It's a fact that people who are overweight or obese are more likely to have heart attacks and strokes. What isn't clear is whether their greater risk is due to the excess weight alone or to other risk factors like high blood pressure, diabetes, and elevated cholesterol levels often associated with obesity. In other words, is obesity an independent risk factor for cardiovascular disease?

This uncertainty explains why obesity was not included by the National Cholesterol Education Program as one of the factors to consider when making decisions on how to treat people with high blood cholesterol levels. On the other hand, increased body weight or waist circumference is an important feature of the metabolic syndrome.

Results of a French study of 140,000 men and 104,000 women indicate that obesity is not an independent risk factor. The study found that the prevalence of high blood pressure, diabetes, and high cholesterol increased with greater body weight. However, when compared with normal weight individuals, overweight and obese subjects had a higher risk of death from cardiovascular disease only if they also had one of these associated risk factors.

High blood pressure appeared to be the key danger leading to cardiovascular deaths. In overweight people, the risk of dying from a heart attack doubled if they also had high blood pressure, and increased 2.5 times if they had both high blood pressure and high cholesterol. In overweight people with high blood pressure, high cholesterol, and diabetes, mortality tripled in men and increased 4.5 times in women.

Even if excessive weight does not independently raise the danger of cardiovascular disease, there are plenty of reasons to stay or get slim to avoid risks such as high blood pressure and high cholesterol. People who are overweight and hypertensive should make every effort to control their blood pressure through lifestyle measures and, if needed, medications.