Retinal vessel abnormalities as a possible biomarker of brain volume loss in obese adolescents

Abstract

ObjectiveEndothelial dysfunction in childhood obesity may precede cerebrovascular damage and cognitive impairment in adulthood. Identifying risk for microvascular damage in obese children requires a non-invasive proxy of microvascular health.Design and MethodsWe assessed the associations of hippocampal volumes and global cerebral atrophy with retinal vessel caliber in 40 normal BMI controls and 62 obese age-matched non-diabetic adolescents and evaluated the contribution of inflammation, obesity and insulin resistance to retinal vessel caliber.ResultsCompared to controls, obese adolescents had smaller retinal arterioles (8.3% decrease, p<.05) and wider venules (5.4% increase, p<.01). Larger retinal arteriole diameters were associated with less global cerebral atrophy (B=−.24(95% CI:−.48,−.002) and larger hippocampal volumes (B=.01(95% CI:0,.02). Inflammation (fibrinogen) predicted venule diameters (B=84.2(95% CI:30.3, 138.1). Insulin resistance, indicated by logHOMA values (B=−17.03(95% CI:−28.25,−5.81) and body mass index (BMI) (B=−.67(95% CI:−1.09,−.24), predicted arteriolar diameters. All analyses were adjusted for mean arterial pressure, sleep apnea, and vessel diameter.ConclusionMeasures of brain health, BMI, and insulin resistance are associated with retinal vessel caliber. If confirmed in larger studies, retinal arteriolar caliber may serve as a possible non-invasive proxy for brain atrophy in obese adolescents, and the identification of elevated risk for cerebral microvascular disease in adulthood.