Smokers who survive to 70 still lose an average of four years of life, according to findings from the Whitehall study presented at ESC Congress 2013 today by Dr. Jonathan Emberson from the UK.
Dr Emberson said: “Despite recent declines in the numbers of people smoking and tar yields of cigarettes, smoking remains the leading preventable cause of death in Europe.”
He added: “Previous studies had demonstrated that prolonged cigarette smoking from early adult life was associated with about 10 years loss of life expectancy, with about one quarter ofsmokers killed by their habit before the ageof 70. Stopping at ages 60, 50, 40 or 30 years gained back about 3, 6, 9 or the full 10 years. However, the hazards of continuing to smoke and the benefits of stopping in older people had not been widely studied.”
In the current study, scientists tracked the health of 7,000 older men (mean age 77 years, range 66 to 97) from 1997 to 2012 who took part in the Whitehall study of London civil servants. Hazard ratios (HRs) for overall mortality and various causes of death in relation to smoking habits were calculated after adjustment for age, last known employment grade and previous diagnoses of vascular disease or cancer.
During the 15-year study 5,000 of the 7,000 men died. Deaths in current smokers were about 50% higher than in never smokers (HR=1.50), due chiefly to vascular disease (HR=1.34), cancer (HR=1.74) and respiratory disease (HR=2.39).
Deaths in former smokers were 15% higher than in never smokers (HR=1.15), due chiefly to cancer (HR=1.24) and respiratory disease (HR=1.58). Compared with never smokers, men who had quit smoking within the previous 25 years (median 14 years) had a 28% higher mortality rate (HR=1.28) while men who quit >25 years ago (median 35 years) had no significant excess risk (HR=1.05).
Dr Emberson said: “Our results clearly show that active smoking continues to increase the risk of death in old age. Risk in former smokers decreases as the time since quitting gets longer and, if one survives long enough, eventually reaches levels of never smokers.”
Average life expectancy from age 70 was about 18 years in men who had never regularly smoked, 16 years for men who gave up smoking before age 70 but only about 14 years in men still smoking at age 70. Two-thirds of never smokers (65%), but only half of current smokers (48%), survived from age 70 to age 85.
Dr Emberson said: “This study shows that even if you were to ignore all the deaths caused by smoking before the age of 70, older smokers still do considerably worse than older non-smokers, losing a considerable amount of subsequent lifespan.”
Dr Robert Clarke (UK), coordinator of the study, concluded: “We have shown that even if a smoker is fortunate enough to survive to age 70 they still lose, on average, about 4 years of subsequent lifespan compared with men who do not smoke. Quitting is beneficial at any age and it really is never too late to stop.”
Women can add nine years to their lives by quitting smoking before the age of 40 but still face a 20-percent higher death rate than those who never smoked, a study said Saturday.
Published in The Lancet, a survey of nearly 1.2 million women in Britain showed that smoking throughout adulthood chopped on average 11 years off lifespan.
These results echoed the findings of earlier research conducted on men.
Among women who kicked the habit before the age of 40, the researchers measured an average lifespan gain of more than nine years compared with those who never stopped.
For those who quit before 30 the gains were even bigger—about 10 years.
“Whether they are men or women, smokers who stop before reaching middle age will on average gain about an extra 10 years of life,” study co-author Richard Peto of the University of Oxford said.
But the paper warned this did not mean that it was safe to continue smoking until 40 before quitting.
“Women who do so have throughout the next few decades [of their lives] a mortality rate 1.2 times that of never-smokers. This is a substantial excess risk, causing one in six of the deaths among these ex-smokers.”
In Europe and the United States, the popularity of smoking reached its peak among women in the 1960s, decades later than for men.
The Lancet study is one of the most extensive probes into the impacts of smoking on this generation of women, the first likely to have smoked substantially throughout their adult lives.
The research is part of a vast survey that enrolled 1.2 million women in the UK between 1996 and 2001. The volunteers were asked to detail their smoking history, and were followed for an average of 12 years.
The women were on average 55 years old when they signed up. Twenty percent of them were smokers, 28 percent ex-smokers, while 52 percent had never smoked.
The researchers found that the group of women who continued smoking had three times the overall mortality rate of never-smokers.
While the risks increased with the amount smoked, “Even those smoking fewer than 10 cigarettes per day… had double the overall mortality rate than never-smokers,” warned the study.
It also cautioned against so-called “light” cigarettes, smoked by most of the women in the study.
“Low-tar cigarettes are not low-risk cigarettes and… more than half of those who smoke them will eventually be killed by them,” the authors warned.
The key causes of death among smokers were chronic lung disease, lung cancer, stroke and heart disease.