Wednesday, December 30, 2009

Is Obesity Hard-Wired in The Brain?

The escalating obesity rate has become a tricky issue for many countries. This is because obesity can eventually lead to development of many diseases, including heart disease, diabetes, hypertension (high blood pressure) and stroke. The expecting cost of dealing with these diseases can be huge, which will become a burden not only on the people but also on the government.

Many health experts have frequently blamed the modern lifestyle of overeating, inappropriate diet and lack of exercise as the cause of overweight and obesity. However, a study by the researchers from the University of Southern California, Los Angeles found that obesity might be hard-wired into the brain from birth so that some people are more prone to overweight than others.

The findings of an animal study, appearing on in the February 2008 issue of Cell Metabolism, showed that obese rats had faulty brain wiring that impaired their response to the hunger-suppressing hormone leptin.

It seemed that appetite and obesity were built into the brain for obesity-prone rats, according to the researchers. The neurodevelopment differences in these animals could be seen as early as the first week. Such results showed that obesity could be wired into the brain from early life.

Leptin, produced by fat tissue, plays a central role in fat metabolism by acting as a signal to the brain about the body's energy status. Though scientists are still not clear about its role in weight regulation, they are aware that the brain calibrates the requirement for food intake partly based on leptin levels.

Learnt from previous research that the brains of obesity-prone rats were insensitive to these leptin signals, the researchers looked for brain abnormalities that could explain this.

In the study, they found defects in the brain circuits that relay leptin signals throughout the hypothalamus. Hypothalamus is the brain’s central switchboard for regulating conditions in the body.

The findings showed that exercising and eating right might improve the rat’s condition, but the propensity to gain weight could not be reversed.

The researchers also pointed out that if the findings are replicated in humans, then those individuals who are genetically predisposed to obesity as a result of their brains’ configuration should carefully pay attention to diet and energy balance.

Meanwhile, they also cautioned that the general belief that weight regulation is all a matter of nutrition or lifestyle choices might not be helpful for people whose biology predisposes them to obesity.

Friday, December 11, 2009

What Can Plavix and Aspirin Do For Heart Disease Patients With AF?

A blood thinner, a common name for an anticoagulant agent, is a drug used to prevent formation of blood clots by hindering coagula. Blood thinner does not really thin the blood; it just prevents the blood from clotting. Doctors usually prescribe blood thinners to heart disease patients who are at risk for heart attack and stroke.

So far, anticoagulants such as warfarin and aspirin have been the only effective therapies in treating heart disease patients suffering from atrial fibrillation (AF). AF is a condition in which the heart's 2 upper chambers, the atria, quiver instead of beating effectively. This will raise the risk of blood clotting or pooling in the chambers that could eventually trigger a heart attack or stroke.

According to the American Heart Association (AHA), there are some 2.2 million Americans suffer from AF. These patients often need to be fitted with a pacemaker. Yet many of them cannot be treated with warfarin to stop blood clotting because warfarin increases the risk of an internal hemorrhage by up to 70 percent.

At the annual conference of the American College of Cardiology in Orlando on March 31, 2009, researchers from Ontario's McMaster University revealed that they managed to help AF patients cut the risk of heart attack and stroke by combining Plavix with aspirin.

Plavix is known under the generic name of clopidogrel. It is used to prevent the platelets in blood from coagulating and forming clots.

ACTIVE-A, a clinical trials involving 7,554 patients, aimed to determine whether the addition of clopidogrel to aspirin could reduce major vascular events and stroke in AF patients at an acceptable risk of increased hemorrhage. In the trials, the researchers showed that combination of Plavix and aspirin could help AF patients who are unable to take other blood thinners like warfarin.

The combination of clopidogrel and aspirin reduced major vascular events by 11 percent, including a 28 percent reduction in stroke and a 23 percent reduction in myocardial infarction (also known as heart attack), as found in the study.

It is believed that this is a new treatment for AF for the first time in 20 years.

Friday, December 04, 2009

Why You Should Not Be Too Skinny?

While being overweight or obese is definitely not healthy, people who are skinny are neither preferable. Why?

Because of modern lifestyle, number of people who are overweight or obese is increasing at a fairly fast rate. As we know, overweight or obesity can easily lead to many other diseases including diabetes, hypertension (high blood pressure), high cholesterol and heart disease. However, it seems that being very skinny is even more dangerous than being overweight or obese.

Japanese researchers from Tohoku University's Graduate School of Medicine recently (June 2009) found that slightly overweight people at the age of 40 could live 6 to 7 years longer than those very skinny people, who have an average life expectancy that is shorter by some 5 years than that of obese people.

The researchers did expect thin people to have shorter life expectancy but were surprised to discover such a large difference.

Working on middle-aged and elderly people, the long-term study involved 50,000 people between the age of 40 and 79 over a period of 12 years in the modern Japanese prefecture of Miyagi. The participants were divided into 4 groups at the age of 40 according to their BMI (body mass index).

BMI is the ratio of a person’s weight in kilos over the square of height in meters. BMI lower than 18.5 is classified as underweight. When BMI is between 18.5 and 25, the person is considered normal. Once the BMI exceeds 25 but lower than 30, the person is slightly overweight and once BMI exceeds 30, the person is considered as obese.

It was thought that thin people having shorter lives because many of them are either sick or smoke. However, the difference remained almost the same, even eliminating these 2 factors.

The researchers argued that skinny people were of shorter lifespan because they are vulnerable to disease such as pneumonia and the fragility of their blood vessels.

Nevertheless, people were not advised to eat as much as they want. Instead, the researchers recommended that thin people should try to gain normal weight but people with normal weight should never be putting on their weight.