INS and type 2 diabetes mellitus: Multiple studies have reported that circulating FST levels are moderately elevated in patients with type 2 diabetes mellitus (T2DM) and are positively correlated with fasting glucose, serum insulin, C-peptide, glycated hemoglobin (HbA1c), and indices of hepatic and adipose tissue insulin resistance (IR).[10–12] FST has also been associated with dyslipidemic traits, including higher serum triglycerides and total cholesterol levels,[11] further suggesting a role in systemic glucose and lipid metabolic regulation.