BMI in Childhood Could Signal AFib Risk Later in Life among Men

Increased body mass index could help predict future risk of atrial fibrillation (AF) and other negative health outcomes, according to a new study from investigators in Sweden.

An analysis of registry data from more than 1.7 million men with a median follow-up of 32 years, results of the study demonstrate those with a BMI greater than 20 kg/m2 were at an increased risk of develop early AF while those with a BMI of 40-50 kg/m2 saw their risk more than triple.

"Whether screening for atrial fibrillation in early adulthood among individuals with long-standing obesity and more robust follow-up and initiation of anticoagulants in people with long-standing obesity and atrial fibrillation may improve survival needs to be addressed in future randomized trials" said study investigator Demir Djekic, MD, PhD, of Sahlgrenska University Hospital, in Sweden, in a statement.

As the prevalence of obesity continues to increase throughout the globe, particularly among pediatric populations, the need to identify potential long-term impact of obesity early in life has become a focal point of many research endeavors. With this in mind, Djekic and a team of colleagues from Sahlgrenska University Hospital and University of Gothenburg designed the current study to assess whether increase BMI in youth might place male patients at an increased risk of AF and other negative cardiovascular outcomes, including all‐cause mortality, incident heart failure, and ischemic stroke later in life.

With this in mind, investigators designed their nationwide, register‐based, cohort study to leverage data from men enrolled in compulsory military service and link this data with data obtained from the Swedish National Inpatient Registry and Cause of Death Register. From their search, investigators identified 1,704,467 men with a mean age of 18.3±0.75 years at enrollment for inclusion in their study and a median follow-up of 32 (IQR, 24-41) years. From these aforementioned data sources, investigates obtained data related to incidence and clinical outcomes of AF as well as data related to height and weight, blood pressure, fitness, muscle strength, intelligence quotient, and medical disorders at baseline.

During the follow-up period, a total of 36,693 cases of AF were recorded among the study cohort, with a mean age at diagnosis of 52.4±10.6 years. Compared to their counterparts with a BMI of 18.5 but less than 20 kg/m2, an increased risk of AF was observed for those with a BMI of 20 kg/m2 or greater, with a multivariable-adjusted HR of 1.06 (95% CI, 1.03-1.10) for those with a BMI greater than 20 kg/m2 but less than 22.5 kg/m2 and 3.72 (95% CI, 2.44-5.66) for those with a BMI greater than 40-50 kg/m2. Further analysis suggested every single kg/m2 increase in BMI was associated with a 6.4% greater risk of AF (HR, 1.064 [95% CI, 1.059-1.068]).

In subgroup analyses examining those who developed atrial fibrillation, which had a median follow-up of 6 years, results suggested an increased risk of all‐cause mortality, incident heart failure, and ischemic stroke was observed in men with a baseline BMI exceeding 30 kg/m2 compared with those with BMI below 20 kg/m2, with aHRs of 2.86 (95% CI, 2.30-3.56), 3.42 (95% CI, 2.50-4.68), and 2.34 (95% CI, 1.52-3.61), respectively.

This study, “Body Mass Index in Adolescence and Long‐Term Risk of Early Incident Atrial Fibrillation and Subsequent Mortality, Heart Failure, and Ischemic Stroke,” was published in Journal of the American Heart Association.