GDF15 and obesity due to melanocortin 4 receptor deficiency: Given that obesity contributes substantially to cardiovascular and other health risks [40], and is one of the most important factors associated with circulating GDF15 levels [17–19], the present study used a BMI cut-off of 25 kg/m2 to assess normal weight or overweight/obesity and analysed the influence of BMI on the relationship between serum GDF15 levels and LEAD.