Serum tryptophan, insulin, and serotonin in type 2 diabetic patients: A pilot study

Introduction and Aim: T2DM being a most prevalent metabolic disorder globally and is mainly triggered by two important factors: decreased insulin secretion by pancreatic β-cells and the defective insulin-sensitivity of tissues. Recent studies found that other factors influence insulin release are amino acids, fatty acids, incretins, certain neurotransmitters, and some of the pituitary hormones. Higher levels of peripheral serotonin in diabetic people have drawn attention to the involvement of metabolic homeostasis and cellular sensors. Thus, the aim of this study is to screen the association of tryptophan, serotonin, and insulin in T2DM. Materials and Methods: Serum samples from T2DM patients (n=80) were divided into 2 groups depending on HbA1C levels having good to moderate (6.5-8) and poor (>8) glycemic control to study the levels of tryptophan, serotonin, and insulin. Results: A boarderline statistically significant increase was observed in Serotonin levels in group 2 when compared with group 1. Statistical analysis showed a negative correlation between insulin and serotonin in group 1, whereas in group 2 a negative correlation has observed between HbA1C and insulin. Conclusion: The study report shows an increase in serum serotonin levels with increase in insulin levels and hyperglycemia.