Clinical ScienceThe serum concentration of allograft inflammatory factor-1 is correlated with metabolic parameters in healthy subjects

Obesity is associated with low-grade chronic inflammation characterized by inflamed adipose tissue with increased infiltration of macrophages. The aim of this study was to investigate the correlations between the serum concentration of allograft inflammatory factor-1 (AIF-1), which is a marker of activated macrophages, and metabolic parameters. The serum AIF-1 concentrations were measured in 303 healthy subjects (163 men and 140 women). We then evaluated the relationships between the serum AIF-1 concentrations and metabolic parameters, including fasting plasma glucose levels, serum lipid concentration, uric acid concentration, and waist circumference. The serum AIF-1 concentrations positively correlated with levels of fasting plasma glucose (r = 0.159, P =.0056), hemoglobin A1c (r = 0.169, P = .0032), triglycerides (r = 0.137, P = .0172), and uric acid (r = 0.146, P = .0108) and with waist circumference (r = 0.221, P = .0001) and body mass index (r = 0.185, P = .0012), whereas the serum AIF-1 concentrations inversely correlated with high-density lipoprotein cholesterol level (r = −0.178, P = .0019). Stepwise multiple regression analysis demonstrated that hemoglobin A1c level (β = .133, F = 5.490, P < .05) and waist circumference (β = .197, F = 11.954, P < .05) were independent predictors of the serum AIF-1 concentrations. The serum AIF-1 concentrations correlated with clinical and biochemical metabolic parameters. Allograft inflammatory factor-1 may be a significant predictor of activated macrophages as well as cardiovascular disease in humans.