Browsing by Author "Veliz, Carlos"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Hypoxic Respiratory Chemoreflex Control in Young Trained Swimmers
    (2021) Arce-Alvarez, Alexis; Veliz, Carlos; Vazquez-Munoz, Manuel; von Igel, Magdalena; Alvares, Cristian; Ramirez-Campillo, Rodrigo; Izquierdo, Mikel; Millet, Gregoire P.; Del Rio, Rodrigo; Andrade, David C.
    During an apnea, changes in PaO2 activate peripheral chemoreceptors to increase respiratory drive. Athletes with continuous apnea, such as breath-hold divers, have shown a decrease in hypoxic ventilatory response (HVR), which could explain the long apnea times; however, this has not been studied in swimmers. We hypothesize that the long periods of voluntary apnea in swimmers is related to a decreased HVR. Therefore, we sought to determine the HVR and cardiovascular adjustments during a maximum voluntary apnea in young-trained swimmers. In fifteen trained swimmers and twenty-seven controls we studied minute ventilation (V-E), arterial saturation (SpO(2)), heart rate (HR), and autonomic response [through heart rate variability (HRV) analysis], during acute chemoreflex activation (five inhalations of pure N-2) and maximum voluntary apnea test. In apnea tests, the maximum voluntary apnea time and the end-apnea HR were higher in swimmers than in controls (p < 0.05), as well as a higher low frequency component of HRV (p < 0.05), than controls. Swimmers showed lower HVR than controls (p < 0.01) without differences in cardiac hypoxic response (CHR). We conclude that swimmers had a reduced HVR response and greater maximal voluntary apnea duration, probably due to decreased HVR.
  • No Thumbnail Available
    Item
    Oscillatory pattern of glycemic control in patients with diabetes mellitus
    (2021) Vasquez-Munoz, Manuel; Arce-Alvarez, Alexis; von Igel, Magdalena; Veliz, Carlos; Ruiz-Esquide, Gonzalo; Ramirez-Campillo, Rodrigo; Alvarez, Cristian; Ramirez-Velez, Robinson; Crespo, Fernando A.; Izquierdo, Mikel; Del Rio, Rodrigo; Andrade, David C.
    Daily glucose variability is higher in diabetic mellitus (DM) patients which has been related to the severity of the disease. However, it is unclear whether glycemic variability displays a specific pattern oscillation or if it is completely random. Thus, to determine glycemic variability pattern, we measured and analyzed continuous glucose monitoring (CGM) data, in control subjects and patients with DM type-1 (T1D). CGM data was assessed for 6 days (day: 08:00-20:00-h; and night: 20:00-08:00-h). Participants (n =172; age =18-80 years) were assigned to T1D (n =144, females = 65) and Control (i.e., healthy; n = 28, females = 22) groups. Anthropometry, pharmacologic treatments, glycosylated hemoglobin (HbA1c) and years of evolution were determined. T1D females displayed a higher glycemia at 10:00-14:00-h vs. T1D males and Control females. DM patients displays mainly stationary oscillations (deterministic), with circadian rhythm characteristics. The glycemia oscillated between 2 and 6 days. The predictive model of glycemia showed that it is possible to predict hyper and hypoglycemia (R-2 =0.94 and 0.98, respectively) in DM patients independent of their etiology. Our data showed that glycemic variability had a specific oscillation pattern with circadian characteristics, with episodes of hypoglycemia and hyperglycemia at day phases, which could help therapeutic action for this population.