Korean J Fam Med 2018; 39(2): 67-73  https://doi.org/10.4082/kjfm.2018.39.2.67
Association of Time to First Morning Cigarette and Chronic Obstructive Pulmonary Disease Measured by Spirometry in Current Smokers
Geonhyeok Kim1, Hongji Song1, Kyunghee Park1, Hyemi Noh1, Eunyoung Lee1, Hyoeun Lee1, Hayoon Kim2, Yujin Paek1,*
1Department of Family Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea
2Department of Family Medicine, Hallym University Kangnam Sacred Heart Hospital, Seoul, Korea
Yujin Paek https://orcid.org/0000-0001-9573-8849
Tel: +82-31-380-3805, Fax: +82-31-380-1782, E-mail: paek@hallym.or.kr
Received: June 29, 2016; Revised: October 17, 2016; Accepted: October 20, 2016; Published online: March 20, 2018.
© Korean Academy of Family Medicine. All rights reserved.

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Background: Time to first cigarette after waking is an indicator of nicotine dependence. We aimed to identify the association between time to first cigarette and spirometry-proven obstructive respiratory impairment, especially chronic obstructive pulmonary disease, in current smokers.
Methods: We included 392 subjects who visited the comprehensive medical examination center of Hallym University Sacred Heart Hospital between July 2014 and September 2015. Subjects with lung disease or anemia were excluded. Obstructive pulmonary impairment was defined as <70% of the predicted value of forced expiratory volume in 1 second/forced vital capacity. Subjects were classified into the early (≤30 minutes) and late (>30 minutes) groups based on the time to first cigarette. Logistic regression and linear regression analyses were used for data analysis.
Results: Ninety-eight subjects (25%) were classified into the early group. After adjusting for smoking behaviors (cigarettes per day and smoking duration), socioeconomic status (education and income), age, and physical activity, an early time to first cigarette was found to be associated with an increased risk of obstructive pulmonary impairment measured using spirometry (adjusted odds ratio, 2.84; 95% confidence interval, 1.22–6.61).
Conclusion: Compared to current smokers with a late time to first cigarette, those with an early time to first cigarette had a higher risk of obstructive pulmonary impairment, especially chronic obstructive pulmonary disease. Classifying smoking-related behaviors, especially time to first cigarette, may help target clinical screening for chronic obstructive pulmonary disease.
Keywords: Smoking; Chronic Obstructive Pulmonary Disease; Time to First Cigarette; Nicotine Dependence; Respiratory Function Tests

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