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The effect of drysuit diving in warm water on body temperature and post immersion orthostatic hypotension.

INTRODUCTION: Warm-water diving can limit heat dissipation, particularly when performed in fully encapsulating protective gear, leading to substantial thermal and cardiovascular strain that may impair diver safety. Following immersion, removal of hydrostatic support combined with heat-induced vasodilation may reduce central blood volume and increase susceptibility to orthostatic intolerance during egress and recovery. The extent to which this thermal strain impairs post-immersion orthostatic tolerance remains unknown. METHODS: Four randomised, crossover immersion trials were conducted at 28&#xb0;C, 33&#xb0;C, 38&#xb0;C without precooling (38&#xb0;C), and 38&#xb0;C with precooling (38&#xb0;C + Cool), with subjects wearing fully encapsulating dive gear. Subjects walked for up to 60 minutes at approximately 50% of O2max heart rate (HR) or until core temperature (Tc) reached 38.5&#xb0;C, or they voluntarily stopped. Tc, HR, and perceptual measures were recorded every 10 minutes. Orthostatic tolerance was assessed after immersion via a 70&#xb0; head-up tilt test. RESULTS: Eight healthy adults completed all aspects of the study. Tc and HR were higher during both 38&#xb0;C conditions compared with 28&#xb0;C and 33&#xb0;C (all P < 0.01) with no differences between 38&#xb0;C and 38&#xb0;C + Cool. Sweat loss exceeded 1.2 (SD 0.67) L&#x22c5;h-1 in both 38&#xb0;C conditions compared with &#x2264; 0.3 (0.32) L&#x22c5;h-1 at 28&#xb0;C and 33&#xb0;C (P < 0.01). Survival analysis showed orthostatic tolerance decreased with increasing thermal stress (log-rank P = 0.027; trend P = 0.003). Precooling did not reduce peak Tc or HR, nor did it improve tolerance time in 38&#xb0;C water. CONCLUSIONS: Encapsulated warm-water diving causes heat stress and cardiovascular strain that persists after immersion, impairing orthostatic tolerance. Precooling does not significantly reduce these outcomes.

Humans

The co-existence of Ehlers-Danlos syndrome and postural orthostatic tachycardia syndrome: A systematic review of the literature.

There is a growing body of literature evaluating both postural orthostatic tachycardia syndrome (POTS) and Ehlers-Danlos syndrome (EDS). We conducted a systematic review to evaluate what is currently known about the co-existence of both conditions. A search of MEDLINE and EMBASE was performed in December 2025 and data were collected in tables and pooled to determine the prevalence of POTS in EDS and EDS in POTS. A total of 30 studies were included with 8421 patients with EDS and 12,983 patients with POTS. The average age across 16 studies that reported mean age was 33.3&#xa0;years. POTS in patients with EDS ranges from 17.5% to 92.7% depending on the population. EDS in patients with POTS ranges from 17.9% to 50.0% depending on the population. One study suggested that patients with EDS and POTS had greater medication use, pain medications and greater number of clinic visits compared to POTS alone while another suggests that these patients have greater gastrointestinal symptoms and the odds were greatest for postprandial distress syndrome, chronic nausea and vomiting syndrome, vomiting and post-prandial fullness. We conclude that EDS and POTS frequently co-occur, and proportions of patients with POTS and EDS depends on the population evaluated. Overall, more research is needed to better understand how to effectively manage patients living with both EDS and POTS.

Humans

Bempedoic Acid and First and Recurrent Limb Outcomes in Statin-Intolerant Patients With Peripheral Artery Disease: Insights From the CLEAR Outcomes Trial.

BACKGROUND: Patients with peripheral artery disease (PAD) are at high risk of major adverse limb events (MALE) and major adverse cardiovascular events (MACE). Recently, bempedoic acid was shown to reduce MACE in primary and secondary prevention patients. Whether bempedoic acid reduces the risk of MALE in patients with PAD is unknown. METHODS: CLEAR Outcomes (Cholesterol Lowering via Bempedoic Acid [ETC1002], an ACL-Inhibiting Regimen) randomized 13&#x2009;970 patients to bempedoic acid 180 mg or placebo from December 22, 2016, to August 14, 2019. The trial primary end point was MACE-4, defined as death resulting from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or coronary revascularization. A clinical history of PAD was reported by investigators at baseline. Two blinded vascular medicine specialists independently adjudicated MALE, including adverse events indicating worsening PAD symptoms leading to revascularization, chronic limb-threatening ischemia, and acute limb ischemia. Outcomes were assessed as time to first event and total (including recurrent) events with a negative binomial approach. RESULTS: A total of 1624 of the enrolled patients (mean&#xb1;SD age, 63.9&#xb1;9.9 years; 915 [56.3%] female) had PAD at baseline. In patients with PAD in the placebo group, 69 (8.3%) had MALE over a median of 40.6 months, with rate of recurrent events of 4.0%/y. Bempedoic acid reduced the risk of MALE by 36% (hazard ratio, 0.64 [95% CI, 0.44-0.93]; P=0.018). Bempedoic acid reduced total MALE by 45% (relative risk, 0.55 [95% CI, 0.35-0.85]; P=0.007). First MACE-4 or MALE was reduced overall by 13% (hazard ratio, 0.87 [95% CI, 0.80-0.95]) with consistent effects with PAD (hazard ratio, 0.82 [95% CI, 0.64-1.04]) and without PAD (hazard ratio, 0.87 [95% CI, 0.79-0.86]; Pinteraction=NS) but not statistically significant within the PAD subgroup alone. Total MACE-4 or MALE was reduced (relative risk, 0.81 [95% CI, 0.73-0.90]) overall with consistent effects in PAD (relative risk, 0.71 [95% CI, 0.54-0.95]) and without PAD (relative risk, 0.82 [95% CI, 0.73-0.92]; Pinteraction=NS). CONCLUSIONS: Patients with PAD are at high risk of MALE and MACE. Bempedoic acid reduces both MACE and MALE in patients with atherosclerotic vascular disease, with notable absolute benefits in patients with PAD. These findings support (1) the importance of lowering low-density lipoprotein cholesterol in patients with PAD to reduce overall vascular risk and (2) the benefits of bempedoic acid in this population.

Humans

Opposite metabolic and gut responses to oral glutamine in male and female mice with diet-induced obesity.

Obesity is often associated with sex-dependent metabolic complications, to which altered intestinal barrier function and gut microbiota contribute. Glutamine supplementation has previously shown beneficial effects on gut barrier function and glycemic control. We thus aimed to characterize, in male and female mice, the effects of oral glutamine supplementation during high-fat-diet-induced obesity. Male and female C57BL/6 mice received a standard (SD) or high-fat diet (HFD; 60 % kcal from fat) for 14&#xa0;weeks (W14). From W12 onward, mice received glutamine in drinking water (2&#xa0;g/kg/day) or no supplementation. Body composition, glucose tolerance, insulin sensitivity, intestinal permeability, colonic inflammatory response, cecal microbiota and inflammatory/endocrine adipose response were assessed. In both male and female mice, glutamine supplementation failed to improve body weight and body composition. However, glutamine reduced glucose intolerance in HFD-fed males (AUC reduced by 14.57 %) that was associated with a partial restoration of plasma resistin and insulin and a trend toward limiting adipose inflammatory response. In males, glutamine did not affect gut microbiota composition and colonic response. Conversely, in HFD-fed females, glutamine supplementation led to gut microbiota changes (increase in Bacteroidota and Pseudomonadota phyla; increase in Muribaculaceae and Tannerellaceae families), increased colonic inflammatory markers (Il1b, Tlr4, Myd88, Irf3), increased inflammatory response in subcutaneous adipose tissue and increased HOMA-IR. Finally, HFD-fed mice exhibited sex-specific responses to glutamine supplementation with protective effects in males and harmful effects in females that need to be further deeply explored.

Animals

Extreme Temperature and Incident Diabetes Risk Among Middle-Aged and Older Adults in China: A National Longitudinal Cohort Study.

BACKGROUND AND AIMS: The metabolic consequences of extreme temperature exposure in nondiabetic populations remain poorly understood. This study aimed to examine associations between heatwave and coldwave exposure and incident diabetes mellitus (DM) and impaired glucose tolerance (IGT) in middle-aged and older Chinese adults. METHODS: A total of 1803 China Health and Retirement Longitudinal Study participants aged &#x2265;45 years with normoglycemia at baseline were followed from Wave 1 (2011) to Wave 3 (2015). Eighteen extreme-temperature indicators were derived from city-level fifth-generation European Centre for Medium-Range Weather Forecasts atmospheric reanalysis data. Outcomes were classified according to American Diabetes Association criteria. Generalized linear mixed-effects models (GLMMs) were pooled across five imputed datasets, with Bonferroni correction for multiple comparisons (&#x3b1; = 0.0028) and sensitivity analysis adjusting for individual follow-up duration. RESULTS: All nine heatwave indicators showed odds ratios (ORs) < 1.0 for DM and IGT. HT9 (&#x2265;97.5th percentile, &#x2265;4 consecutive days) was the sole Bonferroni-significant result: OR = 0.845 (95% confidence interval [CI]: 0.802-0.890). Coldwave indicators showed no consistent associations. Age significantly modified the HT9 effect (P-interaction = 0.004): adults aged 65-84 showed a stronger inverse association (OR = 0.616) than those aged < 65 (OR = 0.921). CONCLUSION: Prolonged heatwave exposure was consistently associated with reduced diabetes risk, with pronounced age heterogeneity. Replication in larger prospective studies is warranted.

Humans

Feasibility and barriers to same-day physical therapy following lumbar fusion surgery.

OBJECTIVE: To evaluate the feasibility of same-day (postoperative day 0; POD0) physical therapy (PT) following lumbar fusion and to identify factors associated with failure to participate. METHODS: This retrospective study analyzed prospectively collected data from patients undergoing single-level posterior spinal fusion (PSF), with or without anterior (ALIF) or lateral (LLIF) interbody fusion, between January and December 2024 at a single institution. A standardized POD0 PT protocol was implemented for eligible patients. Patients were categorized into two groups: successful POD0 PT (ambulatory on POD0) and unable to participate. Demographic and surgical variables were compared between groups. Reasons for inability to participate were recorded and categorized. RESULTS: Among 129 patients in whom POD0 PT was attempted, 84 (65%) successfully participated, while 45 (35%) were unable. There were no significant differences in age, sex, BMI, ASA class, operative time, estimated blood loss, or surgical approach between groups. Patients who successfully completed POD0 PT had a significantly shorter hospital length of stay compared to those who did not (3.4&#xa0;&#xb1;&#xa0;1.6 vs 5.8&#xa0;&#xb1;&#xa0;2.9&#xa0;days, P&#xa0;<&#xa0;0.001), with no differences in complication rates, discharge disposition, emergency department visits, or reoperation rates. The most common barriers to POD0 PT were postoperative pain, medical issues (e.g., orthostatic hypotension, nausea, dizziness), and anesthesia-related somnolence. Less common factors included postoperative restrictions and logistical issues such as brace availability. CONCLUSIONS: POD0 PT following lumbar fusion is feasible in the majority of patients and is associated with a shorter hospital stay without increased complications. Failure to participate was not associated with the baseline patient or surgical characteristics evaluated in this study. Instead, the most common barriers were postoperative pain, transient medical issues, and anesthesia-related somnolence, suggesting that optimization of modifiable perioperative factors may improve the implementation of POD0 PT.

Humans

Effect of atenolol versus ivabradine on heart rate variability in patients of schizophrenia with clozapine-induced tachycardia: a randomized controlled trial.

BACKGROUND: A third of schizophrenia cases are resistant to antipsychotics, where clozapine is the only FDA-approved medication. Clozapine use is often limited by intolerable adverse effects. Persistent tachycardia occurs in approximately 25-54% patients receiving clozapine. Heart rate variability (HRV) is a non-invasive, clinically relevant marker of autonomic nervous system functioning. Atenolol and Ivabradine are usually prescribed for clozapine-induced tachycardia (CIT), although evidence guiding their optimal use remains limited. AIM: This study aimed to compare the effects of atenolol versus ivabradine on HRV in patients with treatment-resistant schizophrenia (TRS) receiving clozapine. METHODS: This open-label randomised clinical trial, conducted at a tertiary-care center over 20 months, involved TRS patients on clozapine for more than three months and having persistent tachycardia. Twenty patients received atenolol 25mg once-daily, while twenty received ivabradine 5mg twice-daily for two months. The primary outcome was the change in the frequency domain of HRV, while the secondary outcomes were time-domains, central and peripheral blood pressure, pulse rate and treatment-emergent adverse events (TEAE). RESULTS: While both drugs significantly reduced pulse-rates (atenolol: -20.56&#xb1;13.00, p<0.001; ivabradine: -21.855&#xb1;12.873, p<0.001). Within-group analysis showed that, the atenolol group had significant improvements in high-frequency [HF] power (p=0.048) and LF/HF ratio (p=0.044), along with a non-significant trend towards increased total power (p=0.053); no significant within-group changes were observed in the ivabradine group. CONCLUSION: No significant between-group differences in HRV parameters were established between atenolol and ivabradine. Ivabradine could be a viable option in patients where atenolol is either contraindicated or not tolerated. Future larger multicentric studies are needed for greater generalisability. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT06505668.

Humans

Cardiovascular risks in psychiatric disorders and psychiatric risks in cardiovascular disorders: implications for prevention and clinical management - a large-scale umbrella review encompassing 76 meta-analyses.

OBJECTIVE: Psychiatric and cardiovascular disorders often co-occur, complicating their assessment and management. No umbrella review(UR) has summarized the meta-analytic evidence on the co-occurrence of psychiatric and cardiovascular disorders and assessed its credibility. METHODS: Meta-analytic systematic reviews of observational studies documenting the prevalence, risk factors, and outcomes associated with the co-occurrence of cardiovascular and psychiatric disorders, indexed from inception through March.16.2026, and meeting established diagnostic criteria, were included. Meta-analytic association and prevalence estimates were recalculated and graded based on established or adapted criteria. The AMSTAR-2 assessed the quality of the meta-analyses, while several subgroup analyses and meta-regressions aimed to explain the heterogeneity. RESULTS: We included 76 meta-analyses yielding 131 meta-analytic estimates. Based on pre-existing meta-analytic evidence, 22/24 prevalence estimates (91.7%) met moderate/strong credibility criteria. Strong credibility emerged for: orthostatic hypotension in Lewy body(58%;95%C.I.&#xa0;=&#xa0;50-66%) and Alzheimer's dementias(28.0%&#xa0;=&#xa0;95%C.I.&#xa0;=&#xa0;17.0-40.0%); pericardial effusion in anorexia nervosa(25.0%;95%C.I.&#xa0;=&#xa0;17.0-34.0%); in heart failure(HF): major depressive disorder(MDD)(41.9%;95%C.I.&#xa0;=&#xa0;36.7-47.1%), mild cognitive impairment(MCI)(41.4%;95%C.I.&#xa0;=&#xa0;38.3-45.6%), anxiety(32.0%;95%C.I.&#xa0;=&#xa0;26.5-37.6%), MDD&#xa0;+&#xa0;anxiety(24.7%;95%C.I.&#xa0;=&#xa0;17.9-34.3%), and dementia(19.8%;95%C.I.&#xa0;=&#xa0;12.9-27.8%); in atrial fibrillation(AF): MCI(26.0%;95%C.I.&#xa0;=&#xa0;21.0-30.0%), anxiety in patients undergoing pulmonary vein isolation(PVI)(25.0%;95%C.I.&#xa0;=&#xa0;12.0-46.0%), MDD in PVI patients (20.0%;95%C.I.&#xa0;=&#xa0;13.0-29.0%); in coronary artery disease: MDD&#xa0;+&#xa0;anxiety(19.8%;95%C.I.&#xa0;=&#xa0;16.0-24.6%): in schizophrenia spectrum disorders: clozapine-associated-cardiomyopathy(0.6%;95%C.I.&#xa0;=&#xa0;0.2-2.3%); clozapine-associated-cardiomyopathy absolute death rates (0.0003;95%C.I.&#xa0;=&#xa0;0.0001-0.0012); clozapine-associated-cardiomyopathy case fatality rate (0.078;95%C.I.&#xa0;=&#xa0;0.018-0.285). Several additional disorders were multimorbid in>5% of people, yet with a lower credibility rating. No re-pooled risk factors/outcomes reached strong credibility criteria. CONCLUSIONS: The present study provides an atlas of cardiovascular and psychiatric multimorbidity across varying levels of credibility, reinforcing the need for an integrated, multidisciplinary approach to patient care and for more research on actionable risk/protective factors and outcomes.

Humans