Clinical Physiology and Functional Imaging最新文献

The pupillary light reflex could serve as a valuable method for measuring dynamic responses in the autonomic nervous system (ANS). However, it remains unclear whether physiological conditions such as fasting and dehydration affect pupillary reflexes. In this study, we investigated the effects of fasting and dehydration on pupillary responses using pupillometry. Measurements were taken after at least 12 h of Ramadan fasting (RF) and under a normal dietary pattern (NDP). Forty-nine volunteers, who had no complaints related to the ANS, participated in the study. The initial pupil diameter (IPD), amplitude of contraction, contraction velocity, contraction latency, dilatation duration, and dilation velocity were recorded. The IPD was 5.91 ± 0.65 mm in the RF condition and 5.72 ± 0.65 mm in the NDP condition (p < 0.001). Both contraction amplitude (CA) and dilatation velocity (DV) were higher in the RF condition (p = 0.010 and p = 0.022, respectively). Females exhibited a greater IPD in the NDP condition (p = 0.023). Differences between genders in the RF condition were observed in CA (p = 0.002), dilation duration (p = 0.016) and dilation latency (p = 0.041). These findings indicate that fasting and dehydration influence IPD, CA and DV. Therefore, it is informative to consider fasting and dehydration status when evaluating pupillometry results.

The present study examined the relationships between trunk tissue distribution, metabolic risk factors, and physical performance in young Japanese individuals using cross-sectional and longitudinal analyses. Thirty-six healthy Japanese men (n = 20, body mass index [BMI]: 20.8 ± 2.0 kg/m²) and women (n = 16, BMI: 19.6 ± 2.0 kg/m²) aged 20–26 years old visited our laboratory twice with an interval of 1 year. The thicknesses of skeletal muscle (MT), subcutaneous adipose tissue (SCAT), and the intra-abdominal cavity (IAT) were assessed by ultrasound imaging and adjusted by body mass^1/3 (BM^1/3). Blood properties related to hepatic function or metabolic syndrome, brachial-ankle pulse wave velocity, hand grip strength, two-step-length/height scores, and sit-and-reach test scores were also measured. As a result of the cross-sectional analysis, significant relationships were observed between SCAT/BM^1/3 and indices of glucose metabolism (HOMA-IR and QUICKI) in men (r = 0.513 and -0.583), and between IAT/BM^1/3 and fasting blood glucose in women (r = 0.524). Longitudinal analyses of women showed that changes (%) in IAT and MT/IAT correlated with % changes in the indices of hepatic function (AST) and glucose metabolism (HOMA-IR and HOMA-β) (r = −0.673 to 0.686). Significant correlations were also observed between MT/IAT and walking ability (two-step-length/height) in cross-sectional and longitudinal analyses of men (r = 0.463 and 0.525). In conclusion, the trunk tissue distribution could be used to detect the early symptoms of metabolic risks and declines in physical performance in young men and women.

Doppler ultrasound can be used to evaluate leg blood flow (Q̇_leg), especially of interest when investigating peripheral vascular limitations in patients with chronic obstructive pulmonary disease (COPD). However, the within-session repeatability, a subdomain of test-retest reliability, of this method remains unknown. This study aimed to provide within-session repeatability estimates of Doppler ultrasound-based Q̇_leg at rest and during single-leg knee-extensor exercise (KEE) in patients with COPD, and to compare these estimates to matched healthy controls. In this case-controlled study, 16 participants with COPD were matched based on sex and age with 16 healthy controls. All participants underwent measurement of Q̇_leg using Doppler ultrasound in a KEE setup at various intensities with the same measurement being performed again separated by 10 s. Smallest real difference (SRD) was lowest at rest in both groups and increased during exercise, reaching values ranging from 164 to 231 mL in COPD and 122–180 mL in the control group. The coefficient of variance (CV) was highest at rest and decreased during exercise to values ranging from 4.0% to 5.0% in COPD and 2.6%–3.2% in the control group. The CV was significantly lower in the control group during 0 watt and exercise at 20% of max watt, but apart from that, no reliability estimates were different between groups. To conclude, Doppler ultrasound showed nearly equal within-session repeatability when evaluating Q̇_leg in COPD patients and healthy individuals with a CV not exceeding 5% during exercise for both groups.