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Obesity not always tied to higher heart risk: study

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An obese person isnt inevitably at increased risk of cardiovascular disease and death, a new United Kingdom study has found. The people really at risk are the ones who have obesity in combination with other metabolic health risk factors, said Mark Hamer, a principal research associate at University College London, who worked on the study. […]

An obese person isnt inevitably at increased risk of cardiovascular disease and death, a new United Kingdom study has found.

The people really at risk are the ones who have obesity in combination with other metabolic health risk factors, said Mark Hamer, a principal research associate at University College London, who worked on the study.

The results are in line with most previous research that defined metabolic health as having normal levels of markers like blood pressure, blood sugar, HDL, or good cholesterol, and C-reactive protein, which is a measure of inflammation in the body.

People with good metabolic health are not at risk of future heart disease even if they are obese, Hamer said.

On the flip side, the non-obese in poor metabolic shape face as much risk as the unhealthy obese, the researchers concluded.

The findings, published in the Journal of Clinical Endocrinology and Metabolism, are based on more than 22 000 middle-aged participants in national health studies conducted in England and Scotland.

According to researchers, results suggest metabolic factors may be more important in predicting a persons risk of cardiovascular disease than excess body weight in itself.

From a clinical perspective, stratifying individuals based upon their metabolic profile may help to identify those both obese and non-obese who should be treated with drugs or changes in diet and exercise, the study authors noted.

We encourage obese people to lose weight for their health, but (some) provision should be made in how we screen people for metabolic risk, Hamer said.

An adult who has a body mass index (BMI) a height-to-weight ratio of 30 or higher is considered obese.

A normal BMI is between 18,5 and 24,9 and a BMI between 25 and 29,9 is considered overweight. During the past 20 years, obesity has increased significantly in the United States.

More than a third of American adults are obese, according to the Centres for Disease Control and Prevention.

For the new report, Hamer and a colleague collected data on participants BMI and metabolic profiles and followed individuals, on average, for seven years.

Then they looked at how many participants had died during the study period and from what causes. None of the participants had heart disease at the start of the study.

Almost a quarter were obese and just under a quarter of those were considered metabolically healthy obese meaning they had no abnormal blood pressure, cholesterol, blood sugar or inflammation readings.

During the study period, more than 600 participants died from heart-related causes and 1 800 from other causes.

The obese individuals in good metabolic health were not at greater risk of dying from cardiovascular disease than the metabolically healthy non-obese, the researchers found.

But both non-obese and obese participants in poor metabolic health had a 59% and 64% increased risk of dying from heart disease, respectively, compared to the healthy non-obese.

Among the metabolically unhealthy participants, the non-obese had high levels of hypertension and inflammation comparable to those in the unhealthy obese group.

The metabolically unhealthy obese also had a 72% higher risk of dying from non-heart-related causes than those in good health.

That was after taking into account study participants age, sex, smoking, physical activity and socioeconomic status.

Researchers found the results to be largely unchanged when they used waist circumference to define obesity instead of BMI.

Hamer and his colleague note in their report that a strength of their study was having a large study population.

But because the researchers only measured participants metabolic risk factors at the beginning of the study, its possible that some of the metabolically healthy obese went on to develop unhealthy readings.

The study shows the need to think more broadly about obesity rather than to focus on body weight alone, said Dr Cora Lewis, a professor of preventive medicine and an epidemiologist at the University of Alabama, Birmingham, who was not involved in the research.

If you are obese and you struggle with weight, but your (metabolic) risk factors are fine, that may not be such a bad place to be, Lewis told Reuters Health adding that only a minority of people fit the description of metabolically-healthy obese.

Equally important, the study shows that people may be at increased metabolic risk no matter what they weigh, she noted.

Excess body fat may be carried not only under the skin, but also inside the abdomen, heart, liver and muscles making it hard to tell she added.

BMI doesnt always tell you everything. If you are non-obese, but you have high cholesterol or hypertension, you have some work to do, Lewis said.