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Electrocardiographic correlates of pacing induced cardiomyopathy and response to cardiac resynchronization therapy.

BACKGROUND: Chronic right ventricular (RV) pacing (RVP) causes pacing-induced cardiomyopathy (PICM) in only a small number of patients. We evaluated ECG correlates of (i) PICM and (ii) response to cardiac resynchronization therapy (CRT) upgrade. METHODS: We conducted a retrospective case-control study by including all CRT upgrades for PICM (LVEF <50%) at our center between 2014 and 2018. Controls were patients with &#x2265;5 ECGs all demonstrating RVP over &#x2265;2&#xa0;years and all echocardiographic LVEF &#x2265;50%. Root-summed-squared (3D) ECG was obtained from reconstructed vectorcardiographic X-Y-Z leads. Predictors of PICM and CRT response were assessed as area under ROC curve (AUC) for pre-CRT and &#x394; (post-CRT - pre-CRT) ECG intervals and QRS voltage-time-integrals (VTI). RESULTS: We included 104 patients with CRT upgrade for PICM (age 73.7&#xa0;&#xb1;&#xa0;10.5&#xa0;years, female 29.1%, QRS duration 167.8&#xa0;&#xb1;&#xa0;25.2&#xa0;ms, LVEF 28.8&#xa0;&#xb1;&#xa0;8.0%, &#x394;LVEF 13.8&#xa0;&#xb1;&#xa0;10.3%) and 178 controls without PICM (age 73.2&#xa0;&#xb1;&#xa0;14.9&#xa0;years, female 52.8%, QRS duration 144.0&#xa0;&#xb1;&#xa0;20.9&#xa0;ms, LVEF 56.7&#xa0;&#xb1;&#xa0;5.2%). PICM was best identified by VTIQRS-3D (AUC 0.851; VTIQRS-3D&#xa0;&#x2265;&#xa0;80 &#x3bc;Vs sensitivity 87.5%, specificity 63.5%), VTIQRS-Y (0.846), and QRS duration (0.775). CRT response (LVEF increase &#x2265;10% at 3-12&#xa0;months) occurred in 73/104 (70.2%) patients. Lack of CRT response was best predicted by longer pre-CRT QRS duration (AUC 0.640; QRS duration &#x2265;180&#xa0;ms sensitivity 45.2%, specificity 83.6%), and less &#x394;VTIQRS-3D (0.609) and &#x394;VTIQRS-X (0.608). CONCLUSION: In patients with chronic RVP, VTIQRS-3D&#xa0;&#x2265;&#xa0;80 &#x3bc;Vs can be used as a screening test for echocardiographic confirmation of PICM. RV-paced QRS duration >180&#xa0;ms, on the other hand, identifies those who may not respond to CRT upgrade.

Humans

Ultra-high-frequency ECG quantifies residual electrical dyssynchrony during left bundle branch area pacing in patients with wide QRS: a paired within-patient study.

BACKGROUND: Left bundle branch area pacing (LBBAP) may restore a more physiological pattern of ventricular activation in patients with conduction delay; however, QRS narrowing alone may incompletely characterize electrical resynchronization. Ultra-high-frequency ECG (UHF-ECG) provides quantitative markers of ventricular activation timing and dyssynchrony. OBJECTIVE: To quantify paired OFF-to-ON changes in conventional ECG and UHF-ECG metrics during LBBAP in patients with baseline wide QRS and to assess the relationship between paced R-wave peak time (RWPT) and residual UHF-ECG dyssynchrony. METHODS: In this prospective single-center paired study, 21 patients with bradycardia and baseline wide QRS underwent standard ECG and UHF-ECG assessment during intrinsic rhythm (pacing OFF) and during LBBAP (pacing ON). Endpoints included QRS duration, signed VED16, absolute VED16 (|VED16|), mean ventricular delay (meanVD), and a clinically interpretable distance-to-normal metric defined as dist&#xa0;=&#xa0;max(|VED16|-20, 0). Paired changes were summarized as medians with bootstrap 95% confidence intervals and tested using the Wilcoxon signed-rank test. Associations between paced RWPT and residual dyssynchrony during pacing were evaluated using Pearson and Spearman correlation coefficients. RESULTS: LBBAP significantly narrowed QRS duration from 136.8 [130.2-153.6] ms during intrinsic rhythm to 116.0 [107.8-125.6] ms during pacing (median &#x394; -21.0&#xa0;ms; 95% CI -33.9 to -18.6; p&#xa0;<&#xa0;0.001). Signed VED16 did not change significantly (median &#x394; 0.4&#xa0;ms; p&#xa0;=&#xa0;1.000), consistent with the mixed conduction-phenotype composition of the cohort. In contrast, severity-oriented UHF-ECG endpoints improved: |VED16| decreased numerically (median &#x394; -5.2&#xa0;ms; p&#xa0;=&#xa0;0.070), whereas dist decreased significantly (median &#x394; -0.7&#xa0;ms; 95% CI -14.4 to 0.0; p&#xa0;=&#xa0;0.015). The proportion of patients within the normal dyssynchrony band (|VED16|&#xa0;&#x2264;&#xa0;20&#xa0;ms) increased from 7/21 (33.3%) to 12/21 (57.1%). Median paced RWPT was 66.6 [58.6-74.6] ms, and shorter RWPT correlated with lower residual |VED16| during pacing (Pearson r&#xa0;=&#xa0;-0.45, p&#xa0;=&#xa0;0.038). CONCLUSIONS: In patients with baseline wide QRS, LBBAP produces marked QRS narrowing, whereas UHF-ECG provides complementary quantification of residual electrical dyssynchrony. Severity-oriented UHF-ECG endpoints, particularly a distance-to-normal metric, may offer an interpretable mechanistic framework beyond conventional ECG alone. Shorter paced RWPT was associated with lower residual dyssynchrony during pacing, supporting physiological coherence between procedural and high-resolution electrocardiographic markers.

Humans

Conduction System Pacing Versus Right Ventricular Pacing in Patients With Atrioventricular Block and Anticipated High Pacing Burden.

Right ventricular pacing (RVP) in patients with atrioventricular (AV) block and high anticipated pacing burden is associated with pacing-induced cardiomyopathy (PICM) in approximately 12% to 20% of patients, whereas conduction system pacing (CSP) preserves more physiologic ventricular activation and may mitigate these consequences; the totality of contemporary randomized evidence has not been systematically pooled. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing CSP with RVP in patients with AV block or anticipated high ventricular pacing burden and a minimum 6-month follow-up, with co-primary outcomes of PICM incidence and change in left ventricular ejection fraction (&#x394;LVEF) and secondary outcomes of heart failure hospitalization (HFH), all-cause mortality, composite clinical endpoint, and paced QRS duration (PROSPERO CRD420261400227); random-effects meta-analysis used DerSimonian-Laird estimation. Five RCTs (LBBP-FAVOUR, CSPACE, Prague CSP, PACE-HF, STAY; N = 806) met inclusion criteria. CSP significantly reduced PICM (hazard ratio [HR] 0.30, 95% confidence interval [CI] 0.18 to 0.48; p <0.001; I&#xb2; = 0%; k = 4), was associated with greater LVEF preservation (pooled mean difference [MD] +4.41%, 95% CI +1.82 to +6.99; p = 0.001; I&#xb2; = 87%; k = 5), and reduced HFH (HR 0.24, 95% CI 0.12 to 0.48; p <0.001; I&#xb2; = 0%; k = 5). CSP shortened paced QRS duration (MD -27.5 ms, 95% CI -32.6 to -22.5; p <0.001; k = 5). All-cause mortality was numerically lower with CSP but did not reach significance (HR 0.57, 95% CI 0.29 to 1.12; p = 0.10; k = 4). In a prespecified sensitivity analysis restricting to multicenter trials with N &#x2265; 150, all findings were concordant with the primary analysis. In conclusion, CSP substantially reduces PICM, preserves LVEF, and reduces HFH compared with RVP in patients with AV block and anticipated high pacing burden, supporting its consideration as the preferred pacing strategy in appropriately selected patients.

Humans

Physical reconfiguration of limb electrodes for Precordial Bipolar Lead acquisition: Morphological validation against digital subtraction.

BACKGROUND: The V2&#xa0;-&#xa0;V1 Precordial Bipolar Lead (PBL) selectively evaluates the right-to-left retrosternal axis and has shown diagnostic value beyond the standard 12&#x2011;lead electrocardiogram. However, its use has been limited by the need for raw electrocardiographic data and post-processing software. This study evaluated whether a simple physical reconfiguration of limb electrodes could reproduce the digitally derived V2&#xa0;-&#xa0;V1 morphology with sufficient accuracy for clinical application. METHODS: Thirty-seven subjects underwent two sequential 10-s 12&#x2011;lead recordings using a Cardiovit FT-1 electrocardiograph sampled at 1000&#xa0;Hz. In the standard recording, the digital PBL was calculated as V2&#xa0;-&#xa0;V1. In the second recording, the right-arm and left-arm electrodes were repositioned to the V1 and V2 sites so that Lead I directly recorded the retrosternal dipole. Signals were filtered, synchronized, and analyzed using median beats. Morphological agreement was assessed with Pearson correlation on Z-normalized signals, while absolute agreement was evaluated using Lin's concordance correlation coefficient (CCC), intraclass correlation coefficient (ICC (Lewis, 1931; Nehb, 1938 [1,2])), root mean square error (RMSE), and Bland-Altman analysis. RESULTS: Mean Pearson correlation between digital and physical PBL was 0.955 (SD 0.043), with segment-specific correlations of 0.953 (SD 0.054) for QRS and 0.967 (SD 0.052) for ST-T. Lin's CCC and ICC(2,1) were both 0.871 (SD 0.110), and RMSE was 0.091 (SD 0.049) mV. Bland-Altman analysis showed minimal bias (-0.008&#xa0;mV). CONCLUSIONS: Physical acquisition of the V2&#xa0;-&#xa0;V1 PBL achieved high agreement with the digitally derived signal, supporting a simplified analog method for broader clinical implementation.

Humans

Optimising Exercise Prescription: A Meta-Analysis Examining the Dose Response of Exercise Duration on Cardiorespiratory Fitness Following HIIT and MICT.

BACKGROUND: High-intensity interval training (HIIT) is often promoted as a time-efficient alternative to moderate-intensity continuous training (MICT) for improving cardiorespiratory fitness, yet the duration of HIIT sessions varies considerably across studies. OBJECTIVE: We aimed to characterise the dose-response relationship between exercise session duration and the improvement in cardiorespiratory fitness for HIIT and MICT. METHODS: A dose-response meta-analysis of randomised controlled trials comparing exercise duration in HIIT and MICT, following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and registered in PROSPERO (CRD42022335590). Effect sizes were calculated using a random-effects meta-analysis. The primary outcome was maximal oxygen uptake (VO2max). Secondary outcomes included blood pressure, lipid profiles, glucose metabolism markers and body composition measures. A one-stage random-effects dose-response meta-analysis was performed to examine the relationship between exercise duration and adaptations. We searched PubMed and Google Scholar; eligibility criteria for selecting studies were randomised controlled trials in humans, published in English and exercise interventions lasting at least 4&#xa0;weeks. RESULTS: We identified 69 randomised controlled trials (2387 participants). High-intensity interval training elicited greater improvements in VO2max than MICT (d = 0.38, 95% confidence interval 0.27-0.49, p < 0.001). High-intensity interval training demonstrated a non-linear dose-response relationship between exercise session duration and VO2max, with 80% of maximal effect (changes in VO2max = 3.45&#xa0;mL/kg/min) achieved with only ~11&#xa0;min/session (95% confidence interval 9.5-40.2). Moderate-intensity interval training showed a linear dose-response relationship between exercise session duration and VO2max, requiring ~52&#xa0;min/session to achieve 80% of the&#xa0;maximal observed&#xa0;effect (95% confidence interval 30.4-55.8). The dose-response relationship was consistent across populations. High-intensity interval training and MICT had comparable effects in improving cardiometabolic risk factors. CONCLUSIONS: High-intensity interval training demonstrated a non-linear dose response, with 80% of maximal effect on VO2max in ~11&#xa0;min/session, whilst MICT required four to five times longer to reach similar responses. The different types of training had comparable effects on cardiometabolic risk factors.

Journal Article

Efficacy and Safety of iGlarLixi Versus IDegAsp by Baseline Age, Disease Duration and HbA1c in Chinese People With Type 2 Diabetes: Post Hoc Analyses of the Soli-D Study.

AIMS: To compare the efficacy and safety of insulin glargine 100&#x2009;U/mL plus lixisenatide (iGlarLixi) with insulin degludec plus insulin aspart (IDegAsp) by baseline age, Type 2 diabetes (T2D) duration and glycated haemoglobin (HbA1c) in the Soli-D study. MATERIALS AND METHODS: In Soli-D, Chinese adults with T2D suboptimally controlled on oral antidiabetic drugs (OADs) were randomized to iGlarLixi or IDegAsp for 24&#x2009;weeks. These post hoc analyses evaluated glycaemic efficacy, insulin dose, body weight and hypoglycaemia outcomes in subgroups defined by baseline age (<&#x2009;65, &#x2265;&#x2009;65&#x2009;years), T2D duration (<&#x2009;10, &#x2265;&#x2009;10&#x2009;years) and HbA1c (&#x2265;&#x2009;7% to &#x2264;&#x2009;8% [&#x2265;&#x2009;53 to &#x2264;&#x2009;64&#x2009;mmol/mol], >&#x2009;8% to &#x2264;&#x2009;9% [>&#x2009;64 to &#x2264;&#x2009;75&#x2009;mmol/mol], >&#x2009;9% [>&#x2009;75&#x2009;mmol/mol]). RESULTS: Among 582 participants (iGlarLixi n&#x2009;=&#x2009;291; IDegAsp n&#x2009;=&#x2009;291), baseline age was <&#x2009;65&#x2009;years in 442 and &#x2265;&#x2009;65&#x2009;years in 140; T2D duration was <&#x2009;10&#x2009;years in 366 and &#x2265;&#x2009;10&#x2009;years in 216; and HbA1c was &#x2265;&#x2009;7% to &#x2264;&#x2009;8% in 205, >&#x2009;8% to &#x2264;&#x2009;9% in 209 and >&#x2009;9% in 168. At Week 24, HbA1c reductions were greater with iGlarLixi versus IDegAsp, with no treatment-by-subgroup interactions for baseline age, T2D duration or HbA1c. Change in other glycaemic outcomes, insulin dose and body weight generally showed no interaction across subgroups. Total insulin daily doses during treatment and hypoglycaemia event rates were consistently lower with iGlarLixi versus IDegAsp in all subgroups. CONCLUSIONS: iGlarLixi provides improved glycaemic control at lower insulin doses with reduced risk of hypoglycaemia in Chinese adults with suboptimally controlled T2D on OADs, regardless of baseline age, disease duration or HbA1c.

Humans

A systematic review of sleep hygiene interventions in physically and operationally demanding occupations.

Workers in physically and operationally demanding (POD) occupations (e.g. military personnel, emergency responders, law enforcement) experience disrupted sleep due to irregular schedules and high-stress work environments. Given the importance of sleep for physical and cognitive performance, interventions to improve sleep in POD occupations are crucial yet remain under-researched. To investigate the effectiveness of sleep hygiene interventions in improving sleep quality and quantity outcomes for POD occupations, a systematic review was conducted across five databases (PubMed, CINAHL, SPORTDiscus, PsycINFO, Web of Science) in September 2024. Eligible studies involved workers in POD occupations where a sleep hygiene intervention was compared against a waitlist or passive control. Ten studies were included, eight randomised controlled trials (RCTs) and two non-randomised controlled trials (NRCTs). Narrative synthesis identified Structured Training Programs (n&#x202f;=&#x202f;7), Phone Assistance Programs (n&#x202f;=&#x202f;2), and Single Lecture Interventions (n&#x202f;=&#x202f;1). Evidence certainty ranged from Very Low to Moderate, converging towards Low quality due to imprecision, risk of bias, and indirectness. Structured Training Programs showed moderate improvements in sleep quality and small-to-moderate effects on sleep duration. Phone Assistance Programs had minimal effects, and Single Lecture Interventions had negligible impact. Higher-quality research is urgently needed to assess sleep hygiene interventions in POD occupations.

Humans

Influence of Repeated-Sprint Bout Duration in Sprint Interval Training Intervention on Physical Performance Adaptations of Young Volleyball Players.

The objective of this study was to examine the effects of repeated-sprint training (RST) with varying bout durations on the physical fitness adaptations of young male volleyball players. Forty athletes were randomly allocated to one of three intervention groups performing RST with varying bout durations and similar repetition volumes, all executed at maximal effort. The 3-sec group (n = 10) completed two sets of 30 bouts, the 6-sec group (n = 10) performed two sets of 15 bouts, and the 9-sec group (n = 10) carried out two sets of 10 bouts, each adhering to a 1:3 work to rest ratio. An active control group (n = 10) engaged solely in regular volleyball training without the RST intervention. Physical fitness measures-including countermovement vertical jump (CMVJ), 10-m and 20-m linear sprints, T-test change-of-direction speed (T-CODS), reactive strength index (RSI), and the Wingate anaerobic power test-were assessed pre- and post-a 6-week training intervention (i.e., 18 sessions). All RST groups showed significant post-intervention improvements in physical fitness (main effect of time, p = 0.001), with greater adaptations compared with the control group and effect sizes ranging from small to very large. The 3-sec bout group demonstrated greater gains in CMVJ, 10-m and 20-m sprint performance, RSI, and peak power output compared with the 9-sec group (all, p < 0.05). Conversely, the 9-sec group exhibited superior adaptations in T-CODS and mean power output relative to the 3-sec group (all, p < 0.05). In conclusion, the 3-sec group experienced greater enhancements in explosive and sprint performances, while the 9-sec group showed superior gains in change of direction and mean power output. These findings indicate that manipulation of sprint-bout duration in RST can be used to optimize distinct performance adaptations in young volleyball players.

Humans

Comparison of opioid-free versus opioid-based total intravenous anaesthesia in elderly patients undergoing short-duration surgery: a randomized controlled trial.

INTRODUCTION: Older adults who undergo short-duration surgery are vulnerable to opioid-related complications. It is uncertain whether an opioid-free total intravenous anaesthesia (OFA) can reduce these events. We aimed to determine whether OFA reduces the incidence of major postoperative adverse events compared with standard opioid-based total intravenous anaesthesia (OBA). PATIENTS AND METHODS: This single-center randomized clinical trial was conducted in China. From May to August 2025, 400 patients aged &#x2265;60&#x2009;years undergoing elective, short-duration surgery (anticipated duration of less than 90&#x2009;min) were randomized 1:1 to receive either OFA (n&#x2009;=&#x2009;200) or OBA (n&#x2009;=&#x2009;200). The primary outcome was a composite of postoperative hypoxemia, delirium, or nausea and vomiting (PONV) within 48&#x2009;h. RESULTS: A total of 400 randomized patients (mean [SD] age, 69.5 [7.0] years; 125 [31.3%] women). The primary composite outcome occurred in 50 patients (25.0%) in the OFA group and 87 patients (43.5%) in the OBA group (adjusted odds ratio, 0.40; 95% CI, 0.25 to 0.62; p < .001). Among the OFA group had a lower incidence of hypoxemia (15.0% vs 32.0%) and PONV (8.0% vs 16.0%). Intraoperative hemodynamic stability was greater in the OFA group. However, the OFA group had a higher incidence of intraoperative bradycardia (10.0% vs 3.0%; p = .005) and longer extubation times (mean, 9.5 vs 7.2&#x2009;min; p < .001). CONCLUSION: These findings suggest that OFA is a viable alternative to opioid-based anesthesia for improving postoperative outcomes by reducing the incidence of hypoxemia and PONV in this population, while warranting careful management of its associated side effects. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2500102550.

Humans

Ultrashort vs Standard-Duration Dual Antiplatelet Therapy in Acute Coronary Syndrome Patients Undergoing PCI: A Meta-Analysis.

BACKGROUND: The efficacy and safety of ultrashort (&#x2264;1-month) dual antiplatelet therapy (DAPT) followed by antiplatelet monotherapy remain uncertain in acute coronary syndrome (ACS) patients. OBJECTIVES: This study sought to compare ultrashort vs standard-duration DAPT in patients with ACS undergoing percutaneous coronary intervention (PCI). METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials until February 15, 2026. Primary outcomes were major adverse cardiac and cerebrovascular events (MACCE), major bleeding, and net adverse clinical event (NACE). Prespecified subgroup analyses examined by ethnicity (East Asian vs non-East Asian) and abbreviation strategy (intensive: &#x2264;1-week DAPT or clopidogrel/aspirin monotherapy vs moderate: &#x2265;2-week DAPT, followed by ticagrelor/prasugrel monotherapy). RESULTS: Across 10 trials (n = 29,232), ultrashort DAPT did not increase MACCE risk (HR: 1.06; 95% CI: 0.93-1.20; P = 0.38; I2 = 24%), with higher MACCE risk observed in ST-segment elevation myocardial infarction (STEMI) but not non-ST-segment elevation ACS (NSTE-ACS), and significantly reduced major bleeding (HR: 0.47; 95% CI: 0.35-0.64; P < 0.00001; I2 = 44%), resulting in a net clinical benefit (HR: 0.83; 95% CI: 0.72-0.97; P = 0.02; I2 = 61%). Bleeding reduction was more pronounced in East Asians (HR: 0.35; 95% CI: 0.25-0.49; P < 0.00001; I2 = 0%) than non-East Asians (HR: 0.63; 95% CI: 0.43-0.93; P = 0.02; I2 = 44%), with a significant interaction (P = 0.02). The abbreviation strategy significantly modified outcomes (P for interaction = 0.003): intensive abbreviation raised MACCE risk (HR: 1.37; 95% CI: 1.11-1.69; P = 0.003; I2 = 0%), while moderate abbreviation had no statistically significant difference (HR: 0.96; 95% CI: 0.85-1.08; P = 0.47; I2 = 0%). CONCLUSIONS: In patients with ACS undergoing PCI, ultrashort DAPT reduced bleeding without increasing ischemic events overall, although a signal of increased MACCE was observed in STEMI but not in NSTE-ACS. Bleeding reduction was greater in East Asians, while &#x2264;1-week DAPT or clopidogrel/aspirin monotherapy may increase ischemic risk.

Humans

The interplay between circadian misalignment or sleep disturbances and cognition and brain function in individuals with different degrees of insulin resistance - a systematic review.

Disruption of sleep increases the risk of type 2 diabetes and worsens cognitive outcomes, yet few studies have evaluated the interaction between insulin resistance and sleep parameters in relation to cognitive outcomes or the risk of dementia. This systematic review examines how circadian misalignment and sleep disturbances affect cognition and neuroimaging findings in individuals with varying degrees of insulin resistance. Across 27 studies, disrupted circadian rhythmicity and sleep disturbances were negatively associated with brain health, possibly through its effects on insulin sensitivity, whereas the impact of sleep duration and quality were inconclusive. Methodological heterogeneity, reliance on cross-sectional designs, and limited control for confounders restricted definitive conclusions and highlighted the need for longitudinal and interventional studies with objective measurements. Nonetheless, the findings support circadian rhythmicity as a potentially modifiable risk factor for preserving cognition in insulin-resistant populations. Future research should prioritise prospective and interventional studies and focus on biological markers rather than self-reported outcomes.

Humans

Clinical Performance in Critical Care Simulation under Sleep Deprivation: Effects of Power Napping in the Recovery Napping Protocol for Anesthesiologist Performance (R-NAP) Randomized Controlled Trial.

BACKGROUND: Sleep deprivation is common among anesthesia residents and impairs both technical and nontechnical skills such as leadership. Napping is recommended in fatigue management across healthcare and other safety-sensitive sectors, yet its effectiveness for healthcare providers remains underexplored. This study evaluated whether a 30-min nap opportunity improved simulated crisis performance after a 24-h shift. METHODS: Residents were tested twice: once rested and once using a 24-h shift to induce partial sleep deprivation. Between sessions, they were trained in fatigue management. In the sleep-deprived condition, they were randomized to a nap opportunity or a control condition. Actigraphy objectively assessed sleep and nap duration. The primary endpoint was overall simulated clinical performance (0 to 200; combined technical and nontechnical scores). Secondary endpoints were technical and nontechnical subscales. Group effects were primarily tested using intention-to-treat regression models adjusted for rested performance, previous sleep, and critical care experience. RESULTS: Thirty-five residents were enrolled (nap opportunity, n = 19; control, n = 16). In the primary analysis sample (n = 27), clinical performance was 14.8 points higher after the nap opportunity compared with controls (95% CI, 2.8 to 26.9; P = 0.018), corresponding to a 7.4% improvement. Technical skills did not differ significantly between groups, although more sleep was associated with better technical performance. Nontechnical skills were higher in the nap opportunity condition (+11.0 points; 95% CI, 2.2 to 19.8; P = 0.016), including significant effects of leadership and resource utilization. Exploratory analyses suggested associations between longer nap duration and multiple performance domains, strongest for technical skills ( P = 0.010). CONCLUSIONS: Napping appears to enhance clinical performance, while the nap opportunity, nap duration, and previous sleep deprivation each influenced technical and nontechnical performance in distinct ways. These findings support integrating napping and recovery into medical education and scheduling.

Adult

Synchronicity of parent-child sleep and potential mechanisms: A systematic review and meta-analysis.

Existing evidence indicates that parent and child circadian rhythms are associated, but studies have mainly examined factors affecting child sleep health. This systematic review addressed two questions: a) is there a synchronous relationship between parent and offspring sleep? and b) what are the potential mechanisms? PubMed, Embase, PsychINFO, and Scopus were searched from inception to April 2025. Forty-six studies comprising over 100000 parent-child dyads across 16 countries were included. Results showed small-to-moderate parent-child synchronicity in sleep duration (r&#x202f;=&#x202f;0.18, 95% CI [0.14, 0.23]), sleep efficiency (r&#x202f;=&#x202f;0.30, 95% CI [0.19, 0.41]), bedtime (r&#x202f;=&#x202f;0.34, 95% CI [0.20, 0.46]), and wake up time (r&#x202f;=&#x202f;0.48, 95% CI [0.24, 0.66]), with stronger effects observed in mother-child dyads. Synchronicity in sleep continuity was moderate, whereas associations in sleep satisfaction were small and non-significant. Mechanisms included genetic and hormonal factors, bedtime routines, shared environments, and attachment. These findings are consistent with family systems theory's premise that sleep is a relational phenomenon. Observed synchronicity in sleep timing may partly reflect shared external constraints like work and school schedules. Most studies were cross-sectional, limiting causal or directional conclusions. Future research should adopt standardized methodologies and longitudinal designs to clarify mechanistic pathways.

Humans

Using Organoids to Unlock the Potential of Human Torpor for Spaceflight.

PURPOSE OF REVIEW: This paper reviews the current understanding of the potential for humans to enter a state of torpor/hibernation, and discusses the possibility of inducing torpor in astronauts for long-duration space travel, including some of the physiological, technological, and ethical considerations associated with its implementation. By exploring means to induce torpor in various human organoid systems, we hope such research can provides insights to comprehensive solutions to overcome some of the major hurdles that limit the potential for human to enter a state of torpor during long-duration deep-space missions, and contribute to the ongoing efforts to make such missions more feasible and safer for astronauts. RECENT FINDINGS: On future deep space missions such as NASA's planned missions to the Moon, Mars, and near-Earth asteroids, astronauts will be continuously exposed to environments that are radically different from those on Earth, each presenting multiple logistical and physiological challenges. Beyond the well-documented physiological effects of microgravity, space travelers will encounter a complex radiation environment that may contribute to significant short- and long-term adverse effects on human physiology and increase the risk of cancer and other diseases. Besides these physical challenges, life support systems must also be designed to mitigate psychological impacts of long-term isolation and confinement - all of which collectively pose formidable engineering problems. Hibernation/torpor is a state of prolonged inactivity and metabolic depression used by a wide variety of mammals to survive periods of cold temperatures and food scarcity, including some primates and perhaps even an extinct early line of hominins that lived nearly half a million years ago. Since modern humans share common ancestry with these hominins and hibernating primates, it is likely the human genome encodes the necessary genetic information to hibernate, or at least enter the similar, more transient state of torpor. The reduced body activity, lowered metabolism, and decreased energy requirements that characterize torpor suggest that developing means of inducing such a state in astronauts could address these challenges, including providing a degree of radioprotection. SUMMARY: This review explores the potential application of human torpor as a countermeasure to address the many challenges posed by long-duration spaceflight beyond low-Earth orbit (LEO), discusses various natural hibernating model systems for studying means of inducing a torpor-like state in humans, and highlights the vast potential of using human organoids to test and validate mechanisms that govern induction and maintenance of torpor to identify the means to one day safely induce this state in astronauts to provide additional protection from the myriad stressors of spaceflight.

Astronaut Health

Association of media use with sleep of children and adolescents: an umbrella review.

Adequate sleep is essential for child and adolescent development, driving extensive research across scientific disciplines. This umbrella review provides a comprehensive overview of existing evidence on media consumption and sleep and thereby lays the foundation for identifying key concepts and gaps. An inclusive systematic search for reviews reporting literature searches was conducted in 02/2021 and updated last in 09/2024. Methodological quality of the included reviews was assessed using AMSTAR-2. We included 84 reviews reporting on the association between media use and sleep in individuals aged 0-18 years. The field is dominated by reviews of low methodological quality, mainly including original cross-sectional studies with subjective measures in older children and adolescents. A total of 475 original articles were covered by the reviews; only 10 of them appeared in at least seven and at most nine reviews. Screen time generally had a negative impact on sleep, though evidence varied from very low to strong. Evidence for effects of conventional books on sleep remains inconclusive. High quality systematic reviews are needed to evaluate robust studies using objective measures of sleep and contemporary media use across all age groups up to adolescence and to explore the impact of non-digital media use on sleep, considering age and gender differences.

Humans

Sleep disturbances in children and adolescents with iron deficiency: Questionnaire-based and actigraphic findings.

OBJECTIVE: Iron deficiency (ID), without or with anemia (IDA), has been linked to restless sleep and sleep-related movement disorders in childhood, but objective correlates are incompletely defined. We aimed to describe caregiver-reported sleep disturbances, restless legs syndrome (RLS) - related symptoms, and actigraphic sleep patterns in children and adolescents with ID/IDA, and to compare these findings with available sleep-asymptomatic control datasets. We finally explored short-term changes after iron supplementation. METHODS: In this single-center pilot observational study, 31 children with ID/IDA underwent baseline clinical/laboratory assessment and caregiver-reported sleep evaluation with the Sleep Disturbance Scale for Children (SDSC) plus RLS-oriented items. Sixteen also completed home actigraphy, and 8 had follow-up after iron treatment prescribed in routine care. Baseline findings were compared with historical healthy control datasets without reported sleep disturbances; iron-status data were not available for the questionnaire control group; within-subject changes were explored in the follow-up subgroup. RESULTS: Compared with healthy controls, the ID/IDA cohort had higher SDSC total scores (43.97&#x202f;&#xb1;&#x202f;9.63 vs 34.61&#x202f;&#xb1;&#x202f;7.50; p&#x202f;<&#x202f;0.001), with significant differences in the subscales difficulty in initiating and maintaining sleep (DIMS), sleep-wake transition disorders (SWTD), and sleep hyperhidrosis (SHY). Ten of 31 screened children (32.25%) had clinically plausible RLS-related symptoms and higher SWTD scores. Actigraphy showed shorter sleep duration, lower sleep efficiency, longer wake after sleep onset, and greater fragmentation. After iron treatment, parent reported restlessness improved, whereas actigraphic parameters showed only partial normalization. CONCLUSIONS: Pediatric ID/IDA was associated with caregiver-reported and actigraphic sleep disruption, characterized by restless and fragmented sleep. These findings support systematic sleep assessment in children with low iron stores and consideration of iron status in the work-up of restless or nonrestorative sleep.

Humans

Transcriptomic insights into thermal stress reveal physiological trade-off between thermal stress adaptation and reproductive investment in Spodoptera litura.

Spodoptera litura, a highly polyphagous lepidopteran pest, poses a major threat to agricultural productivity due to its remarkable adaptability to diverse environmental conditions. Although heat stress is known to trigger transcriptional reprogramming in insects, the molecular mechanisms underlying thermal stress responses in S. litura remain poorly understood. In the present study, fourth-instar larvae were exposed to acute heat stress (44&#xa0;&#xb0;C) and compared with control conditions (27&#xa0;&#xb1;&#xa0;1&#xa0;&#xb0;C) to investigate heat-induced transcriptional alterations affecting physiology and reproduction. High-quality RNA-Seq data achieved more than 80% mapping efficiency, with a total of 15,782 transcripts were identified. Transcriptome analysis of S. litura larvae showed 323 differentially expressed genes (DEGs), of which 262 genes were significantly upregulated and 61 were downregulated in heat-stressed larvae compared to the control group. The DEGs were associated with stress response, reproduction, signalling, proteostasis, detoxification, oxidative stress, metabolism, development, and chromatin regulation. Heat shock proteins genes, including HSP70, HSP90, and HSP27, together with co-chaperones such as TRET-1, STIP1, and Starvin, were strongly upregulated, indicating enhanced cellular protection against protein damage and oxidative stress under heat stress. Conversely, key reproductive and cell cycle-related genes, including BARR, CAPD2, FEO, CDK2 and MORULA, were significantly downregulated, suggesting reproductive impairment and developmental arrest. RT-qPCR validation corroborated the RNA-Seq findings, demonstrating a heat-induced physiological trade-off that prioritizes survival over reproduction. Consistent with these molecular responses, heat-stressed insects exhibited marked reproductive impairment, including significant reductions in gonadosomatic index, eupyrene sperm bundle count, mating frequency, mating success, female calling behaviour, copulation duration, fecundity, and egg fertility. Collectively, these findings provide comprehensive insights into the molecular basis of thermal adaptation in S. litura and demonstrate that acute heat stress compromises reproductive fitness while activating conserved stress-response pathways that promote short-term survival.

Animals

The role of adjunctive aqueous suppressants for anti-vascular endothelial growth factor therapy: A systematic review.

Our goal is to determine whether adjunctive aqueous suppressants (topical &#x3b2;-blockers, carbonic anhydrase inhibitors, or oral acetazolamide) enhance outcomes of anti-vascular endothelial growth factor (anti-VEGF) therapy for diabetic macular edema (DME), retinal vein occlusion (RVO), and neovascular age-related macular degeneration (nAMD), focusing on retinal thickness, visual acuity, injection burden, intraocular pressure (IOP), and safety. DME, RVO, and nAMD are leading causes of vision loss treated with repeated intravitreal injections, yet many eyes show persistent fluid. Aqueous suppressants are inexpensive and widely available, with potential to prolong intravitreal drug residence and improve outcomes, but their clinical value remains uncertain. Following a registered protocol, we searched 4 databases (January, 2000 toMay, 2025) for randomized and comparative studies evaluating adjunct aqueous suppressants with anti-VEGF therapy. Primary outcome was change in retinal thickness; secondary outcomes included visual acuity, injection burden, IOP, and adverse events. Risk of bias was assessed and findings synthesized narratively. Twelve studies (7 randomized trials; 495 eyes) met inclusion criteria. In DME, 3 of 4 trials showed greater thickness reduction with adjunctive dorzolamide (&#xb1;timolol), although visual gains were inconsistent. In RVO, 1 trial suggested transient anatomical benefit, whereas oral acetazolamide showed no added effect. In nAMD, adjunctive dorzolamide-timolol reduced residual fluid in refractory cases without visual or treatment-sparing benefit. Topical therapy produced modest IOP reductions without serious adverse events. Adjunct aqueous suppressants may provide limited short-term anatomical benefit, particularly in DME and refractory nAMD, but consistent functional or durability effects are not found in this study. Larger, longer-term randomized studies are needed.

Humans