The goal of this clinical trial is to learn if metformin can improve asthma control in overweight and obese children with mild, moderate, or severe asthma. It will also evaluate the safety and metabolic effects of metformin in this population. The main questions the study aims to answer are:
1\) Does metformin improve asthma control, as measured by the Asthma Control Test (ACT) score? 2) Does metformin improve lung function, reduce asthma exacerbations, and improve metabolic and inflammatory markers in overweight/obese children with asthma? Researchers will compare metformin with a placebo (a look-alike substance that contains no active drug) to see if metformin improves asthma outcomes in overweight/obese children with asthma. Participants will take either metformin or a placebo in addition to their standard asthma treatment during the study period. They will attend scheduled clinic visits for asthma assessments, lung function testing, and safety monitoring. Blood, stool, and saliva samples, along with clinical information, will be collected from participants to assess asthma control, and markers related to metabolism and inflammation. Participants will also complete asthma control questionnaires and report medication use and asthma symptoms throughout the study period.