Clinical Physiology and Functional Imaging最新文献

Polycystic ovary syndrome (PCOS) is a multifaceted endocrine disorder with profound implications for the reproductive and metabolic health of women. The utilization of anthropometric measures in the diagnosis and management of PCOS has gained increasing attention due to their practicality and predictive capacity for associated conditions such as obesity and insulin resistance. This review rigorously explores the application of various anthropometric indices, including body mass index, waist-to-hip ratio, and advanced metrics such as the body shape index and body roundness index, wrist circumference, neck circumference. These indices offer critical insights into body fat distribution and its association with the metabolic and hormonal perturbations characteristic of PCOS. The review underscores the necessity of addressing obesity, a prevalent comorbidity in PCOS, through lifestyle modifications and personalized therapeutic approaches. By incorporating anthropometric evaluations into routine clinical practice, healthcare professionals can enhance diagnostic precision, optimize treatment strategies, and ultimately improve patient outcomes. This integrative approach not only facilitates the management of the metabolic challenges inherent in PCOS but also contributes to the development of more individualized therapeutic interventions, thereby enhancing the overall quality of life for women affected by PCOS.

Introduction: Limb dominancy has been suggested, by some, to influence arterial occlusion pressure (AOP). However, we hypothesized that the differences in AOP between the dominant and nondominant legs were more likely explained by differences in cuff position.

Aims: To determine the impact of limb dominance, composition, and cuff position on AOP in the context of error associated with measuring AOP twice on the same leg.

Methods: Fifty-eight adults (30 males) volunteered to have AOP measured on their dominant legs with the cuff bladder covering their inner thighs and on their nondominant legs with the bladder covering their inner and outer thighs (in random order). Thigh circumference and muscle and fat thicknesses were also measured on each leg.

Results: We found evidence for differences in AOP between legs [median δ of -0.222, 95% credible interval: (-0.429, -0.016)] when the cuff position was matched. The mean difference was -2.8 mmHg, and the 95% limit of agreement in a Bland-Altman plot was -24.8 to 19.0 mmHg. When plotting this alongside an error range (i.e., 95% limits of agreement) of taking the same measurement twice from our previous study (Spitz et al., 2020), 52 out of 58 measurements were within the error range. This difference was not due to the cuff position. Additionally, there was no evidence that thigh circumference or composition (muscle/fat thickness) moderated any difference between limbs.

Conclusion: The difference in AOP between limbs is small and is mostly indistinguishable from the difference observed from taking the measurement twice on the same limb.

Cross-sectional imaging supplements endoscopy in detecting disease manifestations in inflammatory bowel diseases (IBD). This study aimed to evaluate the accuracy of PET/MRI in a paediatric population suspected of IBD. This prospective study consecutively included patients aged 8-17 years under diagnostic evaluation for IBD. Forty-three patients underwent a PET/MRI scan and subsequent ileocolonoscopy, of whom 26 patients diagnosed with IBD participated in a follow-up scan, hereof 19 with Crohn's disease (CD), five with Ulcerative colitis and two with unclassified IBD. The results of PET alone, MRI alone, and PET/MRI combined were compared to a reference standard of endoscopy and histopathology. Of the 208 intestinal segments analysed, 109 showed inflammation, and 99 had no inflammation. In the per-segment analysis PET had a sensitivity of 0.83 (95% CI 0.73-0.93), specificity of 0.59 (95% CI 0.47-0.71), and area under the receiver operating characteristic curve (AUROC) of 0.73 (95% CI 0.67-0.80). MRI had a sensitivity of 0.52 (95% CI 0.41-0.64), specificity 0.89 (95% CI 0.82-0.96), and AUROC of 0.72 (95% CI 0.66-0.77). PET/MRI had a sensitivity of 0.83 (95% CI 0.74-0.94), specificity of 0.57 (95% CI 0.44-0.69), and AUROC of 0.77 (95% CI 0.71-0.84). At follow-up, PET and MRI scores decreased, and the change in MRI was able to identify patients with a clinical response. The accuracy of the PET/MRI scan in detecting inflammation in the terminal ileum and colon was moderate and not superior to either modality alone. With technological advances and combined reading, PET/MRI may still be valuable in selected cases.

Purpose: Endothelial dysfunction is a pathophysiological change preceding many cardiovascular events. Measuring improvements of endothelial function is challenging when function is already optimal, which may be remediated using a physiological challenge. This study aimed to determine whether imaging assessments can detect microvascular effects of a mixed meal tolerance test (MMTT).

Methods: Twenty healthy volunteers (age ≥45 and ≤70 years) underwent two MMTTs at the beginning (Day 1) and end (Day 84) of a twelve-week period. Imaging methods included laser speckle contrast imaging (LSCI) combined with post-occlusive reactive hyperaemia (PORH) and local thermal hyperaemia (LTH) challenges, passive leg movement ultrasonography (PLM), and sidestream dark field microscopy (SDFM). Measurements were conducted pre-MMTT and at 5 timepoints post-MMTT for PLM and SDFM and 3 timepoints post-MMTT for PORH and LTH.

Results: No consistent effects of the MMTT were detected on LSCI LTH, PLM and SDFM endpoints. LSCI PORH maximum perfusion was significantly suppressed 46, 136, and 300 min post-MMTT administration on Day 1, while residual perfusion decreased significantly 46 and 136 min post-MMTT on Day 1. However, when repeated on Day 84, PORH endpoints were not significantly affected by the MMTT.

Conclusion: SDFM, PLM and LSCI LTH endpoints displayed high intra-subject variability and did not detect consistent effects of MMTT. LSCI PORH endpoints displayed the lowest intra-subject variability of all assessed endpoints and were affected by the MMTT on Day 1, but not on Day 84. Further standardization of methods or more robust challenges to affect vascular endpoints may be needed.

Ultrasound imaging is extensively used by both practitioners and researchers in assessing muscle thickness (MT); however, its use in the field is constrained by the transportability of stationary devices. New portable ultrasound probes pose as a cost-effective and transportable alternative for field-based assessments. This study evaluated the concurrent validity of a portable probe (Lumify) against a laboratory-based device (Vivid S5) in measuring MT. Eighteen participants (nine males and nine females) visited the laboratory and their MT measurements were collected using each device at five different sites (anterior and posterior arm, anterior and posterior thigh, and posterior lower leg). Bland-Altman plots (systematic and proportional bias, random error, and 95% limits of agreement), Pearson's product-moment correlation coefficient (r), and paired samples t-tests with Cohen's d effect sizes (ES) were used to assess the concurrent validity of the Lumify device. Systematic bias was low at all sites ( ≤ 0.11 cm) while proportional bias was detected only at the posterior lower leg (r² = 0.217 [r = 0.466]). The difference in MT between devices was significant only at the anterior thigh (p < 0.05); however, ES for all sites were considered trivial (ES ≤ 0.131). Linear associations were found between the devices at each site of measurement (r ≥ 0.95). These results highlight that the Lumify probe can be used interchangeably with the Vivid S5 for MT measurements, providing practitioners and researchers with a more cost-effective and portable alternative for field-based assessments.

There is no study that has investigated the impact of exercise in a combined hypoxic and hot environment on endothelial function. Therefore, we tested whether aerobic exercise in a combined hypoxic and hot conditions induces further enhancement of endothelial function. Twelve healthy males cycled at a constant workload (50% of their maximal oxygen uptake under normoxic/thermoneutral conditions) for 30 min in four different environments: exercise under normoxic condition (NOR: fraction of inspiratory oxygen or FiO₂ = 20.9%, 20°C), exercise under hypoxic condition (HYP: FiO₂ = 14.5%, 20°C), exercise under hot condition (HOT: FiO₂ = 20.9%, 30°C), and exercise under combined hypoxia and hot conditions (HH: FiO₂ = 14.5%, 30°C). Before, during, and after exercise, cardiovascular variables (e.g., heart rate, blood flow, and shear rate), blood variables, and endothelial function evaluated by flow-mediated dilation (FMD) were assessed. Heart rates were significantly higher throughout the HH trial's experimental period than the other trials (p < 0.05). However, in the HH trial, brachial artery blood flow and shear rate did not differ from those in other trials after exercise. Plasma catecholamines (epinephrine, norepinephrine, and dopamine) elevations in response to exercise were significantly higher in the HH trial than in the other three trials (p < 0.05). No considerable differences were observed in FMD responses among trials before and after the exercise. In conclusion, aerobic exercise in a combined hot and hypoxic environment further activated sympathetic nervous activity but did not considerably enhance blood flow, shear rate, or endothelial function.

Diagnosis of asthma can be confirmed based on variability in peak expiratory flow (PEF) or changes in forced expiratory volume in 1 s (FEV₁) measured with spirometry. Our aim was to use methacholine challenge as a model of induced airway obstruction to assess how well relative changes in PEF reflect airway obstruction in comparison to relative changes in FEV₁. We retrospectively studied 878 patients who completed a methacholine challenge test. To assess congruency along with differences between relative changes in FEV₁ and PEF during airway obstruction, a regression analysis was performed, and a Bland & Altman plot was constructed. ROC analysis, sensitivity, specificity, positive and negative predictive values and κ-coefficient were used to analyze how decrease in PEF predicts decrease of 10% or 15% in FEV₁. The relative change in PEF was on average less than the relative change in FEV₁. In the ROC analysis areas under the curve were 0.844 and 0.893 for PEF decrease to predict a 10% and 15% decrease in FEV₁, respectively. The agreement between changes in PEF and FEV₁ varied from fair to moderate. Airway obstruction detected by change in PEF was false in about 40% of cases when compared to change in FEV₁. Change in PEF is not a very accurate measure of airway obstruction when compared to change in FEV₁. Replacing peak flow metre with a handheld spirometer might improve diagnostic accuracy of home monitoring in asthma.