Background: Metabolic syndrome (MetSy) is characterized by the presence of obesity, hypertension, altered glucose metabolism, and/or increased non-HDL cholesterol. This study aimed at elucidating the association between obesity with subclinical target organ damage and biochemical parameters included in MetSy pathogenesis.

Methods: This study included 130 apparently healthy subjects. Plasma levels of oxidized-LDL-cholesterol (ox-LDL-Chol), nitric oxide (NO) metabolites, inducible NO synthase (iNOS), and plasminogen activator inhibitor-1 (PAI-1) were measured. Non-invasive assessment of liver disease included fatty liver index (FLI) and nonalcoholic fatty liver disease (NAFLD) fibrosis score. Carotid artery plaques were assessed by color Doppler imaging.

Results: A total of 65 patients with MetSy were included in the MetSy group, while 65 without MetSy entered the control group. Ox-LDL-Chol levels were higher in the MetSy group compared to the control group, regardless of obesity. Levels of NO metabolites were similar in obese and non-obese patients with MetSy, but lower than in the control group. Obese patients with MetSy had higher iNOS values compared to non-obese ones, with similar PAI-1 levels. NAFLD was present in all obese patients with MetSy compared to 70% of non-obese subjects. Hypertension, higher values of waist-to-hip ratio, PAI-1, and remnant cholesterol were associated with NAFLD. Finding of asymptomatic carotid plaques was associated with patients' age, hypertension, and higher waist-to-hip ratio.

Conclusion: MetSy and obesity significantly alter the levels of NO metabolites, iNOS, ox-LDL-Chol, and PAI-1. High prevalence of NAFLD in obese patients with MetSy requires active screening and treatment of potential risk factors.