Lipocalin-2 (LCN2) is a glycoprotein synthetized by various cell types, including neutrophils, that acts as siderophores scavenger and play an important role in different chronic inflammatory processes. Metabolic Syndrome (MetS) and Adult Growth Hormone Deficiency (AGHD), both partial and total, are characterized by inflammatory features. The objectives of our cross-sectional study were: 1) to compare LCN2 levels in these clinical pictures; 2) to evaluate the relations between LCN2 levels, BMI and indexes of insulin-resistance. 74 patients were divided in 4 groups as follow: group A, MetS (n=18, 13 males, mean?SEM age 48.63±2.19 ys, BMI 31.22±1.73 kg/m2); group B, total AGHD (n=18, 10 males, aged 52.44±2.61 ys, BMI 30.49±1.87 kg/m2); Group C, partial AGHD (n=19, 6 males, aged 48.63±2.19 ys, BMI 29.11±1.85 kg/m2); Group D, controls (n=19, 6 males, aged 40.26±2.87 ys, BMI 23.25±0.95 kg/m2). AGHD patients were classified according to serum GH peak after iv GHRH+arginine test: total (<9 mg/l if BMI<30 kg/m2 or<4 mg/l if BMI 30 kg/m2), partial (9-16 mg/l if BMI<30 kg/m2 or 4-9 mg/l if BMI > 30 kg/m2). In all patients metabolic parameters were measured (glucose, insulin, HOMA-IR, QUICKI, total- LDL- and HDL-cholesterol, triglycerides, uric acid, IGF-1 and LCN2). LCN2 levels were significantly increased in MetS (mean?SEM A 70.4?5.5; B 54.9?4.0; C 51.5?3.7; D 46.2?4.1 ng/ml), while no significant differences with controls were found in total and partial AGHD. LCN2 levels did not correlate with BMI. A significant positive correlation between LCN2 and HOMA-index was found in controls (r2=0.6, P<0.05), while a positive trend-like, yet not significant, was observed in partial AGHD. Our data showed an increase in LCN2 plasmatic levels in MetS. Different inflammatory patterns characterize MetS and GHD. The correlation between HOMA index and LCN2 in normal subjects and, possibly, in partial AGHD patients may suggest a modulatory action of LCN2 on insulin resistance.