Researchers followed more than 1.6 million Swedish men from adolescence onwards between 1968 and 2005 and found that even men who were within the normal body weight range in adolescence were at an increased risk of heart failure.
Annika Rosengren, Professor of Medicine at the Sahlgrenska Academy, University of Gothenburg, who led the research, said: “Although most studies define a normal weight as having a BMI between 18.5 and 25, this is probably not an appropriate definition in the young, most of whom are naturally thin. This may be why we see an increase in the risk of heart failure starting at a fairly low BMI level. However, it was surprising to see the very steep increase in risk with increasing body weight above a BMI of 20.
“Given the global trend for growing numbers of teenagers to be overweight and obese, our findings suggest that heart failure, which in this study occurred at the relatively early average age of about 47 may well become a major threat to health worldwide. This serves to underline the urgent need for action worldwide to curb the obesity epidemic.
“Action needs to be taken by governments as well as by individuals, for instance by creating an environment that does not promote overweight and obesity, and that encourages people not to be sedentary and not to eat more than they need. This is more important than hassling people into dieting whatever shape they are. Once established, overweight and obesity is much harder to tackle.”
The study, which is published in the European Heart Journal, found that in men with a BMI of 20 and over, the risk of heart failure increased by 16% with every BMI unit, after adjustments for factors that could affect the findings, such as age, year of enlistment into the Swedish armed forces, other diseases, parental education, blood pressure, IQ, muscle strength and fitness.
For this study Professor Rosengren and her colleagues analysed data on 1,610,437 men. They followed the men from the time they were conscripted at 18, for between five to 42 years (an average follow-up time of 23 years). During that time, 5,492 men were admitted to hospital for heart failure, with an average age at diagnosis of nearly 47.
Compared with men who had a BMI of between 18.5 and 20 at the time of conscription, men with a BMI of 20 to 22.5 had a 22% increased risk of heart failure, after adjusting for factors that could affect the results. The risk nearly doubled for those with a BMI between 22.5 and 25, and more than tripled for those with a BMI between 25 and 27.5. The risk increased more than six-fold for those classified as obese with a BMI between 30-35, and was nearly 10-fold for the very obese with a BMI of 35 or more.
To read the full study, click here.