Exercise Performance and Physiological Responses: The Potential Role of Redox Imbalance

Increases in oxidative stress or decreases in antioxidant capacity, or redox imbalance, are known to alter physiological function and has been suggested to influence performance. To date, no study has sought to manipulate this balance in the same participants and observe the impact on physiological function and performance. Using a single-blind, placebo-controlled, and counterbalanced design, this study examined the effects of increasing free radicals, via hyperoxic exposure (FiO2 = 1.0), and/or increasing antioxidant capacity, through consuming an antioxidant cocktail (AOC; vitamin-C, vitamin-E, α-lipoic acid), on 5-kilometer (km) cycling time-trial performance, and the physiological and fatigue responses in healthy college-aged males. Hyperoxic exposure prior to the 5 km TT had no effect on performance, fatigue, or the physiological responses to exercise. The AOC significantly reduced average power output (222 ± 11 vs. 214 ± 12 W), increased 5 km time (516 ± 17 vs. 533 ± 18 sec), suppressed ventilation (VE; 116 ± 5 vs. 109 ± 13 L/min), despite similar oxygen consumption (VO2; 43.1 ± 0.8 vs. 44.9 ± 0.2 mL/kg per min), decreased VE/VO2 (35.9 ± 2.0 vs. 32.3 ± 1.5 L/min), reduced economy (VO2/W; 0.20 ± 0.01 vs. 0.22 ± 0.01), increased blood lactate (10 ± 0.7 vs. 11 ± 0.7 mmol), and perception of fatigue (RPE; 7.39 ± 0.4 vs. 7.60 ± 0.3) at the end of the TT, as compared to placebo (main effect, placebo vs. AOC, respectively). Our data demonstrate that prior to exercise, ingesting an AOC, but not exposure to hyperoxia, likely disrupts the delicate balance between pro- and antioxidant forces, which negatively impacts ventilation, blood lactate, economy, perception of fatigue, and performance (power output and 5 km time) in young healthy males. Thus, caution is warranted in athletes taking excess exogenous antioxidants

Prevalence of sleepwalking in an adult population

Background: Sleepwalking consists of a series of behavioral activities that occur during sleep. These activities may besimple, complex or aggressive in nature. They include motor activities, confusion, and amnesia for the events. Sleepwalking isa disorder of arousal from non-rapid eye movement (NREM) sleep. In children, episodes of sleepwalking are rarely violent; inadults, however, sleepwalking might include violence, which could endanger the patient or others and might precipitate legalissues. There is inadequate information on the prevalence and demographic correlates of sleepwalking in Nigeria.Objectives: One objective of this study was to determine the lifetime prevalence rate of sleepwalking in an adult populationin Ile-Ife, in Southwestern Nigeria. Another objective was to determine the age and sex distribution of sleepwalking amongthose who have experienced it at least once in their lifetime. Materials and Methods: A random sample of 228 healthyindividuals aged 18 – 60 years was obtained and the members were asked to fill out a survey form about lifetime prevalencerate of sleepwalking. Results: The overall lifetime prevalence rate of sleepwalking was 7% (16 of 228 participants). It was10.4% in males and 3.5% in females, but the difference was not statistically significant (p = 0.07). Conclusion: This studyhas shown that sleepwalking is common in the population. In view of the psychological effects of sleepwalking and thepotential physical and legal problems associated with it, adequate efforts should be made for early detection and promptmanagement of the condition

Reduction in alcohol consumption and health status

Aims: This study investigated the association between alcohol consumption and health status using cross-sectional national survey data. Measurements and design: This study relied upon self-report data collected by the 2004 and 2007 Australian National Drug Strategy Household (NDSH) surveys. Households were selected using a multi-stage, stratified-area, random sample design. Both surveys used combinations of the drop-and-collect and computer-assisted telephone interview approaches. Respondents were questioned about their current and past drinking, the presence of formal diagnosis for specific diseases (heart disease, type 2 diabetes, hypertension, cancer, anxiety, depression) and self-perceived general health status. Associations between drinking status, the presence of diagnoses and self-perceptions of general health status among respondents aged 18+ and 45+ were assessed using multivariate logistic regression. Setting and participants: Male and females aged 18 years or older and resident in Australia. The sample sizes for the 2004 and 2007 NDSH surveys were 24 109 and 23 356, respectively. Findings: Respondents with a diagnosis of diabetes, hypertension and anxiety were more likely to have reduced or stopped alcohol consumption in the past 12 months. The likelihood of having reduced or ceased alcohol consumption inthe past 12 months increased as perceived general health status declined from excellent to poor. Conclusions: Experience of ill health is associated with subsequent reduction or cessation of alcohol consumption. This may at least partly underlie the observed 'J-shape' function relating alcohol consumption to premature mortality

Utility of three anthropometric indices in assessing the cardiometabolic risk profile in children

Objectives: To evaluate the ability of BMI, WC and WHtR to identify increased cardiometabolic risk in pre-adolescents. Methods: This is a cross-sectional study involving 192 children (10.92 ± 0.58 years, 56% female) from the United Kingdom between 2010 and 2013. Receiver operating characteristic curves determined the discriminatory ability of BMI, WC and WHtR to identify individuals with increased cardiometabolic risk (increased clustered triglycerides, HDL-cholesterol, systolic blood pressure, cardiorespiratory fitness and glucose). Results: A WHtR ≥ 0.5 increased the odds by 5.2 (95% confidence interval 2.6, 10.3) of having increased cardiometabolic risk. Similar associations were observed for BMI and WC. Both BMI-z and WHtR were fair predictors of increased cardiometabolic risk although BMI-z demonstrated the best trade-off between sensitivity and specificity, 76.1% and 63.6%, compared to 68.1% and 65.5% for WHtR. Cross-validation analysis revealed that BMI-z and WHtR correctly classified 84% of individuals (kappa score = 0.671, 95% CI 0.55, 0.79). The sensitivity of the cut-points suggests that 89.3% of individuals were correctly classified as being at risk with only 10.7% misdiagnosed whereas the specificity of the cut-points indicated that 77.8% of individuals were correctly identified as being healthy with 22.2% of individuals incorrectly diagnosed as being at risk. Conclusions: Findings suggest that WHtR provides similar cardiometabolic risk estimates to age and sex adjusted BMI

Prevalence of Abnormal Lipid Profiles and the Relationship With the Development of Microalbuminuria in Adolescents With Type 1 Diabetes

OBJECTIVE: To explore the prevalence of lipid abnormalities and their relationship with albumin excretion and microalbuminuria in adolescents with type 1 diabetes. RESEARCH DESIGN AND METHODS: The study population comprised 895 young subjects with type 1 diabetes (490 males); median age at the baseline assessment was 14.5 years (range 10-21.1), and median diabetes duration was 4.8 years (0.2-17). A total of 2,194 nonfasting blood samples were collected longitudinally for determination of total cholesterol, LDL cholesterol, HDL cholesterol, TG, and non-HDL cholesterol. Additional annually collected data on anthropometric parameters, A1C, and albumin-to-creatinine ratio (ACR) were available. RESULTS: Total cholesterol, LDL cholesterol, HDL cholesterol, and non-HDL cholesterol were higher in females than in males (all P 5.2 mmol/l (18.6%), non-HDL cholesterol >3.4 mmol/l (25.9%), TG >1.7 mmol/l (20.1%), and LDL cholesterol >3.4 mmol/l (9.6%). Age and duration were significantly related to all lipid parameters (P < 0.001); A1C was independently related to all parameters (P < 0.001) except HDL cholesterol, whereas BMI SD scores were related to all parameters (P < 0.05) except total cholesterol. Total cholesterol and non-HDL cholesterol were independently related to longitudinal changes in ACR (B coefficient +/- SE): 0.03 +/- 0.01/1 mmol/l, P = 0.009, and 0.32 +/- 0.014/1 mmol/l, P = 0.02, respectively. Overall mean total cholesterol and non-HDL cholesterol were higher in microalbuminuria positive (n = 115) than in normoalbuminuric subjects (n = 780): total cholesterol 4.7 +/- 1.2 vs. 4.5 +/- 0.8 mmol/l (P = 0.04) and non-HDL cholesterol 3.2 +/- 1.2 vs. 2.9 +/- 0.8 mmol/l (P = 0.03). CONCLUSIONS: In this longitudinal study of adolescents with type 1 diabetes, sustained lipid abnormalities were related to age, duration, BMI, and A1C. Furthermore, ACR was related to both total cholesterol and non-HDL cholesterol, indicating a potential role in the pathogenesis of diabetic nephropathy

Differential impact of impaired fasting glucose versus impaired glucose tolerance on cardiometabolic risk factors in multi-ethnic overweight/obese children

We aimed to investigate the prevalence of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), and their associations with cardiometabolic risk factors, according to ethnicity in a large obese paediatric cohort. A 75-g oral glucose tolerance test was performed in 1,007 overweight/obese Dutch children of multi-ethnic origin, referred to the obesity outpatient clinics of two Dutch hospitals in Amsterdam (mean age, 11.4 ± 3.2 years; 50.7% boys). Anthropometric parameters and blood samples were collected, and cardiometabolic risk factors were assessed. The cohort consisted of Dutch native (26.0%), Turkish (23.7%), Moroccan (18.8%) and children of ‘other’ (31.5%) ethnicity. The prevalence of IFG was significantly higher in Moroccan and Turkish children as compared to Dutch native children (25.4% and 19.7% vs. 11.8%, respectively, P < 0.05). IGT was most frequently present in Turkish and Dutch native children, relative to Moroccan children (6.3% and 5.3% vs. 1.6%, P < 0.05). Besides pubertal status and ethnicity, components of ‘metabolic syndrome’ (MetS) which were associated with IGT, independent of hyperinsulinaemia, were hypertension [odds ratio (OR), 2.3; 95% CI, 1.1–4.9] while a trend was seen for high triglycerides (OR, 2.0; 95% CI, 0.9–4.3). When analyzing components of MetS which were associated with IFG, only low high-density lipoprotein cholesterol was significantly associated (OR, 1.7; 95% CI, 1.2–2.5) independent of hyperinsulinaemia. In conclusion, in a Dutch multi-ethnic cohort of overweight/obese children, a high prevalence of IFG was found against a low prevalence of IGT, which differed in their associations with cardiometabolic risk factors