Passive smoking linked to increased risk of atrial fibrillation, new study finds

15th April 2024

Any level of passive smoking universally elevates the risk of atrial fibrillation, according to new research presented at the recent European Heart Rhythm Association Congress 2024.

The researchers examined the association between secondhand smoke exposure and the long-term risk of incident atrial fibrillation, aiming to add to existing research that has established links between passive smoking and coronary artery disease and premature death.

They found a dose-dependent relationship between passive smoking duration and atrial fibrillation risk, with each increase in the duration of weekly passive smoking linked with an even greater risk of atrial fibrillation.

The study included 400,493 adults aged 40-69 years (55.2% women) who had used the NHS for any reason and were enrolled in the UK Biobank. Current smokers and those with atrial fibrillation at baseline were excluded from the study.

A touchscreen questionnaire was used to ask participants the number of hours they had been exposed to other people’s smoke in a typical week over the past year at home and in other environments.

Participants were then categorised into the ‘exposed group’ if they had any contact with secondhand smoke and the ‘non-exposed group’ if they had no contact with secondhand smoke.

Some 85,984 (21%) participants had been exposed to secondhand smoke in the previous year, with an average exposure of 2.2 hours per week. During a median follow-up of 12.5 years, atrial fibrillation developed in 23,471 (6%) participants.

After adjusting for factors that could potentially affect the relationship, the group exposed to secondhand smoke had a 6% higher risk of incident atrial fibrillation during follow-up compared with the non-exposed group (hazard ratio 1.06, 95% confidence interval 1.03–1.10, p <0.001).

A dose-dependent relationship was observed, with 7.8 hours of passive smoking per week associated with an 11% higher likelihood of the heart rhythm disorder compared with no passive smoking.

The risk of atrial fibrillation for passive smokers was found to be raised in homes and workplaces as well as in outside spaces.

‘According to our study, once exposed to secondhand smoke, the likelihood of developing atrial fibrillation begins to increase, with the risk escalating significantly as the exposure time lengthens,’ said study author Dr Kyung-Yeon Lee of Seoul National University Hospital, Seoul, Republic of Korea.

‘The dangers of secondhand smoke were significant regardless of whether individuals were at home, outdoors or at work, indicating that exposure universally elevates the risk of atrial fibrillation.’

The authors said the results highlight the importance of smoking bans to protect public health and Dr Lee added that everyone should ‘make every effort to avoid spending time in smoky environments’.

He also urged policymakers to take note and ‘further curb smoking in public areas and support smoking cessation programmes to improve public health’.

In March 2023, the Federation of the Royal Colleges of Physicians in the UK warned of ‘significant and avoidable’ demand on NHS due to socio-economic inequalities, which included the impact of smoking.

Last year, questions were raised over whether the risk of atrial fibrillation increased with fish oil supplementation.

Measures to tackle teenage vaping and create a smoke-free generation set out by UK Government

13th October 2023

The UK Government has launched a public consultation on its plans to create a smoke-free generation at the same time as introducing measures to tackle vaping in teenagers.

It follows proposals announced earlier this month by the Prime Minister that it will become illegal for people born in or after 2009 to buy tobacco products.

Under the plans, the law will stop children turning 14 or younger this year from ever legally being sold tobacco products, raising the smoking age by a year each year until it applies to the whole population.

Several options for cracking down on youth vaping are also included in the consultation after figures form 2023 suggest one in five children has tried it.

Measures will need to balance the need to make vapes available to current adult smokers to help them quit while reducing access and appeal for children and teenagers, the consultation document states.

Possible changes in law range from limits on how vape flavours are described to restrictions on ingredients or flavours, such as tobacco, mint or fruit flavours only.

The public is also being asked for views on regulating displays in shops to being behind the counter but on display or hidden, as with current rules on tobacco products.

Various options for branding and presentation are being considered including banning the use of cartoons, animals and other child-friendly imaging to more stringent restrictions on imagery and colouring used in the packaging.

Questions on whether disposable vapes should be banned are also included in the consultation, and views are also being sought on the cost of vapes compared to tobacco products.

Currently 12.9% of people in the UK are smokers. In setting out the proposals, the Government said no other consumer product kills up to two-thirds of users.

It added that in England, almost every minute of every day someone is admitted to hospital because of smoking, and up to 75,000 GP appointments could be attributed to smoking each month. The consultation also covers Scotland, Wales and Northern Ireland.

Last year a damning review led by Dr Javed Khan into the Government’s ambition to make England smoke-free by 2030 backed England to follow in the footsteps of New Zealand, and recommended ‘increasing the age of sale from 18, by one year, every year until no one can buy a tobacco product in this country’.

Last month, researchers declared that nicotine vaping is the most effective among widely available smoking cessation aids.

Health and social care secretary Steve Barclay said: ‘There has been a surge in vaping amongst children, which is why we’re taking action to reduce the appeal and availability of vapes. Vapes should never be used by children and we’re committed to reversing this trend.

‘We also need to take bold action to protect future generations from the harms of smoking addiction, which damages health at every stage of life and costs the economy billions.’

Professor Chris Whitty, chief medical officer for England said: ‘Ensuring people do not become addicted to smoking, and helping them overcome addiction to stop smoking are two the best interventions for health. 

‘Vaping is less dangerous than smoking but still has risks and can cause addiction. Vaping can be useful for smokers to quit, but should not be marketed to non-smokers and marketing them to children is utterly unacceptable.’

Sarah Woolnough, chief executive at Asthma + Lung UK, said the charity welcomed the consultation as it is clear more must be done urgently to stop children accessing vapes.

‘Disposable vapes at their current pocket money prices, with cartoons and bubble-gum flavour options, are far too attractive and easy for children to access,’ she said.

The public consultation is open until 6 December.

A version of this story was originally published by our sister publication Pulse.

Continued smoking after cancer diagnosis increases risk of adverse CVD event

8th June 2023

Ongoing smoking following a cancer diagnosis, elevates the risk of adverse cardiovascular disease (CVD) events, according to the findings of a study by Korean researchers.

Emerging data indicates how continued smoking following a cancer diagnosis increases the risk of cardiovascular disease mortality.

In fact, nearly 20% of cancer survivors continue to smoke. However, the differential effect on adverse cardiovascular outcomes, of either quitting smoking, cutting down or continuing to smoke is less clear.

The current study, published in the European Heart Journal, assessed the effect of changes to smoking habits on adverse cardiovascular outcomes.

Smoking status was assessed two years before and three years after a cancer diagnosis. Participants were categorised as non-smokers; quitters, initiators and relapsers, and continued smokers.

The primary outcome was a composite of CVD events, comprising hospitalisation for myocardial infarction or stroke, or CVD death.

Smoking status and adverse cardiovascular outcomes

Among 309,095 cancer survivors with a median age of 59 years (51.8% women), 80.9% were non-smokers, 10.1% quit, 7.5% initiated or relapsed to smoking and 7.5% continued to smoke.

During a median follow-up of 5.5 years, 10,255 new CVD events occurred. Using non-smokers as the reference point, the adjusted hazard ratio (aHR) for a CVD event among quitters was 20% higher (aHR = 1.20, 95% CI 1.12 – 1.28). But among those who continued to smoke, the risk was 86% higher (aHR = 1.86, 95% CI 1.74 – 1.98).

There were clear benefits for those who quit smoking. For example, the CVD event risk was significantly lower among those who quit compared to participants continuing to smoke (aHR = 0.64, 95% CI 0.59 – 0.70).

These findings were consistent across both sexes as well as when classifying participants according to their primary cancers. Among those who continued to smoke, cutting down had no effect on their risk of a CVD event (HR = 0.99, 95% CI 0.80 – 1.22).

The authors suggested that continued smoking after a cancer diagnosis and its association with CVD events highlighted the urgent need for initiatives to promote smoking cessation and prevent smoking initiation and/or relapse among patients with cancer.