Serum leptin levels (mean ± SEM; ng/mL) at the end of the treatment period are shown in Figure 4A. There was a significant effect of diabetes (p < 0.0001; F (1,19) = 150.4), vector treatment (p < 0.001; F (1,19) = 17.19) and interaction (p < 0.05; F (1,19) = 7.02). Here, LEP is linked to diabetes mellitus.