Cigarette Smoking and Early Biochemical Indicators of Bone and Metabolic Health in Iraqi Adult Males

Abstract

Background :Cigarette smoking has emerged as a significant extrinsic factor influencing skeletal and metabolic homeostasis, primarily through its modulation of vitamin D metabolism, enzymatic activity associated with bone turnover, and alterations in body composition indices. These disturbances may have cumulative implications for bone integrity and systemic health. Objective: This study aimed to elucidate the potential effects of cigarette smoking on serum 25-hydroxyvitamin D levels, alkaline phosphatase activity, body mass index, and waist circumference among apparently healthy adult Iraqi males. Methods:  A Cross sectional comparative study was conducted between September 2024 and March 2025, involving 240 adult males (n = 120 smokers; n = 120 non-smokers), stratified by age into two subgroups (20–34 and 35–50 years). Anthropometric and biochemical parameters were assessed using standardized procedures. Vitamin D and alkaline phosphatase were measured via Roche/Hitachi Cobas analyzers. Statistical analysis included t-tests, ANOVA, and Pearson’s correlation coefficients; p < 0.05 was considered significant. Results: Although mean serum vitamin D levels did not significantly differ between groups, a substantially higher prevalence of vitamin D deficiency was observed among smokers (75.83%) compared to non-smokers (64.17%). In smokers, alkaline phosphatase levels were positively correlated with both age and smoking duration (p = 0.011 and p = 0.045, respectively). Among non smokers, advancing age was significantly associated with increased body mass index and waist circumference (p = 0.043), as well as a notable decline in vitamin D levels (p = 0.017). A robust inverse correlation was detected between WC and vitamin D among smokers (r = –0.595, p < 0.001). Conclusion: The findings suggest that chronic tobacco exposure is associated with a higher prevalence of vitamin D deficiency. In contrast, non-smokers exhibited age-dependent metabolic alterations. These data underscore the need for vitamin D level surveillance and metabolic risk screening in smokers.