Associations between Sleep Characteristics and Cardiovascular Risk Factors in Adolescents Living with Type 1 Diabetes.

Adolescents living with type 1 diabetes (T1D) have an increased risk of developing cardiovascular disease. Sleep patterns have physiological and behavioral impacts on diabetes outcomes. This study aimed to investigate the associations between sleep patterns and CVD risk factors in adolescents living with T1D and their peers living without T1D. This cross-sectional study assessed CVD risk factors and sleep characteristics (and their associations) in adolescents, aged 12-18 years, living with T1D (n = 48) and their peers (n = 19) without T1D. Outcomes included blood pressure, lipid profiles, and sleep characteristics (accelerometry). Statistical differences between groups were determined with chi-square or independent samples t-tests. The associations between sleep characteristics and CVD risk factors were assessed with multivariate linear regression analyses. We found no significant differences between the two groups in terms of sleep duration, efficiency, sleep onset and offset, and frequency of awakenings, and there were associations between sleep efficiency and LDL-C (ß = -0.045, p = 0.018, model R2 = 0.230) and triglycerides (ß = -0.027, p = 0.012, model R2 = 0.222) after adjusting confounders (diabetes status, sex, age, pubertal stage) in all participants. In conclusion, adolescents with T1D and without T1D sleep less than the recommended eight hours per night. The associations between sleep efficiency and LDL-C and triglycerides are independent of sleep duration, regardless of sex, age, and pubertal stage.

Effect of an Ultra-Endurance Event on Cardiovascular Function and Cognitive Performance in Marathon Runners.

Background: Ultra-marathon running participation has become increasingly more popular in recent years; however, there is inconclusive evidence concerning the effects of participation on cognition and cardiovascular function. The purpose of this study was to examine alterations in cardiovascular function and cognitive performance and their association in ultra-marathon runners prior to and following an ultra-endurance event. Methods: In total, 24 runners (19 males and 5 females) participated in an ultra-marathon race (FatDog120) held in British Columbia, Canada. Participants competed in varying races distances [48 km (n = 2), 80 km (n = 7), 113 km (n = 3), and 193 km (n = 12)]. Cognition was assessed prior to and upon race completion using simple reaction time, choice reaction time, discrimination reaction time, and recognition memory (% correct). Cardiovascular function was assessed prior to and upon race completion using radial applanation tonometry for diastolic pulse contour examination. Results: Cognitive performance displayed significantly (p < 0.001) slower reaction times post-race for simple (30.2%), discrimination (22.7%), and choice reaction time (30.5%), as well as a significant (p < 0.05) reduction in memory test performance (-8.2%). A significant association between systemic vascular resistance and choice reaction time was observed post-race (r = 0.41, p < 0.05). Significant changes in post-race cardiovascular function were observed in resting heart rate (31.5%), cardiac output (27.5%), mean arterial blood pressure (-5.6%), total systemic resistance (-17.6%), systolic blood pressure (-7.0%), pulse pressure (-11.2%), and rate pressure product (22.4%). There was evidence of enhanced cardiovascular function being associated with improved cognitive performance before and after the ultra-endurance event. Conclusion: Ultra endurance running is associated with marked impairments in cognitive performance that are associated (at least in part) with changes in cardiovascular function in healthy adults.

Bilateral difference between lower limbs in children practicing laterally dominant vs. non-laterally dominant sports.

Bilateral asymmetry in lower-limb power and dynamic balance has been associated with increased risk of sport injury, whereas there is a lack of research examining this asymmetry for child athletes. Twenty-eight fencers (19 boys and 9 girls, aged 9.71 ± 1.08 years) and 28 Taekwondo athletes (19 boys and 9 girls, aged 9.71 ± 1.08 years) were examined on the single-leg jump and Star Excursion Balance Test (SEBT) performance. A mixed model design ANOVA (2 [Sex: Boys, Girls] × 2 [Sport group: Fencing, Taekwondo] × 2 [Limb: Dominant, Non-dominant Leg]) was conducted to examine for difference for each test. There was a significant main effect of limb on hop and triple hop distance (p < 0.05). A significant limb by sex interaction (p = 0.000) was shown for the single-leg countermovement jump (CMJ) performance, wherein a bilateral difference was only shown in boys. In SEBT, a main effect (p = 0.007) of limb was identified for posterolateral (PL) reach distance. A limb by sex interaction (p = 0.009) was also shown for posteromedial (PM) reach distance, wherein a bilateral difference was only shown in girls. These findings suggest that child athletes in both laterally dominant and non-laterally dominant sports showed inter-limb asymmetry of leg power and dynamic balance. Sex should be an important consideration when evaluating bilateral difference of leg power and dynamic balance for child athletes.

Effects of Aerobic, Resistance, and Combined Exercise Training on Psychiatric Symptom Severity and Related Health Measures in Adults Living With Schizophrenia: A Systematic Review and Meta-Analysis.

Previous research has demonstrated the efficacy, effectiveness, and safety of exercise training in persons living with schizophrenia. However, the optimal exercise training program remains unclear. The aim of this paper was to conduct a systematic review and meta-analysis of the effects of aerobic, resistance, and combined aerobic and resistance training on health-related physical fitness and positive and negative symptoms in persons living with schizophrenia. Six electronic databases were searched systematically from their inception to December 2020 [MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, SPORTDiscus, and Cumulative Index to Nursing and Allied Health Literature (CINAHL)] to identify literature examining the effects of exercise training on psychiatric symptoms and health-related physical fitness indicators in persons living with schizophrenia. A total of 22 studies (n = 913) were included in this review, and 12 studies (n = 554) included within the meta-analysis reported the effects of exercise training (aerobic, resistance, and combined aerobic and resistance) in persons living with schizophrenia. Aerobic training had a significant decrease on Positive and Negative Syndrome Scale (PANSS) negative scores (ES -2.28, 95% CI -3.57 to -1.00; p = 0.0005) and PANSS general scores (ES -2.51, 95% CI -3.47 to -1.55; p < 0.00001). Resistance training did not lead to significant effects on PANSS total scores. Combined aerobic and resistance training did not lead to significant changes in body mass index, PANSS positive scores, or PANSS total scores. However, grouping together the results from all exercise training modalities (including aerobic training, resistance training, and combined aerobic and resistance training) revealed significant effects on body mass index (ES 1.86, 95% CI 0.84 to 2.88; p = 0.0003), maximal/peak oxygen consumption (ES 2.54, 95% CI 1.47 to 3.62; p = < 0.00001), body weight (ES 6.58, 95% CI 2.94 to 10.22; p = 0.0004), PANSS negative scores (ES -1.90, 95% CI -2.70 to -1.10; p < 0.00001), and Scale for the Assessment of Negative Symptoms (SANS) total (ES -14.90, 95% CI -22.07 to -7.74; p < 0.0001). Collectively, these findings support the importance of exercise participation (aerobic and resistance training) in persons living with schizophrenia.

"With Every Step, We Grow Stronger": The Cardiometabolic Benefits of an Indigenous-Led and Community-Based Healthy Lifestyle Intervention.

Community-based and Indigenous-led health and wellness approaches have been widely advocated for Indigenous peoples. However, remarkably few Indigenous designed and led interventions exist within the field. The purpose of this study was to evaluate an Indigenous-led and community-based health and wellness intervention in a remote and rural Indigenous community. This protocol was designed by and for Indigenous peoples based on the aspirations of the community (established through sharing circles). A total of 15 participants completed a 13-week walking and healthy lifestyle counselling program (incorporating motivational interviewing) to enhance cardiometabolic health. Measures of moderate-to-vigorous physical activity (MVPA; 7-day accelerometry and self-report), predicted maximal aerobic power (VO2max; 6-min walk test), resting heart rate and blood pressure, and other health-related physical fitness measures (musculoskeletal fitness and body composition) were taken before and after the intervention. The intervention led to significant (p < 0.05) improvements in VO2max (7.1 ± 6.3 % change), with the greatest improvements observed among individuals with lower baseline VO2max (p < 0.05, r = -0.76). Resting heart rate, resting systolic blood pressure, and resting diastolic blood pressure decreased significantly (p < 0.05) after the intervention. Self-reported and accelerometry-measured frequency of MVPA increased significantly (p < 0.05), and the total MVPA minutes (~275 min/week) were above international recommendations. Change in VO2max was significantly correlated with change in self-reported (r = 0.42) and accelerometry-measured (r = 0.24) MVPA minutes. No significant changes were observed in weight, body mass index, waist circumference, body fat (via bioelectrical impedance), grip strength, and flexibility. These findings demonstrate that a culturally relevant and safe, community-based, Indigenous-led, health and wellness intervention can lead to significant and clinically relevant improvements in cardiometabolic health and physical activity behaviour, with the greatest changes being observed in the least active/fit individuals.

Cardiovascular Health Benefits of Exercise Training in Persons Living with Type 1 Diabetes: A Systematic Review and Meta-Analysis.

Exercise is advocated in the management of type 1 diabetes (T1D), but the effects of different forms of exercise training on cardiovascular risk factors in T1D still remain unclear. The aim of this study was to conduct a systematic review and meta-analysis on exercise training for cardiovascular risk factors in T1D. Six electronic databases were systematically searched for randomized or non-randomized controlled studies reporting associations between exercise training and cardiovascular risk factors in T1D. Weighted mean differences (WMD) of each cardiovascular risk factor between exercise groups and control groups were calculated using a random effects model. A total of 24 studies reported the effects of exercise training on cardiovascular risk factors. Exercise training increased maximal aerobic power (3.01 mL·kg-1·min-1, 95% confidence interval, CI, 0.94 to 6.38) and reduced glycated hemoglobin (HbA1c; -0.45%, 95% CI -0.73 to -0.17), daily insulin dosage (-0.88 U·kg-1, 95% CI -1.27 to -0.48), and total cholesterol (-0.38 mmol·L-1, 95% CI -0.71 to -0.04). Exercise training did not lead to consistent changes in body mass index (BMI), blood pressure, triglycerides, high-density lipoprotein cholesterol (HDL-C), or low-density lipoprotein cholesterol (LDL-C). In persons living with T1D, exercise training is associated with a beneficial cardiovascular profile, including improvements in lipid profile, glycemic control (decreased daily insulin dosage and HbA1c), and aerobic fitness.

Reduced cardiovascular fitness associated with exposure to clozapine in individuals with chronic schizophrenia.

Studies show that individuals with schizophrenia have impaired cardiovascular fitness (i.e., low peak aerobic power (VO2peak)). It is speculated that antipsychotics with adverse cardiovascular and metabolic profiles, in particular clozapine, have a significant impact on VO2peak. In this cross-sectional study, we examined whether exposure to clozapine was associated with further reduced VO2peak compared with non-clozapine antipsychotics. Thirty participants with chronic schizophrenia or schizoaffective disorder were divided into clozapine and non-clozapine groups. Mean daily doses of antipsychotics were standardized to chlorpromazine equivalents and haloperidol equivalents for antagonism of alpha1- and alpha2-adrenergic receptors. Participants completed an incremental-to-maximal symptom-limited exercise test on a cycle ergometer for the assessment of VO2peak. The clozapine group demonstrated significantly lower VO2peak than the non-clozapine group. Haloperidol equivalents for alpha-adrenergic receptor antagonism, but not chlorpromazine equivalents, demonstrated significant inverse associations with VO2peak. The clozapine group had a significantly higher amount of antagonistic activity at alpha-adrenergic receptors than the non-clozapine group. In conclusion, exposure to clozapine was associated with further reduced cardiovascular fitness, which may be explained by the drug's greater antagonistic activity at alpha-adrenergic receptors. Cardiovascular fitness needs to be promoted in individuals treated with antipsychotics, particularly clozapine, to prevent the risk of cardiovascular disease and mortality.