Differences in urinary excretion patterns of the hLH beta core fragment in premenopausal, perimenopausal, and postmenopausal women

Patterns of LHbetacf among women in health and disease

Urine based gonadotropin assays provide a practical means of analyzing hormone secretion patterns. While research protocols have revealed pulsatile patterns of gonadotropins such as LH in the blood, these assays are of limited clinical use since daily venipuncture sampling is not feasible outside of a research environment. However, collection of several urine samples provides a method to achieve the same visualization of gonadotropin patterns in patients using a convenient and generally applicable technique based on analysis of the highly stable hLHbetacf for monitoring LH and hCGbetacf for monitoring pituitary hCG. We demonstrated that two different sampling techniques for analyzing these gonadotropin metabolites yielded the same information on their excretory patterns, either sampling of spot urines or collecting first morning void urines for several days. Next, we studied the core excretory patterns in several populations: menstruating and postmenopausal women from the general population, and two populations of women from a fertility center, one of which had polycystic ovaries (PCO). The PCO population was also subdivided into those with and without insulin resistance (IR). It was found that our hLHbetacf assay did not measure the form of the LH core (v-hLHbetacf) produced in subjects who were homozygous for a variant form of LH (v-LH). None of our patients tested were homozygous for the variant form of LH. It was also found that in most non-PCO (NPCO) patients, the hLHbetacf peak lasted for 7-9 days while among the PCO patients this peak frequently lasted for less than 7 days and an erratic pattern tended to appear. The overall differences in patterns between the PCO and NPCO patients were confirmed by spectral statistical methods. The prevalence of certain characteristic hLHbetacf patterns may be higher among women with PCO with a more severe clinical presentation. Use of urinary analysis of gonadotropin metabolites, especially hLHbetacf, may supplement subjective ultrasound studies with more sensitive biochemical measurements.

Urinary beta-FSH subunit concentrations in perimenopausal and postmenopausal women: a biomarker for ovarian reserve

OBJECTIVE

The purpose of this study was to develop an integrative assessment of pituitary follicle-stimulating hormone (FSH) secretion and to validate these measurements in a population of perimenopausal (PERI) and postmenopausal (POST) women.

DESIGN

In this cross-sectional study, 170 POST and 20 PERI women collected first-void morning urine samples and had a single blood sample drawn on the same day. For comparison, 11 midreproductive-aged women had urine samples collected for one menstrual cycle. In addition, one 48.5-year-old woman collected daily urine samples for 4 consecutive years during her menopausal transition. Urine samples were assayed for estrone glucuronide (E1G) and pregnanediol-3-glucuronide (PdG) and were normalized to creatinine. An ELISA assay was developed for measurement of the free beta-FSH subunit in urine.

RESULTS

Mean age (+/- SD) of the PERI and POST women were 48.1 +/- 3.0 and 52.8 +/- 4.1 years, respectively. Mean serum FSH levels were 9.5 +/- 5.8 and 79.3 +/- 32 IU/L (P < 0.001) in the PERI and POST women. Mean urinary beta-FSH/Cr for the PERI were 1.8 +/- 1.2 ng/mg; for the POST, 9.3 +/- 4.5 ng/mg (P < 0.001). Mean estradiol, E1G/Cr, and PdG/Cr levels were also significantly different between the two groups. There was a high correlation between serum FSH and urinary beta-FSH/Cr for the PERI (r = 0.584, P = 0.007) and POST (r = 0.54, P < 0.001), with minimal overlap in the urinary beta-FSH/Cr levels between the PERI and POST groups. A significant correlation between PdG/Cr and urinary beta-FSH/Cr was observed for POST (r = 0.581, P = 0.002). No correlation was seen between urinary beta-FSH/Cr and E1G/Cr or estradiol levels. In the perimenopausal participant, who collected 4 years of daily urine samples, urinary beta-FSH/Cr levels progressively increased during the follicular phase and, by the fourth year, there were persistent, almost tonically high elevations of beta-FSH/Cr in the urine.

CONCLUSIONS

Urinary beta-FSH subunit measurements are a useful marker for monitoring ovarian function during the menopausal transition. Urinary free beta-FSH subunit concentrations reflect pituitary FSH secretion and serve as a biomarker for ovarian reserve.