Association of central obesity with retinal neurodegeneration: Cross-sectional and longitudinal evidence from two countries

ObjectiveThis study aimed to evaluate the association of central obesity with retinal neurodegeneration. MethodsDatabases from the UK Biobank study and the Chinese Ocular Imaging Project (COIP) were included for cross-sectional and longitudinal analyses, respectively. Retinal ganglion cell-inner plexiform layer thickness (GCIPLT) measured by optical coherence tomography (OCT) was used as a retinal indicator of neurodegeneration. All subjects were divided into six obesity phenotypes according to BMI (normal, overweight, obesity) and waist to hip ratio (WHR; normal, high). Multivariable linear regression models were fitted to investigate the association of obesity phenotypes with GCIPLT. ResultsA total of 22,827 and 2082 individuals from UK Biobank (mean age: 55.06 [SD 8.27] years, women: 53.2%) and COIP (mean age: 63.02 [SD 8.35 years], women: 61.9%) were included, respectively. Cross-sectional analysis showed GCIPLT was significantly thinner in normal BMI/high WHR individuals compared with normal BMI/normal WHR individuals (& beta; = -0.33 & mu;m, 95% CI = -0.61, -0.04, p = 0.045). But thinner GCIPLT was not observed in individuals with obesity/normal WHR. After 2-year follow-up in COIP, normal BMI/high WHR was associated with accelerated GCIPLT thinning (& beta; = -0.28 & mu;m/y, 95% CI = -0.45, -0.10, p = 0.02), whereas obesity/normal WHR was not. ConclusionsEven with normal weight, central obesity was associated with accelerated GCIPL thinning cross-sectionally and longitudinally.