Comparative assessment of respiratory, hematological and inflammatory profiles of long-term users of cigarettes, shisha, and e-cigarettes in Saudi Arabia.

Introduction: Globally, over 1 billion people smoke, resulting in approximately 8 million deaths each year. Although the health risks associated with traditional cigarettes are extensively documented, there is an increasing need to evaluate the long-term effects of alternative tobacco products, particularly shisha, and e-cigarettes. This study seeks to compare the respiratory, hematological, and inflammatory profiles of long-term users of cigarettes, shisha, and e-cigarettes in Saudi Arabia.

Methods: A cross-sectional, observational study was conducted at the Respiratory Therapy laboratories of Batterjee Medical College (BMC), Jeddah, Saudi Arabia, between February 2022 and August 2023. It involved four groups: cigarette smokers, shisha smokers, e-cigarette users, and non-smokers. Pulmonary function tests (PFTs) measured FEV₁, FVC, and other lung function parameters. Hematological profiles, including WBC, neutrophils, lymphocytes, monocytes, and C-reactive protein (CRP) levels, were assessed.

Results: Cigarette and shisha users demonstrated significantly reduced FEV₁ (cigarettes: 3.11 ± 0.54 L/s, shisha: 3.26 ± 0.71 L/s; p≤0.0001), FEV₁ (% predicted: 81.63 ± 12.11 for cigarettes, 88.09 ± 12.92 for shisha; p≤0.0001), and FVC (3.87 ± 0.68 L for cigarettes, 3.95 ± 0.880 L for shisha; p=0.004), compared to non-smokers and e-cigarette users. Cigarette smokers exhibited significantly elevated WBC (7.92 ± 2.84 ×10⁹/L; p≤0.001), neutrophil (4.03 ± 2.29 ×10⁹/L), lymphocyte (2.95 ± 0.95 ×10⁹/L), and monocyte counts (0.67 ± 0.21 ×10⁹/L) compared to non-smokers, shisha, and e-cigarette users (p≤0.0001). Cigarette smokers and shisha smokers presented different lung function results but similar inflammatory profiles. However, e-cigarette users demonstrated comparatively higher lung function and lower inflammatory markers compared to both cigarette and shisha users.

Conclusions: Compared to non-smokers, long-term cigarette and shisha smoking is associated with airway obstructive changes and increased inflammatory responses. Although e-cigarette users demonstrated lower inflammatory markers and less deviation from normal PFT, some exhibited borderline values with airway obstruction. Further research is needed to clarify the long-term health consequences of e-cigarette use.