The impact of obstructive sleep apnea on nonalcoholic fatty liver disease

Comparison of the predictive value of TyG index and METS-IR for OSA combined with NAFLD: a retrospective observational study based on a physical examination population

BACKGROUND

Obstructive sleep apnoea (OSA), Non-alcoholic fatty liver disease (NAFLD) and insulin resistance (IR) are interlinked. The aim of our study was to investigate the predictive value of metabolic score for insulin resistance (METS-IR) and triglyceride-glucose(TyG) index in relation to OSA combined with NAFLD in physical examination population.

METHODS

This is a retrospective observational study. 329 physical examiners who attended the healthcare centre of the First Affiliated Hospital of Wenzhou Medical University for polysomnography and abdominal ultrasonography (or CT abdominal scanning) from September 2021 to July 2024. Subjects were categorized into two groups according to the presence or absence of combined NAFLD. Logistic regression analysis and restricted cubic spline model (RCS) were used to evaluate the relationship between TyG index and METS-IR and NAFLD. The predictive value of TyG index and METS-IR for NAFLD was determined by receiver operating characteristic curves (ROC curves).

RESULTS

A total of 329 subjects were analyzed. The prevalence of NAFLD increased with increasing TyG index (P for trend < 0.001), and METS-IR showed an increasing-decreasing-increasing trend with NAFLD risk (P for trend < 0.001). RCS analysis showed a dose-response relationship between NAFLD risk and METS-IR (p = 0.012) and a linear relationship with the TyG index (p = 0.078), with a significant increase in the risk of NAFLD when the METS-IR exceeded a threshold of 47.47 (OR = 1). Compared with TyG index (AUC = 0.775, 95% CI: 0.711-0.828), METS-IR (AUC = 0.778, 95% CI: 0.716-0.836) had a higher predictive value for NAFLD in the OSA physical examination population.

CONCLUSIONS

In the OSA population, TyG index and METS-IR had predictive value for the development of NAFLD, with METS-IR being superior to TyG index.

Hidden in the Fat: Unpacking the Metabolic Tango Between Metabolic Dysfunction-Associated Steatotic Liver Disease and Metabolic Syndrome

Metabolic syndrome (MetS) and metabolic dysfunction-associated steatotic liver disease (MASLD) are closely related, with rapidly increasing prevalence globally, driving significant public health concerns. Both conditions share common pathophysiological mechanisms such as insulin resistance (IR), adipose tissue dysfunction, oxidative stress, and gut microbiota dysbiosis, which contribute to their co-occurrence and progression. While the clinical implications of this overlap, including increased cardiovascular, renal, and hepatic risk, are well recognized, current diagnostic and therapeutic approaches remain insufficient due to the clinical and individuals' heterogeneity and complexity of these diseases. This review aims to provide an in-depth exploration of the molecular mechanisms linking MetS and MASLD, identify critical gaps in our understanding, and highlight existing challenges in early detection and treatment. Despite advancements in biomarkers and therapeutic interventions, the need for a comprehensive, integrated approach remains. The review also discusses emerging therapies targeting specific pathways, the potential of precision medicine, and the growing role of artificial intelligence in enhancing research and clinical management. Future research is urgently needed to combine multi-omics data, precision medicine, and novel biomarkers to better understand the complex interactions between MetS and MASLD. Collaborative, multidisciplinary efforts are essential to develop more effective diagnostic tools and therapies to address these diseases on a global scale.

Different expression of circulating microRNA profile in tibetan OSAHS with metabolic syndrome patients

Recent empirical investigations reinforce the understanding of a profound interconnection between metabolic functions and Obstructive Sleep Apnea-hypopnea Syndrome (OSAHS). This study identifies distinctive miRNA signatures in OSAHS with Metabolic Syndrome (Mets) patients from healthy subjects, that could serve as diagnostic biomarkers or describe differential molecular mechanisms with potential therapeutic implications. In this study, OSAHS with MetS patients showed significantly higher Apnea Hyponea Index(AHI), but lower oxygen desaturation index(ODI 4/h) and minimum pulse oxygen saturation(SpO2). A total of 33 differentially expressed miRNAs by Limma method, and 31 differentially expressed miRNAs by DEseq2 method were screened. In addition, GO enrichment analysis of target genes associated with differentially expressed miRNAs revealed significant enrichment in metabolic processes, suggesting that the differential expression of OSAHS-induced miRNAs may contribute to the progression of metabolic disorders through the regulation of metabolic pathways. Furthermore, KEGG pathway enrichment analysis revealed significant enrichment in the p53 signaling pathway and several other pathways. Notably, the Wnt signaling pathway, PI3K-Akt signaling pathway, cAMP signaling pathway, and AMPK signaling pathway are implicated in the metabolic processes of glucose dysregulation and lipid homeostasis, as well as the pathogenesis of hypertension associated with OSAHS. We identified IKBKB, PIK3R1, and MAP2K1 as the target genes most associated with Mets pathogenesis in OSAHS, regulated by miR-503-5p, miR-497-5p, and miR-497-5p, respectively. Additionally, the target genes of differentially expressed miRNAs between Tibetan OSAHS patients with MetS and healthy individuals are regulated by transcription factors such as NR2C1, STAT3, STAT5a, HIF1a, ETV4, NANOG, RELA, SP1, E2F1, NFKB1, AR, and MYC. In conlusion, we found differentially expressed miRNAs in Tibetan OSAHS patients with Metabolic Syndrome for the first time. Enrichment analysis results suggest that differentially expressed miRNAs may involved in the development of OSAHS-related metabolic disorders by regulating metabolic pathways. We also revealed that IKBKB, PIK3R1, and MAP2K1 are mostly associated with metabolic disorder in OSAHS, and miR-503-5p and miR-497-5p may regulate the development of MetS associated with OSAHS by modulating IKBKB, PIK3R1, and MAP2K1.

Association of Obstructive Sleep Apnea with Nonalcoholic Fatty Liver Disease: Evidence, Mechanism, and Treatment

Obstructive sleep apnea (OSA), a common sleep-disordered breathing condition, is characterized by intermittent hypoxia (IH) and sleep fragmentation and has been implicated in the pathogenesis and severity of nonalcoholic fatty liver disease (NAFLD). Abnormal molecular changes mediated by IH, such as high expression of hypoxia-inducible factors, are reportedly involved in abnormal pathophysiological states, including insulin resistance, abnormal lipid metabolism, cell death, and inflammation, which mediate the development of NAFLD. However, the relationship between IH and NAFLD remains to be fully elucidated. In this review, we discuss the clinical correlation between OSA and NAFLD, focusing on the molecular mechanisms of IH in NAFLD progression. We meticulously summarize clinical studies evaluating the therapeutic efficacy of continuous positive airway pressure treatment for NAFLD in OSA. Additionally, we compile potential molecular biomarkers for the co-occurrence of OSA and NAFLD. Finally, we discuss the current research progress and challenges in the field of OSA and NAFLD and propose future directions and prospects.