The metabolic syndrome (MS) is a clinical entity of substantial heterogeneity, represented by the combination of obesity (especially central obesity),insulin resistance, impaired glucose tolerance, atherogenic dyslipidemia (high triglyceride levels and low levels of HDL-cholesterol (HDL-C)), and hypertension. Childhood obesity has become more common as a result of urbanization, bad diets, and more sedentary lifestyles.

The incidence of metabolic syndrome is ten times higher in children with obesity, and a special risk factor is the presence of obesity in the pediatric population, the classification of metabolic syndrome is based on standards set by the International Diabetes Federation (IDF).

Our goal is to summarize the diagnostic procedure of metabolic syndrome as well as comorbidity based on conventional methods and modern imaging procedures by analyzing the published papers.

Bronchiolitis is an acute viral disease of lower respitatory pathways in children under 2 years of age. It is manifested by coughing, whistling and refusing food intake. The most common cause of bronchiolitis is a respiratory syncytial virus. Vitamin D is a steroid hormone which is synthesized in the skin after sun exposure or food intake. With discovery of Vitamin D receptors and hydroxylated enzymes in immune cells, a potential role for Vitamin D in maintaining immune homeostasis was seen. It has been established that Vitamin D induces a change of the antimicrobial polypeptide, cathelicidin, which has both antibacterial and antiviral roles.