INS and endothelial dysfunction: We observed that plasma NO levels are higher in responders than in non-responders, and NO can predict the antihypertensive response to amlodipine, which may be attributed to elevated BMI, insulin, and C-peptide levels in non-responders, indicating the presence of insulin resistance, which mediates endothelial dysfunction leading to reduced NO synthesis and utilization (Clayton et al., 2023).