Association of HIF1α, BNIP3, and BNIP3L with Hypoxia-Related Metabolic Stress in Metabolic Syndrome

Background and Objectives: Metabolic syndrome (MetS) is a complex condition marked by insulin resistance, central obesity, dyslipidemia, and chronic inflammation. Emerging evidence highlights the roles of hypoxia and mitochondrial stress in its pathophysiology. Hypoxia-inducible factor-1 alpha (HIF1α) and the mitophagy-associated proteins BNIP3 and BNIP3L are key components of hypoxia-responsive mitochondrial stress signaling. This study aimed to evaluate the circulating levels of HIF1α, BNIP3, and BNIP3L in MetS and to explore their associations with metabolic and inflammatory parameters. Materials and Methods: Serum concentrations of HIF1α, BNIP3, and BNIP3L were measured by ELISA in 40 patients with MetS and 40 age and sex-matched controls. Biochemical, hematological, and anthropometric parameters were assessed, and receiver operating characteristic (ROC) analyses were performed to evaluate diagnostic performance. Results: Serum levels of HIF1α, BNIP3, and BNIP3L levels were significantly higher in MetS patients compared with controls (p = 0.001). ROC analysis demonstrated strong diagnostic potential, particularly for BNIP3 (AUC = 0.928), followed by HIF1α (AUC = 0.885) and BNIP3L (AUC = 0.770). These markers showed significant associations with metabolic indicators such as BMI, fasting glucose, triglycerides, and inflammatory markers. Conclusions: The coordinated upregulation of circulating HIF1α, BNIP3, and BNIP3L in MetS is associated with metabolic dysregulation and systemic inflammation, reflecting alterations in hypoxia-responsive mitophagy-associated signaling rather than direct functional impairment of mitophagy. These findings support the potential relevance of these markers as indicators of metabolic stress in MetS. Further tissue-based and mechanistic studies are warranted to clarify their role in disease pathophysiology.