Waist-to-height ratio as a marker of low-grade inflammation in obese children and adolescents

Background: The epidemic of childhood obesity is associated with early atherosclerosis. Several reports have related this event to low-grade inflammation described in obesity. CRP and IL6 are markers that correlate with adiposity. The waist-to-height ratio (WtHR) is an anthropometric marker associated with insulin resistance and inflammation. The objective of this study was to assess the correlation between WtHR, metabolic complications and pro-inflammatory factors in obese children and adolescents. Methods: Weight, height, waist circumference, glycemia, insulin, CRP, TNF-alpha and IL-6 were measured in the baseline sample in 280 patients 6-19 years of age with overweight or obesity (OW/OB) and 112 normal-weight controls. Logistic regression was performed using WtHR as an independent variable. p > 0.05 STATA11. Results: Mean WtHR was 0.6 +/- 0.06 in OW/OB and 0.43 +/- 0.02 in controls (p < 0.01). WtHR was increased in 93% of the OW/OB vs. 2% of the controls. In the OW/OB inflammatory markers were significantly increased (p < 0.01) compared to the controls (CRP 2.2 vs. 0.8; Il-6 2.9 vs. 2.1; and TNF-alpha 6.2 vs. 5.5). In the WtHR > 0.5, insulin resistence and inflammatory markers were significantly increased (p < 0.01) compared to the WtHR < 0.5 (HOMA 3.4 vs. 1.4; CRP 2.3 vs. 0.6; Il-6 2.9 vs. 2.1; and TNF-alpha 6.4 vs. 5.55). In logistic regression, a significant independent association was found between WtHR with CRP (OR1.47), IL6 (OR1.60) and TNF-alpha (OR1.79). Conclusions: Obese children and adolescents have high inflammatory markers that may increase cardiovascular risk. WtHR is associated with low-grade inflammation and may be considered a relevant anthropometric marker in the clinical practice.