Investigating the Association of VO2 and VCO2 Rate Variability with Serum Glucose, Insulin and Glucose Intolerance

Objective: To measure the changes in the cellular metabolism evaluated by the variability of oxygen consumption (VO2) and carbon dioxide production (VCO2) as well as the association of serum glucose and insulin to energy spectral density (ESD) of VO2 and VCO2. Materials and Methods: Ten non-glucose intolerant and ten glucose intolerant subjects between the ages of 21 and 70 were included in the study. Glucose and insulin levels, as well as VO2 and VCO2 levels, were measured every 10 minutes for 3 hours. The ESD of VO2 and VCO2 were calculated and related to glucose and insulin concentrations. Results: There was statistical significance in glucose levels, insulin, and ESD of VO2 and VCO2 among non-glucose intolerant subjects, and glucose and insulin among glucose intolerance subjects, at post-load glucose state compared to basal state. Furthermore, for both the basal and post-load glucose states, glucose levels were significantly higher in glucose intolerance subjects than in non-glucose intolerant subjects. Conclusions: These findings show an increase in ESD of VO2 and VCO2 at the post-load glucose state in non-glucose intolerant subjects, implying that their measurement may be a key indicator of the variability of cellular metabolic activity and contribute to the confirmation of glucose metabolism disturbances.  More research is needed to understand the precise behaviour of ESD of VO2 and VCO2 in a larger population that includes diabetic subjects.