Blood Donation May Not Reduce Risk of Testosterone-Induced Polycythemia
Bibliographic record
Abstract
Abstract Background:Polycythemia is the most common adverse effect of testosterone replacement therapy (TRT) and may predispose patients to adverse vascular events. Current Canadian guidelines recommend regular laboratory monitoring and discontinuing TRT or reducing the dose if the hematocrit exceeds 54% (hemoglobin ≥180 g/L). This threshold has been interpreted by some physicians and patients to indicate the need for phlebotomy or blood donation while on TRT. Study Design and Methods: We reviewed all male blood donors in Southwestern Ontario at Canadian Blood Services from December 2013 to March 2016 who self-identified or were found on donor screening to be using TRT in any form. Hemoglobin concentration was measured at the time of donation or clinic visit and with each subsequent appointment in repeat donors. Results:We report a case series of 39 patients on TRT who presented for blood donation over a two-year period. The mean hemoglobin at all donor clinic visits was 173 g/L (range 134-205 g/L, n = 108). Hemoglobin concentrations of ≥180 g/L (calculated hematocrit ≥54%) were measured at 25% of appointments. Of the 27 repeat donors, 12 (44%) had persistently elevated hemoglobin levels (≥180 g/L) at subsequent donations. Conclusions: Hemoglobin concentrations were elevated in blood donors on TRT, with a significant number above levels recommended by current guidelines. These data also suggest that repeat blood donation was insufficient to maintain hematocrit below 54%. Our findings raise concerns about persistent risk of vascular events in these donors, particularly when coupled with the misperception by patients and health care providers that donation has abrogated the risks of TRT-induced polycythemia. Disclosures No relevant conflicts of interest to declare.
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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 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 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) | 0.004 | 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".