Effects of Proton Pump Inhibitors on the bioactivation of dietary nitrate during submaximal exercise

Abstract: Abstract Aim: The purpose of the study is to show the influence of Proton Pump Inhibitors (PPI in form of esomeprazole) on the bioactivation of dietary nitrate (sodium-nitrate solution) in submaximal exercise, through affecting the gastric pH. Method: Randomized, doubled-blinded, placebo-controlled and crossover study with six subjects (mean ± SD, age 29 ± 5years, height 170 ± 5 centimeters, weight 70 ± 5 Kg, BMI 24,36 ± 1,75 Kg/m2 blood pressure 119/ 77 ± 6 mmHg, 3 male and 3 female). They were tested in two different trials. Every trial consisted of two parts. One part was cycling on 4 different submaximal stages (80W/60RPM, 80W/90RPM, 120W/60RPM, 120W/90RPM) for 5 minutes each, with 90 minutes rest in between. The same protocol was repeated. In the beginning of the resting time a sodium nitrate solution (NaNO3-, 10mg/kg body weight) was ingested. VO2, VCO2, RER, VE, Lactate, Glucose, heart rate and blood pressure were recorded. Venous blood samples were taken. Whether esomeprazole (10mg) or a placebo were taken 24h, 12h and directly before being tested in both trials. Subjects were pleased to have a nitrate poor diet starting when taking the pills. An information sheet was provided. Results: No significant differences were found between the post values and the treatment. Tendencies of a higher oxygen consumption when taking esomeprazole (2,62%) in comparison to placebo (0,11%) were observed. Systolic BP decreased by 3,91% with the placebo while it decreased just 2,04% with esomeprazole after intake. Sex-specific differences occurred in the metabolism of esomeprazole and dietary nitrate. RER showed a significant post nitrate difference between the female and male participants with t=.006 and a significance in predietary nitrate intake. VE in female (40,79 ± 7,20 L/min) and (50,03 ± 10,09 L/min) in male were as well significant (t=.017). Conclusion: Tendencies of effects of PPI are seen in the post-values of VO2 and BP after intake of dietary nitrate. Gender-differences are shown in RER and VE. More research is needed to see the impact of dietary nitrate on the human body under submaximal load.