The Association Between Telomere Length and Non-Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis.

[INTRODUCTION] Studies have stated that there has been a close association between the telomere length (TL) and the incidence of non-alcoholic fatty liver disease (NAFLD). The goal of this report is to explore the possible association between TL and NAFLD.

[METHODS] This study adhered to the PRISMA guidelines for systematic reviews. An extensive literature search was conducted in the Cochrane Library, CINAHL, Scopus, PubMed, and Web of Science. The "meta" package in the R programming language, version 4.3.1, was used for statistical analysis.

[RESULTS] The meta-analysis of the included studies showed a pooled standard mean difference (SMD) of -0.25 (95% CI: -0.39 to -0.10), indicating shorter TL in NAFLD patients. Subgroup analyses revealed significant TL shortening in NAFLD patients with body mass index (BMI) <28 (SMD = -0.68, 95% CI: -0.96 to -0.39) and in case-control (-0.35, 95% CI: -0.51 to -0.20) and cohort studies (-0.68, 95% CI: -1.19 to -0.17). An odds ratio (OR) meta-analysis of six studies found that individuals with short TL had 1.72 times higher odds of NAFLD, which was statistically significant (95% CI: 1.23- 2.42, I2 = 85%). Excluding one study reduced heterogeneity (I2 = 37%) and increased the OR to 1.93 (95% CI: 1.45-2.56), confirming a strong association between short TL and NAFLD risk.

[DISCUSSION] The findings suggest a potential link between shorter TL and NAFLD. The odds ratio analyses further emphasized the increased risk of NAFLD in individuals with short TL. Nevertheless, the residual heterogeneity highlights the need for further high-quality, standardized research.

[CONCLUSION] Our findings supported the connection between reduced TL and NAFLD. Regardless of significant between-study diversity, the results remained consistent even after repeated sensitivity evaluations. Despite these findings, the high heterogeneity highlights the need for further well-designed studies to confirm TL as a reliable biomarker for NAFLD risk and progression.