Sex-related differences of fatty acid-binding protein 4 and leptin levels in atrial fibrillation

Aims Adiposity plays a key role in the pathogenesis of atrial fibrillation (AF). Our aim was to study the sex differences in adipokines levels according to AF burden. Methods and results Two independent cohorts of patients were studied: (i) consecutive patients with AF undergoing catheter ablation (n = 217) and (ii) a control group (n = 105). (i) Adipokines, oxidative stress, indirect autonomic markers, and leucocytes mRNA levels were analysed; (ii) correlation between biomarkers was explored with heatmaps and Kendall correlation coefficients; and (iii) logistic regression and random forest model were used to determine predictors of AF recurrence after ablation. Our results showed that: (i) fatty acid-binding protein 4 (FABP4) and leptin levels were higher in women than in men in both cohorts (P<0.01). In women, FABP4 levels were higher on AF cohort (20 +/- 14 control, 29 +/- 18 paroxysmal AF and 31 +/- 17 ng/mL persistent AF; P < 0.01). In men, leptin levels were lower on AF cohort (22 +/- 15 control, 13 +/- 16 paroxysmal AF and 13 +/- 11 ng/mL persistent AF; P < 0.01). (ii) In female with paroxysmal AF, there was a tower acetylcholinesterase and higher carbonic anhydrase levels with respect to men (P < 0.05). (iii) Adipokines have an important role on discriminate AF recurrence after ablation. In persistent AF, FABP4 was the best predictor of recurrence after ablation (1.067, 95% confidence interval 1-1.14; P = 0.046). Conclusion The major finding of the present study is the sex-based differences of FABP4 and leptin levels according to AF burden. These adipokines are associated with oxidative stress, inflammatory and autonomic indirect markers, indicating that they may play a role in AF perpetuation.