What causes coronary heart disease?

Coronary heart disease (CHD) is arguably the the UK's biggest killer. CHD develops when the blood supply to the muscles and tissues of the heart becomes obstructed by the build-up of fatty materials inside the walls of the coronary arteries.

What is coronary heart disease?

Your heart is a pump the size of a fist that sends oxygen-rich blood around your body. The blood travels to the organs of your body through blood vessels known as arteries, and returns to the heart through veins.

Your heart needs its own blood supply to keep working. Heart disease occurs when the arteries that carry this blood, known as coronary arteries, start to become blocked by a build-up of fatty deposits.

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How common is CHD?

• CHD causes round 74,000 deaths each year. That's an average of 200 people every day
• In the UK, there are an estimated 2.3 million people living with the condition
• About one in six men and one in nine women die from the disease
• Death rates are highest in Scotland and northern England
• In the past couple of decades, deaths from CHD have nearly halved due to better treatments

Source: British Heart Foundation

The inner lining of the coronary arteries gradually becomes furred with a thick, porridge-like sludge of substances, known as plaques, and formed from cholesterol. This clogging-up process is known as atherosclerosis.

The plaques narrow the arteries and reduce the space through which blood can flow. They can also block nutrients being delivered to the artery walls, which means the arteries lose their elasticity. In turn, this can lead to high blood pressure, which also increases the risk of heart disease. This same process goes on in the arteries throughout the body, and can lead to high blood pressure which puts further strain on the heart.

If your arteries are partially blocked you can experience angina - severe chest pains that can spread across your upper body - as your heart struggles to keep beating on a restricted supply of oxygen. You are also at greater risk of a heart attack.

Some people have a higher risk of developing atherosclerosis due to genetic factors - one clue to this is a family history of heart disease in middle-age. Lifestyle factors that increase the risk include an unhealthy diet, lack of exercise, diabetes, high blood pressure and, most importantly, smoking.

However, in the past couple of decades deaths from coronary heart disease have nearly halved, thanks to better treatments.

What happens during a heart attack?

A heart attack happens when one of the coronary arteries becomes completely blocked. This usually happens when a plaque, which is already narrowing an artery, cracks or splits open. This triggers the formation of a blood clot around the plaque, and it is this blood clot that then completely blocks the artery.

With their supply of oxygen completely blocked, the heart muscle and tissue supplied by that artery start to die. Emergency medical intervention is needed to unblock the artery and restore blood flow. This may consist of treatment with drugs to dissolve the clot or thrombus, or a small operation done through the skin and blood vessels to open up the blocked artery.

The outcome of a heart attack hinges on the amount of the muscle that dies before it is corrected. The smaller the area affected, the greater the chance of survival and recovery.

While a heart attack will always cause some permanent damage, some areas may be able to recover if they are not deprived of blood for too long. The sooner a heart attack is diagnosed and treated, the greater the chance of recovery.

Other heart diseases

Other diseases that commonly affect the heart include:

• Chronic heart failure - CHD is one of the main causes of heart failure. It affects around one million people in the UK, and many more have it but haven't been formally diagnosed. Here, the heart doesn't works effectively as a pump, and fluid gathers in the lower limbs and lungs. This causes a variety of symptoms and significantly reduces quality of life.
• Infection - bacterial infections such as endocarditis are much rarer these days thanks to antibiotics, but can damage the valves of the heart as well as other tissues. Viral infections can damage the heart muscle leading to heart failure, or cause abnormal heart rhythms.
• Congenital heart disease - a number of defects can develop in the heart as a baby grows in the womb. One example is a hole in the heart, also known as a septal defect. Congenital heart disease may cause abnormal blood flow and put excessive strain on the infant's heart after it has been born.
• Cardiomyopathy - a disease of the heart muscle that can occur for different reasons, including coronary heart disease, high blood pressure, viral infection, high alcohol intake and thyroid disease.
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Nutrition 'must be a global priority', say researchers

Malnutrition is responsible for 45% of the global deaths of children under the age of five, research published in the Lancet medical journal suggests.

Poor nutrition leads to the deaths of about 3.1 million under-fives annually, it says.

An international team reviewed different causes of malnutrition in pregnancy and childhood.

They say the first 1,000 days of life - from conception to two years - have lasting consequences for health.

Malnutrition - which includes being overweight or obese as well as under-nourished - also has an economic impact.

According to a recent United Nations report, malnutrition is estimated to cost the world $3.5tn (£2.3tn) - or $500 for every person - in healthcare and lost productivity.

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If maternal and child nutrition can be optimised, the benefits will accrue and extend over generations, which is why we must work together now to seize this opportunity.”

Dr Richard HortonThe Lancer

A team led by Prof Robert Black, of Johns Hopkins Bloomberg School of Public Health, Baltimore, US, reviewed evidence on maternal and child under-nutrition and obesity in low-income and middle-income countries since 2008.

The team also assessed national and international progress on nutrition programmes.

Prof Black and colleagues say while some progress has been made in recent years, they estimate that more than 165 million children were affected by stunting (low height for age) and 50 million by wasting (low weight for height) in 2011.

An estimated 900,000 lives could be saved in 34 countries if 10 proven nutritional interventions were scaled-up to 90% of the world, they say.

"The nutritional consequences of the months during pregnancy and the conditions during the first two years of life have very important consequences for mortality and for adult chronic disease," Prof Black told BBC News.

"The early nutritional deficit results in developmental consequences for the individual and that has implications for their ability to succeed in school and ultimately in society to have the most productive jobs."

The researchers warn that countries will not break out of poverty unless nutrition becomes a global priority.

Dr Richard Horton, editor-in-chief of the Lancet, said: "If maternal and child nutrition can be optimised, the benefits will accrue and extend over generations, which is why we must work together now to seize this opportunity."

Experts working in development are gathering in London this weekend for a summit on nutrition hosted by the UK and Brazilian governments.

This will be followed by the annual summit of leaders from the G8 countries.

The Enough Food for Everyone IF campaign is calling for $1bn per year in additional aid money to be spend on malnutrition by 2015.

Enough Food for Everyone IF spokesperson Anita Tiessen said:

"These new figures confirm our worst fears - that hundreds of thousands more children are dying from malnutrition than we previously thought.

"We have made incredible progress in tackling child deaths around the world, but malnutrition remains the Achilles' heel in our efforts to prevent millions of needless deaths each year. We must urgently prioritise tackling hunger if we are to continue the progress we have made."

READMORE:http://www.bbc.co.uk/news/health-22779656

HIV inner shell structure revealed

Researchers have for the first time unravelled the complex structure of the inner protein shell of HIV.

The US team, reporting in Nature, also worked out exactly how all the components of the shell or 'capsid' fit together at the atomic level.

Until now the exact structure had proved elusive because of the capsid's large size and irregular shape.

The finding opens the way for new types of drugs, the researchers from the University of Pittsburgh said.

It was already known that the capsid, which sits inside the outer membrane of the virus, was a cone-shaped shell made up of protein sub-units in a lattice formation.

But because it is huge, asymmetrical and non-uniform, standard techniques for working out the structure had proved ineffective.

Computer model of HIV capsid structure

The team used advanced imaging techniques and a supercomputer to calculate how the 1,300 proteins which make up the cone-shaped capsid fit together.

Critical interactions

The process revealed critical interactions between molecules in areas that are necessary for the shell's assembly and stability.

These potential vulnerabilities in the protective coat of the viral genome could be exploited by scientists designing new drugs to tackle the problem of HIV resistance, the researchers explained.

Study leader Dr Peijun Zhang, associate professor in structural biology at the University of Pittsburgh School of Medicine said: "The capsid is critically important for HIV replication, so knowing its structure in detail could lead us to new drugs that can treat or prevent the infection.

"The capsid has to remain intact to protect the HIV genome and get it into the human cell, but once inside, it has to come apart to release its content so that the virus can replicate.

"Developing drugs that cause capsid dysfunction by preventing its assembly or disassembly might stop the virus from reproducing."

She added that the fast mutation rate of HIV made drug resistance a big problem.

"This approach has the potential to be a powerful alternative to our current HIV therapies, which work by targeting certain enzymes."

Prof Simon Lovell, a structural biologist at the University of Manchester, said not only had the researchers managed to achieve something that was very difficult, they had also found some really interesting results.

"The big problem with HIV is that it evolves so quickly that any drug you use you get drug resistance which is why we use a multi-drug cocktail.

"This is another target, another thing we can go after to develop a new class of drugs to work alongside the existing class.

READMORE:http://www.bbc.co.uk/news/health-22708437

Common painkillers 'pose heart risk

Two common painkillers, ibuprofen and diclofenac, can slightly increase the risk of heart problems if taken in high doses for a long time, data suggests.

People with severe arthritis often take the drugs, which also calm inflammation, to go about daily life.

The researchers said some patients would deem the risk acceptable, but they should be given the choice.

A study, published in the Lancet, showed the drugs posed even greater risks for smokers and the overweight.

The risks have been reported before, but a team of researchers at the University of Oxford analysed the issue in unprecedented detail in order to help patients make an informed choice.

The group investigated more than 353,000 patient records from 639 separate clinical trials to assess the impact of non-steroidal anti-inflammatory drugs.

They looked at high-dose prescriptions levels, rather than over-the-counter pain relief, of 150mg diclofenac or 2,400mg ibuprofen each day.

They showed that for every 1,000 people taking the drugs there would be three additional heart attacks, four more cases of heart failure and one death as well cases of stomach bleeding - every year as a result of taking the drugs.

So the number of heart attacks would increase from eight per 1,000 people per year normally, to 11 per 1,000 people per year with the drugs.

"Three per thousand per year sounds like it is quite a low risk, but the judgement has to be made by patients," said lead researcher Prof Colin Baigent.

He added: "So if you're a patient and you go and sit in front of your doctor and discuss it, you are the one who should be making the judgement about whether three per thousand per year is worth it to allow you, potentially, to go about your daily life."

He said this should not concern people taking a short course of these drugs, for example for headaches.

However, he did warn that those already at risk of heart problems would be at even greater risk as a result of the high-dose drugs.

High blood pressure, cholesterol and smoking all increase the risk of heart problems.

Prof Baigent said: "The higher your risk of heart disease, the higher your risk of a complication. Roughly speaking, if you've got double the risk of heart disease, then the risk of having a heart attack is roughly doubled."

He said patients should consider ways to reduce their risk, which could include statins for some patients.

Alternative

A similar drug called rofecoxib (known as Vioxx), was voluntarily taken off the market by its manufacturer in 2004 after similar concerns were raised.

There are more than 17 million prescriptions of non-steroidal anti-inflammatory drugs in the UK each year. Two thirds are either ibuprofen or diclofenac.

A third drug, naproxen, had lower risks of heart complications in the study and some doctors are prescribing this to higher-risk patients.

The drug does a similar job to aspirin by stopping the blood from clotting although this also increases the odds of a stomach bleed.

Prof Alan Silman, medical director of Arthritis Research UK, said the drugs were a "lifeline" for millions of people with arthritis and were "extremely effective in relieving pain".

He added: "However, because of their potential side-effects, in particular the increased risk of cardiovascular complications which has been known for a number of years, there is an urgent need to find alternatives that are as effective, but safer."

Prof Donald Singer, member of the British Pharmacological Society and from the University of Warwick, said: "The findings underscore a key point for patients and prescribers - powerful drugs may have serious harmful effects.

"It is therefore important for prescribers to take into account these risks and ensure patients are fully informed about the medicines they are taking."

READMORE:http://www.bbc.co.uk/news/health-22694858