Plasma GlycA is a recently developed biomarker whose nuclear magnetic resonance signal originates from glycosylated acute-phase proteins. The aim of our study was to determine potential relationships between GlycA and adiposity, insulin resistance (HOMAir), high sensitive C-reactive protein (hs-CRP), leptin, adiponectin, and the leptin/adiponectin ratio, and to test whether GlycA is elevated in subjects with impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM).Plasma GlycA, hs-CRP, leptin, adiponectin, the leptin/adiponectin ratio, and insulin resistance (HOMAir) were measured in 103 fasting subjects (30 with normal fasting glucose, 25 with IFG and 48 with T2DM).In all subjects combined, plasma GlycA was correlated positively with body mass index (BMI), HOMAir, hs-CRP, leptin and the leptin/adiponectin ratio, and inversely with adiponectin (p<0.05 to p<0.001). GlycA did not significantly vary according to glucose tolerance category (p=0.060). GlycA was related positively to the leptin/adiponectin ratio (p=0.049), independent of BMI (p=0.056) and HOMAir (p=0.50).High plasma GlycA reflects a pro-inflammatory state. Adipose tissue-associated inflammatory processes could contribute to increased circulating levels of glycosylated acute-phase proteins.