake in GS and BS patients. Potassium and magnesium-rich foods and supplements are considered together with those that may reduce through different mechanisms the potassium and magnesium plasma level. Magnesium supplementation is often poorly tolerated, causing abdominal pain and diarrhea in most patients. New formulations using liposome and, in particular, sucrosomial technology have been recently proposed for magnesium supplementation in order to increase magnesium supplement tolerability and intestinal absorption. The dietary approach to GS and BS may be very important in the therapeutic approach to these syndromes. Due to the relevance of the dietary approach to these syndromes, a nutritional counseling should always be recommended and the nutritionist should join nephrologists in the follow-up of GS and BS patient care.

Keywords: Bartter’s syndrome; Gitelman’s syndrome; nutritional therapy; potassium supplements; sucrosomial magnesium.

Figure 1

Transport pathways in the thick ascending limb of Henle’s loop and in the distal convoluted tubule depicting the abnormalities of the five types of Bartter’s syndrome and Gitelman’s syndromes.

Figure 2

Sucrosomial magnesium intestinal absorption. Magnesium ions encapsulated within a sucrosomial membrane pass through the intestine without direct interaction with the mucosa and lumen content, and then are absorbed via passive paracellular mechanisms that account for about 90% of the whole intestinal uptake. Only a small part of magnesium (about 10%) is absorbed through membrane transporters (TRP M6/7).