Beta Endorphin Levels in PCOS Women: Relationship With Insulin Secretion

Abstract

Background: An understanding of the relationship between beta endorphin (Beta) with insulin, glucose and gonadotropins may explain how non-pharmacologic treatment options such as exercise and acupuncture may be beneficial to women with Polycystic Ovary Syndrome (PCOS). The objective was to examine the correlation of Beta with insulin, glucose and gonadotropins, controlling for exercise and body mass index (BMI).

Methods: 40 untreated women with a confirmed diagnosis of PCOS (NIH criteria) were tested. Height, exercise frequency and exercise intensity were self-reported; weight was measured by nurses. Blood samples were collected for the biological measures of interest. The setting was an academic US medical center. Statistical analyses consisted of Spearman correlations and partial correlations with an alpha = 0.05. The main outcome measures included plasma Beta, insulin and glucose (fasting and AUC) from a 2-hour oral glucose tolerance test, serum gonadotropins.

Results: The mean Beta level was 7.92 pmol/mL (sd = 4.0, range 1.92 - 18.7, 25%/75% interquartile range 4.56 - 11.29). Beta was associated with log_e AUC-insulin (P = 0.04) after adjustment for exercise as measured via energy equivalents; this correlation was unaffected by additional control of BMI. No relationship between Beta and luteinizing hormone, the luteinizing hormone/follicle stimulating hormone ratio, or glucose was seen after accounting for BMI and exercise.

Conclusion: Beta was positively correlated with AUC-insulin after accounting for exercise. Future studies could investigate the affects of Beta-potentiating therapies, such as exercise and acupuncture, in women with PCOS to determine how these changes in Beta are related to insulin/glucagon balance.



J Endocrinol Metab. 2012;2(1):11-20
doi: https://doi.org/10.4021/jem62w