Secondhand smoke linked to 30% increased stroke risk

Think just because you do not smoke that you are safe from the thousands of toxic chemicals contained in cigarettes?…Think again. Non-smokers who are regularly in the company of people lighting-up, may still be ingesting all those dangerous fumes and having their health put at jeopardy – through what is known as secondhand (passive) smoking.

It seems a new study emerges every single day that further demonstrates how bad smoking is for the body, and the latest research shows that non-smokers exposed to secondhand smoke can be at a significantly increased risk of suffering a stroke.

The study – published in the American Journal of Preventive Medicine - led by Angela M. Malek, PhD, from the Department of Public Health Sciences, Medical University of South Carolina, Charleston, found that secondhand smoke can raise the risk of developing a stroke by an estimated 30%.

Researchers analysed the national, population-based study ‘Reasons for Geographic and Racial Differences in Stroke’ (REGARDS), a study that assesses cardiovascular disease occurrences and death rates of people aged 45 or over.

Within the REGARDS database, 45% of the people were African-American and 55% were Caucasian. For the purpose of their study, the researchers focused on 22,000 individuals, of which 38% were African-American and 45% were males. Around 23% in total of these people were exposed to secondhand smoke.

Researchers delved into the information deeper to determine if certain types of stroke could be linked to smoking, applying adjustments as well as taking into account factors such as diabetes, hypertension and other cardiovascular diseases.

The findings demonstrate that from April 2003 to March 2012, study participants had reported 428 stroke. Of this total, 352 were ischemic, 50 were hemorrhagic and 26 were due to other subtypes of stroke. Even taking into account the variable factors, there was still a 30% risk of stroke for nonsmokers.

“Our findings suggest the possibility for adverse health outcomes such as stroke among nonsmokers exposed to SHS and add to the body of evidence supporting stricter smoking regulations,” commented Malek.

She added: “In the future, it is necessary for studies to analyse the role of heart diseases in the relationship established in this current research. Possible exposure to other environmental factors such as air pollutants in relation to stroke should also be explored.”

E-cigarettes described as life-savers – but how safe are they?

Scientists say that if all the smokers around the world converted to using e-cigarettes instead of smoking regular tobacco cigarettes, millions of deaths could be avoided.

According to public health charity Action on Smoking and Health (ASH), smoking is responsible for the deaths of around 100,000 each year just in the UK alone. Globally, 600,000 lives are lost due to secondhand smoke exposure alone.

ASH also say that an estimated 80% of deaths from lung cancer can be attributed to smoking, in addition to 80% of deaths from bronchitis and emphysema, and around 17% of deaths from heart disease can be put down to smoking.

The pros and cons of e-cigarettes were the source of discussion on Tuesday as 250 scientists, experts, policymakers and industry figures all convened for the E-Cigarette Summit at the Royal Society in London.

In the UK there are currently about 700,000 people using e-cigarettes. There are those who combine ‘vaping’, as it is usually referred to, with regular tobacco-based cigarettes, whereas others quit smoking regular cigarettes and simply use e-cigarettes.

A battery-operated e-cigarette works by vaporising a liquid solution containing nicotine. Regular cigarettes are comprised of thousands of toxic chemicals that are linked to a wide number of health problems such as many types of cancer, heart disease and stroke. Despite still containing nicotine – albeit a much lesser amount – e-cigarettes are considered substantially safer than regular cigarettes.
“Cigarettes are killing 5.4-million people per year in the world,” said health psychology professor and Cancer Research UK director of tobacco studies Robert West as he spoke to delegates.

Professor West said millions of lives could be saved each year if smokers switched to e-cigarettes and added: “The big question, and why we’re here, is whether that goal can be realized and how best to do it…and what kind of cultural, regulatory environment can be put in place to make sure that’s achieved. I think it can be achieved but that’s a hope, a promise, not a reality.”

He also commented how e-cigarettes were involved in nearly a third of all attempts to quit smoking. They are between 95% and 99% safer than regular cigarettes, yet some countries still insist on banning them. Whether or not regulation involving medicinal rules should be introduced was a hot topic for debate among the delegates, of which some voiced concerns about e-cigarettes becoming a gateway for people who have not previously smoked.

Added to the fears about e-cigarettes, is just how safe they are without necessary regulations in place. Some poorly-manufactured e-cigarettes have been reported to overheat and even combust.

ASH CE Deborah Arnott acknowledged the benefits of them for public health, but stressed there is still a certain lack of understanding about their long-term effects. She also said that perhaps worryingly, tobacco companies are buying out the major e-cigarette manufacturers.

She commented: “ASH thinks that e-cigarettes have significant potential. They are a lot less harmful than smoking. Clearly smokers find them attractive, primarily as a way of quitting and moving away from smoking, which they know will kill them. I think the jury’s out and these products need regulating because there’s a real concern that their safety and effectiveness is not guaranteed without regulation.”

Arnott added: “The tobacco companies are moving in. For them it’s potentially a ‘Kodak moment’ because if everyone moved to e-cigarettes, they’d lose their market, so they’ve got to be in there. A lot of the bigger e-cigarette companies have already been bought up. If there are carcinogens in there, you won’t see an immediate effect but 10, 15, 20 years down the line, people will be dying from that. The development of e-cigarettes is definitely running ahead of the science.”

Secondhand smoke could impair childhood kidney function

Whilst many teenagers may believe that smoking cigarettes will improve their popularity amongst friends and gain them misguided admiration in the playground, they should also be aware of the damage that cigarettes do to their adolescent bodies after a study has linked secondhand smoke exposure to effects on kidney function beginning in childhood.

The study, led by Esther Garcia-Esquinas, MD, of the Department of Environmental Health Sciences at John Hopkins University Bloomberg School of Public Health and published April 8 in the journal Pediatrics, was conducted to see if secondhand smoke exposure could be attributed to chronic kidney disease in children.

A cross-sectional study was therefore carried out, comprising of an analysis of 7,516 adolescents aged between 12 and 17; all of whom were involved in the 1999-2010 National Health and Nutrition Examination Survey.

The teens all had blood tests to determine any creatinine and cotinine levels. Creatinine is a waste break-down product from muscle tissue in the body that is filtered through the kidneys. Doctors look at a person’s blood creatinine level as a test to determine kidney function and the kidneys’ ability to handle creatinine is known as the ‘creatinine clearance rate’.

‘Cotinine’, an anagram of nicotine, is an alkaloid chemical contained in tobacco and is also a product that is created by metabolising nicotine. By measuring the levels of cotinine in an individual’s bloodstream, it is possible to extract information on their recent use of tobacco in addition to assessing how much secondhand smoking the person has been exposed to.

The teens within the study who admitted that they smoked or those with serum cotinine levels found to be over 10 ng/mL, were regarded as ‘active smokers’. Those who lived with at least one person who smoked or had cotinine levels measuring at least 0.05 ng/mL, were classified as being exposed to secondhand smoke. In addition, any study participants with serum cotinine levels under 0.05 ng/mL, not living with a smoker and had not smoked in the previous month, were viewed as being unexposed to tobacco.

Researchers analysed the glomerular filtration rate, or eGFR, level by looking at the creatinine levels. This helps to understand how much blood a person’s kidneys are filtering to get a better picture of kidney function.

It was discovered that the teens’ eGFR declined at the same rate that their cotinine concentration in the blood increased. This pattern was evident even after the participants’ weight was taken into account as well as and socioeconomic and demographic factors.

Jeffrey Fadrowski, MD, MHS, co-author of the study and an assistant professor in Pediatric Nephrology at the Johns Hopkins School of Medicine, commented: “Small changes in the distribution of estimated glomerular filtration rate levels in the population could have a substantial impact in kidney-related illness, as it is well known for changes in blood pressure levels and hypertension-related disease. Evaluating potential secondhand smoke exposure and providing recommendations to minimize exposure should continue to be incorporated as part of children’s routine medical care.”

Other researchers in the study added: “Evidence from studies in adult populations suggest that smoking, particularly heavy smoking and cumulative smoking exposure, is an independent risk factor for chronic kidney disease in both genders, as shown in large, prospective observational studies.”