In order to get some further insight into the relationship of PH with obesity, insulin resistance, leptin and hyperglycemia, the present study was designed to analyze the key features of the pulmonary circulation in ZDF at 20 weeks of age, a rat model of obesity, hyperlipidemia, insulin resistance and hyperglycemia, i.e. a clinically relevant model for type 2 diabetes in humans. Here, LEP is linked to obesity due to melanocortin 4 receptor deficiency.