AMSTERDAM – Older men who continued to smoke in their 70s were 50% more likely to die from cancer, cardiovascular disease, and respiratory disease, compared with those who never smoked. They were also less likely to survive to age 85, according to findings from a British survey.
"The real message is that risk remains big for smokers at any age, and the evidence regarding benefits of quitting smoking persists even into old age," said Jonathan Emberson, Ph.D., a senior statistician at the University of Oxford (England), who presented the study at the annual congress of the European Society of Cardiology.
The results were from a prospective study of more than 7,000 surviving men who were initially recruited between 1967 and 1970 in the Whitehall study. The men were surveyed again in 1997-1998, when their mean age was 77 years. Follow-up information was obtained on cause-specific mortality through 2012.
At the resurvey in 1997-1998, 13% were current smokers and smoked a median of 9 cigarettes a day; 58% were former smokers, with median time of 25 years since quitting; and 23% said they never smoked. The remaining 5% said they were never-smokers in the resurvey, but not in the initial survey in 1967-1970, and were handled as a separate category, the researchers noted.
During the median follow-up of 15 years, there were 4,965 deaths, 2,063 of which resulted from cardiovascular disease, 1,167 from cancer, 802 from respiratory disease, and 933 from other causes.
Comparing the 984 smokers with 1,625 never-smokers showed that current smokers had a 50% increase in annual mortality. Their odds of death from vascular causes increased by nearly one-third, and from nonvascular causes by nearly two-thirds.
Meanwhile, a comparison between 4,091 ex-smokers and 1,625 never-smokers showed that ex-smokers had a 15% increase in annual mortality, mainly because of cancer (hazard ratio, 1.24) and respiratory disease (HR, 1.58).
Also, their risk varied considerably depending on the number of years since they had quit smoking. Men who had quit within the past 25 years had a 22% higher mortality than never-smokers, but men who had quit 25 or more years ago had no significant excess risk (HR, 1.05). Men who had quit smoking within the past 10 years had a 44% increase in all-cause mortality, compared with never-smokers.
Also, current smokers had lower odds of surviving to age 85 (48%) than did never-smokers (65%), losing on average of 3-4 years of life expectancy.
Dr. Emberson said that never-smokers not only lived longer, but had a better quality of life. Nevertheless, "quitting remains beneficial at any age," he said.
Dr. Emberson had no disclosures. The study was funded by the U.K. Medical Research Council, the British Heart Foundation, and Cancer Research UK.
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