Background: Retinal microvascular diameters and large artery stiffness are valid biomarkers of cardiovascular risk. This study assessed short- and long-term micro- and macrovascular improvements after bariatric surgery (BS).
Methods: Sixteen patients (44 ± 12 years) underwent BS in this observational study. Two weeks before as well as 6 weeks and 4 years after surgery, retinal vessel analysis and assessment of brachial-ankle pulse wave velocity (baPWV), cardio-ankle vascular index (CAVI), and anthropometry were performed. Three patients were lost to follow-up.
Results: Six weeks after BS, retinal arteriolar diameters (CRAE) were wider (180.1 μm vs. 188.1 μm; p = 0.001), and the arteriolar-to-venular diameter ratio (AVR) was higher (0.82 vs. 0.86; p < 0.001) compared to baseline levels. During the 4 years of follow-up, the retinal changes sustained but further improvements did not occur. Both indices of large artery stiffness, baPWV and CAVI, remained unchanged 6 weeks and 4 years after surgery.
Conclusions: Retinal microvascular phenotype improved 6 weeks after BS. The improvements in microvascular health were maintained during 4 years of follow-up but, despite significant further reductions in body mass index, did not improve further long-term. baPWV and CAVI were unaffected after surgery indicating that BS primarily affects microvascular phenotype rather than large artery stiffness. Retinal vessel imaging seems to be a feasible diagnostic tool to monitor microvascular health after BS. Normalization of BMI and blood pressure may be necessary to achieve long-term improvement of large artery phenotype after BS.
Keywords: Arterial stiffness; Bariatric surgery; Cardio-ankle vascular index; Obesity; Pulse wave velocity; Retinal microcirculation.