The current era of sedentary
lifestyle and unhealthy eating habits is increasingly posing as a major cause
of obesity amongst children. The term obesity refers to excess body fat,
unlike being overweight that could be due to several other reasons such as
increased bone weight.
Studies have shown that amongst adults, obese patients have
approximately 4.5% increased risk of being affected with inflammatory arthritis
than the normal population. A possible link between obesity and arthritis
could be due to the presence of adipokines, which are, proteins
released from the adipose tissue or ''fat tissues''. These proteins play an important role in regulating inflammatory/immune
responses. Thus, in obese patients there is a possibility where excess of
adipokines are released into the joint sockets and cause inflammation of joints
leading to arthritis. Studies have
reported that an increased level of leptin, a pro-inflammatory adipokine, is
seen in Rheumatic Arthritis (RA) patients.
This particular study was
primarily conducted to study the prevalence of obesity in patients with Juvenile Idiopathic Arthritis (JIA) and to observe if
there was an association between obesity and disease activity. The study was
based on a database from JIA patients attending a single pediatric rheumatology
clinic in Boston from October 2009 to September 2010. The disease activity of
these patients were calculated based on the Juvenile Arthritis Disease
Activity Score (JADAS 27) which included four main measures: physician
global assessment of disease activity, parent global assessment of child's
well-being, count of joints with active disease (evaluating 27 joints), and ESR
which tests the inflammation rate in the body. The children were classified as
obese, overweight, normal or underweight based on their body mass index (BMI).
The medication undertaken and duration of use by the patients were also noted.
Several statistical analysis
methods were done to understand the association between the disease activity
score (JADAS 27), obesity level and the ESR/degree of inflammation. The results
showed that 18% of the patients from the study with JIA were obese, however, an
exact association between obesity and the disease activity was not established.
The rate of children who were obese with
JIA was nearly identical to otherwise healthy children. Although earlier
studies have indicated an association between obesity and worsened disease
activity in RA patients, this was not observed in this particular study. Other
studies have also indicated that, inflammation or increased disease activity in
obese children could be due to physical inactivity and not exactly due to being
affected by arthritis.
Although there were several limitations to this study such as
small sample size, lack of physical activity, socioeconomic status of patients,
etc., it can be regarded as one of the first studies to explore a
relationship between obesity and disease activity.
To conclude, an association
between obesity and disease activity in children affected with JIA was not
established from this study. However, as the risk of obesity is higher in
children with JIA, it is important for medical practitioners to discuss this
issue with parents having children with JIA.
Obesity and disease activity in juvenile idiopathic
arthritis; Christina Pelajo et al; Pediatric Rheumatology, 2012.