Obesity is Separate Risk factor for Death – Weight Control and Diet Very Important

January 11th 2006

BMI and Heart Disease

According to a new study, excess weight is an independent risk factor by itself for heart attacks, strokes and diabetes. Cholesterol and high blood pressure have been known risk factors for decades, but even people with normal levels are at risk if they are overweight.

Research done at the Northwestern University tracked 17,643 patients for over three decades and found that those overweight had substantially increased risk of dying of heart disease later in life. This includes the overweight people that began the study with normal blood pressure and cholesterol levels.

Middle ages people need to watch their weight, not just their cholesterol and blood pressure. Last year a US government study said that a little excess weight is OK, but being overweight is not.

The participants were middle age men and women between the ages of 31 and 64. They were divided into five groups for heart disease risk ranging form low to high and were followed for an average of 32 years. The low risk group did not smoke and had normal blood pressure and cholesterol. The moderate group members did not smoke either but may have had a slightly elevated blood pressure or cholesterol. Intermediate group participants had one of the risk factors for heart disease including current smoking, high cholesterol or high blood pressure. The elevated risk group had two of the risk factors and the highest risk group had all three risk factors.

There were 1,187 participants that had normal blood pressure and cholesterol levels. This is defined as a blood pressure of 120 over 80 or lower, and cholesterol under 200. Of this group 494 were overweight or obese. The researchers also logged the Body Mass Index (BMI). Those with a BMI of 25 to 29 were overweight and 30 and above were considered obese.

The researchers were interested in how many eventually got heart diseases. They tracked both deaths from cardiovascular disease and diabetes and the hospitalizations for those diseases after the age of 65.

Of the participants 1,594 died of heart disease. Obese and grossly overweight participants were 43% more likely to die of heart attack than those that had normal weight. Of the group that died of heart disease, 31 of them started out with normal blood pressure and cholesterol.

The obese individuals in the moderate group had a 2.1 times greater risk of death due to heart disease than non-obese individuals. They also found that obese people in the low risk group had a 4.2 times greater risk of hospitalization for heart disease.

Lijing Yan was the study author which has been published in today’s journal of the American Medical Association. She is a researcher at both the Northwestern University in Chicago and the Peking University. She concedes that some participants may have developed high blood pressure and cholesterol on the study, but said researchers increasingly believe that just being too fat causes other cardiovascular problems.