Atrial fibrillation (AF) is a common heart condition affecting over a million people in the UK and 33.5 million people worldwide. It is linked to a fivefold increased risk of stroke, as well as increased risk of heart failure and mortality. The prevalence of AF is rising and is predicted to double in Europe before 2060. In part this is due to an increase in obesity; worldwide almost 2 billion adults are now either overweight or obese. Obesity is an established risk factor for AF, but the relationship between weight change and AF is less certain. It is important to understand this in order to inform global public health strategies.
The researchers looked at data from over 100,000 people across ten individual studies. A weight gain of 5% was linked to a 13% increase in risk of AF (HR 1.13, 95% CI 1.04 to 1.23) in the main pooled analysis. Studies that had looked at other measures of weight gain such as absolute weight gain or change in body mass index also reported a positive association between weight gain and increased risk of AF. Two studies reported that this association appeared to hold true regardless of whether participants were overweight or not at baseline.
The evidence was less consistent as to whether weight loss could reduce this risk of AF. Some individual studies found a reduction in the risk of AF for people who lost weight, but this was not true for all the studies and in the pooled analysis there was no significant association between 5% weight loss and AF risk (HR 1.04, 95% CI 0.94 to 1.16).
Previous research has established that there is a positive association between obesity and the incidence of atrial fibrillation (AF). In this review, for the first time we show that weight gain is also associated with an increased risk of AF. We found no consistent association between non-surgical weight loss and AF risk, though some individual studies did suggest weight loss might reduce AF risk. Our findings suggests public health strategies aimed at helping prevent weight gain could be important in reducing the global burden of AF.
- Nick Jones
There was insufficient evidence to analyse groups by their baseline weight status, which is important for understanding the context of weight change. Only one study reported whether reported weight loss was intentional, meaning unintentional weight loss due to conditions such as cancer (which are also linked to an increased risk of AF) could have influenced the summary results. The researchers emphasise these limitations and suggest their findings can only be seen as tentative. Further research is needed to better understand the relationship between these two conditions, particularly with regard to weight loss and future AF risk. Nonetheless, gaining weight was consistently linked to an increase in the risk of AF and therefore the findings support public health strategies targeted towards preventing weight gain.
