Association of Generalized and Abdominal Obesity with Diabetic Retinopathy in Chinese Type 2 Diabetic Patients

Aims: Obesity has been proposed to promote the progression of diabetic retinopathy (DR), but previous studies have not shown consistent results. We aimed to explore the association between generalized and abdominal obesity and DR risk, and to assess the joint effect of these two different types of obesity on DR development. Methods: A nested case–control study within a large prospective study on type 2 diabetes was conducted in communities in Huai’an City, Jiangsu Province, China. Cases were individuals who had diagnoses of DR during the 6-year follow-up. A total number of 1544 DR cases and 1:1 matched controls were included. Binomial and multinomial logistic regression models were used to investigate the effects of obesity on DR occurrence and DR severity. Results: Compared with individuals in the first tertile of the baseline waist-to-hip ratio (WHR), subjects in the third tertile at baseline had significantly higher risk of DR (OR 1.44, 95% CI 1.17–1.78) during the follow-up period. Conversely, body mass index (BMI) (continuous) had an adjusted OR of 0.97 (95% CI 0.95–0.99) of developing DR. Individuals with low BMI and high WHR levels were identified as a high-risk population with a higher likelihood of developing DR (OR 1.65, 95% CI 1.17–2.33) than those in the lowest BMI category and simultaneously in the first WHR tertile. Conclusions: Type 2 diabetic individuals with low BMI levels and high WHR levels had a significantly increased risk of developing DR which indicated that isolated abdominal obesity might be involved in the pathogenesis of DR.