Association between Diagnostic microRNAs of Non-Alcoholic Fatty Liver Disease and Type 2 Diabetes: A Meta-Analysis

Non- alcoholic fatty liver disease is a high-risk factor for the morbidity and mortality of type 2 diabetes mellitus. Thus, we conducted a meta-analysis to investigate whether the microRNAs associated with non-alcoholic fatty liver disease are associated with diabetes and their potential to predict diabetes in non-alcoholic fatty liver disease individuals. We conducted a systematic literature search using PubMed, Cochrane library and Embase databases. The literature about circulating microRNA levels in nonalcoholic fatty liver disease individuals was screened according to the inclusion and exclusion criteria. The sensitivity, specificity and area under curve of different microRNAs were summarized. These microRNAs with higher diagnostic efficacy and stability were selected for further analysis in people with diabetes. In all, 10 of 1950 studies determining microRNA expression profiles in non-alcoholic fatty liver disease were included in the final analysis. Using area under curve >= 0.7 as the criterion, we screened out 10 microRNAs that have moderate diagnostic efficacy in non-alcoholic fatty liver disease, including microRNA-122, microRNN-34a, microRNA-99a, microRNA-16, microRNA- 379, microRNA-197, microRNA-181d, microRNA- 146b, microRNA-375 and microRNA-12. The pooled area under curve of microRNA-122 and microRNA-34a in the diagnosis of non-alcoholic fatty liver disease was 0.88 (95 % confidence interval: 0.81-0.96) and 0.86 (95 % confidence interval: 0.82-0.91), respectively. Further, 30 of 2674 studies related to diabetes and the above microRNA were included in the final analysis. The results showed that microRNA-122 and microRNA-34a showed higher stability in non-alcoholic fatty liver disease and diabetes. In conclusion, microRNA-122 and microRNA-34a are common biomarkers of both non-alcoholic fatty liver disease and type 2 diabetes mellitus. However, whether they can be used as effective biomarkers for the early prediction of diabetes in patients with non-alcoholic fatty liver disease lacks valid evidence.