Adiponectin, acylation stimulating protein and complement C3 are altered in obesity in very young children

Childhood obesity is increasing worldwide. This, in turn, is associated with chronic disease risk factors including hyperlipidaemia. The aim of the present study was to examine adiponectin, acylation-stimulating protein (ASP) and its precursor, complement C3, in very young obese and nonobese children and the corresponding associations with plasma lipid and lipoproteins. All three adipose tissue secreted factors are involved in fat metabolism, and little is known of the levels in very young children.

A total of 124 healthy children from 2 to 6 years old were evaluated for weight, height, plasma lipids and adipokines. Based on percentage ideal body weight (%IBW), 60 children were nonobese and 64 were overweight/obese.

ASP and C3 were significantly increased (P = 0.0002 and P < 0.0001, respectively) in obese vs. nonobese, and this pattern held true when separated in three age groups: toddler (2-3 years), preschool (4-5 years) and primary school (6 years). By contrast, adiponectin was significantly decreased (P = 0.04). When separated based on a positive family history of obesity, ASP was increased (P = 0.005). Other than a small (23.4%) increase in plasma triglyceride, all other lipids [cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol and nonesterified fatty acids] were normal. ASP, C3 and adiponectin were strongly correlated with %IBW (r = 0.515, P < 0.0001; r = 0.383, P < 0.0001; r = -0.211, P = 0.03, respectively).

Changes in plasma adipokines are seen in very young obese children in the absence of lipid changes. These changes in ASP, C3 and adiponectin in very young obese children may predispose towards enhanced fat storage (ASP) and decreased fat oxidation (adiponectin) further driving the obesity profile.