Introduction:
Metabolic syndrome (MetS) is a complex condition involving obesity, hyperglycemia, dyslipidemia, and hypertension. Preptin, a novel molecule co-secreted with insulin from pancreatic β-cells, has been suggested to play a role in insulin resistance and glucose and lipid metabolism. This study aimed to evaluate the differences in serum preptin levels between healthy controls and MetS patients, and to investigate its relationship with clinical parameters.

Material and methods:
The study included forty MetS patients and forty age- and sex-matched healthy controls. Demographic and clinical data were collected, the serum preptin levels were measured by Enzyme-Linked Immunosorbent Assay (ELISA). The relationships between the serum preptin levels and clinic parameters were assessed.

Results:
Serum preptin levels were significantly higher in MetS patients compared to the control group (53.77 pg/mL vs. 40.77 pg/mL, p<0.001). MetS patients also had higher triglyceride, cholesterol, low-density lipoprotein cholesterol (LDL-C), fasting glucose, Hemoglobin A1c (HbA1c), insulin, and Homeostatic model assessment of insulin resistance (HOMA-IR) values compared to controls (all p<0.001). A positive correlation was found between serum preptin, insulin (r=0.432, %95 CI:0.07-0.57, p=0.0050), and HOMA-IR (r=0.426, %95 CI:0.08-0.56, p=0.0060) in the MetS group.

Conclusions:
The results indicate that serum preptin levels are significantly elevated in MetS patients. Furthermore, high serum preptin levels were positively correlated with insulin and insulin resistance. These results suggest that preptin may be involved in the insulin resistance pathway via insulin-like growth factor II (IGF-II) modulation. Therefore, further extensive studies are required to fully understand the precise role in MetS and underlying mechanisms of preptin.