Short- and Long-Term Effects of Bariatric Surgery on Vascular Phenotype

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 +/- 12years) underwent BS in this observational study. Two weeks before as well as 6weeks and 4years 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 mu m vs. 188.1 mu m; 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 4years of follow-up, the retinal changes sustained but further improvements did not occur. Both indices of large artery stiffness, baPWV and CAVI, remained unchanged 6weeks and 4years after surgery. Conclusions Retinal microvascular phenotype improved 6weeks after BS. The improvements in microvascular health were maintained during 4years 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.