Acid-Base Balance in Healthy Adults: Beneficial Effects of Bicarbonate and Sodium-Rich Mineral Water in a Randomized Controlled Trial: The BicarboWater Study

Table 5

Blood gas analysis at the beginning of the study (), at the interim examination (), and at the end of the intervention () as well as absolute changes (∆).

Parameter	Group	Time			value (time × group)	value (time)	Change
							∆ 3-0	∆ 28-0
pH	HBS	7.381 (0.035)	7.396 (0.048)^b	7.382 (0.045)^b	0.145	<0.001	0.01 (0.04)	−0.01 (0.03)
	LBS	7.397 (0.036)^c	7.383 (0.039)	7.374 (0.037)^c		0.027	0.00 (0.04)	0.00 (0.04)
HCO3^− (mmol/L)	HBS	25.6 (2.70)^a,c	26.00 (2.60)^a	25.80 (3.20)^c	0.001	<0.001	0.60 (2.50)	0.90 (2.20)
	LBS	25.6 (2.50)	25.00 (2.10)	25.10 (1.50)		0.428	−0.30 (1.70)	−0.40 (1.80)
BE (b) (mmHg)	HBS	0.20 (2.30)^a,c	0.90 (2.60)^a,b	0.80 (2.00)^b,c	<0.001	<0.001	0.80 (1.50)	0.70 (1.70)
	LBS	0.20 (1.40)	−0.15 (2.00)	−0.05 (1.30)		0.146	−0.15 (1.30)	−0.45 (1.80)
pCO2 (mmHg)	HBS	43.40 (7.70)^c	43.40 (8.00)	43.60 (9.10)^c	0.303	0.016	1.20 (6.80)	1.90 (5.40)
	LBS	41.85 (7.40)	41.10 (5.50)	43.00 (5.90)		0.132	−0.70 (6.40)	−0.15 (5.10)

Data are shown as median (IQR). HBS = high bicarbonate and sodium, LBS = low bicarbonate and sodium. BE = base excess, HCO₃⁻ = bicarbonate in venous blood, pCO₂ = partial pressure of carbon dioxide in venous blood. Time × group interactions were analyzed using two-way repeated measures ANOVA. Differences over the intervention time within each group were assessed with repeated measurements ANOVA. ^a = sign. Differences between and (short term), ^b = sign. Differences between and (follow-up), ^c = sign. Differences between and (long term). The bold values are significant at p <0.05.