Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe

Sleep, anxiety and electronic device use by athletes in the training and competition environments

This study subjectively assessed sleep quality and quantity, state anxiety and electronic device use during a 7-day training week (TRAIN) and a 7-day competitive tournament (COMP). Eight state-level netball players used wrist-watch actigraphy to provide indirect sleep measures of bedtime, wake time, sleep duration, sleep onset latency, sleep efficiency, wake after sleep onset and fragmentation index. State anxiety was reported using the anxiety sub-scale in the Profile of Mood States-Adolescents. Before bed duration of electronic device use and the estimated time to sleep after finishing electronic device use was also recorded. Significant main effects showed that sleep efficiency (p = 0.03) was greater in COMP as compared to TRAIN. Furthermore, the bedtime and wake time were earlier (p = 0.01) during COMP. No further differences existed between conditions (p > 0.05). However, strong negative associations were seen between state anxiety and the sleep quality rating. Here, sleep efficiency was likely greater in COMP due to the homeostatic need for recovery sleep, resulting from the change in environment from training to competition. Furthermore, an increased anxiety before bed seems to influence sleep quality and should be considered in athletes portraying poor sleep habits

Impact of commonly prescribed exercise interventions on platelet activation in physically inactive and overweight men

The exercise paradox infers that, despite the well-established cardioprotective effects of repeated episodic exercise (training), the risk of acute atherothrombotic events may be transiently increased during and soon after an exercise bout. However, the acute impact of different exercise modalities on platelet function has not previously been addressed. We hypothesized that distinct modalities of exercise would have differing effects on in vivo platelet activation and reactivity to agonists which induce monocyte-platelet aggregate (MPA)formation. Eight middle-aged (53.5 ± 1.6 years) male participants took part in four 30 min experimental interventions (aerobic AE, resistance RE, combined aerobic/resistance exercise CARE, or no-exercise NE), in random order. Blood samples were collected before, immediately after, and 1 h after each intervention, and incubated with one of three agonists of physiologically/clinically relevant pathways of platelet activation (thrombin receptor activatingpeptide-6 TRAP, arachidonic acid AA, and cross-linked collagen-related peptide xCRP). In the presence of AA, TRAP, and xCRP, both RE and CARE evoked increases in MPAs immediately post-exercise (P

Acute Impact of Different Exercise Modalities on Arterial and Platelet Function

Purpose: Acute coronary syndromes and ischemic stroke are associated with arterial events involving platelets, the endothelium, and atherosclerosis. Although regular physical activity is associated with lower risk of cardiovascular events and mortality, risk is transiently increased during and immediately after participation in an acute bout of exercise. No previous study has investigated the acute impact of exercise on platelet activation and arterial function in the same participants; it is also unknown if responses are dependent on exercise modality. We hypothesized that commonly adopted, yet physiologically distinct, modalities of exercise ("aerobic" vs "resistance") have differing effects on in vivo platelet activation and conduit artery diameter. Methods: Eight apparently healthy middle-age (53.5 ± 1.6 yr) male subjects took part in four 30-min experimental interventions (aerobic exercise, resistance exercise, combined aerobic/resistance exercise, or no-exercise), in random order. Blood samples were collected, and the measurement of brachial artery diameter by ultrasound was performed before, immediately after, and 1 h after each intervention. Platelet activation was determined by the positive binding of antibodies to surface receptors exposed on activated platelets (anti-CD62P and PAC-1). Results: Brachial artery diameter increased immediately after all three exercise modalities (P in vivo platelet activation with any experimental protocol. Conclusions: These data suggest that postexercise enhancement in arterial function may mitigate the acute impact of exercise on platelet activation

Land-walking vs. water-walking interventions in older adults: effects on aerobic fitness

BACKGROUND: Low cardiorespiratory fitness is an independent predictor of all-cause and cardiovascular mortality, and interventions that increase fitness reduce risk. Water-walking decreases musculoskeletal impact and risk of falls in older individuals, but it is unclear whether water-walking improves aerobic fitness in the same way as weight-dependent land-walking. This randomized controlled trial involved 3 intervention groups-a no-exercise control group (CG), a land-walking (LW) group, and a water-walking (WW) group-to investigate the comparative impacts of LW and WW to CG on fitness. METHODS: Both exercise groups attended individually tailored, center-based, intensity-matched 3 × weekly sessions for 24 weeks, which progressed to 150 min of exercise per week. This was followed by a 24-week no-intervention period. Maximal graded exercise tests were performed on a treadmill at Weeks 0, 24, and 48. RESULTS: Maximal oxygen uptake increased from Week 0 to Week 24 in both exercise groups (0.57 ± 0.62 mL/kg/min, 0.03 ± 0.04 L/min for LW; 0.93 ± 0.75 mL/kg/min, 0.06 ± 0.06 L/min for WW, mean ± SE) compared to the CG (-1.75 ± 0.78 mL/kg/min, -0.16 ± 0.05 L/min) (group × time, p < 0.05). Time to exhaustion increased significantly following LW only (123.4 ± 25.5 s), which was significantly greater (p = 0.001) than the CG (24.3 ± 18.5 s). By Week 48, the training-induced adaptations in the exercise groups returned to near baseline levels. CONCLUSION: Our study supports current physical-activity recommendations that 150 min/week of moderate-intensity exercise produces improvements in fitness in previously sedentary older individuals. Also, LW and WW elicit similar improvements in fitness if conducted at the same relative intensities. Exercise-naïve older individuals can benefit from the lower impact forces and decreased risk of falls associated with WW without compromising improvements in cardiorespiratory fitness

Effect of evening postexercise cold water immersion on subsequent sleep

PURPOSE: This study investigated the effect of cold water immersion after evening exercise on subsequent sleep quality and quantity in trained cyclists. METHODS: In the evenings (~1900 h) on three separate occasions, male cyclists (n = 11) underwent either no exercise (control, CON), exercise only (EX), or exercise followed by cold water immersion (CWI). EX comprised cycling for 15 min at 75% peak power, then a 15-min maximal time trial. After each condition, a full laboratory-based sleep study (polysomnography) was performed. Core and skin temperature, heart rate, salivary melatonin, ratings of perceived fatigue, and recovery were measured in each trial. RESULTS: No differences were observed between conditions for any whole night sleep measures, including total sleep time, sleep efficiency, sleep onset latency, rapid eye movement onset latency, wake after sleep onset, or proportion of the night spent in different sleep stages. Core temperature in EX and CWI trials was higher than CON, until it decreased below that of EX and CON until bedtime in CWI. After bedtime, core temperature was similar for all conditions throughout the night, except for a 90-min period where it was lower for CWI than EX and CON (3.5-4.5 h postexercise). Heart rates for EX and CWI were both significantly higher than CON postexercise until bedtime, whereas skin temperature after CWI was significantly lower than EX and CON, remaining lower than EX until 3 h postexercise. Melatonin levels and recovery ratings were similar between conditions. Fatigue ratings were significantly elevated after exercise in both CWI and EX conditions, with EX still being elevated compared with CON at bedtime. CONCLUSION: Whole night sleep architecture is not affected by evening exercise alone or when followed by CWI. Copyright © 2013 by the American College of Sports Medicine

Sleep quantity and quality in elite youth soccer players: A pilot study

This study examined the effect of early evening high-intensity training on the sleep of elite male youth soccer players (n = 12) using wrist actigraphy. High-intensity training (TRAIN) nights were compared with a home environment (HOME) condition, created by averaging sleep variables on the night before and after TRAIN nights. Additionally, after TRAIN athletes alternately used cold water immersion (TRAIN+CWI) or none, to assess whether cold water immersion (CWI) had any impact on sleep quality and quantity. Ratings of perceived exertion, fatigue and recovery were recorded after training. Actigraphy sleep measures were bedtime, wake time, sleep duration, sleep onset latency, sleep efficiency and wake after sleep onset. Self-rated scores of sleepiness at bedtime and wake, plus overall sleep quality were also recorded. Only fatigue ratings were higher in TRAIN compared to TRAIN+CWI at bedtime, there were no other differences in training data. Both TRAIN and TRAIN+CWI conditions had significant later (07:45 ± 1:09 h p < 0.01 and 07:34 ± 1:20 h p = 0.01) wake times than HOME (06:44 ± 0:41 h). The TRAIN condition had a significantly higher (7 ± 2; p < 0.01) rating of sleepiness at bedtime compared to HOME (6 ± 1), but no further differences were found in any of the sleep (actigraphy and self-reported) measures. Across all conditions, time spent asleep was ~7:30 (±0:52) h:min and sleep efficiency was ~89% (±6.1). In conclusion, early evening high-intensity training had no impact on subsequent sleep quality and quantity, nor was there any effect on sleep after performing CWI post-training