Adiponectin exhibited positive correlations with hip circumference, HDL-C, and pNN50 while HDL-C showed negative correlations with the number of MetS criteria, obesity, IR, and leptin, but positive correlations with parasympathetic HRV (SDSD and RMSSD) (p < 0.05 all), suggesting a protective role across multiple systems. The gene discussed is LEP; the disease is metabolic syndrome.