Obesity and clustering of cardiovascular disease risk factors are associated with elevated plasma complement C3 in children and adolescents

Objectives To investigate the relationship among obesity, cardiovascular disease risk factors (CVDRFs), and plasma complement C3 concentration in children and adolescents. Methods In a nationwide survey conducted between 1992 and 2000, all school children aged 6–18 yr with abnormal results in repeated urine samples, including hematuria, proteinuria, and glucosuria (n = 97 312; 36 557 boys and 60 755 girls), were investigated for their body mass index (BMI), blood pressure, fasting plasma glucose, total cholesterol, and plasma complement C3 concentrations. Results Children in the higher percentile groups for BMI or having more CVDRFs, namely, hypertension, diabetes, and hypercholesterolemia, had higher plasma C3 concentrations independently (p for both trends