METHODS: Healthy subjects were screened not to have conditions that exerts abnormal EtCO2 nor contraindicated for KD. Subjects underwent seven days of KD while the EtCO2 and blood ketone (beta-hydroxybutyrate; β-OHB) parameters were sampled at day zero (t0) and seven (t7) of ketosis respectively. Statistically, the t-test and Pearson's coefficient were conducted to determine the changes and correlation of both parameters.
RESULTS: 12 subjects completed the study. The mean score ± standard deviation (SD) for EtCO2 were 35.08 ± 3.53 and 35.67 ± 3.31 mm Hg for t0 and t7 respectively. The mean score ±SD for β-OHB were 0.07 ± 0.08 and 0.87 ± 0.84 mmol/L for t0 and t7 respectively. There was no significant difference of EtCO2 between the period of study (p > 0.05) but the β-OHB increased during t7 (p