Attitudes of anonymous and identity-release oocyte donors towards future contact with donor offspring.

STUDY QUESTION: What are the attitudes and expectations of past oocyte donors concerning contact with their donor offspring and contact between donor offspring and their own children? SUMMARY ANSWER: The large majority (95%) of open-identity oocyte donors, as well as voluntarily registered donors (registered before the Finnish 2007 ART law), expressed positive or neutral feelings towards contact with their donor offspring and mainly positive expectations towards contact between donor offspring and their own children. WHAT IS KNOWN ALREADY: Although there is a growing support for openness and identity-release programmes in gamete donation, there is not much knowledge on how donors feel about potential contact with their offspring. Most previous studies have investigated donor expectations with a relatively short follow-up time, using small samples or participants in voluntary donor linkage services. STUDY DESIGN, SIZE, DURATION: A retrospective cross-sectional survey of all women who had donated oocytes between 1990 and 2012 at three fertility clinics in Finland was carried out in 2013. A self-administered questionnaire was sent out to a total of 569 former oocyte donors. PARTICIPANTS/MATERIALS, SETTING, METHODS: In total, 428 former oocyte donors answered a questionnaire assessing experiences and attitudes related to donation (response rate 75.2%). In this study, 358 donors who were unknown to the recipient were included. The mean follow-up time after the donation was 11.2 years. Before 2008, donors were non-identifiable but could voluntarily consent to release their identifying information to their donor offspring. After 2008, persons born as a result of gamete donation can, from the age of 18, receive information identifying the donor. Altogether 290 respondents had participated in a donation programme in 1990-2007 (before the Finnish ART-law), and 68 participated after the enactment of the ART-law, enabling us to compare attitudes by type of legislation during donation. MAIN RESULTS AND THE ROLE OF CHANCE: Most voluntarily registered and open-identity donors welcomed or were neutral to potential contact with their donor offspring but were slightly more cautious towards contact between their own children and a donor-conceived child. Open-end comments revealed some ambiguity and uncertainty as to what to expect from such contact and feelings varied from neutral curiosity and interest to desire to meet the donor-conceived child. LIMITATIONS, REASON FOR CAUTION: It is not possible to assess whether the opinions of the study participants is representative of all donors in 1990-2012, as 25% of all contacted former donors did not respond to the survey. WIDER IMPLICATIONS OF THE FINDINGS: This study is one of only a few studies among oocyte donors to evaluate long-term psychosocial consequences of the donation and expectations towards contact with donor offspring, using a large sample. Results from this study show that persisting concerns about adverse outcomes of identity release policies are largely unwarranted, but there is a need to develop counselling practices and material for identity-release donors about how to prepare for and adjust to potential contact with donor offspring. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by grants from the Medical Society Life and Health, and from the Otto A. Malm Foundation. The authors have no competing interests to report. TRIAL REGISTRATION NUMBER: N/A.

Attitudes and disclosure decisions of Finnish parents with children conceived using donor sperm.

STUDY QUESTION: What are disclosure intentions and experiences of heterosexual parents with children born after assisted donor insemination (DI) or IVF with donor sperm (dIVF)? SUMMARY ANSWER: Only 16.5% of Finnish DI/dIVF heterosexual parents had told their child of his/her origin; 18% of all children above 3 years of age had received the information. Parents with older children were more unwilling to tell or were more uncertain regarding what to do than parents with younger children. WHAT IS KNOWN ALREADY: In general, 10-35% of parents of DI offspring are willing to inform their child about their conception. Men who need donor sperm to become a father are more secretive than women who need donated oocytes and are less willing to participate in counselling about parenthood. In the past, couples conceiving through gamete donation were adviced to maintain secrecy or sufficient advice on information sharing was not available. Evidence suggests that parental attitudes are moving towards greater openness. In 2007, Finland enacted a law on assisted fertility treatments (1237/2006) stating that gamete donors have to register their identifying information in a registry so that at the age of 18 years, offspring can obtain information about their donor. STUDY DESIGN, SIZE AND DURATION: This retrospective questionnaire study included 139 mothers and 127 fathers with altogether 240 children born after DI or dIVF during 1992-2007. PARTICIPANTS, SETTING AND METHODS: Questionnaires were sent to heterosexual couples who had undergone DI/dIVF treatment at the Väestöliitto Fertility Clinic in Helsinki resulting in live birth (n = 277, 252 mothers and 239 fathers). The parents were asked to report their disclosure intentions towards the child and towards other people about the decision to use donated sperm, their concerns about donor characteristics, their evaluation of the counselling that they received and their views about the current Finnish assisted reproduction law. MAIN RESULTS AND THE ROLE OF CHANCE: The response rate was 55% (139/252) among the mothers and 53% (127/239) among the fathers. Answers provided information on 58% (240/415) of the children born, 91% of whom were at least 3 years old at the time. Of all parents, 16.5% reported that they had already told their child of his/her conception. Of all 240 children, 16.3% had already received information about their conception. The children had been between 3 and 14 years of age (mean 6.8 years) when they were told. Parents of older children were significantly more unwilling to tell their child than parents of younger children (P < 0.005). No difference in disclosure between DI and dIVF emerged. Less than half of the parents (42%) had been satisfied with the psychological support offered to them, with parents of older children having been most dissatisfied. LIMITATIONS, REASONS FOR CAUTION: Although the response rate was relatively high, more than 40% of the parents chose not to participate. As has been shown before, it is likely that those who do not take part are less inclined to disclose and this should be taken into consideration when conclusions are drawn. WIDER IMPLICATIONS OF THE FINDINGS: Our results on disclosure rates are in agreement with previous studies. General attitudes have moved towards greater openness about the use of donated gametes. Furthermore, the availability of psychological counselling before treatment has increased the understanding of the importance of disclosure. People who have become parents after DI or dIVF should also be offered counselling after the child has been born. STUDY FUNDING/COMPETING INTERESTS: This study was supported by grants from the Wilhelm and Else Stockmann Foundation and the Medical Society Life and Health. There are no competing interests to disclose. TRIAL REGISTRATION NUMBER: None.

Elective single-embryo transfer in women aged 40-44 years.

STUDY QUESTION: Is an elective single-embryo transfer (eSET) policy feasible for women aged 40 or older? SUMMARY ANSWER: For older women (aged 40-44 years) with a good prognosis, an eSET policy can be applied with acceptable cumulative clinical pregnancy rates and live birth rates. WHAT IS KNOWN ALREADY: Various studies have shown the effectiveness of eSET in women aged <35 years with high cumulative pregnancy rates and low rates of multiple births. STUDY DESIGN, SIZE, DURATION: This retrospective cohort study included 628 women treated between 2000 and 2009. PARTICIPANTS, SETTING, METHODS: Women aged 40-44 years underwent a fresh cycle of IVF or ICSI treatment with eSET (n = 264) or double-embryo transfer (DET) (n = 364). In the subsequent frozen-thawed embryo transfer cycles, SET/DET was performed in both groups according to the number of embryos available and the opinion of the couple. The study was performed at the Family Federation of Finland Helsinki Fertility Clinic. MAIN RESULTS AND THE ROLE OF CHANCE: In the fresh cycles, the clinical pregnancy rates were 23.5 and 19.5% in the eSET and DET groups, respectively, and live birth rates were 13.6 and 11.0%, respectively. In the fresh cycles with eSET, there were no twin pregnancies, but in the DET group, there were three sets of twins (7.5%). The cumulative clinical pregnancy rates per oocyte retrieval were 37.1 and 24.2% in the eSET and DET groups, respectively (P < 0.001), and the cumulative live birth rates were 22.7 and 13.2%, respectively (P = 0.002). Cumulative twin rates were 6.7% (n = 4) in the eSET group and 8.3% (n = 4) in the DET group (P = 0.726). All of the twin pregnancies in the eSET group resulted from frozen and thawed DET embryo transfer cycles. LIMITATIONS: The characteristics of the two patients groups are not comparable because the suitability of eSET was individually assessed by a clinician based on both clinical prognostic factors and the outcome of IVF or ICSI, i.e. the number and quality of embryos. WIDER IMPLICATIONS OF THE FINDINGS: This study may be generalized to IVF units having experience in eSET and cryopreservation.

Does long in vitro culture promote large for gestational age babies?

STUDY QUESTION: Does the length of time during which embryos are cultured in vitro affect the birthweight of the infants? SUMMARY ANSWER: The duration of the embryo culture period is a significant factor in determining the birthweight of the infants. WHAT IS ALREADY KNOWN: IVF children show adverse perinatal outcome when compared with the general population and increased incidence of preterm birth and low birthweight is commonly observed. STUDY DESIGN, SIZE, DURATION: A retrospective cross-sectional cohort study including 1079 infants born after treatment at the Family Federation of Finland Fertility Clinic in Helsinki, between 2000 and 2010. PARTICIPANTS, SETTING, METHODS: All singleton IVF children were included. The gestation- and gender-adjusted birthweights of the babies were analyzed according to mother's age, BMI, and parity, type of treatment (IVF or ICSI), main cause of infertility and embryo culture period. Two outcomes were investigated: the birthweight and the proportion of small and large for gestational age (SGA and LGA) infants. Multiple linear regression analysis was performed to show the significance of each individual factor on determining the birthweight of the babies born. MAIN RESULTS AND THE ROLE OF CHANCE: In the study group as a whole, the distribution of the SGA and LGA babies showed no deviation from the growth charts of the general population. However, when the birthweight of the children was analyzed according to the length of embryo culture from Day 2 to Days 5-6, an increase in the proportion of LGA babies was found (D2 9.4%, D3 11.5%, D5-6 18.8%; D2 n = 871, D3 n = 139, D5-6 n = 69). Multiple linear regression analysis showed that BMI (P < 0.001) and parity (P < 0.001) of the mother, as well as the embryo culture period (P = 0.007) had a significant effect on the birthweight. The value of the adjusted R(2) was 0.437. LIMITATIONS, REASONS FOR CAUTION: Small number of D5-6 infants and a lack of pregnancy-associated factors contributing to birthweight. WIDER IMPLICATIONS OF THE FINDING: This study warrants larger studies to analyze the birthweight of the IVF children, particularly after blastocyst culture. STUDY FUNDING/COMPETING INTEREST: The study was funded by the Family Federation of Finland, Fertility Clinic Helsinki. No competing interests.

Increasing openness in oocyte donation families regarding disclosure over 15 years.

BACKGROUND: Worldwide there is an increasing number of families created by oocyte donation (OD). The aim of this study was to gather information about parents' plans of disclosure to their child and to other people, as well as parents' attitudes and level of satisfaction up to 15 years after their OD treatment. METHODS: A questionnaire with separate material for each partner was sent to all parents (167 mothers, 163 fathers) who had had a child after treatment with donated oocytes at Väestöliitto Fertility Clinics in Helsinki during 1992-2006. These parents had a total of 231 children aged 1-14 years. Parents were asked if they had told or intended to tell their child about his/her origin and how and when they had done so and about the reasons to disclose or not. Other questions were about openness towards other people, concerns about donor characteristics, counselling and feelings towards the child. RESULTS: Of the mothers, 61.1%, and of the fathers, 60.0%, had told or intended to tell the child of his/her conception. Of children over 3 years of age, 26% had already been informed. There was a statistically significant difference between parental telling in different age groups of children (P = 0.011, χ(2)). In the youngest age group (1-3 years), 83.3% of parents were inclined to disclosure compared with 44.4% in the oldest age group (13-14 years). A high proportion of mothers (86.7%) and fathers (71.0%) had told other people about the nature of their child's conception. The majority of parents did not have much concern about the characteristics of the donor. A higher proportion of the mothers (24%) compared with fathers (11%) thought that the psychological support had been insufficient. They thought that discussions with health professionals should be arranged routinely after delivery or when it was time to inform the child. CONCLUSIONS: Parents with young OD children are clearly more inclined to disclosure compared with parents with older children.

Perinatal outcome of children born after frozen and fresh embryo transfer: the Finnish cohort study 1995-2006.

BACKGROUND: The number of children born after frozen embryo transfer (FET) is steadily rising. However, studies on obstetric and perinatal outcomes are limited. Our primary aim was to compare the perinatal health of children born after FET and fresh embryo transfer, and to use data from children born after spontaneous conception as a reference. METHODS: In a register-based cohort study we evaluated the obstetric and perinatal outcomes of children born after FET (n = 2293), fresh embryo transfer (n = 4151) and those born after spontaneous pregnancy (reference group; n = 31 946). Data were collected from the registers of two infertility outpatient clinics, two university hospitals and the Finnish Medical Birth Register (1995-2006). RESULTS: After adjusting for confounding factors the FET group showed decreased risks of preterm birth [adjusted odd ratio (AOR) 0.83, 95% confidence interval (CI) 0.71-0.97], low birthweight (AOR 0.74; 0.62-0.88) and being small for gestational age (AOR 0.63; 0.49-0.83) compared with the fresh embryo transfer group. Mean birthweight was 134 g higher in the FET singletons versus the fresh embryo transfer singletons (P< 0.0001). When FET singletons were compared with the reference group, increased risks of preterm birth (AOR 1.45; 1.25-1.68) and low birthweight (AOR 1.22; 1.03-1.45) and a decreased risk of being small for gestational age (AOR 0.71; 0.54-0.92) were found. No excess of perinatal and infant mortality occurred between the groups. CONCLUSIONS: Embryo freezing does not adversely affect perinatal outcome in terms of prematurity, low birthweight and being small for gestational age versus the fresh embryo transfer and the outcome is similar or even better, particularly regarding fetal growth. Our study, which is one of the largest on FET pregnancies, provides further evidence on the safety of FET.

Identification by hybridization histochemistry of human endometrial cells expressing mRNAs encoding a uterine beta-lactoglobulin homologue and insulin-like growth factor-binding protein-1.

A beta-lactoglobulin homologue (beta LG/PP14) and insulin-like growth factor-binding protein-1 (IGFBP-1) are two major secretory proteins of the human endometrium. In the present study, we have shown that beta LG/PP14 mRNA is expressed in the endometrium in a cyclic manner, being hardly detectable in midcycle and most abundant during the late secretory phase. IGFBP-1 mRNA is also expressed in endometrium, but in amounts smaller than those encoding beta LG/PP14 and with maximal accumulation earlier in the secretory phase. The expression of these two mRNAs occurs in different cell types of the endometrium, as revealed by in situ hybridization techniques using single-stranded RNA probes. The glandular epithelial cells accumulate beta LG/PP14 mRNA during the late secretory phase of the cycle, whereas only the stromal cells of the late secretory endometrium express IGFBP-1 mRNA. In contrast to the endometrium, the two mRNAs are present at very low abundance in the fallopian tubes where they are expressed in the epithelial cells of the mucosa.

Characterization of functional type I insulin-like growth factor receptors from human choriocarcinoma cells.

Specific receptors for insulin-like growth factor I (IGF-I) on cultured human choriocarcinoma cells (JEG-3 and BeWo) were characterized. The binding of 125I-labeled recombinant (Thr59)IGF-I to the cells was reversible and time, temperature, and pH dependent. Steady state of binding occurred after 16 h at 4 C, pH 7.4. Natural human IGF-I (hIGF-I), hIGF-II, recombinant (N-Met)IGF-I, rat multiplication-stimulating activity, and insulin were 200%, 37%, 37%, 1.6%, and 0.1% as potent as (Thr59)IGF-I in inhibiting the binding of [125I]iodo-(Thr59)IGF-I to JEG-3 cells, respectively. Epidermal growth factor was ineffective. The half-maximal displacement of [125I]iodo-(Thr59)IGF-I by unlabeled (Thr59)IGF-I occurred at 11 +/- 2 ng/ml (mean +/- SEM) in both JEG-3 and BeWo cells. Scatchard analysis of the competitive binding data revealed linear plots indicating a single species of binding sites with an association constant of 0.8 X 10(9) M-1 for the binding of [125I]iodo-(Thr59)IGF-I to both cell lines. The binding capacity was 30,000 and 20,000 sites/cell for JEG-3 and BeWo cells, respectively. Chemical cross-linking of [125I]iodo-(Thr59)IGF-I to JEG-3 cells revealed two receptor complexes of 130K and 260K. Their formation was completely inhibited by an excess of unlabeled (Thr59)IGF-I or hIGF-II. Increasing amounts of insulin affected both labeled bands equally, suggesting that the 130K and 260K bands represent the monomer and dimer forms, respectively, of the ligand-binding alpha-subunit of type I IGF receptor. (Thr59)IGF-I, in a dose-dependent manner, stimulated uptake of nonmetabolizable alpha-[3H]aminoisobutyric acid by JEG-3 cells, showing that the receptor is biologically active. Our results demonstrate that choriocarcinoma cells possess functional high affinity type I IGF receptors and suggest that IGF-I is involved in the growth-regulating processes of JEG-3 and BeWo cells. These cells may provide a useful model to study the role of IGFs in trophoblast physiology.

Insulin-like growth factor (IGF) binding protein from human decidua inhibits the binding and biological action of IGF-I in cultured choriocarcinoma cells.

The placenta expresses genes for insulin-like growth factors (IGFs) and possesses IGF-receptors, suggesting that placental growth is regulated by IGFs in an autocrine manner. We have previously shown that human decidua, but not placenta, synthesizes and secretes a 34 K IGF-binding protein (34 K IGF-BP) called placental protein 12. We now used human choriocarcinoma JEG-3 cell monolayer cultures and recombinant (Thr59)IGF-I as a model to study whether the decidual 34 K IGF-BP is able to modulate the receptor binding and biological activity of IGFs in trophoblasts. JEG-3 cells, which possess type I IGF receptors, were unable to produce IGF-BPs. Purified 34 K IGF-BP specifically bound [125I]iodo-(Thr59)IGF-I. Multiplication-stimulating activity had 2.5% the potency of (Thr59)IGF-I, and insulin had no effect on the binding of [125I] iodo-(Thr59)IGF-I. 34 K IGF-BP inhibited the binding of [125I] iodo-(Thr59)IGF-I to JEG-3 monolayers in a concentration-dependent manner by forming with the tracer a soluble complex that could not bind to the cell surface as demonstrated by competitive binding and cross-linking experiments. After incubating the cell monolayers with [125I]iodo-(Thr59)IGF-I in the presence of purified binding protein, followed by cross-linking, no affinity labeled bands were seen on autoradiography. In contrast, an intensely labeled band at 40 K was detected when the incubation medium was analyzed, suggesting that (Thr59)IGF-I and 34 K IGF-BP formed a complex in a 1:1 molar ratio. Also, 34 K IGF-BP inhibited both basal and IGF-I-stimulated uptake of alpha-[3H]aminoisobutyric acid in JEG-3 cells. RNA analysis revealed that IGF-II is expressed in JEG-3 cells. We conclude that decidual 34 K IGF-BP inhibits the cellular binding and biological action of IGFs in JEG-3 cells. Our data show that JEG-3 cells represent a cell type that can produce IGF, but not IGF-BPs. These cells may thus provide a useful model system for a better understanding of autocrine growth regulation mediated by the IGFs.

Human granulosa cells synthesize low molecular weight insulin-like growth factor-binding protein.

Human follicular fluid contains insulin-like growth factor I (IGF-I) and its low molecular weight binding protein (IGF-BP). We studied the synthesis of IGF-BP by the granulosa cells obtained after ovarian hyperstimulation for in vitro fertilization. The granulosa cells were cultured for 72 hours in Ham's F-10 medium supplemented with 10% fetal calf serum (FCS). Samples of the culture medium were collected every 24 hours. The IGF-BP concentration in culture medium increased from 1.2 to 2.1 micrograms/l at 48 h and to 3.3 micrograms/l at 72 h. De novo synthesis of IGF-BP was shown by incorporation of labeled methionine into immunoreactive IGF-BP, as detected by SDS polyacrylamide electrophoresis (PAGE) and fluorography. Our results demonstrate synthesis of IGF-BP in the human ovary.

Insulin-like growth factor (IGF) binding protein-3 in pregnancy serum binds native IGF-I but not iodo-IGF-I.

Although serum immunoreactive insulin-like growth factor binding protein-3 (IGFBP-3) increases during pregnancy, radioligand binding methods such as ligand blotting with iodinated IGFs fail to detect the protein in pregnancy serum. Since IGFBP-3 must bind IGF-I or IGF-II to form a complex with the acid-labile subunit (alpha-subunit), we have used ternary complex formation from [125I]alpha-subunit as a measure of IGF binding to serum IGFBP-3. High-pressure liquid chromatography fractions containing IGFBP-3 from pregnancy serum did not bind [125I]IGF-I, although the equivalent fractions from nonpregnancy serum showed dose-dependent binding. In contrast, IGFBP-3 fractions from nonpregnancy and pregnancy sera both bound [125I]alpha-subunit in the presence of either exogenous IGF-I or endogenous serum IGFs, implying that non-iodinated IGFs could bind to the IGFBP-3. Substitution of nonradioactive iodo-IGF-I for native IGF-I in the complex formation assay confirmed that the pregnancy-induced alteration in IGFBP-3, probably resulting from proteolysis, prevents it from binding iodo-IGF-I while having little effect on its binding of the native peptide. This provides an explanation for the failure to detect IGFBP-3 in pregnancy by radioligand binding methods, and raises the question of the significance of proteolysis of IGFBP-3.

Insulin-like growth factor-binding protein-3 is functionally normal in pregnancy serum.

Insulin-like growth factor-binding protein-3 (IGFBP-3) carries most of the serum IGFs as a 150K ternary complex which increases during pregnancy. However, recent studies have demonstrated that IGFBP-3 is absent in pregnancy serum when measured by ligand blotting after electrophoresis. In the present study we demonstrate that, by several criteria, IGFBP-3 appears functionally intact in pregnancy serum. Serum samples were collected from pregnant women between 2-40 weeks gestation. Serum immunoreactive IGFBP-3 and acid-labile (alpha) subunit increased linearly throughout pregnancy. Ligand blotting confirmed diminution of IGFBP-3 at 2 weeks gestation and complete absence after 4 weeks gestation or when nonpregnancy serum was preincubated with amniotic fluid. When less harsh methods (neutral chromatography or transient acidification) were used, IGFBP-3 appeared functionally normal in pregnancy serum. Fractionation of pregnancy serum by Superose-12 gel permeation chromatography showed similar elution profiles for both IGFBP-3 and alpha-subunit compared to those for nonpregnancy serum. Preincubation of nonpregnancy serum with pregnancy serum or amniotic fluid had no effect on IGFBP-3 recovery. After acidification and neutralization of serum to destroy endogenous alpha-subunit, ternary complex formation, measured by radiolabeled alpha-subunit binding, was essentially identical in all nonpregnancy and pregnancy serum, except for a slight loss of activity in first trimester serum. Since the 150K complex cannot form unless IGFBP-3 binds IGFs and alpha-subunit normally, these results suggest that IGFBP-3 in native pregnancy serum is functionally normal.

Different insulin-like growth factor binding species in human placenta and decidua.

Previous studies demonstrated that human decidua secretes a 34K insulin-like growth factor binding protein (34K IGF-BP) earlier designated placental protein 12, whereas placenta contains IGF receptors and IGF mRNA. We studied binding of [125I]IGF-I to paired placental and decidual tissues using competitive binding, gel filtration, RIA, and cross-linking techniques, and compared the binding characteristics of these two tissues which are located in close proximity in vivo. The effect of decidual cytosols on [125I]IGF-I binding to placental membranes also was studied. Consistent with previous data the dominating binding species in placental membranes were IGF receptors. In contrast, the binding of [125I]IGF-I to decidual membranes was mainly due to binding species with mol wts of 34K and 39K. The 34K IGF-BP was more readily detected in decidual cytosols than in decidual membranes and little was detected in placental cytosols. Purified 34K IGF-BP as well as decidual cytosols inhibited [125I]IGF-I binding to placental receptors. The inhibitory effect of decidual cytosol on IGF receptor binding was linearly correlated to the decidual content of 34K IGF-BP. The results suggest that the decidual 34K IGF-BP might act as a local modulator of the IGF action at the interface between the decidua and the placenta.

Dose-response characteristics for suppression of low molecular weight plasma insulin-like growth factor-binding protein by insulin.

We previously demonstrated that supraphysiological insulin concentrations reduced the plasma 34K insulin-like growth factor-binding protein (IGF-BP) concentrations in humans. In this study we examined whether physiological changes in plasma insulin concentrations regulate IGF-BP and, if so, whether the regulation is influenced by race, glucose tolerance, or rate of glucose metabolism. For these purposes we 1) analyzed the relationship between fasting plasma insulin and IGF-BP concentrations in 2 racial groups (23 caucasians and 35 southwestern American Indians), 2) measured the response of plasma IGF-BP to oral glucose in 20 normal subjects, and 3) determined the dose-response characteristics of plasma IGF-BP to glucose and insulin in 23 normal subjects at 4 different insulin and glucose concentrations. The fasting plasma insulin concentration was inversely related to the plasma IGF-BP concentration in both the caucasian and Indian groups (P less than 0.0001). In the caucasian group the mean plasma IGF-BP concentration was higher [15 +/- 4 (+/- SE) micrograms/L] than in the Indian group (8 +/- 2 micrograms/L; P less than 0.05). This difference was independent of race and glucose tolerance, and it could be explained by lower plasma insulin concentrations in the caucasian (387 +/- 50 pmol/L) than in the Indian group (215 +/- 43 pmol/L; P less than 0.001). After oral glucose administration, the insulin concentration (423 +/- 72 pmol/L) was maximal 30 min after glucose treatment, and significant suppression of the IGF-BP concentration occurred at 90 min. Analysis of the dose-response curves revealed maximal suppression of IGF-BP at about 1150 pmol/L insulin, and half-maximal suppression at about 290 pmol/L. The plasma glucose concentration or the rate of glucose metabolism had no effect on the IGF-BP concentration. These data suggest that insulin is a major regulator of plasma IGF-BP concentrations under physiological conditions.

Prolonged exercise increases serum insulin-like growth factor-binding protein concentrations.

We studied the response of serum 34K insulin-like growth factor-binding protein (IGF-BP) to two types of prolonged exercise. In the first study, 11 normal men performed cycle ergometer exercise, after an overnight fast, for 3 h at the intensity corresponding to 45-50% of their maximal aerobic power. After the exercise, the mean serum IGF-BP concentration was 4.9-fold higher than the baseline level (P less than 0.01), while the IGF-I concentration did not change. Resting for the same time period resulted in a 38% fall in the serum IGF-BP level (P less than 0.01). In the second study, 10 normal men and 8 type 1 diabetic men exercised, on the average, for 7.5 h in a 75-km cross-country ski race. The mean serum IGF-BP concentration increased 5.4-fold (P less than 0.01) in the normal men and 4.2-fold (P less than 0.01) in the diabetic men. The serum IGF-I concentration decreased by 19% and 21% in the normal and diabetic men, respectively (P less than 0.01). After completion of the ski race, the serum insulin and IGF-BP levels (r = -0.70; P less than 0.05), and serum IGF-I and IGF-BP levels (r = -0.72; P less than 0.05) were inversely correlated in the normal men. No such correlations were found in the diabetic men. We conclude that 1) long term exercise increases serum IGF-BP concentrations in both normal and type 1 diabetic men; and 2) the increases are inversely related to alterations in serum IGF-I and insulin concentrations in normal men. These data suggest that IGF-BP may be involved in regulation of the biological action of IGF-I during prolonged exercise.

Regulation of insulin-like growth factor-binding protein-1 production in human granulosa-luteal cells.

Human follicular fluid contains the insulin-like growth factor-binding protein (IGFBP-1) synthesized by ovarian granulosa cells. We studied the regulation of IGFBP-1 production by the granulosa-luteal cells from the hyperstimulated follicles of patients attending an in vitro fertilization program. The cells were first allowed to attach and recover from the hyperstimulation for 2 days. Then, a protein kinase-C activator, 12-O-tetradecanoyl phorbol-13-acetate (TPA), and adenylate cyclase activators, gonadotropins, FSH, hCG, cholera toxin, or prostaglandin E2 (PGE2) were added to the cells. The gonadotropins failed to increase IGFBP-1 production, whereas it was enhanced by TPA and to a lesser extent by cholera toxin and PGE2. The maximal response to TPA occurred at the concentration of 1.0 ng/mL, and the enhancing effect of TPA was detected at 24 h. PGE2 stimulated IGFBP-1 production; the lowest effective concentration was 10(-8) mol/L. The mean highest response was 4.3-fold and occurred at the PGE2 concentration of 10(-5) mol/L. The effect of PGE2 on IGFBP-1 production became detectable at 24 h, and it continued to increase up to 72 h. PGE2 also increased granulosa-luteal cell progesterone production in a dose- and time-dependent manner. Incorporation of [35S]methionine into immunoreactive IGFBP-1, as detected by sodium dodecyl sulfate-polyacrylamide electrophoresis and fluorography, was also increased by TPA. This suggests that TPA accelerated the synthesis of IGFBP-1. Our results indicate that the production of IGFBP-1 by human granulosa-luteal cells can be regulated both via protein kinase-C- and adenylate cyclase-dependent pathways.

Insulin regulates the serum levels of low molecular weight insulin-like growth factor-binding protein.

The serum levels of 34K insulin-like growth factor (IGF)-binding protein were measured by RIA in 88 type 1 diabetic patients, 9 patients with type 2 diabetes, 7 patients with insulinoma, 19 normal subjects (all after an overnight fast), and 82 normal subjects after a breakfast meal. In addition, the effect of 2- to 3-h euglycemic steady state hyperinsulinemia on serum IGF-binding protein and IGF-1 levels was studied in some subjects in each of the fasted groups. Compared with normal subjects, the mean serum IGF-binding protein levels were 4-fold (P less than 0.001) higher in type I diabetic patients treated with conventional insulin injections, 2.5-fold (P less than 0.001) higher in those treated with continuous sc insulin infusion, and 2-fold (P less than 0.05) higher in patients with type 2 diabetes. In the patients with insulinoma, the mean IGF-binding protein level was 63% below normal (P less than 0.001), and it normalized after removal of the tumor. There was a slight negative correlation between the IGF-binding protein level and insulin dose in the diabetic patients (r = -0.22; P less than 0.05). In normal subjects, serum insulin concentrations were 2-fold higher (P less than 0.001) and the IGF-binding protein level was 29% lower after a meal (P less than 0.05) than in the fasting state. Serum IGF-I concentrations were virtually identical in the type 1 and 2 diabetic patients, insulinoma patients, and normal subjects. During steady state euglycemic hyperinsulinemia, the IGF-binding protein level fell by 40-70% in each group (P less than 0.001), whereas the IGF-I level declined (P less than 0.05) in the type 2 diabetic patients only. The decline of binding protein was closely related to the baseline level (r = 0.94; P less than 0.001). No correlation was found between serum IGF-I and binding protein levels in any group. In conclusion, 1) serum 34K IGF-binding protein levels are elevated in type 1 and 2 diabetic patients and decreased in patients with insulinoma; 2) the serum binding protein, but not IGF-I concentration is decreased by acute hyperinsulinemia; and 3) these data suggest that the serum insulin concentration plays a role in regulation of the serum 34K IGF-binding protein concentration.

Oral contraceptives increase insulin-like growth factor binding protein-1 concentration in women with polycystic ovarian disease.

UNLABELLED: Insulin-like growth factor-I (IGF-I) stimulates ovarian androgen production. Insulin-like growth factor binding protein-1 (IGFBP-1) inhibits IGF actions in vitro. OBJECTIVE: To investigate the effect of oral contraceptive (OC) pills, given for 3 months, on serum gonadotropin, androgen, IGF-I, and IGFBP-1 concentrations, and glucose tolerance in seven women with polycystic ovarian disease (PCOD) and in five healthy control subjects. PATIENTS: Seven women with PCOD and five healthy control subjects. INTERVENTIONS: An oral glucose tolerance test (OGTT) was performed before and after treatment with OC. RESULTS: After treatment with OC, serum luteinizing hormone, androstenedione, and free testosterone levels decreased, and sex hormone-binding globulin concentration increased in the women with PCOD as well as in the control subjects. The cumulative response of serum insulin to OGTT was larger in the women with PCOD than in the control subjects both before and after treatment. Serum IGF-I concentration, which was unchanged during OGTT, decreased from basal level of 326 +/- 70 micrograms/L to 199 +/- 28 micrograms/L after treatment with OC in the women with PCOD, whereas no change was found in the control subjects (from 235 +/- 11 micrograms/L to 226 +/- 11 micrograms/L). Treatment with OC caused an increase of the mean basal IGFBP-1 concentration from 24 +/- 7 micrograms/L to 73 +/- 14 micrograms/L in the women with PCOD. This increase was constant during the OGTT. In the control subjects, treatment with OC did not result in any significant change in IGFBP-1 concentrations (from 44 +/- 11 micrograms/L to 61 +/- 9 micrograms/L). CONCLUSION: The combination of decreased total IGF-I concentration and increased IGFBP-1 concentration induced by OC may decrease ovarian androgen production in PCOD.

PIP: Insulin-like growth factor-I (IGF-I) stimulates ovarian androgen production. Insulin-like growth factor binding protein-1 (IGFBP-1) inhibits IGF actions in vitro. The objective of this study was to investigate the effect of oral contraceptives (OCs), administered for 3 months, on serum gonadotropin, androgen, IGF-I, and IGFBP-1 concentrations, and glucose tolerance in 7 women with polycystic ovarian disease (PCOD) and in 5 healthy subjects. An oral glucose tolerance test (OGTT) was performed before and after treatment with OCs. After treatment, serum luteinizing hormone, androstenedione, and free testosterone levels decreased, and sex hormone-binding globulin concentrations increased in the women with PCOD as well as in the controls. The cumulative response of serum insulin to OGTT was larger in women with PCOD than in the controls, both before and after treatment. Serum IGF-I concentration, which was unchanged during OGTT, decreased from a basal level of 326 +or- 70 mcg/L to 199 +or- 28 mcg/L after OC treatment in those women with PCOD, whereas no change was found in the controls (from 235 +or- 11 mcg/L to 22 +or- 11 mcg/L). Treatment with OCs caused an increase in the mean basal IGFBP-1 concentrations from 24 +or- 7 mcg/L to 73 +or- 14 mcg/L in the women with PCOD. This increase was constant during OGTT. Among the control subjects, treatment with OCs did not result in any significant change in IGFBP-1 concentrations (from 44 +or- mcg/L to 61 +or- 9 mcg/L). The combination of decreased total IGF-1 concentration and increased IGFBP-1 concentration induced by OCs may decrease ovarian androgen production in PCOD.

Effect of naloxone on plasma insulin, insulin-like growth factor I, and its binding protein 1 in patients with polycystic ovarian disease.

Insulin and insulin-like growth factors (IGFs) stimulate ovarian steroidogenesis, and hyperinsulinemia is often accompanied by hyperandrogenemia in women with polycystic ovarian disease (PCOD). Because opioid peptides are involved in the regulation of insulin secretion, we studied the effect of naloxone-induced opiate receptor blockade on the circulating levels of insulin, IGF-I, and IGF binding protein 1 (IGFBP-1) in 13 nonobese and 7 obese PCOD patients and in 6 healthy subjects. In obese PCOD patients, the mean basal insulin concentration was significantly higher and the IGFBP-1 concentration lower than in nonobese PCOD patients. Plasma IGF-I levels were elevated both in obese and nonobese PCOD patients. After an intravenous bolus of 10 mg naloxone, no significant changes were found in the circulating insulin or IGF-I levels, whereas IGFBP-1 levels decreased in nonobese PCOD patients and remained low in obese PCOD patients. No significant decrease was found in healthy subjects. These results suggest that, in addition to insulin, endogenous opioids are involved in the regulation of serum IGFBP-1 level.