Exploring serum miR-33b as a novel diagnostic marker for hypercholesterolemia and obesity: insights from a pilot case-control study

Obesity and atherosclerosis are significant metabolic diseases characterized by disrupted lipid metabolism. MicroRNAs (miRNAs) are small, conserved, non-coding RNA sequences consisting of approximately 22 nucleotides, playing crucial roles in biological and pathological functions. Among these, miR-33a/b is particularly associated with metabolic diseases, notably obesity and atherosclerosis. In this pilot case-control study, 45 subjects were examined, and serum miR-33b levels were measured in three groups: a control group, hypercholesterolemic (HC) subjects without obesity (HC group), and obese subjects without hypercholesterolemia (obese group). Serum miR-33b levels were determined using the real-time PCR method. The expression of miR-33b was significantly higher in the HC and obese groups compared to the control group (p < 0.001). The Body mass index (BMI) in the obese group was significantly higher than in the control and HC groups (p < 0.001). Additionally, serum total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-c) levels were higher in the HC group compared to both the control and obese groups. Our study demonstrated a correlation between serum miR-33b levels and HC and obesity. Finally, the ROC analysis demonstrated that miR-33b had an AUC of 0.74 for identifying hypercholesterolemia and an AUC of 0.76 for identifying obesity, indicating its acceptable diagnostic value alongside traditional markers. Therefore, serum miR-33b levels can be considered as a potential biomarker for obesity and hypercholesterolemia, but these finding are preliminary and further investigation is necessary in larger samples to confirm these associations.