Endocrine Abstracts

Introduction

The polycystic ovary syndrome (PCOS) affects about 6–10% of women of reproductive age and is associated with oligomenorrhoea and anovulation. Recently, a possible impairment of bone accrual in women with PCOS due to the chronic inflammation disposition has been postulated [Kalyan, 2017]. The lack of progesterone due to anovulation may also have effects on bone metabolism [Seifert-Klauss, 2015]. A progestin test is a classic tool for assessing oligo- and amenorrhoea. The presented observational study monitors the effects of the progestin test for oligomenorrhoea on bone metabolism markers, LH and other hormones as well as ovulation rates in the following cycle.

Methods

60 premenopausal women (18–45 years), all pre-diagnosed with PCOS, without steroid treatment for at least 4 months are monitored for five visits in three consecutive cycles. Women with menstrual cycle lengths of ≥50 days, severe obesity (BMI >36 kg/m²) and other endocrine diseases or metabolic disorders are excluded from the study. At baseline, medical history, hip and waist circumference, ovarian morphology and serum samples are taken in the early follicular phase of the cycle, before the participants take 10 mg dydrogesterone for 14 days for their progestin test. Serum samples are drawn at four defined follow-up time points (day 10–12 of the gestagen test, day 3–7 and day 19–26 of the following cycle as well as day 3–7 of the third cycle). Analytes determined in serum samples include CRP, progesterone, estradiol, LH, FSH, prolactin, testosterone, DHEAS and SHBG as well as the bone metabolism markers procollagen type I N-terminal propeptide, bone-specific alkaline phosphatase, osteocalcin, C-terminal collagen type I telopeptide and tartrate-resistant acidic phosphatase 5b.

Results

12 participants of the targeted 60 PCO-patients have completed the study to date. Whereas progesterone levels at day 3–7 of all cycles were below 0.4 ng/ml, 75% of the participants exceeded progesterone levels of 2 ng/ml during the progestin test (average 6.2 ± 3.6 ng/ml) and 42% at day 19–26 of the following cycle without exogenous progestin (average 12.7 ± 7.0 ng/ml). The luteal phase was missed in 3 patients (27%), who showed significantly elevated LH levels on the scheduled day of visit 4 (cycle days 22, 26 and 31), most likely due to delayed ovulation in the cycle following the progestin test. Bone metabolism parameters will be presented.

Discussion

This study systematically characterizes changes in bone metabolism which may be attributable to inflammation, ovulation vs. anovulation and/or progestin deficiency.