# Mannitol Stimulates Copeptin for Diagnosing Arginine Vasopressin Deficiency

- Published: 2026-11-06 23:03 UTC
- Section: Life & Health › Medicine
- Tags: arginine vasopressin, diagnostic test, mannitol infusion, copeptin levels, clinical trial
- URL: https://realtech.media/news/rt-78be4572c986c89f641fd48b_mannitol_stimulates_copeptin/

**A study shows mannitol infusion significantly increases copeptin levels, offering a potential new diagnostic method for AVP deficiency.**

![Mannitol Stimulates Copeptin for Diagnosing Arginine Vasopressin Deficiency](https://realtech.media/media/2026/11/713a570b013d446e.jpg)
*Goleisureintl, Wikimedia Commons, CC BY 4.0*

Differentiating arginine vasopressin (AVP) deficiency from primary polydipsia is challenging. The most accurate test, hypertonic saline–stimulated copeptin, requires intensive monitoring. Intravenous mannitol stimulates AVP release and may provide a simpler alternative. In a randomized double-blind crossover trial, 22 healthy adults received mannitol and placebo in random order, of whom 21 were included in the primary analysis. In a pilot study, 10 patients with AVP deficiency and 10 with primary polydipsia received mannitol. The primary outcome was copeptin after mannitol infusion. Mannitol resulted in a 2.29-fold higher copeptin at 90 minutes (+6.4 pmol/L (95% CI: +5.2, +7.7; p <0.001)) than after placebo at mean baseline copeptin levels in healthy adults. In patients, copeptin after 30 minutes was 11.7 pmol/L (95% CI: 6.5, 17.0) higher in primary polydipsia than in AVP deficiency. Mannitol infusion shows promise as a new diagnostic approach. Larger confirmatory studies are required to validate both the optimal diagnostic cut-off and patient safety. Trial Registration number:NCT06542198.

## Sources

1. [Nature Communications](https://doi.org/10.1038/s41467-026-78875-1)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-78be4572c986c89f641fd48b_mannitol_stimulates_copeptin/