NASH/Liver Fibrosis Prevalence and Incidence of Nonliver Comorbidities among People with NAFLD and Incidence of NAFLD by Metabolic Comorbidities: Lessons from South Korea

Abstract

Background: NAFLD incidence, NASH prevalence, NAFLD fibrosis prevalence, incidence of metabolic comorbidities, as well as mortality data in the NAFLD population remain limited. Aims: We used a meta-analytic approach to “stage” NAFLD among the Korean population. Methods: We searched PubMed, Embase, Cochrane Library, and KoreaMed from inception until June 29, 2019 and calculated pooled estimates via random-effects model. Results: We screened 1,485 studies and analyzed 191 eligible studies: 179 (3,556,579 participants) for NAFLD prevalence and outcome analysis and 32 (1,089,785 participants) for NAFLD incidence analysis. NAFLD prevalence was 31.46% overall and 50-60% in those with metabolic risks. The incidence (per 1,000 person-years) of NAFLD was 42.8 overall and 70-77% in those with metabolic risk. The incidence (per 1,000 person-years) of new onset T2DM, hypertension, cardiovascular disease, and chronic kidney disease were found to be 16.9, 47.9, 100.6, and 13.9, respectively. From biopsy data, 30.21% of the NAFLD population had moderate-to-severe steatosis (9 studies, 2,461 participants) and 52.27% had NASH (7 studies, 1,168 participants); 85.41% had fibrosis < stage 2 (8 studies, 1,995 participants). All-cause mortality was 2.6 (1.3 if without malignancy) per 1,000 person-years. Conclusions: The overall prevalence of NAFLD was 31.46% with an incidence rate of 42.8 per 1000 person-years. NASH prevalence was 52% but <15% had significant fibrosis. The prevalence and incidence of non-liver comorbidities was high especially for cardiovascular disease incidence. The burden of NAFLD is high in Korea. Health policy efforts need to be directed towards reversing the course of NAFLD disease.

KASL clinical practice guidelines: Management of nonalcoholic fatty liver disease

“…17 In a meta-analysis of Korean studies, the prevalence of diabetes in patients with NAFLD was 14.2%, higher than the 5.2% of the control group. 83 The results of a meta-analysis of other studies also showed an increase of about 2.2 times in the incidence of T2DM. 84…”

“…85 In a meta-analysis of Korean studies, the incidence of metabolic syndrome was 40.7% in patients with NAFLD and 11.2% in the control group. 83…”

“…In a large-scale cohort study of healthy Koreans, the prevalence and incidence of T2DM in patients with NAFLD (assessed using the NFS) increased with the degree of hepatic fibrosis [ 17 ]. In a meta-analysis of Korean studies, the prevalence of diabetes in patients with NAFLD was 14.2%, higher than the 5.2% of the control group [ 83 ]. The results of a meta-analysis of other studies also showed an increase of about 2.2 times in the incidence of T2DM [ 84 ].…”

“…A prospective Korean cohort study of 46,874 men reported that patients with mild and moderate NAFLD (diagnosed by abdominal ultrasound) had a risk of metabolic syndrome 1.5 and 2 times higher, respectively, than the control group [ 85 ]. In a meta-analysis of Korean studies, the incidence of metabolic syndrome was 40.7% in patients with NAFLD and 11.2% in the control group [ 83 ].…”

Differences among Three Skeletal Muscle Mass Indices in Predicting Non-Alcoholic Fatty Liver Disease: Korean Nationwide Population-Based Study

“…As the Westernized lifestyle and the rate of receiving health screenings have increased, the recent prevalence of NAFLD in Korea has also increased. The prevalence of NAFLD is estimated to be over 30% in Korea [ 10 ]. NAFLD ranges from simple liver steatosis to steatohepatitis, and it can progress to liver cirrhosis and liver failure [ 11 ].…”