Nutritional Status and Clinical Characteristics in Children With Juvenile Rheumatoid Arthritis

Growth patterns in early juvenile idiopathic arthritis: Results from the Childhood Arthritis Prospective Study (CAPS)

OBJECTIVES

To investigate early vertical growth patterns and factors associated with poor growth in a modern inception cohort of UK children with juvenile idiopathic arthritis (JIA) using data from the Childhood Arthritis Prospective Study (CAPS).

METHODS

A study period of 3 years was chosen. Children included in this analysis had a physician diagnosis of JIA and had height measurements available at both baseline and at 3-years of follow-up. Height is presented as z-scores calculated using World Health Organisation growth standards for age and gender. Growth over the 3-year period was assessed using change in z-score and height velocity. Univariable and multivariable linear regressions were used to identify factors associated with height z-score at baseline and change of height z-score at 3 years.

RESULTS

568 patients were included; 65% female, median baseline age 7.4 years [interquartile range (IQR) 3.6, 11.2], median symptom duration at presentation 5.5 months [IQR 3.1, 11.6]. Height z-score decreased significantly from baseline to 3 years (p ≤ 0.0001); baseline median height z-score was -0.02 (IQR -0.71, 0.61), decreasing to -0.47 (IQR -1.12, 0.24) at 3 years. Growth restriction, defined as change of height z-score ≤-0.5, was observed in 39% of patients. At 3 years, higher baseline height z-score was the strongest predictor for a negative change in height z-score [-0.3 per unit of baseline height z-score (95% CI: -0.36, -0.24), p < 0.0001].

CONCLUSIONS

Although overall height at 3 years after initial presentation to rheumatology is within the population norm, as a cohort, children with JIA experience a reduction of growth in height over the first 3 years of disease. Late presentation to paediatric rheumatology services is associated with lower height at presentation. However, patients with the lowest height z scores at presentation were also the most likely to see an improvement at 3 years. The impact of JIA on growth patterns is important to children and families and this study provides useful new data to support informed clinical care.

Inactive Disease in Enthesitis-related Arthritis: Association of Increased Body Mass Index

OBJECTIVE

Patients with enthesitis-related arthritis (ERA) were less likely to achieve and sustain inactive disease than children with other subtypes of juvenile idiopathic arthritis. The aim of this study was to evaluate the effect of increased body mass index (BMI) on clinical features of the disease and to investigate whether being overweight or obese limits the possibility of achieving clinically inactive disease in patients with ERA.

METHODS

The hospital charts of 72 patients with ERA were reviewed. Demographic and clinical findings were recorded. Patients were divided into 2 groups according to whether they had "healthy weight" (BMI < 85th percentile) or "increased weight" (BMI ≥ 85th percentile) at baseline. The primary outcome of this study was to achieve inactive disease at 1 year after the initiation of therapy. The inactive disease criterion of Wallace, et al was used to define inactive disease status.

RESULTS

Twenty patients had increased BMI. The frequency of tarsitis and ankle involvement was higher in patients with increased weight. Thirty-seven patients were inactive at the end of 1 year. In univariate analyses, male sex, increased BMI, ankle involvement, and tarsitis were found to be associated with failure to achieve inactive disease. Multivariate backward stepwise regression analyses revealed that failure to achieve clinically inactive disease was associated with increased BMI and ankle involvement.

CONCLUSION

Being overweight or obese was associated with failure to achieve inactive disease in patients with ERA. Because body weight is a modifiable factor, individualized interventions may have clinical implications for better therapeutic outcome.

Obesity and disease activity in juvenile idiopathic arthritis

BACKGROUND

Children with physical disabilities may have an increased risk for obesity and obesity might be a risk factor for inflammatory arthritis. The aims of this study were: to determine the prevalence of obesity in children and adolescents with juvenile idiopathic arthritis (JIA), and to examine the association between obesity and disease activity in this population.

FINDINGS

A cross-sectional analysis of all patients with JIA attending a pediatric rheumatology clinic, between October 2009 and September 2010, was performed. A linear regression model was used to explore the association between obesity and disease activity in patients with JIA. A total of 154 subjects were included in the analysis; median age was 10.6 years, 61% were female, and 88% were white. Obesity was found in 18%, 12% were overweight, and 3% were underweight. There was no association between obesity and JADAS-27 (Juvenile Arthritis Disease Activity Score 27), physician's assessment of disease activity, parent's assessment of child's well-being, erythrocyte sedimentation rate, number of active joints, or C-reactive protein (p-value range 0.10 to 0.95).

CONCLUSIONS

Although 18% of patients with JIA were obese, we did not find an association between obesity and disease activity. As obesity confers an additional health risk in children with arthritis, addressing this co-morbidity should be a health priority in patients with JIA. Future studies are necessary to further explore potential associations between obesity, development of JIA, and disease activity.