Diabetes Associated with Increased Risk of Atrial Fibrillation

Research from Denmark finds that people with diabetes are nearly twice as likely as non-diabetic people to develop atrial fibrillation (AF).

The study team used 16 years worth of national records to trace the development of AF in all 5.2 million adult Danes who did not have the condition in 1996. Those records showed that 5.6% of all diabetics, but only 3.3% of all other people, developed AF by 2012.

The figures for diabetic patients included both the 75,197 people who had diabetes at the outset of the study period and the 235,327 who developed it during the follow-up. Overall, the mean time between the first diagnosis of diabetes and the first diagnosis of AF was 5 years.

The variability in relative risk between diabetic and non-diabetic patients — as calculated by comparing the incidence rate ratios for developing AF per 1,000 person-years of follow-up — was significant for patients of all ages, said Jannik L. Pallisgaard, MD, who presented the study findings at the annual congress of the European Society of Cardiology,

Still, Pallisgaard noted, diabetes appeared to heighten the risk of AF far more in younger patients than older ones.

Diabetic patients between the ages of 18 and 39 had 2.5 times the risk of developing AF as their non-diabetic peers. Diabetic patients aged 65 and over, on the other hand, had roughly 1.3 times the AF risk as healthier seniors.

Such finding suggest that AF, which has always been very rare among younger adults, may become significantly more common in that age group if cases of diabetes continue their dramatic climb, said Pallisgaard, who also argued that the team’s analysis might justify new standards of care for all people with diabetes.

He said doctors should probably consider doing routine pulse palpation, ECGs and oral interviews designed to detect signs of arrhythmias in all diabetics, especially younger diabetics who have had the condition for less than 5 years.

The figures from the Danish study largely echo those from previous research projects, which have also linked diabetes to AF risk.

In the early 1990s, for example, the Framingham study found diabetes to be an independent risk factor for AF (odds ratio, 1.4 for men and 1.6 for women) after 38 years follow-up. An analysis of 41,436 Japanese patients from 2008, moreover, found the prevalence of diabetes was much greater in AF patients (20%) than in controls (12%).

That said, other studies have reached different conclusions, particularly after multivariate analysis that adjusted for potential confounding factors. Post hoc analysis of the ALLHAT study in 2009, for example, found that diabetes is not an independent predictor of AF in patients with hypertension.

What’s more, research to date has not proven the link between diabetes and AF (if it exists at all) to be causal. Some researchers have posited that the apparent connection between the two conditions may stem from a common cause such as inflammation, which has been linked to both AF and diabetes. Others have suggested that glucose and insulin disturbances, which can affect the heart, may trigger the AF.