Global REACH 2018: renal oxygen delivery is maintained during early acclimatization to 4,330 m
Bibliographic record
Abstract
Early acclimatization to high altitude is characterized by various respiratory, hematological, and cardiovascular adaptations that serve to restore oxygen delivery to tissue. However, less is understood about renal function and the role of renal oxygen delivery (RDO 2 ) during high altitude acclimatization. We hypothesized that 1) RDO 2 would be reduced after 12 h of high altitude exposure (high altitude day 1) but restored to sea level values after 1 wk (high altitude day 7) and 2) RDO 2 would be associated with renal reactivity, an index of acid-base compensation at high altitude. Twenty-four healthy lowlander participants were tested at sea level (344 m, Kelowna, BC, Canada) and on day 1 and day 7 at high altitude (4,330 m, Cerro de Pasco, Peru). Cardiac output, renal blood flow, and arterial and venous blood sampling for renin-angiotensin-aldosterone system hormones and NH 2 -terminal pro-B-type natriuretic peptides were collected at each time point. Renal reactivity was calculated as follows: (Δarterial bicarbonate)/(Δarterial Pco 2 ) between sea level and high altitude day 1 and sea level and high altitude day 7. The main findings were that 1) RDO 2 was initially decreased at high altitude compared with sea level (ΔRDO 2 : −22 ± 17%, P < 0.001) but was restored to sea level values on high altitude day 7 (ΔRDO 2 : −6 ± 14%, P = 0.36). The observed improvements in RDO 2 resulted from both changes in renal blood flow (Δ from high altitude day 1: +12 ± 11%, P = 0.008) and arterial oxygen content (Δ from high altitude day 1: +44.8 ± 17.7%, P = 0.006) and 2) renal reactivity was positively correlated with RDO 2 on high altitude day 7 ( r = 0.70, P < 0.001) but not high altitude day 1 ( r = 0.26, P = 0.29). These findings characterize the temporal responses of renal function during early high altitude acclimatization and the influence of RDO 2 in the regulation of acid-base balance.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".