Severe hypoxaemic hypercapnia compounds cerebral oxidative-nitrosative stress during extreme apnoea: Implications for cerebral bioenergetic function

Cognitive impairments after maximal repeated breath-holding in elite breath-hold divers

BACKGROUND

Breath-hold (BH) training over several years may result in mild but persistent neurocognitive impairment. Paradoxically, the acute effects of repeated BH generating intermittent hypoxia on neurocognitive functions are still poorly understood. Therefore, we decided to examine the impact of five-repeated maximal BH on attention, processing speed, and reasoning abilities.

METHODS

Thirty six men separated in 3 groups (12 elite BH divers: EBHD; 12 novice BH divers: NBHD; and 12 non BH divers: CTL) performed before and after 5 maximal BHs, neuropsychological computerized tasks sensitive to hypoxia. Heart rate (HR) and peripheral oxygen saturation were recorded continuously during all tests.

RESULTS

Immediately after the five BHs, all the participants presented lower response time on the visual reaction task. EBHD did not exhibit difference in neuropsychological performance compared to NBHD and CTL, despite enduring longer BH durations.

CONCLUSIONS

Regardless of BHD training level, repeated maximal BH may affect certain aspects of neuropsychological performance, in particularly visual reaction times. However, elite BHDs may have developed adaptive mechanisms that allow them to maintain their neurocognitive function at levels comparable to those of less trained BHDs and CTL, even with a higher dose of hypoxia.

The link between sleep bruxism and oxidative stress based on a polysomnographic study

Oxidative stress is proven to increase cardiovascular risk and to diminish healthy life expectancy. Sleep bruxism (SB) is a prevalent masticatory muscle activity during sleep characterized by heterogeneous etiology and inadequately recognized pathophysiology. Recent theories have proposed a potential association between SB and oxidative stress. The aim of the research was to compare the antioxidant status between individuals with SB in contrast to those without SB. A total of 80 adults participated in a full-night polysomnography, assessed according to the American Academy of Sleep Medicine (AASM) standards. Blood samples were subsequently drawn via venipuncture for analysis. Participants were stratified into two groups based on their bruxism episode index (BEI). Using successive receiver operating characteristic (ROC) curves, optimal cut-off values were identified, enabling the detection of correlations with moderate (BEI > 2) and severe (BEI > 4) sleep bruxism. In the investigated group of patients we observed the relationship between bruxism and the examined parameters: total antioxidant status (TAS), advanced protein products (AOPP) and thiobarbituric acid-reacting substances (TBARS). Low TAS (≤ 0.14 mM and ≤ 0. 16 mM), high AOPP (≥ 82.44 µmol/l) and high TBARS (≥ 723.03 µmol/l and ≥ 1585.45 µmol/l) serum levels result in significantly higher sleep bruxism parameters. Sleep bruxism is related to oxidative stress markers. Elevated markers of lipid and protein peroxidation may be associated with endovascular damage and cardiovascular risk in sleep bruxers, but further research is needed in this topic.

Spinal pain prevalence and associated determinants: A population-based study using the National Survey for Wales

Spinal pain (SP) remains the leading cause of disability worldwide. The present study aimed to establish a current prevalence of SP and associated determinants in Wales by retrospectively analyzing data from the National Survey for Wales Dataset (NSWD). The NSWD is a large-scale cross-sectional, representative sample of adults across Wales, UK. A univariable and multivariable regression analysis was carried out on self-reported answers to health and well-being questions contained within the NSWD (2016-2020) to determine the strength of association of various determinants and comorbidities related to spinal pain. A total population of 38,954 of adults were included in the analysis. The study population included interview responses of 21,735 females and 17,219 males. The prevalence of SP in Wales was 4.95% (95% CI: 4.74%-5.15%) with a total of 847 males (4.92%, CI: 4.60%-5.24%) and 1082 females (4.98%, CI: 4.69%-5.27%) reporting spinal pain. The age group with the highest prevalence of SP was in the 70+ years age group for both males (5.44%, CI: 4.82%-6.07%) and females (5.95%, CI: 5.37%-6.54%). The strength of association between age and SP reaches its peak at 50-59 years with an adjusted Odds Ratio (aOR) of 3.74 (p = <0.001), that decreases slightly at 60-69 years and 70+ years. For various comorbidities included in the NSWD, significant associations with SP were confirmed for: mental illness (aOR = 1.42, p = <0.001), migraine (aOR = 2.73, p = <0.001), nervous system issues (aOR = 1.61, p = <0.001), arthritis (aOR = 1.30, p = <0.001) and issues with bones/joints/muscles (aOR = 1.93, p = <0.001). For lifestyle factors, associations were confirmed for current smokers (aOR = 1.41, p = <0.001) and ex-smokers (aOR = 1.23, p = 0.003). This study demonstrates a low prevalence of SP in Wales when compared to global estimates and strong associations to a variety of determinants. This still represents a significant societal burden and these findings may help inform public health initiatives to encourage prevention and evidence-based interventional strategies and ultimately, improve the quality of life for those suffering with SP in Wales.