Smoking Status, Intensity of Smoking, and Their Relation to Left Ventricular Hypertrophy in Working Aged Korean Men

Introduction: Smoking is an established risk factor for atherosclerotic cardiovascular disease. However, the effect of smoking on left ventricular (LV) structure has been less studied. This study was designed to assess the association of smoking status and smoking intensity with left ventricular hypertrophy (LVH).

Methods: Study subjects were 53,666 working aged Korean men who received echocardiography as an item of health check up. They were grouped by smoking status (never, former, and current smokers), pack-year of smoking (never, <10, 10-19.9, and ≥20 pack-year), and urine cotinine excretion (<100, 100-999, ≥1000 ng/mL). Multivariate logistic regression analysis was used in calculating adjusted odds ratios (ORs) and 95% confidence interval for LVH (adjusted odds ratios [95% confidence interval]). The proportions of abnormal LV geometry patterns were compared among groups.

Results: Former and current smokers had the higher levels in LV mass index, relative wall thickness, and the prevalence of LVH than never smoker. The association with LVH increased in order of never (reference), former (1.44 [1.01-2.04]), and current smokers (2.10 [1.44-3.05]). LVH showed the proportional relationship with pack-year of smoking (never smoker: reference, <10: 1.45 [1.01-2.08], 10-19.9: 1.73 [1.17-2.57], ≥20: 2.43 [1.58-3.74]) and urine cotinine excretion (never smoker: reference, 100-999: 1.70 [1.21-2.37], >1000: 1.97 [1.43-2.72]). The proportions of abnormal LV geometry patterns were higher in smoking groups than never smoking group.

Conclusion: Exposure to tobacco use and intensity of smoking was associated with LVH in working aged population.

Implications: In working aged Koreans with mean age of 39.9 ± 7.0 years, former and current smokers are more likely to have LVH than never smoker. Dose-dependent relationship was found between the smoking status (never, former, and current smokers), pack-year of smoking, urine cotinine excretion, and LVH. These findings indicate that smoking has an adverse influence on LV structure even in relatively young age group.