Abstract 17919: Cigarette Smoking Explains Excess Deaths Associated with Being Underweight among Middle-Aged Korean Men
Introduction: It is unclear whether smoking affects a relationship between being underweight and the risk of all-cause mortality.
Hypothesis: We assessed the hypothesis that smoking causes excess mortality among middle-aged Korean men with low body mass index (BMI).
Methods: We analyzed data on the body mass index (BMI), smoking status, and all-cause mortality in a population-based cohort study (108,461 Korean men aged 35-59 years as of 1990 and 1992). To minimize the possibility of reverse causality, we excluded men (1) who had reported to have a disease at baseline, (2) whose information on their smoking status had been missing and (3) who had died in 1993-1995. Finally, 95,019 men were enrolled for analysis. The mean follow-up period was 13.7 years. The BMI was divided into five categories according to WHO criteria for Asians: underweight, <18.5 kg/m2; normal weight, 18.5-22.9 kg/m2; overweight at risk, 23.0-24.9 kg/m2; obese I, 25.0-29.9 kg/m2; obese II, ≥30.0 kg/m2. Smoking status was categorized into ‘current smoker’, ‘ex-smoker’ and ‘non-smoker’. We divided all participants into 15 groups based on the BMI and smoking status for analysis. The reference group was non-smokers with normal weight. The main outcome variable was all-cause mortality.
Results: The number of total mortality was 6297 (6.63%). Mortality rates were 4.74% (n=957) among non-smokers, 5.47% (n=1081) among ex-smokers, and 7.74% (n=4259) among current smokers. Compared to non-smokers with normal weight, current smokers who were also underweight showed a significantly higher HR (3.55; p<0.001), but this finding did not hold either for non-smokers who were underweight (HR 1.13 and p=0.72) or ex-smokers who were underweight (HR 1.25 and p=0.56).
Conclusions: Excess mortality associated with being underweight may be caused by current smoking among middle-aged Korean men.
Author Disclosures: J. Lee: None. H. Kim: None. K. Park: None. S. Ahn: None. C. Ahn: None. D. Kang: None. I. Suh: None.
- © 2014 by American Heart Association, Inc.