Clinical Physiology and Functional Imaging最新文献

The present study investigates the relationship between obesity and metabolic, hormonal, and clinical indicators in adolescent girls. A total of 75 girls aged 15–19 years (mean age: 17.53 ± 1.29 years) were enrolled, including 58 with excess weight or obesity and 17 with normal weight. Anthropometric parameters related to obesity, various clinical scores, fasting glucose, fasting insulin, insulin resistance indices, lipid profile, blood pressure, and thyroid-stimulating hormone (TSH) were assessed. Mann-Whitney U test compared differences between the groups, while Spearman's rho correlation analysed the associations among adiposity, metabolic, and clinical parameters. Simple linear regression predicted insulin resistance indices using BMI, WHR, and WHtR. Receiver operating characteristic (ROC) analysis evaluated the predictive ability of BMI, WHR, and WHtR for insulin resistance. Girls with obesity exhibited significantly higher weight, BMI, WC, WHR, and WHtR (p < 0.05). Acanthosis scores and insulin resistance indices strongly correlated with BMI, WHR, and WHtR, while lipid profile parameters showed no significant association with adiposity. Regression analysis identified BMI and WHtR as strong predictors of HOMA-IR, while WHR and WHtR inversely correlated with QUICKI and GIR. The McAuley Index moderately correlated with BMI and WHtR. ROC analysis confirmed BMI (AUC = 0.779, p = 0.000) and WHtR (AUC = 0.776, p = 0.000) as strong predictors of insulin resistance. Concluding that, obesity in adolescent girls is strongly linked to insulin resistance but not lipid profile parameters. BMI and WHtR emerge as reliable predictors, with acanthosis as a potential clinical marker.

Breath-hold ECG-gated cardiovascular magnetic resonance (CMR) imaging is challenging during exercise due to motion, ECG-problems, and lengthy scans. To facilitate time-resolved volumetric measures from exercise-CMR, we aimed to develop a method for constructing time-resolved ventricular cines from real-time free-breathing exercise-CMR. Time-resolved ventricular cines were semi-automatically constructed from real-time exercise-CMR by identifying end-expiratory timeframes, identifying one R-R interval within these timeframes, and synchronizing R-R intervals across slice positions. To investigate utility, ECG-gated rest CMR and real-time exercise-CMR images were collected from ten healthy volunteers and ten heart failure patients. The consistency of the left ventricular mass (LVM) was assessed between rest and exercise at end diastole (ED), mid systole (MS), end systole (ES), and early rapid filling (ERF). When comparing LVM between rest and exercise for healthy volunteers, bias ± SD was 1.5 ± 2.7 g at ED, 0.9 ± 3.3 g at MS, 1.3 ± 3.3 g at ES, and 1.2 ± 3.3 g at ERF. When comparing LVM between rest and exercise for heart failure patients, bias ± SD was 1.6 ± 2.8 g at ED, 1.0 ± 2.7 g at MS, 1.5 ± 2.6 g at ES, and 1.6 ± 2.5 g at ERF. The bias ± SD between ED and ES in standard rest images was 0.0 ± 0.7 g for healthy volunteers, and 0.0 ± 0.5 g for heart failure patients. The method for constructing time-resolved ventricular cines from real-time exercise-CMR demonstrated utility for time-resolved volumetric measurements in healthy volunteers and heart failure patients.

Although force transfer during elongation occurs longitudinally and transversely, the influence of transverse force transfer between the biceps femoris long head and short head remains unclear. This study aimed to investigate whether separating the intermuscular connections between the biceps femoris long head and short head alters tension in the biceps femoris long head. Eight human cadaver legs were used, and ultrasonic shear wave elastography measurements were performed under four conditions: (1) intact, (2) removal of all tissues from the skin to the deep fascia, (3) intermuscular dissection, and (4) biceps femoris short head detachment. Measurements were taken in four limb positions, defined by hip and knee joint angles, under each tissue condition. The shear modulus of the biceps femoris long head significantly increased by 62.2% after intermuscular dissection compared to fascia removal, and further increased by 174.7% after biceps femoris short head detachment. In contrast, the shear modulus of the biceps femoris short head significantly decreased by 36.0% following intermuscular dissection and by 75.1% after detachment. In conclusion, reducing biceps femoris short head tension while increasing biceps femoris long head tension may influence muscle stress distribution, particularly during movement.

Blood pressure (BP) management in acute ischaemic stroke presents uncertainties regarding whether systolic BP (sys), mean BP (mean), or diastolic BP (dia) should be used for therapeutic guidance. Repeated assessments of BP-dependent cerebral autoregulation (CA) could help identify a suitable BP modality for this purpose. Forty-nine patients (median age 75 [62–81] years; 13 women) with unilateral acute ischemic stroke (NIHSS 5 [1.75–15.0]), underwent stroke center care and dynamic cerebral autoregulation (dCA) assessments on days 1 to 3 after the stroke event. Using frequency-dependent transfer function analysis between BP and cerebral blood flow velocity (CBFV), gain indicates the amplitude transmission, and phase shift represents the phase difference between the two. CA failure is typically indicated by a low or absent phase shift in the very low (0.02–0.07 Hz) or low frequencies (0.07–0.20 Hz) ranges, leading to a direct transmission of BP changes to CBFV changes. BP values were averaged, with their standard deviation indicating BP variability (BPV). Averaged sys, mean, or dia BP did not predict gain or phase, but BPV did. In the stroke-affected hemisphere (AH), sys, mean and dia BPV on day 1 predicted low frequency gain on days 1 and 2 (p < 0.02 - p < 0.001). On day 2, dia more than mean BPV predicted linearly (p < 0.001) very low frequency phase with small phase values associated with a low BPV and large phase values with high BPV values. In acute stroke, dia BPV predicts best phase shift, and could be a promising candidate for BP guidance.

Accurate body composition assessment is crucial for evaluating health and guiding interventions. Four-compartment (4 C) models, which separately quantify fat mass, lean body mass, bone mineral content and total body water, offer improved accuracy but usually require multiple devices. This study aimed to validate dual-energy X-ray absorptiometry (DXA)–derived body volume (BV) equations—specifically those from Wilson and Smith-Ryan—against air displacement plethysmography (ADP), and to modify the Smith-Ryan equation for enhanced BV estimates in a 4 C model. Ninety healthy adults (50 females, 40 males; aged 18–66 years; BMI 18–34 kg/m²) were recruited at a single-centre facility. Participants underwent DXA scanning (GE Lunar DXA) for tissue composition, ADP (Bod Pod) for BV, and bioelectrical impedance spectroscopy for total body water, with all measurements performed by trained technicians. BV was estimated using the original Wilson and Smith-Ryan equations and a regression-modified Smith-Ryan equation, and these estimates were incorporated into the 4 C model to calculate percent body fat (%BF) and fat mass (FM). All DXA-based BV estimates correlated highly with ADP (r ≥ 0.99). Although the original equations showed small, statistically significant differences in %BF and FM compared to ADP (p < 0.05), the modified Smith-Ryan equation produced BV estimates equivalent to ADP (p = 0.998). These findings suggest that calibrated DXA-derived BV equations can reliably substitute for ADP in 4 C models, enhancing the accessibility and cost-effectiveness of body composition analysis. Future research should validate these findings in more diverse populations.