Publications Search - Abstract View
||Quantifying the association of low-intensity and late initiation of tobacco smoking with total and cause-specific mortality in Asia.
||Yang JJ, Yu D, Shu XO, Freedman ND, Wen W, Rahman S, Abe SK, Saito E, Gupta PC, He J, Tsugane S, Gao YT, Xiang YB, Yuan JM, Tomata Y, Tsuji I, Sugawara Y, Matsuo K, Ahn YO, Park SK, Chen Y, Pan WH, Pednekar M, Gu D, Sawada N, Cai H, Li HL, Koh WP, Wang R, Zhang S, Kanemura S, Ito H, Shin MH, Wu PE, Yoo KY, Ahsan H, Chia KS, Boffetta P, Inoue M, Kang D, Potter JD, Zheng W
||BACKGROUND: Little is known about the health harms associated with low-intensity smoking in Asians who, on average, smoke fewer cigarettes and start smoking at a later age than their Western counterparts. METHODS: In this pooled analysis of 738 013 Asians from 16 prospective cohorts, we quantified the associations of low-intensity (<5 cigarettes/day) and late initiation (≥35 years) of smoking with mortality outcomes. HRs and 95% CIs were estimated for each cohort by Cox regression. Cohort-specific HRs were pooled using random-effects meta-analysis. FINDINGS: During a mean follow-up of 11.3 years, 92 068 deaths were ascertained. Compared with never smokers, current smokers who consumed <5 cigarettes/day or started smoking after age 35 years had a 16%-41% increased risk of all-cause, cardiovascular disease (CVD), respiratory disease mortality and a >twofold risk of lung cancer mortality. Furthermore, current smokers who started smoking after age 35 and smoked <5 cigarettes/day had significantly elevated risks of all-cause (HRs (95% CIs)=1.14 (1.05 to 1.23)), CVD (1.27 (1.08 to 1.49)) and respiratory disease (1.54 (1.17 to 2.01)) mortality. Even smokers who smoked <5 cigarettes/day but quit smoking before the age of 45 years had a 16% elevated risk of all-cause mortality; however, the risk declined further with increasing duration of abstinence. CONCLUSIONS: Our study showed that smokers who smoked a small number of cigarettes or started smoking later in life also experienced significantly elevated all-cause and major cause-specific mortality but benefited from cessation. There is no safe way to smoke-not smoking is always the best choice.