HbA1c of 5.8% or higher as the most useful indicator for recommendation of ultrasonography to detect nonalcoholic fatty liver disease

Figure 1. Study flow diagram. We studied 6538 participants. Participants were included if they fulfilled the following criteria: (i) they had undergone abdominal ultrasonography; (ii) they did not have alcoholic liver disease (alcohol intake of ≥20 g/day); (iii) they had no markers of hepatitis B virus (HBV) infection (hepatitis B surface antigen [HBsAg]) or hepatitis C virus (HCV) infection (anti‐HCV antibodies); and (iv) they had no history of HBV infection, HCV infection, autoimmune hepatitis (AIH), or primary biliary cholangitis (PBC). Finally, 4310 participants were enrolled. Of these, 1224 (28.4%) had nonalcoholic fatty liver disease (NAFLD).Study population N = 4310.

Figure 2. Prevalence of dyslipidemia (DL), hypertension (HT), and diabetes mellitus (DM) among participants undergoing health checkups. In total, 2046 (47.5%) of participants had DL, 735 (17.1%) had HT, and 347 (8.1%) had DM. A total of 1425 (33.1%) had only DL, 196 (4.5%) had only HT, and 43 (1.0%) had only DM. A total of 357 (8.3%) had DL and HT, 122 (2.8%) had DL and DM, 40 (0.9%) had HT and DM, and 142 (3.3%) had all three diseases. Many participants had only DL, but very few had only DM.

Figure 3. Prevalence of nonalcoholic fatty liver disease (NAFLD) in the dyslipidemia (DL)‐only, hypertension (HT)‐only, and diabetes mellitus (DM)‐only groups. Among all groups, the prevalence of NAFLD was highest in the DM‐only group. The prevalence of NAFLD in the DM‐only, DL‐only, and HT‐only groups were significantly different from that in participants with none of these three diseases (P < 0.001). DM only, DL(−)HT(−)DM(+); DL only, DL(+)HT(−)DM(−); HT only, DL(−)HT(+)DM(−); None, DL(−)HT(−)DM(−). **P < 0.001, *P < 0.005 (χ2‐test).

Figure 4. Comparison of the prevalence of non‐fatty liver and nonalcoholic fatty liver disease (NAFLD) in the dyslipidemia (DL)‐only, hypertension (HT)‐only, and diabetes mellitus (DM)‐only groups. The prevalence of non‐fatty liver was higher than that of NAFLD in the DL‐only and HT‐only groups. In the overall cohort and in males, the prevalence of NAFLD was higher than that of non‐fatty liver in the DM‐only group. The prevalence of NAFLD was higher in males than in females in all groups. , non‐fatty liver; , NAFLD.

Figure 5. Comparison of the prevalence of non‐fatty liver and nonalcoholic fatty liver disease (NAFLD) in the complications of dyslipidemia (DL), hypertension (HT), and diabetes mellitus (DM). The prevalence of NAFLD was higher than that of non‐fatty liver in participants with complications of two or more factors of metabolic syndrome (DL, HT, and DM) except in females with DL and HT complications. , non‐fatty liver; , NAFLD.

Figure 6. Cutoff value for HbA1c. The prevalence of nonalcoholic fatty liver disease (NAFLD) decreased in the order of an HbA1c level of ≥6.5% (70.8%), 6.0–6.5% (49.3%), 5.6–6.0% (27.2%), and <5.6% (15.8%). There was a significant difference between the groups (P < 0.0001). The HbA1c cutoff value was 5.8% (sensitivity, 57.9%; specificity, 72.6%; area under the curve, 0.70) by receiver operating characteristic curve. The prevalence of NAFLD was significantly higher in participants with an HbA1c level of ≥5.8% (45.6%) than <5.8% (18.7%) (P < 0.0001). HbA1c, hemoglobin A1c. *P < 0.0001 (χ2‐test).