After considering the adjustment for confounders, participants in Q1 of HDL-C/ApoA-I index had a higher probability of having hypertriglyceridemia (OR: 7.31, 95% CI: 5.03–10.7, p < 0.001), hypoalphalipoproteinemia (OR: 8.40, 95% CI: 5.60–12.7, p < 0.001), NAFLD (OR: 1.72, 95% CI: 1.15–2.58, p = 0.008) and MS (OR: 3.10, 95% CI: 1.97–4.94, p < 0.001) (Supplementary Table 3). The gene discussed is APOA1; the disease is hypoalphalipoproteinemia.