Consequences and countermeasures of sedentary behaviour on arterial wave reflection
Bibliographic record
Abstract
Cardiac load is directly influenced by central wave reflections, with increases in reflected wave magnitude and reductions in return time contributing to increased systolic pressure, afterload, and impaired coronary blood flow. Prolonged sitting has known vascular consequences such as increased arterial stiffness and endothelial dysfunction, yet the impact on wave reflections and efficacy of interruption methods to mitigate these effects is unknown. This study was designed to investigate whether seated elliptical exercise or standing breaks alleviated the deleterious effects of prolonged sitting on central wave reflections. Eighteen healthy adults (9 females, 25±3 years) completed three hours of uninterrupted sitting, sitting with periodic standing, and sitting with seated elliptical breaks, on separate days. Central and lower limb pulse wave velocity were measured before and after the intervention as well as central wave reflection which was calculated via pressure-flow analysis of aortic blood flow and carotid arterial pressure. A main effect of time was observed for forward wave amplitude (40.0±8.2 to 35.2±6.0 mmHg; p = 0.02) and reflected wave amplitude (11.9±1.6 to 11.3±2.0 mmHg; p = 0.03). Central relative wave reflection magnitude increased during sitting control (0.31±0.05 to 0.35±0.05; p < 0.01) but did not change with seated elliptical (0.30±0.05 to 0.30±0.04; p > 0.99) or standing breaks (0.30±0.05 to 0.32±0.04; p = 0.19). Augmentation index increased with sitting control (-9.3±9.2 to -4.6±12.2 %; p < 0.01) and standing (-12.4±9.8 to -5.6±9.4 %; p < 0.01), but not with seated elliptical (-9.9±9.4 to -10.2±11.1 %; p = 0.82. Lower limb pulse wave velocity did not change with sitting control (9.5±1.7 to 9.6±1.0 m·s-1; p = 0.73) or standing (9.1±1.5 to 9.7±1.7 m·s-1; p = 0.21) but decreased with seated elliptical (9.8±1.4 to 9.1±1.5 m·s-1; p = 0.03) Central pulse wave velocity increased during sitting control (5.3±0.8 to 5.7±0.9 m·s-1; p < 0.01) and standing (5.3±0.7 to 5.7±0.7 m·s-1; p < 0.01) but not with seated elliptical (5.5±0.5 to 5.6±0.6 m·s-1; p = 0.43). Prolonged sitting without interruptions increased central wave reflection, central pulse wave velocity, augmentation index, and decreased femoral blood flow while seated elliptical but not standing breaks were able to ameliorate these sitting-induced vascular consequences. Future work should examine the long-term effectiveness of interruption methods, as well as the optimal type, frequency, and duration for reducing CVD risk associated with sedentary behaviours.
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 | 0.000 | 0.001 |
| 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".