Objective: Waist circumference (WC) is widely accepted as risk factor for cardiovascular disease and metabolic syndrome (MS). Non-alcoholic fatty liver disease (NAFLD) is a feature of the MS. A contribution of MS, and especially of WC, to liver fibrosis in children with NAFLD is strongly suspected.
Design: Cross-sectional study.
Setting: Department of Hepatogastroenterology and Nutrition, Paediatric Hospital 'Bambino Gesù', Roma, Italy.
Patients: 197 consecutive Caucasian children with NAFLD (136 males and 61 females) aged 3 to 19 years.
Main outcome measures: Multivariable logistic regression models were used to examine the contribution of gender, age, body mass index (BMI) and MS components (WC, HDL-cholesterol, triglycerides, blood pressure and glucose) to the odds of liver fibrosis as detected by liver biopsy.
Results: 92% of the children had BMI ≥ 85th percentile and 84% had a waist ≥ 90th percentile for gender and age. Ten percent of the children had MS and 60% had liver fibrosis, mostly of low degree. At multivariable analysis, waist was the only MS component to be associated with liver fibrosis. This was seen both when the components of the MS were coded as dichotomous (OR = 2.40; 95%CI 1.04 to 5.54) and continuous (OR = 2.07, 95%CI 1.43 to 2.98 for 5 cm increase of waist). In the latter case, also age was associated with the outcome (OR = 0.70, 95%CI 0.55 to 0.89 for 1 year increase).
Conclusions: Abdominal rather than generalized obesity contributes to liver fibrosis in children with NAFLD. Waist is also the only component of the MS to be associated with fibrosis in these children. Therefore, the presence of abdominal obesity is an additional criterion for the selection of children and adolescents who should undergo extensive investigation, including liver biopsy.