Relationship of ovarian stromal volume and serum 17-hydroxyprogesterone concentrations in patients with PCOS

F. Kelestimur1 and Y. Sahin2

1 Department of Endocrinology and 2 Department of Obstetrics and Gynecology, Erciyes University Medical School, Kayseri 38039, Turkey

Dear Sir,

We read with interest the recent article (Kyei-Mensah et al., 1998Go), which investigated the relationship between ovarian stromal volume and serum androgen concentrations in patients with polycystic ovary syndrome (PCOS) and have found that the serum androgen concentrations resulting from cytochrome P450c17-regulated enzyme activity in the theca are significantly increased, and serum androstenedione concentrations show positive correlation with stromal volume in PCOS women. They have found no positive correlation between stromal volume and serum 17-hydroxyprogesterone (17-OHP) concentration. In our opinion, this conclusion may not be correct.

We have previously shown that basal testosterone, androstenedione, dehydroepiandrosterone sulphate (DHEA-S) and 11-deoxycortisol values were higher in women with PCOS than in controls (Sahin and Kelestimur, 1997aGo,bGo). However, we have found that basal 17-OHP concentrations were similar in both PCOS and control women Sahin and Kelestimur, 1993, 1997a,b). We have also investigated whether there is a correlation between ovarian volume and peak 17-OHP concentrations in response to stimulation with the gonadotrophin-releasing hormone (GnRH) agonist, buserelin, and found that there was a significant positive correlation between ovarian volume (mean ± SEM, 12.38 ± 0.88 ml; range, 6.69–27.17 ml) and the peak value of serum 17-OHP (Sahin and Kelestimur, 1993Go).

Although we measured the total ovarian volume rather than ovarian stromal volume, it might bear some relationship to total ovarian volume. PCOS is thought to be caused by an increased activity of steroidogenesis through 17-hydroxylation and/or increased but relatively inefficient activity of 17,20-Iyase. 17-hydroxylation and 17,20-Iyase activity arise from the same enzyme, cytochrome P450c17{alpha}. We think that the increased ovarian volume in patients with PCOS may play an important role in the elevated production of 17-OHP in response to the GnRH agonist. Kyei-Mensah et al. did not carry out the GnRH agonist stimulation test and suggested that there was no correlation between the basal 17-OHP value and stromal volume in PCOS women. However, basal 17-OHP concentrations may not reflect theca cell activity. We think that the measurement of 17-OHP responses to GnRH agonist stimulation is more correct than the measurement of basal 17-OHP concentrations in the evaluation of the relationship between 17-OHP values and ovarian stromal volume.

References

Kyei-Mensah, A.A., Tan, S.L., Zaldi, J. and Jacobs, H.S. (1998) Relationship of ovarian stromal volume to serum androgen concentrations in patients with polycystic ovary syndrome. Hum. Reprod., 13, 1437–1441.[Abstract]

Sahin, Y. and Kelestimur, F. (1993) 17-Hydroxypogesterone response to buserelin testing in the polycystic ovary syndrome. Clin. Endocrinol., 39, 151–155.[ISI][Medline]

Sahin, Y. and Kelestimur, F. (1997a) 17-Hydroxyprogestrone responses to gonadotrophin-releasing hormone agonist buserelin and adrenocorticotropin in polycystic ovary syndrome:investigation of adrenal and ovarian cytochrome P450c17{alpha} dysregulation. Hum. Reprod., 12, 910–913.[ISI][Medline]

Sahin, Y. and Kelestimur, F. (1997b) The frequency of late-onset 21-hydroxylase and 11ß-hydroxylase deficiency in women with polycystic ovary syndrome. Eur. J. Endocrinol., 137, 670–674.[ISI][Medline]