FRI130 Usefulness Of The Upright Posture Test In The Diagnosis Of Primary Aldosteronism
Bibliographic record
Abstract
Abstract Disclosure: N. Younes: None. M. St-Jean: None. M. Desrochers: None. I. Bourdeau: None. A. Lacroix: None. Objectives: Renin-independent aldosterone excess characterizes primary aldosteronism (PA). We have previously shown that PA is frequently regulated by aberrant stimuli, including the upright posture stimulation test (UPT), in which plasma aldosterone concentrations (PAC) increase in a renin-independent manner. In this study, we further examined the usefulness of UPT in diagnosing PA. Methods: We conducted a retrospective analysis of the medical records of 187 adult patients who underwent an UPT as part of their evaluation for possible PA and 25 control subjects, in 2 referral university centers between January 2011 and December 2021. UPT was conducted in an ambulatory setting, mostly in patients with potential false negative or borderline results of oral/IV saline confirmation tests. UPT was performed in a fasting state, early morning, 72 hours off beta-blockers, ACE, or ARBS. Patients were in a supine posture for 1 hour, followed by ambulation for 2 hours. Blood samples were collected for PAC, renin, and cortisol, at baseline and at 30 minutes intervals during ambulation. An abnormal response was defined as a ≥50% rise in PAC with a suppressed renin (≤10.1 ng/L or ≤1 ng/mL/h) and a cortisol increase ≤50%. Results: Median age of patients was 55.0 [IQR (46.0; 63.0)], 52.4% were female. 93.6% were taking at least one antihypertensive medication and 32% had hypokalemia. 43.5% did not have adrenal nodules at imaging. 76.5% (n=143) were diagnosed with PA, based on either IV/oral sodium load or UPT. When compared to controls, PA patients had higher basal PAC and lower basal renin levels (p<.0001) and achieved a higher maximal PAC and lower maximal renin (renin max) in response to posture [median PAC (IQR): 802.0 pmol/L (569.0, 1244.0) in PA v/s 624.0 pmol/L (500.0, 736.0) in controls, p=0.0081 and median renin 5.0 ng/L [IQR (3.0, 8.0)] in PA v/s 27.5 ng/L in controls (19.0, 46.0); p<.0001]. Renin max ≤10.1 had the best sensitivity and specificity for predicting PA (90% and 92%, respectively). 95.3% of PA patients increased PAC by at least 50% on UPT (median increase 363%), while renin remained suppressed. All 42 PA patients with a false negative (PAC ≤162 pmol/L) on IV saline test had a renin max ≤10.1 during UPT and 97.6% increased aldosterone by at least 50%. 84% of PA patients with a borderline response (162-240 pmol/L) on IV saline test, had a renin max ≤10.1 and all patients increased aldosterone by at least 50%. 42 patients underwent adrenal vein sampling: 50% had lateralized PA (potassium was lower than in bilateral PA, p=0.003). However, the aldosterone and renin response to UPT did not significantly differ between the two subtypes of PA. Conclusion: A renin-independent aldosterone increase during UPT can be used to confirm PA diagnosis, which was particularly useful in patients with false negative saline loading tests. Renin-independent PAC response to UPT occurred equally in lateralized and bilateral PA. Presentation: Friday, June 16, 2023
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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) | 0.000 | 0.001 |
| 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) | 0.000 | 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".