Unveiling the Influence of the Graded Impact of Cigarette Smoking Intensity on the Biochemical and Morphological Alterations of Erythrocytes.

The detrimental effect of cigarette smoking on erythrocyte morphology and biochemical characteristics is well documented. However, limited attention has been given to the dose-dependent impact of smoking intensity, neglecting the potential gradations in smoking habits. Therefore, this study aimed to elucidate the dose-dependent adverse effects of smoking on erythrocyte morphology and physicochemical properties by recruiting 30 non-smokers (NS), 30 light smokers (LS), 30 moderate smokers (MS), and 30 heavy smokers (HS). Morphological alterations, including increased spherocytes and stomatocytes, were evident in smokers, particularly HS. Biochemical assays showed significant, dose-dependent increases in intracellular ROS, co-oxidation rates, and methemoglobin formation. Methemoglobin content and membrane-bound hemoglobin were also progressively elevated. Erythrocyte membrane protein carbonyl content rose significantly from NS (0.39 ± 0.12) to LS (1.22 ± 0.29), MS (1.73 ± 0.30), and HS (2.86 ± 0.31; p < 0.05), while lipid peroxidation increased from NS (0.74 ± 0.08) to HS (1.58 ± 0.27; p < 0.05). In parallel, membrane thiols were significantly depleted (NS 2.64 ± 0.26; LS 2.48 ± 0.22; MS 1.89 ± 0.15; HS 1.74 ± 0.14; p < 0.05). Functional assessments revealed reduced membrane fluidity, greater osmotic fragility, and enhanced oxidative hemolysis, increasing from NS (0.82 ± 0.21) to HS (1.04 ± 0.15; p < 0.05). Overall, our findings demonstrate that cigarette smoking dose-dependently compromises erythrocyte morphology and stability through oxidative degradation of membrane lipids and proteins, along with alterations in hemoglobin physicochemical properties.