Comparative cross‑sectional study between conventional and IQOS smoking and impact on fatty acid‑binding protein 4

Smoking tobacco remains a leading global health threat, particularly in Jordan, where a notable portion of the population, including children, are smokers. Despite health campaigns, traditional smoking persists, prompting interest in the health impacts of alternatives such as heat-not-burn (HNB) devices such as 'I quit ordinary smoking' (IQOS). Examining biomarkers such as fatty acid-binding protein 4 (FABP4), a marker of early vascular and metabolic damage, may provide insight into the health outcomes of these smoking methods. The present study aimed to compare the effects of both traditional cigarette smoking and IQOS use on FABP4 levels. Venous blood samples from 204 participants (65 IQOS users, 75 conventional smokers and 64 non-smokers) were analyzed for complete blood count, alanine transaminase (ALT), C-reactive protein, superoxide dismutase (SOD) and FABP4 levels. Male cigarette smokers exhibited significantly elevated mean corpuscular volume compared with non-smokers (P=0.003), and IQOS smokers compared with non-smokers showed similar trends (P=0.035). ALT levels were significantly higher in IQOS smokers compared with both non-smokers (P<0.0001) and cigarette smokers (P=0.001). FABP4 levels were also highest in IQOS smokers, significantly surpassing both non-smokers (P<0.0001) and cigarette smokers (P=0.001). ALT and FABP4 were positively correlated (ρ=0.234, P=0.001). In the IQOS group, weight was positively correlated with hemoglobin, red blood cell count and FABP4 levels. Moreover, IQOS users who exercised had lower FABP4 levels compared with non-exercisers (P=0.001), indicating notable health marker differences associated with smoking habits, particularly among IQOS users. Smoking, whether through conventional cigarettes or alternative options such as IQOS, significantly affects blood composition, liver function indicated by high ALT and markers of oxidative stress, such as SOD. IQOS smoking significantly increases FABP4 levels, a marker of inflammation and tissue damage. To the best of our knowledge, the present study is the first to assess the impact of IQOS and smoking on FABP4.