Neutralization of Western diet inhibits bone resorption independently of K intake and reduces cortisol secretion in humans.
Am J Physiol Renal Physiol. 2003 Jan;284(1):F32-40. Epub 2002 Sep 24. PMID: 12388390
Marc Maurer, Walter Riesen, Juergen Muser, Henry N Hulter, Reto Krapf
A Western-type diet is associated with osteoporosis and calcium nephrolithiasis. On the basis of observations that calcium retention and inhibition of bone resorption result from alkali administration, it is assumed that the acid load inherent in this diet is responsible for increased bone resorption and calcium loss from bone. However, it is not known whether the dietary acid load acts directly or indirectly (i.e., via endocrine changes) on bone metabolism. It is also unclear whether alkali administration affects bone resorption/calcium balance directly or whether alkali-induced calcium retention is dependent on the cation (i.e., potassium) supplied with administered base. The effects of neutralization of dietary acid load (equimolar amounts of NaHCO(3) and KHCO(3) substituted for NaCl and KCl) in nine healthy subjects (6 men, 3 women) under metabolic balance conditions on calcium balance, bone markers, and endocrine systems relevant to bone [glucocorticoid secretion, IGF-1, parathyroid hormone (PTH)/1,25(OH)(2) vitamin D and thyroid hormones] were studied. Neutralization for 7 days induced a significant cumulative calcium retention (10.7 +/- 0.4 mmol) and significantly reduced the urinary excretion of deoxypyridinoline, pyridinoline, and n-telopeptide. Mean daily plasma cortisol decreased from 264 +/- 45 to 232 +/- 43 nmol/l (P = 0.032), and urinary excretion of tetrahydrocortisol (THF) decreased from 2,410 +/- 210 to 2,098 +/- 190 microg/24 h (P = 0.027). No significant effect was found on free IGF-1, PTH/1,25(OH)(2) vitamin D, or thyroid hormones. An acidogenic Western diet results in mild metabolic acidosis in association with a state of cortisol excess, altered divalent ion metabolism, and increased bone resorptive indices. Acidosis-induced increases in cortisol secretion and plasma concentration may play a role in mild acidosis-induced alterations in bone metabolism and possibly in osteoporosis associated with an acidogenic Western diet.
Article Published Date : Jan 01, 2003
Therapeutic Actions DIETARY MODIFICATION Less Acid-More Alkaline
Modifications to bicarbonate conductivity: A way to increase phosphate removal during hemodialysis? Proof of concept.
Hemodial Int. 2016 Oct;20(4):601-609
Authors: Bertocchio JP, Mohajer M, Gaha K, Ramont L, Maheut H, Rieu P
Introduction Hyperphosphatemia and cardiovascular mortality are associated particularly with end-stage renal disease. Available therapeutic strategies (i.e., diet restriction, calcium [or not]-based phosphate binders, calcimimetics) are associated with extrarenal blood purification. Compartmentalization of phosphate limits its depuration during hemodialysis. Several studies suggest that plasmatic pH is involved in the mobilization of phosphate from intracellular to extracellular compartments. Consequently, the efficiency of modified bicarbonate conductivity to purify blood phosphate was tested. Methods Ten hemodialysis patients with chronic hyperphosphatemia (>2.1 mmol/L) were included in the two three-sessions-per week periods. Bicarbonate concentration was fixed at 40 mmol/L and 30 mmol/L in the first and second periods, respectively. Phosphate depuration was evaluated by phosphate mobilization clearance (KM ). Findings Although bicarbonatemia was lower during the second period (21.0 ± 2.7 vs. 24.4 ± 3.1 mmol/L, P < 0.01), no difference was observed in phosphatemia (2.4 ± 0.5 vs. 2.3 ± 0.4 mmol/L, P = NS). The in-session variation of phosphate was lower (-1.45 ± 0.42 vs. -1.58 ± 0.44 mmol/L, P < 0.05) and KM was higher during the second period (82.94 ± 38.00 vs. 69.74 ± 24.48 mL/min, P < 0.05). Discussion The decrease of in-session phosphate and the increase in KM reflect phosphate refilling during hemodialysis. Thus, modulation of serum bicarbonate may play a role in controlling the phosphate pool. Even though correcting metabolic acidosis during hemodialysis remains important, alkaline excess can impair phosphate mobilization clearance. Clinical trials are needed to test the efficiency and relevance of a strategy where bicarbonatemia is corrected less at the beginning of sessions.
PMID: 27060343 [PubMed - indexed for MEDLINE]