Nocturnal hypoxemia severity influences the effect of CPAP therapy on renal renin–angiotensin–aldosterone system activity in humans with obstructive sleep apnea
Bibliographic record
Abstract
STUDY OBJECTIVES: Nocturnal hypoxemia (NH) in obstructive sleep apnea (OSA) is associated with renal renin-angiotensin-aldosterone system (RAAS) up-regulation and loss of kidney function. Continuous positive airway pressure (CPAP) therapy is associated with RAAS down-regulation, though the impact of NH severity remains unknown. We sought to determine whether NH severity alters the effect of CPAP on renal hemodynamics and RAAS activity in humans. METHODS: Thirty sodium-replete, otherwise healthy, OSA participants (oxygen desaturation index ≥ 15 h-1) with NH (SpO2 < 90% ≥ 12%/night) were studied pre- and post-CPAP (>4 h/night∙4 weeks). NH severity was characterized as moderate (mean SpO2[MSpO2] ≥ 90%; N = 15) or severe (MSpO2 < 90%; N = 15). Glomerular filtration rate (GFR), renal plasma flow (RPF), and filtration fraction (FF) were measured at baseline and in response to angiotensin-II (3 ng/kg/min∙30 min, 6 ng/kg/min∙30 min), a marker of RAAS activity. RESULTS: Pre-CPAP, baseline renal hemodynamics did not differ by NH severity. Pre-CPAP, severe NH participants demonstrated blunted GFR (Δ30 min, -9 ± 4 vs 1 ± 3 mL/min, p = 0.021; Δ60 min, -5 ± 5 vs 8 ± 5 mL/min, p = 0.017) and RPF (Δ30 min, -165 ± 13 vs -93 ± 19 mL/min, p = 0.003; Δ60 min, -208 ± 18 vs -112 ± 22 mL/min, p = 0.001; moderate vs severe) responses to angiotensin-II. Post-CPAP, severe NH participants demonstrated maintained GFR (112 ± 5 vs 108 ± 3 mL/min, p = 0.9), increased RPF (664 ± 35 vs 745 ± 34 mL/min, p = 0.009), reduced FF (17.6 ± 1.4 vs 14.9 ± 0.6%, p = 0.009), and augmented RPF responses to Angiotensin-II (Δ30 min, -93 ± 19 vs -138 ± 16 mL/min, p = 0.009; Δ60 min, -112 ± 22 vs -175 ± 20 mL/min, p = 0.001; pre- vs post-CPAP), while moderate participants were unchanged. CONCLUSIONS: Correction of severe, but not moderate, NH with CPAP therapy was associated with improved renal hemodynamics and decreased renal RAAS activity in humans with OSA.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".