Enhancing Spinal Cord Injury Care: Using Wearable Technologies for Physical Activity, Sleep, and Cardiovascular Health.

Wearable devices have the potential to advance health care by enabling real-time monitoring of biobehavioral data and facilitating the management of an individual's health conditions. Individuals living with spinal cord injury (SCI) have impaired motor function, which results in deconditioning and worsening cardiovascular health outcomes. Wearable devices may promote physical activity and allow the monitoring of secondary complications associated with SCI, potentially improving motor function, sleep, and cardiovascular health.

Mechanisms underlying the health benefits of intermittent hypoxia conditioning.

Intermittent hypoxia (IH) is commonly associated with pathological conditions, particularly obstructive sleep apnoea. However, IH is also increasingly used to enhance health and performance and is emerging as a potent non-pharmacological intervention against numerous diseases. Whether IH is detrimental or beneficial for health is largely determined by the intensity, duration, number and frequency of the hypoxic exposures and by the specific responses they engender.

The hypoxic ventilatory response and hypoxic burden are predictors of the magnitude of ventilatory long-term facilitation in humans.

Mild intermittent hypoxia initiates progressive augmentation (PA) and ventilatory long-term facilitation (vLTF) in humans. The magnitude of these forms of plasticity might be influenced by anthropometric and physiological variables, as well as protocol elements. However, the impact of many of these variables on the magnitude of respiratory plasticity has not been established in humans.

The Clinical Relevance of Autonomic Dysfunction, Cerebral Hemodynamics, and Sleep Interactions in Individuals Living With SCI.

A myriad of physiological impairments is seen in individuals after a spinal cord injury (SCI). These include altered autonomic function, cerebral hemodynamics, and sleep. These physiological systems are interconnected and likely insidiously interact leading to secondary complications.

Intermittent hypoxia: a call for harmonization in terminology.

Mild intermittent hypoxia may be a potent novel strategy to improve cardiovascular function, motor and cognitive function, and altitude acclimatization. However, there is still a stigma surrounding the field of intermittent hypoxia (IH). Major contributors to this stigma may be due to the overlapping terminology, heterogeneous methodological approaches, and an almost dogmatic focus on different mechanistic underpinnings in different fields of research.

Racial differences in upper airway collapsibility and loop gain in young adult males.

Study Objectives: Previous studies reported that the apnea-hypopnea index was similar in young adult Black and White participants. However, whether this similarity reflects an analogous combination of apneas and hypopneas is unknown. Likewise, the physiological mechanisms underlying this similarity has not been explored.

Divergent Ventilatory and Blood Pressure Responses are Evident Following Repeated Daily Exposure to Mild Intermittent Hypoxia in Males with OSA and Hypertension.

Resting minute ventilation and ventilation during and following hypoxia may be enhanced following daily exposure to mild intermittent hypoxia (MIH). In contrast, resting systolic blood pressure (SBP) is reduced following daily exposure to MIH. However, it is presently unknown if the reduction in resting SBP following daily exposure, is coupled with reduced SBP responses during and after acute exposure to MIH.

Daily Exposure to Mild Intermittent Hypoxia Reduces Blood Pressure in Male Patients with Obstructive Sleep Apnea and Hypertension.

Daily exposure to mild intermittent hypoxia (MIH) may elicit beneficial cardiovascular outcomes. To determine the effect of 15 days of MIH and in-home continuous positive airway pressure treatment on blood pressure in participants with obstructive sleep apnea and hypertension. We administered MIH during wakefulness 5 days/week for 3 weeks.

Is Sleep Disordered Breathing Confounding Rehabilitation Outcomes in Spinal Cord Injury Research?

The purpose of this article is to highlight the importance of considering sleep-disordered breathing (SDB) as a potential confounder to rehabilitation research interventions in spinal cord injury (SCI). SDB is highly prevalent in SCI, with increased prevalence in individuals with higher and more severe lesions, and the criterion standard treatment with continuous positive airway pressure remains problematic. Despite its high prevalence, SDB is often untested and untreated in individuals with SCI.

A comprehensive review of respiratory, autonomic and cardiovascular responses to intermittent hypoxia in humans.

This review explores forms of respiratory and autonomic plasticity, and associated outcome measures, that are initiated by exposure to intermittent hypoxia. The review focuses primarily on studies that have been completed in humans and primarily explores the impact of mild intermittent hypoxia on outcome measures. Studies that have explored two forms of respiratory plasticity, progressive augmentation of the hypoxic ventilatory response and long-term facilitation of ventilation and upper airway muscle activity, are initially reviewed.

Effect of repeated locomotor training on ventilatory measures, perceived exertion and walking endurance in persons with motor incomplete spinal cord injury.

Study Design: Pre-Post, Repeated Measures.

Objectives: To determine if a warm-up bout of exercise could elicit a phasic ventilatory response to constant work rate (CWR) exercise in individuals with incomplete spinal cord injury (iSCI) during unsupported CWR treadmill walking. Describe the changes in ventilatory kinetics, ventilatory variability and ratings of perceived exertion (RPE) before and after 12 and 24 weeks of overground locomotor training (OLT).

Walking endurance, muscle oxygen extraction, and perceived fatigability after overground locomotor training in incomplete spinal cord injury: A pilot study.

The purpose of this study was to examine the effects of overground locomotor training (OLT) on walking endurance and gastrocnemius oxygen extraction in people with chronic cervical motor-incomplete spinal cord injury (SCI). Prospective single-arm pre-post pilot study. Human Performance Research Laboratory.

Variations in loop gain and arousal threshold during NREM sleep are affected by time of day over a 24-hour period in participants with obstructive sleep apnea.

We investigated whether time of day affects loop gain (LG) and the arousal threshold (AT) during non-rapid eye movement (NREM) sleep. Eleven men with obstructive sleep apnea (apnea-hypopnea index > 5 events/h) completed a constant-routine protocol that comprised 3-h sleep sessions in the evening [10 PM (1) to 1 AM], morning (6 AM to 9 AM), afternoon (2 PM to 5 PM), and subsequent evening [10 PM (2) to 1 AM]. During each sleep session LG and the AT were measured during NREM sleep with a model-based approach.

Increased Oxidative Stress, Loop Gain And The Arousal Threshold Are Clinical Predictors Of Increased Apnea Severity Following Exposure To Intermittent Hypoxia.

Purpose: We determined if oxidative stress prior to sleep onset is correlated to loop gain (LG) and the arousal threshold (AT) during non-rapid eye movement (NREM) sleep. We also explored if LG and AT are correlated with apnea severity and indices of upper airway collapsibility during NREM sleep.

Methods: Thirteen male participants with obstructive sleep apnea (apnea-hypopnea index > 5 events/hr) were administered an antioxidant or placebo cocktail while exposed to mild intermittent hypoxia in the awake state.

Effect of overground locomotor training on ventilatory kinetics and rate of perceived exertion in persons with cervical motor-incomplete spinal cord injury.

Study Design: Pre-post, pilot study.

Objectives: To characterize ventilatory () responses to exercise following warm-up walking in individuals with chronic incomplete spinal cord injury (iSCI) during constant work rate (CWR) exercise. Secondarily, to investigate and tidal volume () variability, and ratings of perceived exertion (RPE) before and after overground locomotor training (OLT).

Exposure to mild intermittent hypoxia increases loop gain and the arousal threshold in participants with obstructive sleep apnoea.

Key Points: Repeated daily mild intermittent hypoxia has been endorsed as a therapy to promote the recovery of respiratory and limb motor dysfunction. One possible side-effect of this therapy is an increase in apnoeic event number and duration, which is particularly relevant to participants with motor disorders coupled with an increased incidence of sleep apnoea. In this study, we report that increases in apnoeic event number and duration, following exposure to daily intermittent hypoxia, are the result of an increase in respiratory loop gain and the arousal threshold, in participants with obstructive sleep apnoea.