Résumé
Purpose: obesity is associated with increased cardiovascular risk and death. Bariatric surgery for weight reduction improves the clinical and metabolic profile. Retinal caliber changes could precede cardiovascular events. Different studies have shown an improvement in retinal caliber after surgery. The aim of this study was to examine retinal caliber before and after bariatric surgery and assess the predictors of this improvement.Methods: patients with World Health Organization grade 2 or 3 obesity undergoing bariatric surgery were included in this monocentric, prospective cohort study. Biologic features, vessel stiffness, echocardiograph variables and retinal caliber were assessed at baseline and 6 and 12 months. A mixed linear model adjusted for age and sex was used to evaluate factors associated with retinal caliber changes.Results: we included 88 patients (75 women). The median (interquartile range) age was 43 years (35-51) and median baseline weight 111 kg (101-127). In the first year after bariatric surgery, patients showed a decrease in central retinal vein equivalent (CRVE) (-5.1 µm/year, p<0.0001) and an increase in arteriole-to-venule ratio (AVR) (+0.02, p<0.0001), as well as a decrease in systolic blood pressure (-4.0 mmHg/year, p=0.04), glycemia (-1.4 mmol/L/year, p<0.0001), natural logarithm of C-reactive protein (ln (CRP; -1.0 mg/L/year, p<0.0001), triglycerides level (-0.86 g/L/year, p<0.001), and left ventricular mass (-54.0 g/year, p=0.0005). Decreased CRVE was correlated with increased eGFR (r= -0.29, p<0.001), and increased AVR was correlated with decreased central pulse blood pressure (r= -0.21, p=0.0012). We observed no significant improvement in arterial stiffness markers (pulse wave velocity, -0.22 m/s/year, p=0.14). Predictors of improvement in CRVE were high baseline weight (p=0.030), male sex (p=0.025) and no diabetes history (p=0.047). Predictors of improvement in AVR were high baseline weight (p=0.013) and low baseline ventricular mass (p=0.025). Conclusions: the retinal microvascular phenotype improved during the first year after bariatric surgery, with decreased CRVE and increased AVR. This retinal microvascular plasticity was associated with improvement in other target organ damage such as glomerular filtration rate and central pulse blood pressure. Factors associated with retinal microvascular plasticity were male sex, high baseline weight, low baseline left ventricular mass and absence of diabetes. Our data also suggest that longitudinal assessment of retinal vascular calibers may offer new insights into the pathophysiology of subclinical vascular processes.