Unmasking silent cardiometabolic risk: the role of fragmented QRS in obese young adults

BACKGROUND: It is well-established that obesity increases the risk of cardiovascular illnesses. Even in the absence of apparent illness, obesity may affect cardiac electrical activity. The present study sought to explore the association between body mass index (BMI) and the occurrence of arrhythmias, average heart rate, and fragmented QRS (fQRS) patterns in a population of healthy individuals aged 40 years or younger. METHODS: A study population of 193 asymptomatic individuals without known cardiovascular disease under 40 years of age was collected and categorized into three groups according to their BMI: normal weight (18.5–24.9 kg/m²), overweight (25.0–29.9 kg/m²), and obese (≥ 30.0 kg/m²). Every patient underwent standard 12-lead ECG testing and ongoing rhythm monitoring. Arrhythmia, mean heart rate, and fQRS have been evaluated and compared between the groups. ANOVA and chi-square tests were used for statistical analyses when needed. RESULTS: The prevalence of fQRS was significantly higher in the obese group compared to the normal and overweight groups (p < 0.05). With an AUC of 0.80, BMI demonstrated good discriminative capacity for predicting fQRS. The ideal threshold was 27.06 kg/m² (specificity: 87%, sensitivity: 64%). There was not a significant variance in the mean heart rate or arrhythmias between the groups. The results suggest a clear link between subclinical cardiac conduction problems and obesity, and fQRS is a promising early ECG marker. CONCLUSION: Our findings suggest that early subclinical cardiac conduction problems may be present, as obesity in individuals under 40 is associated with a higher prevalence of fQRS. fQRS may be a simple, non-invasive ECG measure for detecting early cardiac involvement and potential cardiometabolic risk. Even in the absence of clinical symptoms, these results show the importance of early cardiovascular risk screening in young, obese people.