Monday, May 13, 2013

Why living near a busy road could be dangerous for your child's health: Traffic pollution linked to diabetes risk in children

Not quite same old, same old.  It is encouraging that the authors below were aware of the potential confounding from social class.  They controlled only for family socioeconomic status, however, leaving out such important variables as income and IQ -- with the first of those having potentially large explanatory power.  The correlations between social class variables are only modest.  To take just one instance, in England you can be both poor and upper class  -- depending on your accent.

Exposure to traffic fumes can set children on the road to diabetes, a study has shown.

Living near a busy road and increased levels of pollution from cars and lorries significantly raised the risk of insulin resistance in ten-year-olds, scientists found.

The condition, which reduces the body’s ability to control blood sugar with the hormone insulin, is a recognised precursor of Type 2 diabetes.

Researchers in Germany looked at the effect of two kinds of traffic pollution on 397 children.

Blood tests were taken and measurements made of pollution emissions in areas where the children lived.

For every defined step-rise in levels of nitrogen dioxide (NO2) and sooty particulate matter (PM) from diesel exhausts, the risk of insulin resistance increased by 17 per cent and 19 per cent respectively.

The risk also rose by 7 per cent every 500 yards closer to a major road a child lived.

Study leader Dr Joachim Heinrich, from the German Research Centre for Environmental Health in Neuherberg, said: ‘To our knowledge, this is the first prospective study that investigated the relationship of long-term traffic-related air pollution and insulin resistance in children.

‘Insulin resistance levels tended to increase with increasing air pollution exposure, and this observation remained robust after adjustment for several factors, including socio-economic status, BMI (body mass index, a measurement relating height and weight), and passive smoking.’

The findings appear in the latest edition of the journal Diabetologia.

Previous research has linked air pollution, especially sooty particulates, with heart disease and premature death.

However, studies looking at associations between long-term exposure to traffic pollution and Type 2 diabetes in adults have been inconclusive.

'Oxidative stress caused by exposure to air pollutants may.. play a role in the development of insulin resistance,' Dr Heinrich said.

'In addition, some studies have reported that short-term and long-term increases in particulate matter and nitrogen dioxide exposure lead to elevated inflammatory biomarkers, another potential mechanism for insulin resistance.'

The researchers are continuing to study the children, whose progress will be monitored for 15 years.

They want to see how the children fare as they grow older and become adults. Individuals who stay in the area where they grew up and those who move will also be compared.

'Moving from a polluted neighbourhood to a clean area and vice versa would allow us to explore the persistence of the effect related to exposure and to evaluate the impact of exposure to increased air pollution concentration later in life,' Dr Heinrich added.

'Whether the air pollution-related increased risk for insulin resistance in school-age has any clinical significance is an open question so far.

'However, the results of this study support the notion that the development of diabetes in adults might have its origin in early life including environmental exposures.'

Environmental health expert Professor Frank Kelly, from King's College London, pointed out that children were especially vulnerable to air pollution.

'They have a larger lung-to-body volume ratio, their airway epithelium is more permeable to air pollutants, and the lung defence mechanisms against particulate matter pollution and gaseous pollution are not fully evolved,' he said.

'Breathing the same pollutant concentrations, children may have a two to four-fold higher dose reaching the lung compared with adults.'

He added that traffic pollution studies had largely focused on particulate matter and overlooked the effects of nitrogen dioxide.

'It is of interest that this new study demonstrates that both PM and NO2 are linked to increased risk of insulin resistance in children,' said Prof Kelly.

'This finding is especially relevant for cities in the UK such as London which regularly exceeds current EU (European Union) limit values for NO2.

'Only last week the Supreme Court ruled that the UK Government was not doing enough to minimising NO2 pollution and protecting the health of its citizens.'

The possible link with oxidative stress highlighted the importance of childhood diet, he added.

'This is a timely reminder for Government that as well as improving air quality in our cites they need to ensure children have access to quality school meals which include fresh fruit and vegetables to ensure our children have good supply of antioxidants which will help protect them from the worst effects of traffic pollution,' said Prof Kelly.


Suffering on statins? Stop taking them now: Cholesterol-busting medicines may be causing more harm that good

When one of my patients – let’s call him John – recently returned to me with disabling chest pains a year after heart surgery, we both feared the worst.

But after numerous investigations found nothing untoward, we recognised the real problem: his statins. So I told him to try going without them for two weeks.

These drugs, taken by eight million Britons, are routinely prescribed to anyone who suffers a heart attack as they lower the likelihood of a second attack. They have an anti-inflammatory effect, which reduces the risk of a clot forming in the heart arteries.

Statins are also regularly prescribed by GPs to many more patients to lower the levels of cholesterol in their blood, in the hope that it will prevent a heart attack from happening in the first place. They are the most commonly prescribed drug in Britain, with more than 55 million statin prescriptions dispensed last year.

John returned and he was elated. For the first time in months his chest pains had gone. But he now had a new concern: his GP had since told him: ‘You must never stop your statin!’

He was confused. But I was steadfast: he shouldn’t be on the drugs. In fact, I often stop patients taking statins when I believe they are causing distressing side effects, which happens in about one in five of those I see. It may seem cavalier. But in such cases – and there are many thousands – statins do more harm than good. And it is possible to control cholesterol through diet alone, as actress Michelle Pfeiffer says she has done.

Statins do what they claim to: they lower cholesterol. But increasingly the medical profession is discovering that the health benefits of lower cholesterol have been exaggerated.

Two recent studies have cast serious doubt on early clinical trials into statins in the 1980s. These trials overplayed how good for us they could be, which contributed to a culture of over-prescribing the drug. The studies also suggested significant side effects of statins may have been underplayed.

Last month one of the world’s most respected sources of medical information, the British Medical Journal, presented serious doubts. According to its report, GPs have put an extra three million people on statins in the UK over the past ten years – and have received extra funding for meeting these targets.

Yet we have seen no obvious benefit in either a reduction in diagnoses of heart disease. There has, though, been a 40 per cent reduction in the number of heart attack deaths. But while statin prescriptions may have played a role, there have been no studies that prove this link.

Studies have shown a connection between reduction in deaths and the now-routine practice of undergoing emergency angioplasty as soon as someone suffers a heart attack – unblocking the artery with a stent or balloon through keyhole surgery.

Another known cause for reduction in heart disease mortality is that far fewer people are smoking today than 30 years ago. The number of smokers has dropped from approximately 40 per cent of the population in the 1980s to 20 per cent now.

There was a dramatic 17 per cent reduction in heart-attack hospital admissions in 2007, a year after the ban on smoking in indoor public places was introduced. It has also been consistently shown in studies over the past few decades that aspirin taken at first indication of a heart attack reduces deaths – as does a daily low dose after an attack.


What of the early hopes that statins would cut cardiac disease by 30 per cent? A 1995 study suggested they would, but the number of sufferers has increased from about eight per cent of the adult population in 1995 to 12 per cent today.

Last month the Annals Of Internal Medicine reported that 20 per cent of those on statins suffered a significant side effect – muscle pains, stomach complaints and memory disturbance – far higher than the one per cent that was first suggested by drug companies.


So what next for millions reading this who are on statins? If you have no trouble with them, there is no reason to stop. But if you, like John, are suffering discomfort, you should consider stopping them for a trial period of two weeks.

Start by seeing your GP to tell them what you are experiencing, and ask: ‘Could this be a side effect of the statins?’

They should be able to tell from your history whether this is the case. Stopping a statin short term won’t harm you and you will know within ten days or so whether it was causing the problem as that is how long it usually takes for side effects to wear off.

If a GP refuses, sometimes your cardiologist can speak to them, as I have done. John’s doctor eventually agreed. Even if they refuse, and offer a lower dose, this might reduce or halt the side effects, so it’s worth trying.



Wireless.Phil said...

It took how many years for the people in the Daily Mail to finally think that up?

As bad as the non smokers and ex-smokers bitching about tobacco smoke, but they suck in worse stuff from auto exhaust.

Elwyn Jones said...

I stopped taking Statins after suffering distressing side effects. I also read a book "The Great Cholesterol Con" that convinced me that I had made the right decision.