Whilst it is apparent that other chronic inflammatory conditions can exacerbate asthma, there has been some suggestion that obesity alone may not always be sufficient to drive heightened AHR, with a particular study by Karampatakis and co-workers highlighting that only subjects with obesity and impaired glucose control and/or insulin resistance may drive AHR [78]. Here, AHR is linked to obesity due to melanocortin 4 receptor deficiency.