Comparison Of Whole-forearm And Skin Post-occlusive Reactive Hyperemia As Indices Of Microvascular Function
Bibliographic record
Abstract
BACKGROUND: Post-occlusive reactive hyperemia (PORH) is often used as a test of microvascular function. However, the method of PORH measurement and the reporting of PORH values varies widely between studies, from measurements on the skin or whole-forearm to reporting peak or cumulative PORH values. As such, the optimal measurement and reporting of PORH values remains unclear. PURPOSE: To compare whole-forearm and skin PORH between older adults with conditions typically associated with microvascular dysfunction (type 2 diabetes, T2D), macrovascular dysfunction (non-diabetic coronary artery disease, CAD) and healthy controls (CTRL). METHODS: We retrospectively analyzed data obtained from 13 T2D patients (61 ± 9 years, 6 M ; 7 W), 21 CAD patients (65 ± 9 years, 18 M ; 3 W) and 13 CTRL (65 ± 7 years, 9 M ; 4 W). Forearm vascular conductance (FVC, duplex ultrasound) and cutaneous vascular conductance (CVC, laser-Doppler) were measured simultaneously before and for 3 minutes after 5 minutes of forearm ischemia. PORH was quantified as: absolute peak (Peak), change from baseline to peak (∆) and area under the curve above baseline (AUC). RESULTS: Baseline FVC (P=0.84) and CVC (P=0.31) were similar between groups. Peak FVC was similar between groups (P=0.24), while ∆FVC tended to be reduced in T2D compared to CAD (P=0.06) and CTRL (P=0.07). FVC AUC was reduced in T2D compared to CTRL (P=0.03), while values in CAD did not differ from T2D or CTRL. Peak CVC (T2D: P=0.04, CAD: P=0.02) and ∆CVC (T2D: P=0.03, CAD: P=0.01) were reduced in T2D and CAD. There was a trend for CVC AUC to differ between groups (P=0.06). The different indices of PORH for a given measurement (forearm vs skin) were strongly correlated (r=0.755 to 0.906 between FVC descriptors, r=0.768 to 0.991 between CVC descriptors, all P<0.001). However, FVC indices of PORH weakly correlated with CVC indices (r=0.237 to 0.374, P=0.01 to 0.11). CONCLUSIONS: Whole-forearm and skin PORH provide different information on microvascular function in older adults. A decreased PORH in the whole-forearm appears to be a feature of T2D and not CAD, while a decreased PORH in forearm skin seems to be detectable in both T2D and CAD.
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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 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".