Circulating oxytocin levels plummet in obesity and newly diagnosed type 2 diabetes, correlating with adverse metabolic markers

The global prevalence of obesity and type 2 diabetes (T2D) continues to rise, posing significant public health challenges. These metabolic disorders are characterized by dysregulated energy balance, impaired insulin sensitivity, and chronic low-grade inflammation. Current treatments often manage symptoms but struggle to address the underlying metabolic dysregulation comprehensively. Oxytocin, a hypothalamic neuropeptide, has emerged as a potential key regulator of energy balance, appetite, and insulin sensitivity, suggesting a role beyond its classical reproductive functions. Understanding its circulating levels in these conditions could reveal novel biomarkers and therapeutic targets.

This cross-sectional study investigated circulating oxytocin levels and metabolic parameters in 96 participants. The cohort was divided into 48 individuals with normal glucose tolerance (NGT) and 48 with newly diagnosed T2D, with each group further subdivided into normal-weight and obese categories. Researchers measured anthropometric indices, glucose and lipid profiles, insulin, HbA1c, and high-sensitivity C-reactive protein (hs-CRP). Insulin resistance and β-cell function were quantitatively assessed using the HOMA model to provide a comprehensive metabolic evaluation.

Circulating oxytocin levels were markedly reduced in patients with type 2 diabetes compared to NGT individuals (p < 0.01), and similarly, in obese participants compared to their normal-weight counterparts (p < 0.01). This reduction in oxytocin was consistently associated with a poorer metabolic profile. Specifically, low oxytocin levels showed a significant negative correlation with BMI, waist circumference, HbA1c, glucose, insulin, various lipids, and hs-CRP. Conversely, oxytocin levels were positively correlated with β-cell function, suggesting a protective role. Multiple regression analysis further identified 2-hour glucose, BMI, and total cholesterol as independent predictors of circulating oxytocin levels. These findings underscore a strong link between oxytocin deficiency and metabolic dysfunction.

Circulating oxytocin levels were significantly lower in patients with T2D compared to NGT (p < 0.01), and in obese compared to normal-weight participants (p < 0.01).