An association between smoking status and homocysteine levels and whether this association is modified by sex hormones and cholesterol.

Background/objective: Environmental and dietary exposures alter the levels of homocysteine in the human body; little is known about the effect of smoking status on homocysteine levels. This study aimed to examine the effect of smoking status on homocysteine levels and to determine if the association is modified by estradiol and cholesterol. Methods: National representative data (n=4,580) were obtained for adults aged ≥20 years. The outcome was homocysteine and exposure was smoking status, categorized as current, former or never smoker. Current smoker defined as a person who smoked ≥100 cigarettes in their lifetime and at least once in the last month; former smoker- one who had smoked ≥100 cigarettes and had quit smoking at the time of the interview; never smoker- adult who never smoked cigarettes in their lifetime. General linear models (GLM) were used to examine the associations between smoking status and homocysteine levels; while assessing the impact of estradiol and cholesterol. Estradiol was stratified as low (/ml), normal (10-40 pg/mL), and high (\u3e40 pg/ml). Cholesterol- stratified as normal (\u3c200mg/dl) or high (≥200mg/dl). Results: Adjusting for age, gender, ethnicity, education, and income level, smoking status was associated with the levels of serum homocysteine using unadjusted GLM (p0.05). Adjusting for multiple comparisons using Tukey’s method, there were statistically significant differences between former smokers and never smokers (p Conclusion: Homocysteine levels were found to vary among smoking strata. Statistically significant differences exist between former smokers and never smokers. Former smokers may be more prone to having risk factors of elevated homocysteine levels compared to never and current smokers, putting them at risk of cerebrovascular accidents and acute coronary syndromes. These findings suggest that it is vital for people not to initiate smoking. Keywords: Smoking, Homocysteine, Sex hormones, Estradiol, Cholesterol