Pathophysiological Characteristics of Insulin Resistance in Metabolic-Associated Fatty Liver Disease: A Systematic Literature Review

Abstract

The recent nosological transition from non-alcoholic fatty liver disease to metabolic-associated fatty liver disease represents a fundamental paradigm shift in contemporary hepatology, explicitly recognizing systemic metabolic dysfunction as the primary pathogenic driver. This systematic analytical review rigorously deconstructs the multidimensional interrelation between insulin resistance and hepatic steatosis progression. Synthesizing empirical data from 15 top-tier clinical and epidemiological studies published between 2018 and 2025, the research identifies insulin resistance not merely as a comorbidity, but as the central pathophysiological catalyst dictating the severity of liver tissue remodeling. The aggregated statistical modeling demonstrates that severe hepatic insulin resistance, mathematically quantified by a HOMA-IR index exceeding 3.8, correlates exponentially with active steatohepatitis and accelerated fibrogenesis. The analysis systematically maps the defective intracellular signaling cascades, specifically highlighting the impaired phosphorylation of insulin receptor substrate-1 (IRS-1) and the subsequent pathological upregulation of sterol regulatory element-binding protein 1c (SREBP-1c), which aggressively amplifies de novo lipogenesis. Furthermore, the review isolates the toxic influx of free fatty acids from insulin-resistant peripheral adipose tissue, which induces severe endoplasmic reticulum stress, mitochondrial beta-oxidation failure, and an aggressive pro-inflammatory cytokine storm driven by TNF-alpha and Interleukin-6. The empirical findings dictate a critical reassessment of existing diagnostic pathways, mandating the routine integration of advanced insulin sensitivity biomarkers and non-invasive elastography in primary care settings. Addressing the underlying metabolic dysregulation through targeted pharmacotherapy—specifically utilizing insulin-sensitizing agents—provides the only mathematically viable strategy to intercept the progression of end-stage liver complications in this high-risk demographic.