Monocyte chemoattractant protein-1 is produced in isolated adipocytes, associated with adiposity and reduced after weight loss in morbid obese subjects

Background: Obesity is associated with insulin resistance and premature atherosclerosis. The human adipose tissue produce several adipokines including monocyte chemoattractant protein (MCP)-1, associated with cardiovascular disease and found to be involved in the pathogenesis of atherosclerosis in vitro. Objective: (1) To compare mRNA levels of MCP-1, leptin and a macrophage-specific marker (CD68) in isolated adipocytes vs stromal-vascular (SV) cells, (2) to compare mRNA levels of MCP-1 in human adipose tissue to circulating MCP-1 and adiposity (eg BMI: kg/m(2)) and (3) investigate the effect of weight loss in obese subjects on circulating MCP-1 and leptin. Results: (1) MCP-1 and CD68 mRNA levels in isolated adipocytes vs SV cells were 17% (P<0.01) and similar to 2% (P<0.001), respectively. Leptin mRNA levels in SV cells were similar to1% of that in isolated adipocytes (P<0.01). ( 2) MCP-1 mRNA levels correlated with circulating MCP-1 (P<0.05) and BMI (P<0.05). (3) A 12% weight loss (P<0.001) was associated with a 25% decrease in insulin levels (P<0.01). Circulating MCP-1 and leptin decreased by 20% (P<0.001) and by 24% (P<0.001), respectively. Discussion: The findings demonstrate that MCP-1 is produced in isolated human adipocytes. In addition, the findings suggest that MCP-1 may be involved in obesity-related health complications and support the hypothesis that weight loss is beneficial by improving the low-grade inflammation observed in obesity.