Systemic biomarkers of inflammation, oxidative stress and tissue injury and repair among waterpipe, cigarette and dual tobacco smokers

Abstract

Background: Waterpipe tobacco (WPT) smoking is associated with deleterious effects on cardio-pulmonary systems which may have adverse repercussions in pathophysiology and progression of chronic lung and cardiovascular diseases. We compared the biomarkers of systemic inflammation, lipid mediators, injury/repair and oxidative stress between groups of non-smokers (NS), exclusive WPT smokers (WPS), exclusive cigarette smokers (CS) and dual WPS and CS (DS).

Methods: Two cohorts were recruited. Cohort I consisted of WPS (n=12), CS (n=26), DS (n=10) and NS (n=25). Cohort II consisted of WPS (n=33) and NS (n=24). Plasma and urine samples were collected and analysed for various systemic biomarkers.

Results: Compared with NS, plasma levels of inflammatory mediators (interleukin (IL)-6, IL-8, IL1β and tumor necrosis factor-α) were significantly higher in WPS and CS, and were further augmented in DS. Endothelial biomarkers (intracellular adhesion molecule-1, prostaglandin E-2 and metalloproteinase-9) were significantly higher in CS. Most notably, pro-resolving lipid mediator (resolvin E1) and biomarkers of immunity, tissue injury, and repair were significantly lower in WPS and CS. Urinary levels of 8-isoprostane were significantly higher in all smoking groups in cohort I, while 8-isoprostane, myeloperoxidase, receptor for advanced glycation end products (RAGE), En-RAGE and matrix metalloproteinase-9 were significantly higher in all smoking groups in cohort II.

Conclusions: Biomarkers of inflammation, oxidative stress, immunity, tissue injury and repair were elevated in WPS and CS groups. Furthermore, concurrent use of WPT and cigarettes is more harmful than cigarette or WPT smoking alone. These data may help inform the public and policy-makers about the dangers of WPT smoking and dual use of tobacco products.

Keywords: biomarkers; cigarette smokers; hookah; inflammation; oxidative stress; waterpipe.

Figure 1

Biomarkers of systemic inflammation and oxidative stress measured in plasma. Quantification of systemic inflammatory and endothelial activation biomarkers in plasma of non-smokers, cigarette, waterpipe tobacco and dual smokers. Data are presented as mean±SEM (n=5–11). Statistical significance was determined by one-way analysis of variance using multiple comparison with Tukey’s post hoc analysis for comparison between the different groups. *P<0.05, **P<0.01, ***P<0.001. G-CSF, granulocyte-colony stimulating factor; IL, interleukin; MMP, matrix metalloproteinase-9; RAGE, receptor for advanced glycation end products; ICAM-1, intracellular adhesion molecule-1; TNF-α, tumor necrosis factor- α; CC-16, Club cell protein-16.

Figure 2

Plasma levels lipid mediators and biomarkers of immunity, tissue and repair and stress mediators. Plasma levels of (A) lipid mediators and (B) biomarkers of immunity, tissue injury/repair and stress mediators were determined in non-smokers, cigarette smokers, waterpipe tobacco smokers and dual smokers. Data are presented as mean±SEM (n=4–10). Statistical significance was determined by one-way analysis of variance using multiple comparison with Tukey’s post hoc analysis for comparison between the different groups. *P<0.05, **P<0.01. PAI-1, plasminogen activator inhibitor-1; PGE, prostaglandin E₂; CRP, c-reactive protein.

Figure 3

Biomarkers of oxidative stress and inflammation measured in urine samples of both cohorts. Urinary levels of 8-isoprostane, MPO, galectin-3, RAGE, En-RAGE and MMP-9 were determined in non-smokers, cigarette smokers, waterpipe tobacco smokers and dual smokers from cohort I (A) and between non-smokers and waterpipe smokers of cohort II (B). Data are presented as mean±SEM (n=7–33). Statistical significance was determined by one-way analysis of variance using multiple comparison with Tukey’s post hoc analysis for comparison between the different groups for cohort I. For cohort II, statistical significance was determined by unpaired t-test. *P<0.05, **P<0.01. MMP-9, matrix metalloproteinase-9; MPO, myeloperoxidase; RAGE, receptor for advanced glycation end products.