In males, compared with lower SI levels, participants with a higher SI were younger, had higher educational levels, more likely to live in cities, more married, non-smoking, more likely to have dyslipidemia and diabetes, less likely to have arthritis and asthma, and higher creatinine, TG, LDL-c, UA, HB, and lower eGFR, CRP, HDL-c, and Cystatin C, all P < 0.05. The gene discussed is CST3; the disease is metabolic syndrome.