The Study

Juvenile idiopathic arthritis (JIA) is a rare disease that causes inflammation in the joints. It is of unknown origin and has no cure.

Previous investigations in studies with rheumatoid arthritis (another inflammatory disease) have indicated that overweight patients typically have worse disease progression and a poorer response to treatment. In general, we know that excess weight can pose mechanical stress on even an otherwise healthy individual. Additionally, we know that inflammatory molecules can be released by fat tissue.

However, until now, there hasn’t been a study specifically investigating the effect of body weight in JIA.

A new study published in Frontiers in Pharmacology has suggested that their may be a correlation between body weight and JIA disease course. General findings included-

• Overweight/obese patients were more likely to experience inflammation in their lower limb joints.
• Higher body weight could have a negative effect on patient’s response to JIA treatment
• Higher body weight could have a negative effect on JIA disease course
• Being overweight may also exacerbate symptoms of other inflammatory diseases

The research team analyzed the records of JIA patients treated at Meyer Children’s Hospital in Italy. 110 records were reviewed in total. 80 of the patients had a BMI in-between the 5th and 85th percentile (a healthy weight). 30 of the patients had a BMI over the 85th percentile (an overweight or obese weight).

Before the patients received treatment, those in the overweight group had a significantly greater amount of inflammation of the joints in their legs. However, levels of C-reactive protein, another measure of inflammation, did not vary significantly between the two groups. Since other levels of inflammation were not significant, the researchers weren’t able to confirm whether or not the observed joint inflammation in the heavier group was just a coincidence.

After the patients received DMARD treatment, 69 of them achieved remission. Of these, 35 individuals later relapsed. However, neither of these evaluations were statistically significant. That said, slightly fewer patients in the overweight group achieved remission and slightly more individuals in the overweight group relapsed.

Limitations

There is a major issue with this study. The sample size was very small. With such small numbers, its hard to know whether or not the results came by chance or fact. This is especially true because the results were not very dramatic.

However, this research made clear that there is at least a strong possibility of correlation, and hopefully other studies will be initiated based on these findings. With further studies including more patients, results should be more clear.

In the meantime, we can continue to act on the knowledge we already have. For instance, we know from other, large studies, that obesity is not favorable for overall health. Since we already know that staying at a healthy weight is beneficial, it doesn’t hurt to heed the warnings from this study.

You can read more about this investigation and its findings here.