Clinical, functional, and nutritional-metabolic characteristics of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a global medical and social problem, with its prevalence increasing amid the obesity pandemic. Studying disease progression in patients with different nutritional statuses requires the development of differentiated diagnostic approaches. The study aimed to evaluate clinical, functional, and nutritional-metabolic parameters and develop additional diagnostic markers for nutritional disorders in NAFLD. Materials and methods .A crosssectional, open-label, non-randomized study was conducted, involving 349 participants (235 NAFLD patients 113 without obesity and 122 with obesity and 114 controls). All participants underwent nutritional status assessment, including anthropometric measurements, bioimpedance analysis, evaluation of eating behavior , and dietary intake analysis. NAFLD patients additionally underwent non-invasive fibrosis assessment via transient elastography and calculated indices (FIB-4, BARD). Laboratory tests included adipokine profiling (visfatin, adipsin, PAI-1), 25(OH) vitamin D levels, and protein metabolism markers (prealbumin). Results . NAFLD patients exhibited significant nutritional disturbances: reduced protein intake (< 0.7 g/kg body weight), predominant emotional eating (40.1 % in obese vs. 19.8 % in controls), and physical inactivity (72.1 %). Bioimpedance analysis revealed decreased active cell mass (42 % in obese vs. 49 % in controls) and increased fat mass (41 % vs. 32 %). Laboratory findings confirmed hypoprealbuminemia (18.1 vs. 23.0 mg/dL), vitamin D deficiency (17.5 vs. 23.0 ng/mL), and adipokine dysregulation. Fibrosis stage F2–F4 was 5.5 times more frequent in obese patients (p < 0.001). Multivariate analysis identified significant fibrosis-associated predictors: waist circumference (β = 0.420), fat mass percentage (β = 0.900), prealbumin (β = –0.184), and 25(OH)D (β = –0.058). Conclusions . Differentiated diagnostic models were developed: for non-obese patients, key markers were anthropometric indices (waist-to-hip ratio), adipokines, and vitamin D; for obese patients – active cell mass percentage (% ACM), prealbumin, and vitamin D. Universal fibrosis predictors included body composition parameters, prealbumin levels, and adipokines.