Extracellular buffer choice influences acid-base responses and gastrointestinal symptoms

Abstract

To compare the bicarbonate kinetics and gastrointestinal (GI) symptom responses between an equal dose of sodium bicarbonate and sodium citrate using delayed-release capsules. Thirteen active males (age 20.5 ± 2.1 y, height 1.8 ± 0.1 m and body mass [BM] 76.5 ± 9.6 kg) consumed either 0.3 g . kg −1 BM sodium bicarbonate, sodium citrate or a placebo, using a double-blind, randomized crossover design.

A Comparison of Sodium Citrate and Sodium Bicarbonate Ingestion: Blood Alkalosis and Gastrointestinal Symptoms

“…The similar peak alkalosis observed here is in accordance with the sole prior investigation to compare these supplements using the same doses as the current study (Potteiger et al, 1996). Ingestion of equal SC and SB doses (300 mg/kg BM) has previously returned equivocal blood alkalosis comparisons (Kumstát et al, 2018;Parry-Billings & MacLaren, 1986;Peacock et al, 2021;Tiryaki & Atterbom, 1995). One of these studies reported that SB elicited greater alkalosis compared with SC (Peacock et al, 2021), and earlier investigations reported no difference between the supplements for indicators of magnitude of blood alkalosis (Kumstát et al, 2018;Parry-Billings & MacLaren, 1986;Tiryaki & Atterbom, 1995).…”

“…Ingestion of equal SC and SB doses (300 mg/kg BM) has previously returned equivocal blood alkalosis comparisons (Kumstát et al, 2018;Parry-Billings & MacLaren, 1986;Peacock et al, 2021;Tiryaki & Atterbom, 1995). One of these studies reported that SB elicited greater alkalosis compared with SC (Peacock et al, 2021), and earlier investigations reported no difference between the supplements for indicators of magnitude of blood alkalosis (Kumstát et al, 2018;Parry-Billings & MacLaren, 1986;Tiryaki & Atterbom, 1995). It remains unclear why there is this inconsistency; however, a possible explanation may include variations in the timing and duration of the postingestion blood sampling across previous investigations, and may also be contributed to by differing sampling sites (i.e., venous, arterial, and capillary) and presampling procedures (e.g., arterialization) across studies.…”

“…Separate investigations have reported that peak blood alkalosis occurs ∼180-240 min postingestion for SC (Urwin et al, 2016(Urwin et al, , 2019(Urwin et al, , 2021 and ∼30-180 min postingestion for SB (Boegman et al, 2020;Gough et al, 2018;Jones et al, 2016), suggesting that peak alkalosis may occur later with SC supplementation. Indeed, a recent study which directly compared the two supplements using the same dose (i.e., 300 mg/kg BM) reported a significantly later peak for blood [HCO 3 − ] with SC when compared with SB (Peacock et al, 2021). Interestingly, when the recommended doses for each supplement were compared (Potteiger et al, 1996), there also appeared to be a delayed blood [HCO 3 − ] peak with SC (120 vs. 100 min); however, it was unclear from the report whether this time difference was statistically significant.…”

“…However, no prior studies have statistically compared GIS between SC and SB using the recommended dose of both supplements (SC = 500 mg/kg BM; SB = 300 mg/kg BM). Only one investigation has conducted statistical comparisons of GIS following ingestion of SC and SB (Peacock et al, 2021), where 300 mg/kg BM SB elicited a greater number and severity of GIS when compared with 300 mg/kg BM SC. Therefore, there is currently limited evidence on which to make recommendations on the comparative suitability of SC and SB with regard to GIS when the recommended doses of each supplement are consumed.…”

The Hyperhydration Potential of Sodium Bicarbonate and Sodium Citrate

“…A handful of older studies have profiled changes in acid-base balance after CIT ingestion (Kowalchuk et al, 1989;McNaughton, 1990), but these were ingested in solution and in a fasted state. A more recent body of evidence would suggest time-to-peak increase in [HCO 3 − ] after CIT ingestion is often protracted when compared with BIC (Peacock et al, 2021;Urwin et al, 2021). This might explain the discrepancy in the present study, as the relative rise in both pH and HCO 3 − was slower in the CIT condition, compared with BIC, and ultimately lower at 180 min (Figure 2a and 2b).…”