Lawrence LeBlond for redOrbit.com – Your Universe Online
Everyone knows that smoking is bad for their health. Studies have shown that even moderate to light smokers are taking a huge risk by lighting up. Now, a new study tracking the health of 101,000 US nurses In the Nurses´ Health Study over three decades further shows that smoking is deadly.
The study, published in the American Heart Association´s (AHA) journal Circulation: Arrhythmia & Electrophysiology, has found that smoking more than doubles a woman´s risk of sudden cardiac death. And even those who smoke only one cigarette a day are nearly twice as likely to die. Those who are long-term smokers are at the greatest risk, but those who can quit can reduce the risk significantly over time.
Sudden cardiac death is the leading cause of heart-related deaths in the US and is responsible for up to 400,000 deaths every year.
“Cigarette smoking is a known risk factor for sudden cardiac death, but until now, we didn’t know how the quantity and duration of smoking effected the risk among apparently healthy women, nor did we have long-term follow-up,” said study lead author Roopinder K. Sandhu, MD, MPH, a cardiac electrophysiologist at the University of Alberta´s Mazankowski Heart Institute.
Most of the participants in the study were white, and all were between 30 and 55 at the start of the study. On average, those who smoked reported that they started the habit in their late teens. During the course of the thirty-year study, 351 participants died of sudden cardiac death.
In women under 35 who die of sudden cardiac death, the association is more often than not linked to family medical history. But in older women, such as those in the study, sudden cardiac death is more readily attributable to factors such as smoking. In the 351 sudden cardiac deaths in the study, 75 were among current smokers, 148 were among recent or past smokers and 128 were non-smokers.
After taking other heart risk factors into account, such as high blood pressure, high cholesterol and family history of heart disease, Sandhu and colleagues found the women who smoked were more than twice as likely to die suddenly as those who never smoked. And for every five years of continued smoking, that risk rose 8 percent. Even those who smoked less than 14 cigarettes per day had a nearly two-fold increase in risk of sudden cardiac death.
The women who see the biggest benefit are those who quit smoking and remain smoke-free for 20 years, with risk of sudden cardiac death falling to that of someone who never smoked.
“What this study really tells women is how important it is to stop smoking. The benefits in terms of sudden cardiac death reduction are there for all women, not just those with established heart disease,” said Sandhu. “It can be difficult to quit. It needs to be a long-term goal. It’s not always easily achievable and it may take more than one attempt.”
“This study shows that smoking just a couple of cigarettes a day could still seriously affect your future health,” Ellen Mason, senior cardiac nurse at the British Heart Foundation, told the BBC´s Michelle Roberts in an interview. “As we approach the New Year, many of us will be making resolutions and giving up smoking will be top of the list for lots of people.”
“If you’re thinking of quitting and need a nudge, this research adds to the wealth of evidence that stopping smoking is the single best thing you can do for your heart health,” noted Mason.
The evidence is supported by a recent study in The Lancet of 1.2 million women that found those who gave up smoking by the age of 30 would almost completely avoid the risks of dying early from tobacco-related diseases.
“This is an important study because it links smoking to sudden cardiac death in those unfortunate women who don´t make it to the hospital,” Nieca Goldberg, MD, medical director of the women’s heart program at New York University´s (NYU) Langone Medical Center, told WebMD´s Jennifer Warner.
“The study shows that even modest levels of smoking can increase the risk of sudden cardiac death,” added Goldberg, a spokesperson for the American Heart Association. “People should know that just one cigarette is too much.”
Nicotine is believed to have some immediate effects that can lead to life-threatening irregular heartbeats and sudden cardiac death. And cigarette smoke is known to cause scarring of the heart tissue. This effect can persist for long after a person quits smoking and is a contributor to the risk of sudden cardiac death.
“Cigarette smoking is an important modifiable risk factor for sudden cardiac death for women both with and without heart disease,” Sandhu said. “Women shouldn´t wait until the development of heart disease to quit.”