A recent META regression analysis study suggested that leptin levels were significantly higher in severe asthma cases than in mild asthma cases in the overall population and in Asians, independent of age and the sex ratio of the overall population, and may be a risk predictor and prognostic marker of asthma, which may be related to the association of leptin with obesity and body mass index in asthmatics (Wang et al., 2023d). Here, LEP is linked to obesity due to melanocortin 4 receptor deficiency.