A study published in the American Heart Association’s journal Circulation has found that men develop atrial fibrillation (AF) about a decade earlier than women on average, and being overweight is a major risk factor.
Untreated AF increases the risk of heart-related death and is linked to a five times increased risk of stroke. In the new research, AF patients’ risk of death more than tripled compared to those without the condition.
“It’s crucial to better understand modifiable risk factors of atrial fibrillation,” says study author Christina Magnussen, Internal Medicine and Cardiology, University Heart Center, Hamburg, Germany. “If prevention strategies succeed in targeting these risk factors, we expect a noticeable decline in new-onset atrial fibrillation.”
This would lead to less illness, fewer deaths and lower health-related costs, she says.
Atrial Fibrillation and Body Mass Index
Researchers reviewed records of 79,793 people (aged 24 to 97) in four community-based studies in Europe. The participants did not have AF at the outset. Later assessments of their health—with a median follow-up period of 12.6 to a maximum of 28.2 years—showed that 4.4 percent of the women and 6.4 percent of the men had been diagnosed with AF.
Researchers noted that AF diagnosis rates jumped when men were 50 or older and women were 60 or older, developing in about 24 percent of both men and women by age 90. The onset was tied to higher blood levels of C-reactive protein (inflammation marker) in men, and new AF cases increased more in men than women with increases in body mass index (BMI): 31% in men and 18% in women.
“We advise weight reduction for both men and women,” Magnussen says. “As elevated body mass index seems to be more detrimental for men, weight control seems to be essential, particularly in overweight and obese men.”
Researchers were surprised to find that higher total cholesterol, a risk factor for heart disease, lowered risk for developing AF, especially in women, although exactly why is not clear.
Due to its design, the study could not shed light on pathophysiological factors causing sex differences in AF risk. The authors also note that AF might have been underdiagnosed at the study’s start and later records may not reflect all cases. Strengths of the research include that it studied the condition in the general population and noted how individuals fared over long periods.
Since study participants were from both northern and southern Europe, the findings will probably apply to other Caucasian populations but cannot be generalised to other groups, Magnussen said. However, since BMI in the study was such a strong risk factor for atrial fibrillation, it is likely to also be impactful in other groups, she added.