0021-972X/91/7304-0811$03.00/0 Journal of Clinical Endocrinology and Metabolism Copyright (O 1991 by The Endocrine Society
Vol. 73, No. 4 Printed in U.S.A.
Serum Bioactive and Immunoreactive Luteinizing Hormone and Follicle-Stimulating Hormone Levels in Women with Cycle Abnormalities, with or without Polycystic Ovarian Disease* BART C. J. M. FAUSER, THIERRY D. PACHE, STEVEN W. J. LAMBERTS, WIM C. J. HOP, FRANK H. DE JONG, AND KRISTINE D. DAHL Section of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology (B.C.J.M.F., T.D.P.) and Department of Medicine (S. W.J.L., F.H.J.), Dijkzigt University Hospital; and the Department of Epidemiology and Biostatistics, Erasmus University (W.C.J.H.), Rotterdam, The Netherlands; and the Department of Medicine, Veterans Administration Medical Center (K.D.D.), Seattle, Washington 98108
malities, individual BIO/IRMA-LH ratios correlated with BIOLH (r. = 0.48), FAI (r. = 0.39), free estrogens (E2/SHBG ratios; rs = 0 0.47), and dehydroepiandrosterone sulfate (r8 = 0.60) concentrations. Mean IRMA-, RIA-, and BIO-FSH levels and BIO/IRMA-FSH ratios were not significantly different when various groups were compared. Although RIA- and IRMA-LH levels showed good correlation (r8 = 0.88), RIA-LH levels were consistently higher, resulting in distinctly higher RIA-LH/FSH ratios (mean, 4.5) compared to IRMA-LH/FSH ratios (median, 1.8) in PCOD patients. The results presented in this study indicate: 1) there were no differences in mean serum levels of IRMA-FSH, RIA-FSH, and BIO-FSH when comparing PCOD, non-PCOD patients, and controls; 2) the LH/FSH ratio estimated by IRMA in PCOD patients is substantially lower than that measured by RIA (IRMA may not be useful to identify PCOD patients); 3) free asubunit levels in PCOD patients are elevated compared to those in controls and non-PCOD patients; 4) BIO/IRMA-LH ratios in PCOD patients are significantly increased compared to those in non-PCOD patients; and 5) in women with cycle abnormalities, BIO/IRMA-LH ratios are correlated with FAI, E2/SHBG ratios, and dehydroepiandrosterone sulfate levels. (J Clin Endocrinol Metab 73: 811-817,1991)
ABSTRACT. Serum steroid, gonadotropin, and a-subunit levels were assessed in 35 women with cycle abnormalities [11 with and 24 without polycystic ovarian disease (PCOD) according to strict clinical and biochemical criteria] and 8 regularly cycling women in the early (cycle day 3 or 4) and mid (cycle day 7 or 8) follicular phase. LH and FSH levels were estimated using two immunological techniques [RIA and immunoradiometric assay (IRMA)] and in vitro bioassays (BIO), using mouse Leydig cells and rat granulosa cells, respectively. In PCOD patients mean asubunit, free androgen index [FAI; testosterone x 100/sex hormone-binding globulin (SHBG)], androstenedione, estrone, and estradiol (E2) were significantly elevated compared to levels in the early follicular phase of control cycles and non-PCOD patients. In addition, in PCOD patients mean IRMA-LH and RIALH levels were distinctly increased (2.8- to 3.6 fold, respectively; both comparisons, P < 0.001) compared to control values, but in the same order of magnitude (1.3- to 1.4-fold increments) as that in non-PCOD patients. However, the median BIO-LH level in PCOD patients was 5.9-fold higher than that in non-PCOD patients and 4.0-fold higher than the BIO-LH in the early follicular phase of control women. Consequently, the median BIO/IRMA-LH ratio was 4.8-fold higher in PCOD patients compared to non-PCOD patients. In women with cycle abnor-
D
ing from PCOD, the significance of inappropriate gonadotropin secretion (i.e. selectively increased LH levels) has been emphasized (2, 3). Although some PCOD patients appeared to have normal LH concentrations (3), augmented LH levels (and LH/FSH ratios) (4, 5), estimated by RIA, have been considered the crucial biochemical criterion for the diagnosis of PCOD. The recent availability of more selective immunological techniques for the detection of gonadotropins using monoclonal antibodies [immunoradiometric assay (IRMA)] together with the use of in vitro bioassays, by which the functional activity of circulating gonadotropins can be estimated, made hormone estimates obtained by classical RIAs in various clinical and pharmacological conditions ques-
IAGNOSIS and classification of polycystic ovarian disease (PCOD) remains controversial, since this syndrome involves a heterogenous group of patients, and clear, well validated diagnostic criteria are limited (1). Signs and symptoms are considered to be the main clinical standards for PCOD diagnosis. Next to high serum androgen levels in the majority of patients suffer-
Received December 27, 1990. Address requests for reprints to: Dr. B. C. J. M. Fauser, Section of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Dijkzigt University Hospital, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands. * This work was supported in part by the Erasmus University and the Stichting Menselijke Voortplanting, Rotterdam.
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FAUSER ET AL.
tionable (6, 7). Altered urinary excretion of LH bioactivity in SteinLeventhal syndrome patients has been described over 3 decades ago (8). In PCOD patients, elevated bioactive LH levels and increased bioactive to immunoreactive LH ratios have recently been reported (5, 9). Information obtained in these studies should be revised, since discrepancies between various immunological techniques were recently established (7), and LH levels measured by RIA could have been overestimated because of the considerable cross-reactivity of free circulating a-subunits in these assays (10). No data are presently available on gonadotropin levels estimated by IRMA and bioactive FSH levels in this type of patient. The bioactivity of circulating FSH seems to be of special interest, since the previously described aromatase defect in ovaries of PCOD patients (11, 12) together with observed normal FSH-induced aromatase activity of cultured granulosa cells obtained from PCOD patients (13, 14) suggest diminished FSH bioactivity either in the circulation or within ovarian follicles. The major objective of the present study was to estimate circulating gonadotropin concentrations using various immunological techniques and in vitro bioassays in patients with cycle abnormalities without and with PCOD according to strict clinical and biochemical criteria. Materials and Methods Subjects and study protocol Eight regularly cycling young healthy women (controls) and 35 women attending our Infertility Clinic presenting with oligomenorrhea (n = 21; mean cycle length, 53 ± 4 days) or amenorrhea (n = 14; no vaginal bleeding for at least 6 months) and infertility (3.5 ± 2.6 yr) were enrolled in the study (see Table 1). Underweight women (body mass index,
Vol. 73, No. 4 Printed in U.S.A.
Serum Bioactive and Immunoreactive Luteinizing Hormone and Follicle-Stimulating Hormone Levels in Women with Cycle Abnormalities, with or without Polycystic Ovarian Disease* BART C. J. M. FAUSER, THIERRY D. PACHE, STEVEN W. J. LAMBERTS, WIM C. J. HOP, FRANK H. DE JONG, AND KRISTINE D. DAHL Section of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology (B.C.J.M.F., T.D.P.) and Department of Medicine (S. W.J.L., F.H.J.), Dijkzigt University Hospital; and the Department of Epidemiology and Biostatistics, Erasmus University (W.C.J.H.), Rotterdam, The Netherlands; and the Department of Medicine, Veterans Administration Medical Center (K.D.D.), Seattle, Washington 98108
malities, individual BIO/IRMA-LH ratios correlated with BIOLH (r. = 0.48), FAI (r. = 0.39), free estrogens (E2/SHBG ratios; rs = 0 0.47), and dehydroepiandrosterone sulfate (r8 = 0.60) concentrations. Mean IRMA-, RIA-, and BIO-FSH levels and BIO/IRMA-FSH ratios were not significantly different when various groups were compared. Although RIA- and IRMA-LH levels showed good correlation (r8 = 0.88), RIA-LH levels were consistently higher, resulting in distinctly higher RIA-LH/FSH ratios (mean, 4.5) compared to IRMA-LH/FSH ratios (median, 1.8) in PCOD patients. The results presented in this study indicate: 1) there were no differences in mean serum levels of IRMA-FSH, RIA-FSH, and BIO-FSH when comparing PCOD, non-PCOD patients, and controls; 2) the LH/FSH ratio estimated by IRMA in PCOD patients is substantially lower than that measured by RIA (IRMA may not be useful to identify PCOD patients); 3) free asubunit levels in PCOD patients are elevated compared to those in controls and non-PCOD patients; 4) BIO/IRMA-LH ratios in PCOD patients are significantly increased compared to those in non-PCOD patients; and 5) in women with cycle abnormalities, BIO/IRMA-LH ratios are correlated with FAI, E2/SHBG ratios, and dehydroepiandrosterone sulfate levels. (J Clin Endocrinol Metab 73: 811-817,1991)
ABSTRACT. Serum steroid, gonadotropin, and a-subunit levels were assessed in 35 women with cycle abnormalities [11 with and 24 without polycystic ovarian disease (PCOD) according to strict clinical and biochemical criteria] and 8 regularly cycling women in the early (cycle day 3 or 4) and mid (cycle day 7 or 8) follicular phase. LH and FSH levels were estimated using two immunological techniques [RIA and immunoradiometric assay (IRMA)] and in vitro bioassays (BIO), using mouse Leydig cells and rat granulosa cells, respectively. In PCOD patients mean asubunit, free androgen index [FAI; testosterone x 100/sex hormone-binding globulin (SHBG)], androstenedione, estrone, and estradiol (E2) were significantly elevated compared to levels in the early follicular phase of control cycles and non-PCOD patients. In addition, in PCOD patients mean IRMA-LH and RIALH levels were distinctly increased (2.8- to 3.6 fold, respectively; both comparisons, P < 0.001) compared to control values, but in the same order of magnitude (1.3- to 1.4-fold increments) as that in non-PCOD patients. However, the median BIO-LH level in PCOD patients was 5.9-fold higher than that in non-PCOD patients and 4.0-fold higher than the BIO-LH in the early follicular phase of control women. Consequently, the median BIO/IRMA-LH ratio was 4.8-fold higher in PCOD patients compared to non-PCOD patients. In women with cycle abnor-
D
ing from PCOD, the significance of inappropriate gonadotropin secretion (i.e. selectively increased LH levels) has been emphasized (2, 3). Although some PCOD patients appeared to have normal LH concentrations (3), augmented LH levels (and LH/FSH ratios) (4, 5), estimated by RIA, have been considered the crucial biochemical criterion for the diagnosis of PCOD. The recent availability of more selective immunological techniques for the detection of gonadotropins using monoclonal antibodies [immunoradiometric assay (IRMA)] together with the use of in vitro bioassays, by which the functional activity of circulating gonadotropins can be estimated, made hormone estimates obtained by classical RIAs in various clinical and pharmacological conditions ques-
IAGNOSIS and classification of polycystic ovarian disease (PCOD) remains controversial, since this syndrome involves a heterogenous group of patients, and clear, well validated diagnostic criteria are limited (1). Signs and symptoms are considered to be the main clinical standards for PCOD diagnosis. Next to high serum androgen levels in the majority of patients suffer-
Received December 27, 1990. Address requests for reprints to: Dr. B. C. J. M. Fauser, Section of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Dijkzigt University Hospital, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands. * This work was supported in part by the Erasmus University and the Stichting Menselijke Voortplanting, Rotterdam.
811
The Endocrine Society. Downloaded from press.endocrine.org by [${individualUser.displayName}] on 08 April 2015. at 07:11 For personal use only. No other uses without permission. . All rights reserved.
812
FAUSER ET AL.
tionable (6, 7). Altered urinary excretion of LH bioactivity in SteinLeventhal syndrome patients has been described over 3 decades ago (8). In PCOD patients, elevated bioactive LH levels and increased bioactive to immunoreactive LH ratios have recently been reported (5, 9). Information obtained in these studies should be revised, since discrepancies between various immunological techniques were recently established (7), and LH levels measured by RIA could have been overestimated because of the considerable cross-reactivity of free circulating a-subunits in these assays (10). No data are presently available on gonadotropin levels estimated by IRMA and bioactive FSH levels in this type of patient. The bioactivity of circulating FSH seems to be of special interest, since the previously described aromatase defect in ovaries of PCOD patients (11, 12) together with observed normal FSH-induced aromatase activity of cultured granulosa cells obtained from PCOD patients (13, 14) suggest diminished FSH bioactivity either in the circulation or within ovarian follicles. The major objective of the present study was to estimate circulating gonadotropin concentrations using various immunological techniques and in vitro bioassays in patients with cycle abnormalities without and with PCOD according to strict clinical and biochemical criteria. Materials and Methods Subjects and study protocol Eight regularly cycling young healthy women (controls) and 35 women attending our Infertility Clinic presenting with oligomenorrhea (n = 21; mean cycle length, 53 ± 4 days) or amenorrhea (n = 14; no vaginal bleeding for at least 6 months) and infertility (3.5 ± 2.6 yr) were enrolled in the study (see Table 1). Underweight women (body mass index,
