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

Authors


  • Relevant conflicts of interest/financial disclosures: Nothing to report. Full financial disclosures and author notes may be found in the online version of the article

  • Disclosure: The authors declared no conflicts of interest.

  • Funding agencies: This study was supported by the National Institutes of Health DK083537 and supported in part by grant 1UL1RR029893 from the National Center for Research Resources.

    Author contributions: AT, AC, and CL collected data and analyzed retinal and brain images. WT created the image analyses tools and the tools for retinal evaluations. MD analyzed the data and drafted the manuscript. AC and CL conceived the study and AC obtained funds for and directed the study. All authors were involved in writing the paper and had final approval of the submitted and published versions.

Abstract

Objective: Endothelial dysfunction in childhood obesity may precede cerebrovascular damage and cognitive impairment in adulthood. A noninvasive proxy of microvascular health is required to identify the risk for microvascular damage in obese children.

Design and Methods

The associations of hippocampal volumes and global cerebral atrophy were assessed with retinal vessel caliber in 40 normal BMI controls and 62 obese age-matched nondiabetic adolescents and the contribution of inflammation, obesity, and insulin resistance to retinal vessel caliber was evaluated.

Results

Compared to controls, obese adolescents had smaller retinal arterioles (8.3% decrease, P < 0.05) and wider venules (5.4% increase, P < 0.01). Larger retinal arteriole diameters were associated with less global cerebral atrophy (B = −0.24 [95% confidence interval, CI: −0.48, −0.002]) and larger hippocampal volumes (B = 0.01 [95% CI: 0, 0.02]). Venule diameters (B = 84.2 [95% CI: 30.3, 138.1]) were predicted by inflammation (fibrinogen). Arteriolar diameters were predicted by insulin resistance, indicated by logHOMA (homeostatic model assessment, HOMA) values (B = −17.03 [95% CI: −28.25, −5.81)] and body mass index (BMI) (B = −.67 [95% CI: −1.09, −0.24)]. All analyses were adjusted for mean arterial pressure, sleep apnea, and vessel diameter.

Conclusions

Measures 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 noninvasive proxy for brain atrophy in obese adolescents, and the identification of elevated risk for cerebral microvascular disease in adulthood.

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