Associations of nutritional intake and body mass index with branch retinal vein occlusion: A cross-sectional study using data from a Korean national survey

ObjectiveThis study aimed to evaluate the associations between body mass index (BMI), dietary nutrient intake, and the risk of branch retinal vein occlusion (BRVO) in a nationally representative Korean population, with a focus on sex- and BMI-specific differences.MethodsThis population-based cross-sectional study analyzed data from adults aged ≥40 years who participated in the 7th and 8th Korea National Health and Nutrition Examination Surveys (KNHANES) conducted between 2017 and 2021. BRVO was diagnosed using standardized fundus photography and optical coherence tomography interpreted by certified retinal specialists. BMI was categorized according to Asia-Pacific criteria, and dietary intake of macronutrients and micronutrients was assessed using structured nutrition surveys. Comparisons were performed between participants with and without BRVO, stratified by sex and BMI category. Survey-weighted logistic regression models were applied to account for the complex sampling design and to adjust for age, smoking status, alcohol consumption, hypertension, diabetes mellitus, and BMI.ResultsA total of 15,790 participants (6,629 men and 9,161 women) were included, of whom 96 (43 men and 53 women) were diagnosed with BRVO. Participants with BRVO were significantly older and had a higher prevalence of hypertension (all P < 0.001). Overall, individuals with BRVO showed significantly lower intakes of protein, crude fiber, iron, sodium, and potassium (all P < 0.05). Although overall BRVO prevalence did not differ significantly across BMI categories, sex-stratified analyses revealed an increasing prevalence with higher BMI in women. Associations between dietary nutrient intake and BRVO varied across BMI strata.ConclusionsLower nutrient intake and metabolic risk factors, including hypertension and BMI, may be associated with BRVO risk. The observed sex- and BMI-specific differences highlight the importance of tailored nutritional and metabolic risk assessment. Longitudinal studies are warranted to clarify causal relationships.