Why Body Shape Still Matters To The Risk Of Heart Attack

Online, April 6, 2011 (Newswire.com) - Does having an apple or pear shaped body affect your heart risk?

People who are apple-shaped carry the bulk around their waist, while those who are pear-shaped carry their weight in the hip or thighs.

Many doctors believe your waist size is more important than your weight when assessing your health risks.

However in some recent reports doubts have been raised over the idea that being overweight and "apple shaped" increases heart attack risk. A study in the Lancet found the risk of heart attack was not increased by fat being concentrated around the waist.

But then today - "A medical U-turn has cast doubt on warnings that being overweight and 'apple-shaped' is especially dangerous to the heart", the Daily Mail has reported.

The news is based on a high-quality review drawing together data on more than 220,000 people to see how well measures of fat, such as body mass index (BMI), waist circumference and waist-to-hip ratio, predict new diagnoses of heart disease or stroke.

Despite what some news reports have suggested, these measures were all associated with an increased risk of fatal or non-fatal coronary heart disease, stroke and overall cardiovascular disease.

The point missed by many newspapers is that the researchers only found that conventional risk assessments, which already look at established risk factors such as smoking and high blood pressure, were not improved by adding data on these body fat measures. As the researchers have said, their findings do not diminish the importance of controlling body fat to help prevent cardiovascular disease.

This research confirms the health risks associated with being overweight and obese, and simply says that the harmful effects of being overweight mainly act through the other established risk factors for heart disease and stroke. Recommendations to follow a balanced diet, exercise regularly and maintain a healthy weight do not change.

The researchers conclude that BMI, waist circumference and waist-to-hip ratio, whether assessed singly or in combination, do not significantly improve cardiovascular disease risk prediction when information on conventional risk factors of blood pressure, diabetes and cholesterol is available.

This was well conducted research that has combined data from 58 cohort studies featuring 221,934 people and constituting 1.87 million person-years of follow-up. Each standard unit rise in BMI, waist circumference and waist-to-hip ratio was found to be independently associated with an increased risk of fatal or non-fatal coronary heart disease, stroke or the combined outcome of cardiovascular disease.

However, adding these measures into risk prediction models based on conventional risk factors (for example smoking, diabetes, blood pressure and bad cholesterol) did not alter heart disease and stroke risk estimates. This means that none of the measures, individually or in combination, could improve risk prediction when information on other risk factors was available.

A key point to remember is that these findings do not mean that body shape is not important or that BMI, waist circumference and waist-to-hip ratio cannot be used to predict cardiovascular risk.

Rather, they mean that their inclusion in conventional clinical risk assessments does not appear to be of benefit. As the researchers have said, their findings "do not diminish the importance of adiposity as a major modifiable determinant of cardiovascular disease" and, indeed, their results demonstrate that a rise in any of these factors does increase cardiovascular risk. Adiposity levels were also found to contribute to the other cardiovascular risk factors of diabetes, cholesterol and high blood pressure.

In this context, the researchers have said that their findings "reliably refute previous recommendations to adopt baseline waist-to-hip ratio instead of BMI as the principal clinical measure of adiposity". This does not mean that waist-to-hip ratio is of no importance or that it is not associated with cardiovascular disease, rather that it does not appear to be of greater predictive value than BMI, the currently preferred clinical measure. BMI, waist circumference and waist-to-hip ratio were all found to have a similar strength of association with coronary heart disease, stroke and cardiovascular disease overall.

This well conducted systematic review also appears to be reliable, aggregating a large quantity of individual patient data from 58 cohorts. Importantly, all participants (average age 58) were also confirmed to be free of cardiovascular disease at the start of the study, ruling out the possibility that pre-existing cardiovascular disease had clouded the results.

Further study is needed, however, particularly in other population groups, as 90% of those included in this study were of European descent.

The findings of this review do not change current recommendations that people should try to eat a balanced diet, take regular exercise and maintain a healthy weight.

High Blood Pressure Insider uses its online presence to encourage people to manage their high blood pressure through a healthy lifestyle and enjoy the many benefits of a healthy heart. It supports the view that people should try to eat a balanced diet, take regular exercise and maintain a healthy weight.

If you're concerned about your health and would like to learn how a healthy lifestyle can help to control cholesterol and blood pressure levels without taking medication, then visit High Blood Pressure Insider at http://highbloodpressureinsider.org