The Importance of Fatty acid binding protein 4 (FABP4) in the diagnosis of Peripheral Arterial Disease (PAD) in the presence of Type 2 Diabetes (T2D)

Background Peripheral arterial disease (PAD) is a serious atherosclerotic cardiovascular disease frequently associated with prolonged type 2 diabetes mellitus (T2D). It is marked by arterial plaque formation that impairs blood flow to the limbs, leading to symptoms like claudication, ischemic rest pain, ulcers, and gangrene. Fatty acid binding protein 4 (FABP4) is a molecule that plays an important role in lipid transport and metabolism regulation. But the role of Fatty acid binding protein 4 in PAD remains poorly understood. Understanding the involvement of FABP4 in PAD could aid early diagnosis and therapeutic strategies. Methodology This is a cross-sectional study cum observational trial. Trial was registered in CTRI (CTRI/2022/12/047992) and the date of registration is 12/12/2022. The study enrolled 90 individuals from West Bengal, India, categorised into healthy controls (n = 30), T2D patients (n = 30), and PAD patients (n = 30; all with T2D and ABI < 0.9). Serum FABP4 levels were measured using ELISA, and physical (ABI, blood pressure, BMI) and biochemical (lipid profile, glucose levels) parameters were evaluated. Statistical analyses included ANOVA, correlation studies, and ROC curve analysis to assess FABP4’s diagnostic utility. Results FABP4 levels were significantly higher in PAD patients compared to both T2D patients and healthy controls. ROC analysis confirmed FABP4’s diagnostic value for PAD (AUC = 0.8257, p < 0.0001), with a cut-off > 3.95 ng/mL indicating PAD and 2.88–3.95 ng/mL indicating the T2D range. FABP4 positively correlated with BMI, ABI, diastolic BP, and fasting glucose, while negatively correlating with systolic BP, total cholesterol, HDL, and LDL cholesterol. Conclusion FABP4 may be a promising biomarker for identifying PAD in individuals with advanced T2D, with cut-off > 3.95 ng/mL aiding in diagnosis in Indian population.