04/06/2009 - Articles

Being Overweight Increases Your Risk of Heart Failure

By: Robert W. Griffith, MD

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It's well known that really obese people are likely to die prematurely from congestive heart failure, but how big is the risk for those of us who are "just a little bit overweight"? A new study has provided the answer.

Introduction

Five million people in the USA currently have congestive heart failure; it's the most common diagnosis in people over 65 who are admitted to hospital. It's well known that extremely obese people are likely to die prematurely from heart failure, but how big is the risk in those who are "just a little overweight"? A new study, supported by the US National Heart, Lung, and Blood Institute, has provided the answer.

What was done

Boston researchers used the body-mass index (BMI) to categorize participants in the renowned Framingham Heart Study. This index number is calculated from the height and weight, 1 and is frequently used for such purposes. (You can find out your BMI -- see the first link below.) People with a BMI of 18.5 to 24.9 were considered normal; those with a BMI of 25.0 to 29.9 were 'overweight'; and those 30.0 or more, 'obese'.

There were over 5,800 participants, whose average age was 55. Just over half of them were women. They were followed carefully for an average of 14 years, during which time all diagnoses of heart failure were noted.

What was found

Heart failure developed in 258 women and 238 men. After adjusting for known risk factors (like smoking, alcohol consumption, heart valve disease, or diabetes), it was found that obese individuals (BMI over 30) were twice as likely to develop heart failure as 'normal weight' persons.

'Overweight' people (BMI 25 to 30) were 34% more likely to develop heart failure than 'normal weight' people. Put another way, the risk of developing heart failure increased by 5% in men, and by 7% in women, for each 1-point increase in BMI.

Comment

It's estimated that 34% of US adults are overweight, and 27% are obese. Worse, an estimated 13% of children aged 6 to 11 are overweight, as are 14% of adolescents aged 12 to 19. Obesity has reached epidemic proportions, according to one expert, and is increasing. And although the overall death rate from heart disease is declining, the death rate from heart failure remains unchanged. So being at risk for heart failure is not something to take lightly; half of all patients diagnosed will be dead within 5 years.

Other studies have shown a similar effect of obesity on the occurrence of heart attacks (acute myocardial infarction, or MI) -- an earlier age for the first attack, and an increased likelihood of a second attack after the first. It's clear that overweight and obesity are prime targets in our attempts to improve individual health, both for ourselves, and for family and friends.

Source

Obesity and the Risk of Heart Failure. S. Kenchaiah, JC. Evans, D. Levy, N Eng J Med, 2002, vol. 347, pp. 305--313

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Footnotes

1. The BMI is the body weight in kilograms divided by the square of the height in meters.

Created on: 12/17/2002
Reviewed on: 04/06/2009

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