NPPB and obesity due to melanocortin 4 receptor deficiency: In our study the inverse association between BMI and NTproBNP, observed in non-diabetic patients without CVD, was no longer significant after the inclusion of insulin resistance (HOMA-IR) into the model (Table 3, Model 2), confirming that insulin-resistance is important in linking overweight/obesity to reduced NTproBNP levels.