Sex-based differences in the associations between abdominal obesity and diabetic retinopathy in diabetic patients with normal weight

Purpose: To investigate sex-specific differences in associations of abdominal obesity indexes, systemic factors, and diabetic retinopathy (DR) in type 2 diabetes mellitus (T2DM) subjects with normal body mass index (BMI). Methods: This cross-sectional study comprised 653 T2DM subjects (402 women and 251 men) with normal BMI (18.5 kg/m(2)<BMI<24.0 kg/m(2)). All participants completed a standard questionnaire and underwent comprehensive ocular and systemic examinations. Anthropometric parameters were measured and recorded, including weight, height, waist circumference (WC), hip circumference, waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). Sex-specific associated factors for DR were assessed using logistic regression models. Results: In the multivariate logistic regressions, the presence of any DR was associated with a longer duration of T2DM (OR = 1.07, p = 0.007) and higher HbA1c (OR = 1.40, p = 0.001) in women, while any DR was associated with younger age at T2DM diagnosis (OR = 0.94, p = 0.020) and higher HbA1c (OR = 1.29, p = 0.011) in men. For women, we identified a positive association between WC (OR = 1.07, p = 0.011), WHR (OR = 1.67, p = 0.002), and WHtR (OR = 1.57, p = 0.004) with any DR after adjusting for confounders, and the third tertiles of WC (OR = 2.29, p = 0.028), WHR (OR = 3.03, p = 0.003), and WHtR (OR = 2.84, p = 0.007) were at high risk of any DR. For men, there were no associations between abdominal obesity indexes and any DR in either continuous variables or categorical variables (all p > 0.05). Main conclusions: There were sex differences in the relationships between WC, WHR, WHtR, and DR in this T2DM population with normal BMI. Our findings provide new insight into a sex-specific mechanism of DR and management of the condition.