Reproducibility Of The Hemodynamic And Leg Vascular Response To Cold-Pressor Stimulation
Bibliographic record
Abstract
The cold-pressor test (CPT) is commonly used to assess the cardiovascular response to physiological stress. The day-to-day reproducibility and intra-subject variability of the physiological response to the CPT has not been established. PURPOSE: To determine the reproducibility and within-subject variability of the hemodynamic and leg vascular response to CPT stimulation. It was hypothesized that the hemodynamic and leg vascular response would be reproducible. METHODS: Young, healthy males (mean ± SD; Age: 25 ± 3 yrs; Height: 175 ± 4 cm; Body Mass: 76 ± 13 kg; n=6) completed a CPT at approximately the same time of day on 3 separate occasions. Trials were separated by a minimum of 24 hours. Testing began with a 5 min supine baseline period, after which subjects immersed their hand in -1°C ice water for 5 min, followed by a 5 min recovery period. Mean arterial pressure (MAP) was calculated on a beat-by-beat basis from the blood pressure waveform using finger photoplethysmography (Finometer; Finapres Medical Systems). Cardiac output was determined by the Modelflow method and total peripheral resistance (TPR) was calculated. Femoral artery blood flow was measured continuously via Doppler ultrasound (Vivid-I; GE Medical) and femoral vascular resistance (FVR; mmHg.mL-1.min-1) was calculated. The change of each variable at min 2 of the CPT was calculated as a percent change from the supine baseline value. Reproducibility of the response across days was determined by one-way repeated measures ANOVA. Within subject variability was assessed by coefficient of variation (CV). RESULTS: The changes in MAP (Day 1: 27 ± 10%; Day 2: 31 ± 10%; Day 3: 31 ± 10%; p > 0.05), TPR (Day 1: 20 ± 10; Day 2: 22 ± 9; Day 3: 19 ± 9; p > 0.05) and FVR (Day 1: 117 ± 50; Day 2: 118 ± 58; Day 3: 86 ± 40; p > 0.05) were not different between days. The within subject CV ranged from 9 to 32 %, 10 to 74 %, and 19 to 42 % for MAP, TPR and FVR, respectively. CONCLUSION: The hemodynamic and leg vascular response to a CPT appears to be reproducible across days, however the substantial intra-subject variability suggests that it is advisable to average repeat tests on an individual to determine vascular reactivity to the CPT. Supported by NSERC, Canada.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".