Virto L, et al. - Researchers assessed if melatonin could interfere with the mechanisms of co-morbidity linking obesity and periodontitis. Significantly lower melatonin concentrations were demonstrated by obese and periodontitis when compared with controls, but these concentrations were even significantly lower in obese experimental model with periodontitis when compared with either periodontitis or obese experimental model. As per data, a key mechanism explaining the co-morbidity effect in the association between obesity and periodontitis could be melatonin.