INS and metabolic syndrome: Notably, participants with higher CMI tended to be males [37.62% (95% CI: 35.91–39.37) in CMIQ1 vs. 59.34% (95% CI: 57.56–61.1) in CMIQ4], with older ages, higher smoking status, higher education levels, more non-drinkers, more overweight or obese, married, with lower income, and more likely to have lower levels of HDL, higher levels of BMI, WC, WT, FPG, HbA1c, INS, HOMA-IR, TC, TG, LDL, BUN, and Scr (all P < 0.05), with higher prevalence of hypertension, dyslipidemia, CVD, CKD, and cancer.