This study aimed to assess the association between GnRH use/PCa diagnosis and worsening dyslipidaemia through investigating the changes of atherogenic lipid levels, cholesterol ratio and the escalation of lipid-lowering therapy (LLT) in men with T2DM and PCa on/not on GnRH in the nationwide population-based cohorts. The gene discussed is GNRH1; the disease is type 2 diabetes mellitus.