Search Results (274)

Background/Objectives: Beetroot supplementation is a rich source of inorganic nitrate and has been proposed to enhance nitric oxide bioavailability and support cardiovascular recovery after exercise. This study aimed to evaluate the effects of beetroot supplementation on post-exercise cardiovascular and autonomic recovery in postmenopausal women. Methods: A systematic review and meta-analysis were conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Searches were performed in PubMed, Scopus, and Web of Science databases from inception to July 2025. Ten trials involving postmenopausal women were included. Outcomes assessed included cardiovascular measures (blood pressure and vascular function), autonomic parameters derived from heart rate variability (HRV)—specifically the root mean square of successive differences (RMSSD), the standard deviation of normal-to-normal intervals (SDNN), and high-frequency power (HF)—as well as physical performance (peak oxygen uptake [VO_2peak or VO_2max] and functional fitness tests). Four independent reviewers extracted data, assessed risk of bias, and evaluated the certainty of evidence using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Results: Pooled analyses from two trials (n = 54) revealed a statistically significant improvement in RMSSD with beetroot supplementation (mean difference: 6.68 ms; 95% CI: 0.86 to 12.50; p = 0.02), suggesting enhanced parasympathetic reactivation after exercise. No significant effects were detected for HF (mean difference: 61.75 ms²; 95% CI: −70.92 to 194.43; p = 0.36) or SDNN (mean difference: 6.20 ms; 95% CI: −9.69 to 22.09; p = 0.44). Substantial to considerable heterogeneity was identified across outcomes (I² = 73–86%). Certainty of evidence was rated moderate for RMSSD, low for SDNN, and very low for HF. Conclusions: Beetroot supplementation may enhance post-exercise autonomic recovery in postmenopausal women, primarily through improvements in RMSSD. However, further trials with standardized protocols, larger samples, and longer intervention durations are required to clarify its impact on broader HRV domains, cardiovascular function, and clinical outcomes. Full article

Background: Rapid-eye-movement (REM) sleep disinhibition—shorter REM latency and a larger nightly REM fraction—is a well-described laboratory correlate of major depression. Whether the same pattern can be captured efficiently with consumer wearables in everyday settings remains unclear. We therefore quantified REM latency and proportion of REM sleep out of total sleep duration (labeled “REM sleep coefficient”) from Apple Watch recordings and examined their association with depressive symptoms. Methods: 191 adults wore an Apple Watch for 15 consecutive nights while a custom iOS app streamed raw accelerometry and heart-rate data. Sleep stages were scored with a neural-network model previously validated against polysomnography. REM latency and REM sleep coefficient were averaged per participant. Depressive severity was assessed twice with the Beck Depression Inventory and averaged. Descriptive statistics, normality tests, Spearman correlations, and ordinary-least-squares regressions were performed. Results: Mean ± SD values were BDI 13.52 ± 6.79, REM sleep coefficient 24.05 ± 6.52, and REM latency 103.63 ± 15.44 min. REM latency correlated negatively with BDI (Spearman ρ = −0.673, p < 0.001), whereas REM sleep coefficient correlated positively (ρ = 0.678, p < 0.001). Combined in a bivariate model, the two REM metrics explained 62% of variance in depressive severity. Conclusions: Wearable-derived REM latency and REM proportion jointly capture a large share of depressive-symptom variability, indicating their potential utility as accessible digital biomarkers. Larger longitudinal and interventional studies are needed to determine whether modifying REM architecture can alter the course of depression. Full article

Traditional training methods for first responders are often limited by time, resources, and safety constraints, which reduces their consistency and effectiveness. This study focused on two main issues: whether exposure to virtual reality training scenarios induces measurable physiological changes in heart rate and heart rate variability, and whether these responses differ between police and firefighter contexts. The aim of this study was to explore the integration of virtual reality technologies into responder training and to evaluate how biomedical monitoring can be used to assess training effectiveness. A pilot measurement was conducted with ten participants who completed systematic crime scene investigation scenarios in both domains. Heart activity was continuously recorded using a wearable sensor and analyzed for heart rate and heart rate variability parameters, while cognitive load and task performance were also assessed. The collected data were statistically evaluated using tests of normality and paired comparisons between baseline and virtual reality phases. The results showed a significant increase in heart rate and a decrease in heart rate variability during virtual reality exposure compared to baseline, with higher cognitive load and success rates in police scenarios compared to firefighter scenarios. These findings indicate that virtual reality scenarios can elicit measurable psychophysiological responses and highlight the potential of combining immersive technologies with biomedical monitoring for the development of adaptive and effective training methods for first responders. Full article

Background and Clinical Significance: The pathology of the round ligament (RL) is rare and often remains in the shadow of common surgical emergencies. The preoperative diagnosis is challenging, leaving the surgeon perplexed as to whether and when to operate. The presented case deserves attention due to the difficult decision to operate based solely on the clinical picture, despite negative imaging diagnostic results. Case presentation: A 76-year-old woman was admitted to the Emergency Department with 6 h complaints of epigastric pain, nausea, and vomiting. She was afebrile with stable vital signs. The abdomen was slightly tender in the epigastrium, without rebound tenderness or guarding. The following blood variables were beyond the normal range: WBC—13.5 × 109/L; total bilirubin 26 mmol/L; amylase—594 U/L; CRP 11.4 mg/L; ASAT—158 U/L; and ALAT—95 U/L. The ultrasound (US) and multislice computed tomography (MSCT) of the abdomen were normal. A working diagnosis of acute pancreatitis was established, and intravenous infusions were initiated. The next day, the patient became hemodynamically unstable with blood pressure 80/60 mm Hg, heart rate 130/min, chills and fever of 39.5 °C, and oliguria. There was remarkable guarding and rebound tenderness in the epigastrium. The blood analysis revealed the following: WBC—9.9 × 109/L; total bilirubin—76 µmol/L; direct bilirubin—52 µmol/L; amylase—214 U/L; CRP 245 mg/L; ASAT—161 U/L; ALAT—132 U/L; GGT—272 U/L; urea—15.7 mmol/L; and creatinine—2.77 mg/dL. She was taken to the operating room for exploration, which revealed local peritonitis and phlegmon of the RL. Resection of the RL was performed. The microbiological analysis showed Klebsiella varicola. The patient had an uneventful recovery and was discharged on the 5th postoperative day. In the next months, the patients had several readmissions due to mild cholestasis and pancreatitis. The magnetic resonance demonstrated a duodenal diverticulum adjacent to the papilla, located near the junction of the common bile and pancreatic duct. This clinical manifestation and the location of the diverticulum were suggestive of Lemmel’s syndrome, but a papillary dysfunction attributed to the diverticulum or food stasis cannot be excluded. Conclusion: To our knowledge, we report the first association between RL gangrene and Lemmel’s syndrome. We speculate that duodenal diverticulitis with lymphatic spread of the infection or transient bacteriemia in the bile with bacterial translocation due to papillary dysfunction, as well as cholestasis resulting from the diverticulum, could be plausible and unreported causes of the RL infection. The preoperative diagnosis of RL gangrene is challenging because it resembles the most common emergency conditions in the upper abdomen. The present case warrants attention due to the difficult decision to operate based solely on the clinical picture, despite negative imaging results. A high index of suspicion should be maintained in a case of unexplained septic shock and epigastric tenderness, even in negative imaging findings. MSCT, however, is a valuable tool to avert unnecessary operations in conditions that must be managed conservatively, such as acute pancreatitis. Full article

Background: Benign Prostatic Hyperplasia (BPH) causes Lower Urinary Tract Symptoms (LUTS), impairing quality of life (QoL). Transurethral Resection of the Prostate (TURP) is the gold-standard surgical treatment for Bladder Outlet Obstruction (BOO), but its effects on Autonomic Nervous System (ANS) function—assessed via Heart Rate Variability (HRV)—remains underexplored. To our knowledge, this is the first study to correlate HRV with specific LUTS domains pre- and post-TURP, establishing HRV as a potential biomarker for BPH management. Methods: In a prospective study, 242 men with BPH underwent TURP (2018–2024). Inclusion required age ≥ 50 years, International Prostate Symptom Score (IPSS) ≥ 8, and BOO evidence. HRV (Standard Deviation of Normal-to-Normal Intervals [SDNN], Low-Frequency/High-Frequency [LF/HF] ratio), IPSS, and QoL were assessed preoperatively and 3 months postoperatively. Paired t-tests, Pearson correlations, and multivariate regression (adjusted for age, Body Mass Index [BMI], prostate volume) were used (p < 0.05). Results: HRV (SDNN) increased from 36.97 ± 22.80 ms to 51.67 ± 27.59 ms (p = 0.032), and LF/HF ratio decreased from 1.63 ± 1.60 to 0.73 ± 0.52 (p = 0.028). IPSS fell from 18.5 ± 6.2 to 8.3 ± 4.1 (p < 0.001), with improved voiding (p = 0.004) and storage (p = 0.002) subscores. QoL improved from 3.5 ± 1.2 to 1.8 ± 0.9 (p = 0.003). HRV correlated inversely with IPSS voiding (r = −0.42, p = 0.012; r = −0.38, p = 0.019 post-TURP) and storage subscores (r = −0.29, p = 0.045). Older patients (≥65 years) and those with larger prostates (≥50 mL) showed greater improvements. Conclusions: TURP enhances LUTS, QoL, and ANS function. HRV’s correlation with LUTS suggests its biomarker potential, with possible cardiovascular benefits. Longitudinal studies are needed. Full article

Background/Objectives: Dental fear and anxiety are areas of concern in clinical pediatric dentistry, often leading to treatment avoidance and negative oral-health consequences. Cortisol and alpha amylase, measurable in saliva, have been proposed as biomarkers of stress and may provide an objective means of assessing and monitoring distress over time. This study examined measures of psychological and physiological distress in pediatric patients undergoing dental procedures and their correlation. Methods: 7-to-17-year-old new patients scheduled for a dental procedure or orthodontic bonding completed a psychological battery assessing dental fear (using Children’s Fear Survey Schedule—Dental Subscale), stress (Perceived Stress Scale), and dental anxiety (Modified Children Dental Anxiety Scale). Before the dental appointment, we assessed anticipated pain intensity, heart rate (HR), and collected two saliva samples to quantify cortisol and alpha amylase. Correlations between psychological and physiological measures were assessed with Pearson’s correlation and treatment groups were compared with independent t-tests. Results: Out 34 participants (12.8 ± 2.7 y/o, 52.9% females, 73.5% pediatric patients and 26.5% orthodontic patients), 38.2% endorsed moderate anxiety; 85.3% reported moderate to high stress; and 29.6% indicated dental fear. Psychological distress was not influenced by procedure type. Dental fear positively correlated with dental anxiety (p < 0.001) and HR (p < 0.001); dental anxiety positively correlated with anticipated pain (p = 0.010) and HR (p = 0.003); stress positively correlated with HR (p = 0.006). Even if 72.2% of participants had cortisol value outside normal range and those with greater stress exhibited elevated cortisol, cortisol and alpha amylase levels (measured on n = 18) were not correlated with psychological variables. Conclusions: Cortisol and alpha amylase levels were not correlated with psychological measures in a cross-sectional study on pediatric patients undergoing dental procedures. Full article

Detecting physical fatigue can help prevent overexertion. While typically defined at the muscle level, systemic fatigue remains less clear. Heart rate variability (HRV) reflects autonomic adaptability to physical stressors and may provide insight into fatigue-related responses. This study investigated the impact of physical fatigue on HRV and its correlation with endurance performance. Twenty participants (9 F, 11 M; 23.4 ± 5.0 y) walked on the treadmill at 1.25 m/s with progressively increased incline. HRV metrics were derived from baseline standing (STAND), pre-fatigued (PRE) and post-fatigued walking (POST). Time-domain HRV measures (lnTRI and lnTINN) were significantly reduced at POST compared to PRE or STAND (p < 0.05). Non-linear measures (DFA-α1, lnApEn, and lnSampEn) decreased at POST, while lnPoincaré SD2/SD1 increased. Normalized frequency-domain measures showed no condition effects. Baseline non-linear measures (lnApEn, lnSampEn, lnPoincaré SD2/SD1), normalized frequency measures and Total Power were significantly correlated with total fatiguing duration. Significant reductions in HRV and irregularity were observed post-fatigue. Greater baseline variability, irregularity, and high-frequency band power, reflecting parasympathetic activity, were associated with better endurance performance. Time-domain and non-linear measures were more sensitive to fatigue, whereas frequency-domain measures remain useful for identifying associations with endurance. The findings highlight HRV features that could enhance wearable sensing for fatigue and performance. Full article

Objectives: Virtual reality (VR) has emerged as a promising tool for assessing anxiety-related disorders through immersive exposure and physiological monitoring. This study aimed to evaluate whether multimodal data, including heart rate variability (HRV), skin conductance response (SCR), and self-reported anxiety, collected during VR exposure could classify patients with panic disorder and agoraphobia using machine learning models. Methods: Seventy-six participants (38 patients with panic disorder and agoraphobia, 38 healthy controls) completed 295 total VR exposure sessions. Each session involved two road and two supermarket scenarios designed to induce anxiety. Inside the sessions, self-reported anxiety was measured along with physiological signals recorded by photoplethysmography and SCR sensors. HRV measures of heart rate, standard deviation of normal-to-normal intervals, and low-frequency to high-frequency ratio were extracted along with SCR peak frequency and average amplitude. These features were analyzed using Gaussian Naïve Bayes (GNB), k-Nearest Neighbors (k-NN), Logistic Ridge Regression (LRR), C-Support Vector Machine (SVC), Random Forest (RF), and Stochastic Gradient Boosting (SGB) classifiers. Results: The best model achieved an accuracy of 0.83. Most models showed specificity and precision ≥0.80, while sensitivity varied across models, with several reaching ≥0.82. Performance was stable across major hyperparameters, VR-stimulus settings, and medication status. The patients reported higher subjective anxiety but exhibited blunted physiological responses, particularly in SCR amplitude. Self-reported anxiety demonstrated higher feature importance scores compared to other physiological properties. Conclusion: VR exposure with self-reported anxiety and physiological measures may serve as a feasible diagnostic aid for panic disorder and agoraphobia. Further refinement is needed to improve sensitivity and clinical applicability. Full article

Trail running involves constant changes in terrain and slope, complicating the accurate assessment of energy expenditure during performance. This study aimed to examine the relationship between running power output (RPO), oxygen consumption (VO₂), carbon dioxide production (VCO₂), and energy expenditure per minute (EE_min) across positive and negative slopes in trained trail runners under standardized laboratory conditions. Fifteen male trail runners performed five randomized 5 min treadmill runs at 70% of VO₂ maximal speed on −7%, −5%, 0%, +5%, and +7% slopes. VO₂, VCO₂, EE_min, respiratory exchange ratio (RQ), heart rate (HR), and RPO were recorded. Statistical analysis included Shapiro–Wilk tests for normality, repeated-measures ANOVA to compare variables across slopes, and Spearman or Pearson correlations between RPO and physiological variables. Moderate to strong positive correlations were found between RPO and VO₂ (Rho = 0.80–0.84, p < 0.001) and between RPO and EE_min (Rho= 0.74–0.87, p < 0.01) across all conditions. These findings suggest that RPO measured via a wearable device may reflect changes in energy expenditure and supports the integration of wearable power metrics into training and nutritional strategies for trail running. However, further studies in female athletes, outdoor settings, extreme slopes, and altitude conditions are needed to confirm the generalizability of these results. Full article

Background: Persistent fatigue is among the most commonly reported symptoms in patients suffering from post-acute sequelae of SARS-CoV-2 infection (long COVID). Autonomic dysfunction, measurable via heart rate variability, has been implicated as a contributing factor. Osteopathic manipulative treatment is a manual therapeutic approach that targets autonomic balance and may offer a novel intervention for long COVID-related fatigue. Methods: In this single-blind, randomized controlled trial, 42 participants (mean age 51 ± 11 years; fatigue severity score: 31 ± 5 points) with long COVID and persistent fatigue ≥12 weeks post-infection were allocated to either a 45 min standardized osteopathic treatment (n = 21) or a sham-treatment group (n = 21). Heart rate variability was assessed using a 10 min resting electrocardiogram before intervention, immediately after, and again 48 h later. The analysis of heart rate variability encompassed time-domain indices, including the root mean square of successive differences, the standard deviation of normal-to-normal intervals, mean heart rate, and mean RR interval. Additionally, frequency-domain measures such as low-frequency, high-frequency, total power, and the LF/HF ratio were considered. Results: The osteopathy group showed a statistically significant increase in root mean square of successive differences post-treatment (p < 0.01), accompanied by a decrease in the stress index (p < 0.05) and an increase in the mean of the standard deviations of RR intervals (p < 0.05). Significant between-group differences were observed for mean heart rate and mean of RR intervals (p < 0.05). Frequency-domain measures also improved significantly from baseline in the intervention group. Outlier patterns suggest potential subgroup effects, possibly due to underlying dysautonomia. Conclusions: A single session of osteopathic treatment significantly enhanced short-term heart rate variability in long COVID patients with fatigue. These findings highlight the potential role of manual autonomic modulation as a supportive therapy in long COVID management. Further research is needed to assess the long-term effects and optimal treatment frequency of osteopathic manipulative treatment in this population. Full article

Early detection of physiological dysregulation is critical for timely intervention and effective health management. Traditional monitoring systems often rely on labeled data and predefined thresholds, limiting their adaptability and generalization to unseen conditions. To address this, we propose a framework for label-free classification of physiological states using Heart Rate Variability (HRV), combined with unsupervised machine learning techniques. This approach is particularly valuable when annotated datasets are scarce or unavailable—as is often the case in real-world wearable and IoT-based health monitoring. In this study, data were collected from participants under controlled conditions representing rest, stress, and physical exertion. Core HRV parameters such as the SDNN (Standard Deviation of all Normal-to-Normal intervals), RMSSD (Root Mean Square of the Successive Differences), DFA (Detrended Fluctuation Analysis) were extracted. Principal Component Analysis was applied for dimensionality reduction. K-Means, hierarchical clustering, and Density-based spatial clustering of applications with noise (DBSCAN) were used to uncover natural groupings within the data. DBSCAN identified outliers associated with atypical responses, suggesting potential for early anomaly detection. The combination of HRV descriptors enabled unsupervised classification with over 90% consistency between clusters and physiological conditions. The proposed approach successfully differentiated the three physiological conditions based on HRV and fractal features, with a clear separation between clusters in terms of DFA α1, α2, LF/HF, and RMSSD (with high agreement to physiological labels (Purity ≈ 0.93; ARI = 0.89; NMI = 0.92)). Furthermore, DBSCAN identified three outliers with atypical autonomic profiles, highlighting the potential of the method for early warning detection in real-time monitoring systems. Full article

Objectives: To assess the impact of intravenous ferric carboxymaltose (FCM) on fetal and maternal adverse effects in pregnant women diagnosed with iron deficiency anemia (IDA). Methods: This is a multicenter retrospective study on 472 pregnant women diagnosed with moderate to severe IDA undergoing treatment with FCM between 2019 and 2025 at Careggi University Hospital (Florence) and Vittore Buzzi Children Hospital (Milan). Fetal wellbeing was assessed using computerized cardiotocography (cCTG) or ultrasound, based on gestational age at treatment. Maternal side effects were evaluated through clinical evaluation. Results: cCTG was performed in 377/472 patients (80%), with a mean short-term variability of 10.2 ms. Normal cCTG criteria were met in 98.4% of cases; six patients exhibited transient reduced variability, which resolved following intrauterine resuscitation. Ultrasound assessment was performed in 95 patients (20%), revealing no fetal heart rate abnormalities. Maternal side effects occurred in seven patients (1.4%). Hemoglobin concentrations increased by a median of 1.4 g/dL after five weeks, reaching up to 2.8 g/dL in women with a baseline Hb < 8 g/dL. Conclusions: Our findings support the potential safety and efficacy of intravenous FCM for the treatment of IDA during pregnancy, demonstrating low rates of maternal side effects and no adverse fetal heart rate patterns. However, prospective studies are necessary to confirm these results. Full article

The Poincaré plot was introduced as a tool to analyze heart rate variations caused by arrhythmias. Later, it was applied to time series with normal beats. The plot shows the relationship between the inter-beat interval (IBI) of one beat to the next. Several parameters were developed to characterize this relationship. The short and long axis of the fitting ellipse, SD1 and SD2, respectively, their ratio, and their product are used. The difference between the IBI of a beat and m beats later are also studied, SD1(m) and SD2(m). We studied the mathematical relations between heart rate variability measures and the Poincaré measures in the time (standard deviation of IBI, SDNN, root mean square of successive differences, RMSSD) and frequency domain (power in low and high frequency band, and their ratio). We concluded that SD1 and SD2 do not provide new information compared to SDNN and RMSSD. Only the correlation coefficient r(m) provides new information for m > 1. Novel findings are that ln(SD2(m)/SD1(m)) = tanh⁻¹(r(m)), which is an approximately normal distributed transformation of r(m), and that SD1(m) and SD2(m) can be calculated by multiplying the power spectrum by a weighing function that depends on m, revealing the relationship with spectral measures, but also the relationship between SD1(m) and SD2(m). Both lagged parameters are extremely difficult to interpret compared to low and high frequency power, which are more closely related to the functioning of the autonomic nervous system. Full article

Wood, as a natural material that stores carbon, is gaining increasing attention and has potential for use in interior architectural applications. Given the long indoor stay time characteristic of modern society, it is important to scientifically understand the effects of indoor wood application on the occupants. In this study, three residential buildings with an identical area and structure were constructed with different degrees of wood coverage (0%, 45%, 90%) using Larix kaempferi. Subsequently, indoor air quality (IAQ) evaluations and relative humidity measurements were conducted to assess the physical and chemical changes in each environment. The IAQ in wooden and non-wooden environments met the recommended IAQ standards established in South Korea. The results of the 8-month observation showed that, the higher the wood coverage ratio, the more the indoor humidity fluctuations were alleviated, and, in the case of the 90% wood coverage ratio condition, the humidity was maintained 5.2% lower in the summer and 10.9% higher in the winter compared to the 0% condition. To further assess the physiological responses induced by the wooden environment, the heart rate variability (HRV) was measured and compared for 26 participants exposed to each environment for two hours. In environments with a 0% and 90% degree of wood coverage, no statistically significant differences were found in the participants’ HRV indicators. But, in the group exposed to the 45% wooden environment, the results showed an increase in HRV indicators, natural logarithm of high frequency power (lnHF): 4.87 → 5.40 (p < 0.05), and standard deviation of normal-to-normal intervals (SDNN): 30.57 → 38.48 (p < 0.05), which are known indicators of parasympathetic nervous system activation. Full article

Objective: To investigate the effect of an 8-week inspiratory muscle training (IMT) intervention on respiratory muscle strength and cardiovascular autonomic regulation in obese young men. Methods: The study included 36 obese young men who met the inclusion and exclusion criteria. Participants were randomly divided into two groups: the IG (inspiratory muscle training group, n = 17), which underwent high-intensity IMT intervention for 8 weeks, 5 times a week, and the CG (control group, n = 18), which was not given any additional intervention. Assessed parameters included maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR), as well as heart rate variability metrics such as the standard deviation of normal-to-normal intervals (SDNN), root mean square of successive differences (RMSSD), standard deviation of successive differences (SDSD), low-frequency power component (LF), high-frequency power component (HF), and LF/HF ratio. These measurements were taken both at baseline and following the completion of the 8-week intervention period. Results: After 8 weeks of IMT, the MIP and MEP of the IG increased by 31.8% and 26.5%, respectively (p < 0.01). In addition, SBP, DBP, and HR decreased by 2.2%, 3.2%, and 2.1%, respectively (p < 0.01). In the HRV time domain, SDNN and RMSSD increased by 54.1% and 33.5%, respectively (p < 0.01), and there was no significant improvement in SDSD (p > 0.05); in the HRV frequency domain, LF decreased by 40.5%, HF increased by 59.4% (p < 0.01), and the LF/HF ratio decreased by 58.2% (p < 0.05). Conclusion: An 8-week 80%MIP IMT intervention significantly improves respiratory muscle strength and cardiovascular autonomic regulation in obese young men, suggesting that IMT is a promising non-pharmacological strategy for mitigating obesity-related cardiovascular risk. Full article