# Introducing heat-not-burn tobacco improves hematocrit and cigarette smoking-related symptoms in patients with smokers’ polycythemia and polycythemia vera

**Authors:** Kazuhide Iizuka, Yoshikazu Iizuka, Shun Ito, Toshihide Endo, Hironao Nukariya, Yuichi Takeuchi, Takashi Koike, Kazuya Kurihara, Hiromichi Takahashi, Masaru Nakagawa, Takashi Hamada, Shimon Ohtake, Noriyoshi Iriyama, Katsuhiro Miura, Tomohiro Nakayama, Yoshihiro Hatta, Hideki Nakamura, Norio Komatsu, Billy Morara Tsima, Billy Morara Tsima, Billy Morara Tsima, Billy Morara Tsima, Billy Morara Tsima

PMC · DOI: 10.1371/journal.pone.0323437 · PLOS One · 2025-05-28

## TL;DR

Switching to heat-not-burn tobacco can reduce red blood cell levels and improve symptoms in smokers with polycythemia.

## Contribution

This study shows that heat-not-burn tobacco can be an effective alternative for smokers who struggle to quit.

## Key findings

- Switching to heat-not-burn tobacco improved hematocrit and symptoms like numbness and headache.
- Hematocrit levels in heat-not-burn users were comparable to those who quit smoking.
- Both heat-not-burn and smoking cessation reduced sputum volume and other symptoms.

## Abstract

Cigarette smoking induces relative and absolute erythrocytosis (smokers’ polycythemia). In patients with smokers’ polycythemia complicated by chronic obstructive pulmonary disease, the incidence and mortality rate of pulmonary embolism increase. Therefore, improving erythrocytosis by smoking cessation is important; however, smoking cessation is often difficult to achieve. This study investigated the influence of introducing heat-not-burn tobacco in patients with smokers’ polycythemia. Fifteen smokers with erythrocytosis were diagnosed with smokers’ polycythemia (n = 13) or polycythemia vera (n = 2) groups. The patients selected a switch to heat-not-burn (HNB) tobacco or smoking cessation, and the subsequent changes in hematological data and symptoms were evaluated. Eight patients with smokers’ polycythemia and two with polycythemia vera selected a switch to HNB tobacco, and the other five patients with smokers’ polycythemia selected smoking cessation. In both the HNB tobacco and smoking cessation groups, all patients showed improved hematocrit (Hct) and sputum volume and ameliorated numbness, headache, and vertigo. In the patients with smokers’ polycythemia, Hct of the HNB tobacco group was equivalent to that in the patients with smoking cessation group (47.51 ± 3.48% vs. 45.63 ± 2.79%, P = 0.605). Introduction of HNB tobacco may be useful for reducing erythrocytosis in smokers for whom smoking cessation is difficult.

## Linked entities

- **Diseases:** polycythemia vera (MONDO:0009891), chronic obstructive pulmonary disease (MONDO:0005002), pulmonary embolism (MONDO:0005279)

## Full-text entities

- **Diseases:** numbness (MESH:D006987), vertigo (MESH:D014717), pulmonary embolism (MESH:D011655), erythrocytosis (MESH:D011086), chronic obstructive pulmonary disease (MESH:D029424), burn (MESH:D002056), polycythemia vera (MESH:D011087), headache (MESH:D006261)
- **Species:** Nicotiana tabacum (American tobacco, species) [taxon 4097], Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

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## References

32 references — full list in the complete paper: https://tomesphere.com/paper/PMC12118817/full.md

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Source: https://tomesphere.com/paper/PMC12118817