Obesity as a comorbidity in children and adolescents with autoimmune rheumatic diseases

White adipose tissue is no longer considered an inert tissue mainly devoted to energy storage but is emerging as an active participant in regulating physiologic and pathologic processes, including immunity and inflammation. Macrophages are components of adipose tissue and actively participate in its activities. Furthermore, cross-talk between lymphocytes and adipocytes can lead to immune regulation. Adipose tissue produces and releases a variety of proinflammatory and anti-inflammatory factors, including the adipokines leptin, adiponectin, resistin, and visfatin, as well as cytokines and chemokines, such as TNF-alpha, IL-6, monocyte chemoattractant protein 1, and others. Proinflammatory molecules produced by adipose tissue have been implicated as active participants in the development of insulin resistance and the increased risk of cardiovascular disease associated with obesity. In contrast, reduced leptin levels might predispose to increased susceptibility to infection caused by reduced T-cell responses in malnourished individuals. Altered adipokine levels have been observed in a variety of inflammatory conditions, although their pathogenic role has not been completely clarified.

Juvenile idiopathic arthritis is a broad term that describes a clinically heterogeneous group of arthritides of unknown cause, which begin before 16 years of age. This term encompasses several disease categories, each of which has distinct methods of presentation, clinical signs, and symptoms, and, in some cases, genetic background. The cause of disease is still poorly understood but seems to be related to both genetic and environmental factors, which result in the heterogeneity of the illness. Although none of the available drugs has a curative potential, prognosis has greatly improved as a result of substantial progresses in disease management. The most important new development has been the introduction of drugs such as anticytokine agents, which constitute a valuable treatment option for patients who are resistant to conventional antirheumatic agents. Further insights into the disease pathogenesis and treatment will be provided by the continuous advances in understanding of the mechanisms connected to the immune response and inflammatory process, and by the development of new drugs that are able to inhibit selectively single molecules or pathways.

A systematic review and meta-analysis was performed to investigate the ability of simple measures of childhood obesity such as body mass index (BMI) to predict future obesity in adolescence and adulthood. Large cohort studies, which measured obesity both in childhood and in later adolescence or adulthood, using any recognized measure of obesity were sought. Study quality was assessed. Studies were pooled using diagnostic meta-analysis methods. Fifteen prospective cohort studies were included in the meta-analysis. BMI was the only measure of obesity reported in any study, with 200,777 participants followed up. Obese children and adolescents were around five times more likely to be obese in adulthood than those who were not obese. Around 55% of obese children go on to be obese in adolescence, around 80% of obese adolescents will still be obese in adulthood and around 70% will be obese over age 30. Therefore, action to reduce and prevent obesity in these adolescents is needed. However, 70% of obese adults were not obese in childhood or adolescence, so targeting obesity reduction solely at obese or overweight children needs to be considered carefully as this may not substantially reduce the overall burden of adult obesity.