The OXTR Polymorphism Stratified the Correlation of Oxytocin and Glucose Homeostasis in Non-Diabetic Subjects

Abstract

Objective

Previous animal studies have shown that the oxytocin system might affect glucose homeostasis through the hypothalamus–pituitary–adrenal (HPA) axis and peripheral organs. Moreover, whether the effect is stratified by the polymorphism of oxytocin receptor gene (OXTR) remains unclear.

Methods

In this study, we recruited 89 non-diabetic participants. Their plasma oxytocin and serum insulin profiles were obtained, and the polymorphism of OXTR rs53576 was genotyped.

Results

There were significant correlations between the oxytocin level and fasting glucose level (r = –0.29, P <0.01), insulin level (r = –0.26, P = 0.01), and homeostasis model assessment-estimated insulin resistance (HOMA-IR) (r = –0.25, P = 0.01), when adjusted for age, gender, and body mass index (BMI). When further considering the stratification effects of OXTR variation, we found that the oxytocin level was significantly correlated with the fasting glucose level (r = –0.25, P = 0.04), insulin level (r = –0.35, P = 0.03), and HOMA-IR (r = –0.35, P < 0.01) in subjects with the OXTR A allele (n = 75) after adjustment for age, gender, and BMI. In addition, the oxytocin level in those with the GG genotype of OXTR was significantly negatively correlated with the leptin level (n = 14, r = –0.66, P = 0.02).

Conclusion

The results demonstrated that the polymorphism of OXTR plays an important role in individual differences in the correlation of oxytocin and glucose homeostasis in non-diabetic subjects.

Keywords:

• glucose
• insulin
• oxytocin
• OXTR
• polymorphism

Acknowledgments

This study was financially supported by the National Science Council of Taiwan (MOST 103-2320-B-006 -013, MOST 104-2320-B-006-024, MOST 105-2320-B-006-014, MOST 105-2321-B-006-020, MOST 106-2320-B-006-040, MOST 107-2320-B-006-071, MOST 108-2320-B-006-004, and MOST 108-2320-B-006-047-MY3). This research also received funding (NCKUH-10301003, NCKUH-10509004, and NCKUH-10703057) from the National Cheng Kung University Hospital. The authors thank Mr. Chien Ting Lin for his administrative support.

Author Contributions

All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; took part in drafting the article or revising it critically for important intellectual content; gave final approval of the version to be published; and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that they have no conflicts of interest in relation to this work. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.