Youth with type 2 diabetes who participated in the TODAY (Treatment Options for Type 2 Diabetes in Adolescents and Youth) study were followed for 2–6.5 years. Digital fundus photographs were obtained in the last year of the study. Blood samples during the study were processed for inflammatory biomarkers, and these were correlated with obesity tertiles and presence of retinopathy.

Higher BMI was associated with an increase in circulating levels of metabolic biomarkers including high sensitivity C-reactive protein (hsCRP), plasminogen activator inhibitor 1 (PAI-1), fibrinogen, LDL-cholesterol (LDL-C) and Apolipoprotein B (ApoB), tumor necrosis factor receptors 1 and 2 (TNFR-1 and -2), interleukin 6 (IL-6), E-selectin, and homocysteine, as well as a decrease in the metabolic risk markers HDL-cholesterol (HDLC), and insulin-like growth factor binding protein 1 (IGFBP-1). Although NPDR risk decreased with increasing obesity, it was not associated with any of the measured biomarkers.