Reduction of Metabolic Acidosis in Patients With Chronic Kidney Disease in Stage 4 and 5 (REMA-CKD)

The goal of this clinical trial is to learn about and test the effect of an acid/base diet, in chronic kidney patients with CKD stage 4 and 5 in an interventional study with a historical control. Our hypothesize is that an acid/base diet will reduce the degree of acidosis and the need for oral bicarbonate supplements.

Observational studies indicate that diets with a low "potential renal acid load (PRAL)" is associated with a lower serum-bicarobante value. Therefore we aim to investigate this association with an interventional studydesign. Participants will be asked to follow a restricted diet with a low "PRAL" during a 6 week trial divided in three periodes: two week free living control, two week intervention and a two week free living follow-up. The PRAL calculation tool will be used to create a diet low in acid, based on this the patients will recieve individual diet plans. The diet will comply with national treshold guidlines for potassium and protein, this is due to the high risk of hyperkalemia in patients with chronic kidney disease. The patients will be asked to document their food and drink intake by taking pictures of their plates and cups before and after a meal, over a 24 hour period.

Potential renal acid load, PRAL, Study design, Diet, Humans, Elderly, Bicarbonate/blood, Muscle strength, Hand strength, Chair stand test, Calorimetry, indirect, Bone mineralization, Carbon dioxide/blood, Phosphor/urine, Potassium/urine, Urea/blood, Urea/urine

Crossover design: 1 arm consisting of three consecutive periods of two weeks (control, intervention and follow up).

Crossover design: 1 arm consisting of three consecutive periods of two weeks (control, intervention and follow up).

Inclusion Criteria: Chronic acidosis (plasma-bicarbonat under 22 mmol/l at multiple measures within the last 12 months). Diagnosed with non-dialysis needed chronic kidney disease in stage 4 and 5 (eGFR below 30 ml/min/1,73 m2) Of legal age and over 18 of years Understand danish and understand the written material Able to cooperate about the diet Able to take pictures with their phone or willing to learn Exclusion Criteria: Vegan and vegetarian with very low intake of animal protein (below 25 g/day) Pregnant or breast feeding Patients with short bowel syndrome, brickre's bladder, pancreatitis or any other known malabsorption problem Potassium above 5 mmol/l Ongoing infection