Background/AimsThe prevalence of nonalcoholic fatty liver disease (NAFLD) in Korea has increased recently. The aim of the present study was to determine the regional differences in the prevalence and characteristics of NAFLD.MethodsFrom January 2009 to December 2010, 161,891 Seoul and Gyeonggi-do residents receiving a health examination at our institution were enrolled in this cross-sectional study. After applying exclusion criteria, the data of 141,610 subjects (80,943 males, 60,667 females) were analyzed. The presence of NAFLD was established by ultrasound examination.ResultsThe overall prevalence of NAFLD was 27.3% (38.3% in men, 12.6% in women). When standardized according to age, area, and sex, the prevalence of NAFLD was 25.2%. The age and area standardized prevalence of NAFLD was higher for men (34.4%) than for women (12.2%; P<0.001). The overall prevalence of NAFLD was higher in Gyeonggi-do (27.7%) than in Seoul (26.9%; P<0.001). Among the men, the prevalence of NAFLD was higher in Gyeonggi-do (39.2%) than in Seoul (37.4%; P<0.001), while for the women it was higher in Seoul (13.2%) than in Gyeonggi-do (12.0%; P<0.001).ConclusionsThe regional prevalence of NAFLD differed between Seoul and Gyeonggi-do. Further studies are needed to establish the etiology of this difference.

The ApoB/AI ratio was associated with the prevalence of NAFLD in nondiabetic subjects and was independent of obesity and other metabolic components. This result suggests that NAFLD may provide additional information for atherosclerosis progression and CV risks.

Background/AimsWaist circumference (WC) is a risk factor for metabolic syndrome and is related to insulin resistance (IR) and nonalcoholic fatty liver disease (NAFLD). The purpose of this study was to determine the association between WC and IR and NAFLD in apparently healthy Korean adults.MethodsThe volunteers included in this cross-sectional study comprised 9,159 adults (5,052 men, 4,107 women) who participated in a comprehensive health checkup program. IR was evaluated by the homeostasis model assessment of IR (HOMA-IR) and was considered to be present when the HOMA-IR score was >2. NAFLD was evaluated by ultrasound examination. Elevated alanine aminotransferase (ALT) was defined as >40 IU/L in men and >35 IU/L in women. Logistic regression was performed to determine the odds ratios (ORs) and 95% confidence intervals (95% CIs) for NAFLD, IR, and ALT according to categorized levels of WC.ResultsNAFLD was found in 2,553 (27.9%) of the participants (82.6% men, 17.4% women), while IR and elevated ALT were found in 17.2% (68.1% men, 31.9% women) and 10% (83% men, 17% women), respectively. After adjusting for confounding factors, the prevalence of NAFLD, IR, and elevated ALT was significantly associated with increases in WC quartile: highest quartile for NAFLD in men, OR=15.539, 95% CI=12.687-19.033; highest quartile for NAFLD in women, OR=48.732, 95% CI=23.918-99.288 (P<0.001); and highest quartile for IR in men, OR=17.576, 95% CI=13.283-23.255; highest quartile for IR in women, OR=11.078, 95% CI=7.813-15.708 (P<0.001); highest quartile for elevated ALT in men, OR=7.952, 95% CI=6.046-10.459; and highest quartile for elevated ALT in women, OR=8.487, 95% CI=4.679-15.395 (P<0.001).ConclusionsWC contributes to IR and NAFLD in apparently healthy Korean adults, and thus may be an important factor in the development of IR and NAFLD.