Response of plasma β-endorphin and insulin to oral glucose tolerance test in non-obese women with polycystic ovaries

Abstract

Increased responses of plasma insulin and endorphins to the oral glucose tolerance test (oGTT) have earlier been found in obese women. We studied responses of immunoreactive β-endorphin (ir β-E) and insulin in plasma to the oCTT in 8 non-obese women with polycystic ovaries (PCO) and in 10 healthy women. An additional control group consisted of 5 healthy women who were fasting during the study period. In the PCO group the insulin and glucose responses to the oGTT were increased, and an increase of ir β-E from 5.9 ± 1.5 to 8.6 ± 2.8 pmol/l was found during the 1st half-hour period of the oGTT. In contrast, no significant change was found during the oGTT in healthy women (3.2 ± 0.5 and 2.7 ± 0.65 pmol/l, respectively), and in the fast- ing control women the mean ± P-E level (± SE) decreased, from 4.5 ± 1.2 to 3.6 ± 1.1 pmol/l. These findings revealed increased responses of both plasma ir β-E and insulin to the oGTT in non-obese women with PCO but their possible causal relationship remained unsolved.