Serum Amyloid A concentration is increased in obese children and adolescents

To compare the circulating concentrations of the acute-phase protein serum amyloid A (SAA) in lean, overweight, and obese children and adolescents and analyze the influence of body fat.

A total of 63 children and adolescents (65% girls) with an average age of 12.1 +/- 2.7 years (range, 6 to 18 years) were included in the study. Each child was classified on the basis of age- and sex-specific body mass index (BMI) percentile as normal weight (BMI <85th percentile; n = 17), overweight (BMI >/=85th and <95th percentiles; n = 26), or obese (BMI >/=95th percentile; n = 20). Body fat was estimated by air-displacement plethysmography.

Both overweight and obese children exhibited significantly increased circulating SAA concentrations (log SAA: lean, 0.66 +/- 0.20; overweight, 0.83 +/- 0.29; obese, 0.96 +/- 0.21; P = .002) compared with the lean children. Significant correlations were found between log SAA and body fat (r = 0.48; P < .0001). In multiple linear regression analysis, log C-reactive protein (CRP) (P = .014) and body fat (P = .031) emerged as significant predictors of log SAA.

Plasma SAA concentrations are elevated in overweight and obese children, being strongly related to adiposity and log CRP. This finding suggests that increased body fat may contribute to the development of a low-grade chronic proinflammatory state at an early age, possibly contributing to the obesity-associated cardiovascular disease risk.