Influence of obesity on the early atherosclerosis in children with juvenile idiopathic arthritis

Background : Chronic inflammatory diseases in children, and among them juvenile idiopathic arthritis (JIA), are considered to be one of the high-risk factors of premature cardiovascular disease. The aim of the study was to assess the relationship between the onset form of the JIA, activity of the disease, traditional risk factors and early atherosclerosis changes in children with JIA.

Material and methods: The study group consisted of 37 children, diagnosed with JIA, with disease duration > 1 year, aged 12.9 yrs, while the control group included 26 healthy children, age and gender matched (Table I). BMI, blood pressure, insulin resistance index (HOMA), lipids, CRP and fibrinogen were assessed as risk factors. Ultrasonographically IMT (intima-media thickness) of common carotid arteries was measured.

Results : In children with JIA, as compared to the control group, we have found a higher SDS-BMI ratio: 0.7 vs. –0.02, p = 0.02; higher level of CRP: 0.39 vs. 0.06 mg/dl, p = 0.008; fibrinogen: 356 vs. 205 mg/dl, p = 0.003; higher systolic blood pressure: 120 vs. 111 mm Hg, p = 0.002 and increased early atherosclerosis changes (IMT): 0.51 vs. 0.43 mm, p = 0.001 (Table II). In 9 overweight/obese JIA children (24%) we found a higher insulin resistance index (HOMA): 3.4 as compared to the healthy group – 1.8 (p = 0.04), and compared to thin JIA children – 1.7 (p = 0.04), higher triglyceride level and systolic blood pressure. Obese JIA children had increased IMT: 0.54 vs. 0.49 mm, p = 0.001 when compared to thin JIA children (Table III, Figure 1). In the correlation analysis we found significant relations between IMT and BMI (r = 0.32, p = 0.026); IMT and SDS-BMI (r = 0.38, p = 0.007); IMT and HOMA (r = 0.38, p = 0.035); CRP and BMI (r = 0.33, p = 0.009), as well as between CRP and systolic blood pressure (r = 0.41, p = 0.004 (Figures 2, 3).

Conclusions : Frequently coexisting overweight/obesity in children with JIA is connected with insulin resistance, higher triglyceride level, higher systolic blood pressure and increased early atherosclerosis in ultrasonographic studies. Medical care of children with JIA should include strategies to maintain proper body weight in order to prevent cardiovascular diseases in the future.