The authors added that as the risk grows with time, those in the most danger are long-term smokers. However, as soon as somebody quits, their chances of sudden cardiac death start falling.
Lead author, Roopinder K. Sandhu, M.D., M.P.H., from the University of Alberta's Mazankowski Heart Institute in Edmonton, Alberta, Canada, said:
"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."
The research team, from Alberta University, Harvard Medical School, and Brigham and Women's Hospital, gathered and assessed data on sudden cardiac death from the Nurse's Health Study involving 101,000 healthy females. The survey collected information twice a year from nurses throughout the USA from 1976, and includes 30 years' worth of follow-up data. Most of the nurses were Caucasian and aged from 30 to 55 years when the study began. Most of the regular smokers had started during their late teenage years.
During the follow-up period, 351 women died of sudden cardiac death.
Female smokers have a much higher risk of sudden cardiac death
Below are some highlighted data the researchers discovered regarding smoking and sudden cardiac death:
- Light-to-moderate smokers overall are twice as likely to experience sudden cardiac death compared to their counterparts who did not smoke
- Healthy women - those with no history of stroke, cancer or heart disease - who smoke, are nearly two-and-a-half times as likely to experience sudden cardiac death compared to lifetime non-smoking healthy women
- The risk of cardiac death increases by 8% every five years among light-to-moderate smokers
- Women with heart disease who stop smoking have the same risk as a nonsmoker within 15 to 20 years after giving up
- Women with no heart disease who give up smoking have an immediate reduction in sudden cardiac death risk (within five years)
About sudden cardiac deathSudden cardiac death occurs when the heart suddenly ceases to function properly - usually the heart stops completely within minutes.
Sudden cardiac death is most commonly defined as an unexpected death due to heart (cardiac) problems - the person dies within one hour from the start of any heart-related symptoms.
Sudden cardiac death is the main cause of heart-related deaths, and is responsible for between 300,000 and 400,000 deaths in the USA annually, according to the Centers for Disease Control and Prevention.
Experts from The Mayo Clinic wrote that heart attack survivors face the greatest risk of sudden cardiac death during the first thirty days after being discharged from hospital.
"Sudden cardiac death is often the first sign of heart disease among women, so lifestyle changes that reduce that risk are particularly important. Our study shows that cigarette smoking is an important modifiable risk factor for sudden cardiac death among all women. Quitting smoking before heart disease develops is critical."
How to reduce sudden cardiac death riskThe risk of sudden cardiac death can be reduced by adopting several lifestyle habits, researchers from Brigham and Women's Hospital and Harvard Medical School, Boston, reported in the June 2011 issue of JAMA.
The authors explained that over half of all cardiac deaths in the USA are cases of sudden cardiac death.
The following lifestyle choices, if adopted, can significantly reduce the risk of sudden cardiac death:
- Be physically active - exercise for at least 30 minutes each day
- Maintain a healthy body weight - keep your body mass index (BMI) below 25. However, one study found that non-obese patients with heart failure had a greater risk of sudden cardiac death compared to obese individuals with heart failure
- Eat a healthy and well balanced diet - which includes a high intake of vegetables, fruits, legumes, whole grains, fish, nuts, and only moderate alcohol use
- Do not smoke
Smoking not only linked to sudden cardiac deathRegular smoking raises the risk of:
- Sudden cardiac death - as explained in this article
- Lung cancer - approximately 87% of lung cancers are related to smoking and inhaling the carcinogens in tobacco smoke
- Other cancers - smokers have a significantly higher risk of developing cancer of the stomach, lip, throat, larynx, esophagus, bladder and cervix.
- Other lung diseases - most lung diseases, such as chronic bronchitis and emphysema are caused by smoking. About 90% of Americans who die from COPD (chronic obstructive lung disease) were regular smokers
- Asthma - a smoker is more likely to develop asthma than a non-smoker of the same age and overall health
- Cardiovascular problems - regular smokers are much more likely to die of heart attack, peripheral artery disease, stroke, or angina than non-smokers.
- Aging skin - the skin of a regular smoker ages faster than a non-smoker's
- Infertility - women who smoke regularly are more like to be infertile
- Erectile dysfunction (male impotence) - regular male smokers are much more likely to have problems either getting an erection, or maintaining one
- Pregnancy - a woman who smokes regularly while she is pregnant has a much greater risk of having a miscarriage, giving birth to low weight infants, and having babies who die of SIDS (sudden infant death syndrome)
- Respiratory infections - regular smokers catch more colds and flu than non-smokers
- Insulin resistance - regular smokers have a larger risk of developing insulin resistance, which in turn makes them more likely to eventually become diabetic
- Shorter lifespans - a man who spends his adult life as a regular smoker lives, on average, ten years less than his non-smoking counterpart