Serum SHBG levels during normal menstrual cycle and after insertion of levonorgestrel-releasing IUD

Sex-specific differences in bone mineral density loss after sleeve gastrectomy

Background

Sleeve gastrectomy is an effective bariatric procedure; however, sleeve gastrectomy-related adverse skeletal outcomes have been increasingly reported. High levels of sex hormone-binding globulin (SHBG) have been documented to be a risk factor of bone mineral density (BMD) loss with different effects observed between sexes. The aim of this study was to identify sex-specific changes in BMD following sleeve gastrectomy and to evaluate the role of SHBG in this process.

Methods

This retrospective study included 19 middle-aged men and 30 non-menopausal women with obesity who underwent sleeve gastrectomy in China. Anthropometrics, bone turnover markers, calciotropic hormones, BMD, SHBG, and gonadal steroids were measured preoperatively and at 6 and 12 months postoperatively. Longitudinal changes in BMD, bone turnover markers and SHBG were compared between sexes by linear mixed models. Multiple stepwise regression analysis was used to identify the predictors of BMD loss at the investigated bone sites.

Results

Over the 12-month study period, total hip and femoral neck BMD decreased, while lumbar spine BMD remained largely unchanged in both sexes. Linear mixed models revealed significant sex × time interaction effects in total hip BMD and SHBG, showing that men had a significantly greater reduction in total hip BMD and less increase in SHBG after sleeve gastrectomy than women. In the multivariate model, SHBG was significantly associated with total hip BMD loss in men (adjusted β = −0.533, P = 0.019) but not women while total estrogen was significantly associated with total hip BMD loss in women (adjusted β = 0.508, P = 0.01) but not men.

Conclusion

Significant sex-specific BMD changes were observed after sleeve gastrectomy in the current study. Sleeve gastrectomy-related increase in SHBG may be a specific risk factor for total hip BMD loss in men. Our results indicate that sex-specific screening may be warranted to facilitate personalized postoperative bone care in this population.

Serum sex hormone-binding globulin levels are reduced and inversely associated with intrahepatic lipid content and saturated fatty acid fraction in adult patients with glycogen storage disease type 1a

PURPOSE

De novo lipogenesis has been inversely associated with serum sex hormone-binding globulin (SHBG) levels. However, the directionality of this association has remained uncertain. We, therefore, studied individuals with glycogen storage disease type 1a (GSD1a), who are characterized by a genetic defect in glucose-6-phosphatase resulting in increased rates of de novo lipogenesis, to assess the downstream effect on serum SHBG levels.

METHODS

A case-control study comparing serum SHBG levels in patients with GSD1a (n = 10) and controls matched for age, sex, and BMI (n = 10). Intrahepatic lipid content and saturated fatty acid fraction were quantified by proton magnetic resonance spectroscopy.

RESULTS

Serum SHBG levels were statistically significantly lower in patients with GSD1a compared to the controls (p = 0.041), while intrahepatic lipid content and intrahepatic saturated fatty acid fraction-a marker of de novo lipogenesis-were significantly higher in patients with GSD1a (p = 0.001 and p = 0.019, respectively). In addition, there was a statistically significant, inverse association of intrahepatic lipid content and saturated fatty acid fraction with serum SHBG levels in patients and controls combined (β: - 0.28, 95% CI: - 0.47;- 0.09 and β: - 0.02, 95% CI: - 0.04;- 0.01, respectively).

CONCLUSION

Patients with GSD1a, who are characterized by genetically determined higher rates of de novo lipogenesis, have lower serum SHBG levels than controls.

Relationship between de novo lipogenesis and serum sex hormone binding globulin in humans

OBJECTIVE

Obesity and liver fat are associated with decreased levels of serum sex hormone binding globulin (SHBG). Laboratory studies suggest that hepatic de novo lipogenesis (DNL) is involved in the downregulation of SHBG synthesis. The aim of the present study was to address the role of DNL on serum SHBG in humans.

DESIGN

A cross-sectional study examining the association between DNL, measured by stable isotopes, and serum SHBG, stratified by sex.

PARTICIPANTS

Healthy men (n = 34) and women (n = 21) were combined from two cross-sectional studies. Forty-two per cent of participants had hepatic steatosis, and the majority were overweight (62%) or obese (27%).

RESULTS

DNL was inversely associated with SHBG in women (β: -0.015, 95% CI: -0.030; 0.000), but not in men (β: 0.007, 95% CI: -0.005; 0.019) (p for interaction = .068). Adjustment for study population, age and body mass index did not materially change these results, although statistical significance was lost after adjustment for serum insulin.

CONCLUSIONS

An inverse association between DNL and SHBG may explain the decreased SHBG levels that are observed in obesity, at least in women.

Bleeding pattern difference between levonorgestrel intrauterine system and copper intrauterine devices inserted immediately post-abortion: a multicenter, prospective, observational cohort study in Chinese women

BACKGROUND

To describe the bleeding pattern (primary outcome), side effects, treatment satisfaction and 6 month continuity rates associated with the 52 mg levonorgestrel intrauterine system (LNG-IUS) and the copper intrauterine device (Cu-IUD) inserted immediately after abortion.

METHODS

This multicenter, prospective, observational cohort study enrolled healthy women (aged ≥18 years) inserted with LNG-IUS or Cu-IUD immediately after first-trimester surgical abortion and followed up to 6 months. Bleeding pattern was obtained through daily patient bleeding diaries.

RESULTS

From 2013 to 2014, we enrolled 512 women (LNG-IUS = 312 [median age: 32.0 years] and Cu-IUD = 200 [median age: 30.0 years]) from nine Chinese centers. LNG-IUS resulted in a significantly lower number of bleeding/spotting days in the second 90 day reference period compared with Cu-IUD (median 14.5 vs. 18.0 days, p < .0001). Amenorrhea rate (no bleeding/spotting day in the second 90 day reference period) and no menstrual bleeding rate (absence of bleeding days in the second 90 day reference period) were significantly higher in LNG-IUS compared to Cu-IUD (13.9% vs. 0% and 39.5% vs. 0%; p < .001 for all). No dysmenorrhea was higher at the last follow-up in LNG-IUS users than Cu-IUD users (81.2% vs. 76%; p = .0047). Both treatments had a high satisfaction rate among women at both the follow-up visits, and the majority of them continued with the treatment. The rates of adverse events (e.g. oligomenorrhea, amenorrhea) in the LNG-IUS and Cu-IUD groups were 77.2% and 44.5% (p < .0001), respectively.

CONCLUSION

LNG-IUS post-abortion shows better bleeding patterns, and reduced dysmenorrhea and bleeding amount, but with a similar safety profile compared with Cu-IUD. ClinicalTrials.gov identifier: NCT01958684.

Circulating androgens and SHBG during the normal menstrual cycle in two ethnic populations

The objective of this study was to study possible ethnic differences in steroid hormones and sex hormone-binding globulin (SHBG) during the menstrual cycle. Serum levels of the ovarian steroids estradiol (E2) and progesterone (P) and of follicle-stimulating hormone (FSH), luteinizing hormone (LH), SHBG, dehydroepiandrosterone (DHEA) and testosterone (T-ria) were all measured by immunoassay during the menstrual cycle in 15 Swedish and 11 West Asian regularly menstruating women. Testosterone (T-ms) was also measured by LC-MS/MS and so were 4-androstene-3,17-dione (A-4) and 17-alpha-hydroxyprogesterone (17-OHP). There were no ethnic differences in levels of ovarian steroids, gonadotrophins, A-4, 17-OHP and T-ms. DHEA were significantly higher and SHBG significantly lower in West Asian than in Swedish women. Surprisingly, T-ria was significantly higher in West Asian than in Swedish women and higher than T-ms (47% in Swedish and 107% in West Asian women). The difference (T-ria - T-ms) showed strong positive correlations to DHEA in the total and in West Asian but not in Swedish women, indicating an influence of DHEA/DHEAS metabolites on the T-ria results. In conclusion, ethnic differences in cross reacting steroids may cause erroneous results in one ethnic group by a steroid immunoassay having reasonable specificity in another. The reasons for the lower SHBG and the higher DHEA levels in West Asian women are not known. The results raise the question about establishing different reference values for certain analytes in different ethnic groups.

Risk of intracranial hypertension with intrauterine levonorgestrel

OBJECTIVES

The objective of this study was to quantify the risk of intracranial hypertension (ICH) with the intrauterine levonorgestrel (IUL) device Mirena(®).

METHODS

We used the United States Food and Drug Administration's Adverse Events Reporting System (FAERS) database to quantify a reporting odds ratio (ROR) for ICH and Mirena(®). We also conducted a retrospective cohort study using the IMS LifeLink(®) database, comparing the risk of two oral contraceptives ethinyl estradiol (EE) with Mirena(®). A Bayesian sensitivity analysis was performed to account for the effect of body mass index (BMI).

RESULTS

The reported odds ratios (ORs) for ICH and papilledema with Mirena(®) were 1.78 (95% confidence interval [CI] 1.41-2.25) and 1.50 (95% CI 1.10-2.05), respectively. In the cohort study, the OR for ICH and EE-norgestimate and EE-norethindrone compared with Mirena(®) were 1.29 (95% CI 0.83-2.00) and 0.31 (95% CI 0.04-2.29), respectively. The presence of a strong confounder BMI did not affect the estimated OR (OR = 1.31, 95% CI 0.73-2.41 for EE-norgestimate; OR = 0.18, 95% CI 0.01-1.27 for EE-norethindrone).

CONCLUSION

We found a higher than expected number of reports of ICH with Mirena(®) in the FAERS database. We also found a similar risk of ICH with Mirena(®) compared with the oral contraceptive EE-norgestimate. The higher risk of ICH with EE-norethindrone, another oral contraceptive should be further investigated.

Estradiol Binds to Insulin and Insulin Receptor Decreasing Insulin Binding in vitro

RATIONALE

Insulin (INS) resistance associated with hyperestrogenemias occurs in gestational diabetes mellitus, polycystic ovary syndrome, ovarian hyperstimulation syndrome, estrogen therapies, metabolic syndrome, and obesity. The mechanism by which INS and estrogen interact is unknown. We hypothesize that estrogen binds directly to INS and the insulin receptor (IR) producing INS resistance.

OBJECTIVES

To determine the binding constants of steroid hormones to INS, the IR, and INS-like peptides derived from the IR; and to investigate the effect of estrogens on the binding of INS to its receptor.

METHODS

Ultraviolet spectroscopy, capillary electrophoresis, and NMR demonstrated estrogen binding to INS and its receptor. Horse-radish peroxidase-linked INS was used in an ELISA-like procedure to measure the effect of estradiol on binding of INS to its receptor.

MEASUREMENTS

Binding constants for estrogens to INS and the IR were determined by concentration-dependent spectral shifts. The effect of estradiol on INS binding to its receptor was determined by shifts in the INS binding curve.

MAIN RESULTS

Estradiol bound to INS with a K d of 12 × 10(-9) M and to the IR with a K d of 24 × 10(-9) M, while other hormones had significantly less affinity. Twenty-two nanomolars of estradiol shifted the binding curve of INS to its receptor 0.8 log units to the right.

CONCLUSION

Estradiol concentrations in hyperestrogenemic syndromes may interfere with INS binding to its receptor producing significant INS resistance.

The benefits and risks of using a levonorgestrel-releasing intrauterine system for contraception

The contraceptive profile of the levonorgestrel-releasing intrauterine system (LNG-IUS; Mirena®) is well established, with efficacy similar to that achieved with sterilization and rapid return to fertility after discontinuation of use. The LNG-IUS is typically associated with transient menstrual disturbance during the first few months of use, but this usually settles with continued use, with a concomitant decrease in menstrual blood loss. Overall, the safety profile of the LNG-IUS has been well established across a wide population of women, and the available data do not suggest that the LNG-IUS adversely affects bone health or increase the risk of adverse cardiovascular events or breast and uterine cancers. This article reviews the literature to provide updated information on the risks and benefits associated with the LNG-IUS, particularly focusing on its use in contraception.

Serum levonorgestrel levels and endometrial thickness during extended use of the levonorgestrel-releasing intrauterine system

BACKGROUND

The levonorgestrel-releasing intrauterine system (LNG-IUS) is a contraceptive method approved for five years of use. However, there is some evidence that its life span may be longer. The aim of the study was to evaluate serum levonorgestrel (LNG) and estradiol (E(2)) levels and endometrial thickness every 6 months from 7 to 8 1/2 years after insertion.

STUDY DESIGN

At the end of the approved 5-year life span, no replacement devices were available; therefore, 86 women were allowed to retain the same device for a further 2 years. At the 7-year follow-up visit, the women who consented were again allowed to retain the same device for a further 18 months and were followed-up at six-monthly intervals. At each visit, vaginal sonography was performed to measure endometrial thickness, and a blood sample was taken to measure LNG and E(2).

RESULTS

Eighty-four months after insertion, 67 women aged 34.3+/-0.8 years (mean+/-SEM) (range, 25-49 years) returned for follow-up. Mean+/-SEM LNG levels decreased from an initial 253+/-27 pg/mL (range, 86-760) during the first 2 months following insertion to 137+/-12 (range, 23-393) at 84 months and 119+/-9 pg/mL (range, 110-129) at 102 months of use (+/-SEM). At 84 months of use, mean+/-SEM endometrial thickness was 2.8+/-0.1 mm, increasing to 3.8+/-0.5 mm at 102 months of use. The incidence of amenorrhea decreased from 41.8% at 84 months to 31.5% at 102 months of use. No correlation was found between LNG levels and bleeding patterns; however, a weak correlation was found between high body mass index (kg/m(2)), high weight, and low serum LNG levels. E(2) levels were similar to those of the follicular phase of the menstrual cycle of regularly menstruating women.

CONCLUSIONS

During extended use of the LNG-IUS, serum LNG levels were nearly half those found in the first 2 months of use (Wilcoxon signed rank test); serum E(2) levels were normal. Despite the very thin endometrium, menstrual bleeding was reinstated in many cases. At the end of its 5-year life span, there is a window for changing the LNG-IUS, and physicians and users should not be concerned about delaying replacement of the device for a short time beyond the approved life span; however, maintaining the same device long after its approved life span cannot be recommended.

Levonorgestrel-releasing intrauterine system as an adjunct to estrogen for the treatment of menopausal symptoms-a review

Exogenous estrogen is an effective means of prevention for postmenopausal symptoms. Estrogen treatment should be combined with progesterone in non-hysterectomized women to prevent estrogen-induced malignant transformation of the endometrium. Progesterone supplementation using continuous combined estrogen + progesterone treatment may result in an increased incidence of breast cancer and cardiovascular disease. In addition, progesterone supplementation with sequential estrogen + progesterone treatment may cause immediate adverse effects, such as irregular bleeding and spotting, breast congestion, fluid retention, abdominal distention, and a change in lipid profile. All these effects are related, at least in part, to the progesterone component of the therapy.To avoid these complications, researchers are seeking safer progestational components and different modes of administration. In this article we review the findings on the use of the novel levonorgestrel-releasing intrauterine system as a therapeutic tool for localized, rather than systemic, progesterone administration in postmenopausal women.

A cross-sectional study of the forearm bone density of long-term users of levonorgestrel-releasing intrauterine system

BACKGROUND

There are concerns about the effect of hormonal contraceptives on bone mineral density (BMD), but there is currently no information available on the effect of the levonorgestrel-releasing intrauterine system (LNG-IUS) on BMD. The objective of this study was to compare the BMD of LNG-IUS users with that of controls using the TCu380A intrauterine device (IUD).

MATERIALS AND METHODS

A cross-sectional study paired 53 women, aged 25-51 years, who had been using the LNG-IUS for 7 years, with 53 IUD users, according to age (+/-1 year) and body mass index (BMI; kg/m2) (+/-1). BMD was evaluated at the midshaft of the ulna and the distal radius of the nondominant forearm using double X-ray absorptiometry.

RESULTS

Mean age of women was 34 years. BMI was slightly over 25 in both groups. Estradiol was normal. Mean BMD was 0.469 +/- 0.008 and 0.467 +/- 0.009 and 0.409 +/- 0.009 and 0.411 +/- 0.009 at the midshaft of the ulna and distal radius in LNG-IUS and IUD users, respectively, without significant differences.

CONCLUSIONS

Women aged 25-51 years, using the LNG-IUS for 7 years, had a mean BMD similar to that of the control group of TCu380A IUD users.

Benefit-Risk Assessment of the Levonorgestrel Intrauterine System in Contraception

The levonorgestrel-releasing intrauterine system (IUS) is a long-acting, fully reversible method of contraception. It is one of the most effective forms of contraception available, and combines the advantages of both hormonal and intrauterine contraception. The levonorgestrel-releasing IUS also gives the users many non-contraceptive benefits: the amount of menstrual bleeding and the number of days of menstrual bleeding are reduced, which makes it suitable for the treatment of menorrhagia (heavy menstrual blood loss). Dysmenorrhoea (painful menstruation) and premenstrual symptoms are also relieved. In addition, the levonorgestrel-releasing IUS provides protection for the endometrium during hormone replacement therapy. The local release of levonorgestrel into the uterine cavity results in a strong uniform suppression of the endometrial epithelium as the epithelium becomes insensitive to estradiol released from the ovaries. This accounts for the reduction in menstrual blood loss. All possible patterns of bleeding are seen among users of the levonorgestrel-releasing IUS; however, most of the women who experience total amenorrhoea continue to ovulate. The first months of use are often characterised by irregular, scanty bleeding, which in most cases resolves spontaneously. The menstrual pattern and fertility return to normal soon after the levonorgestrel-releasing IUS is removed. The contraceptive efficacy is high with 5-year failure rates of 0.5-1.1 per 100 users. The absolute number of ectopic pregnancies is low, as is the rate per 1000 users. The levonorgestrel-releasing IUS is equally effective in all age groups and the bodyweight of the user is not associated with failure of the method. In Western cultures continuance rates among users of the levonorgestrel-releasing IUS are comparable with those of other long-term methods of contraception. Premature removal of the device is most often associated with heavy menstrual bleeding and pain, as with other long-term methods of contraception, and is most common in the youngest age group. When adequately counselled about the benign nature of oligo- or amenorrhoea, most women are very willing to accept life without menstruation. The risk of premature removal can be markedly diminished with good pre-insertion counselling, which also markedly increases user satisfaction. User satisfaction is strongly associated with the information given at the time of the levonorgestrel-releasing IUS insertion. Thus, the benefits of the levonorgestrel-releasing IUS make it a very suitable method of contraception for most women.

Intrauterine 10 microg and 20 microg levonorgestrel systems in postmenopausal women receiving oral oestrogen replacement therapy: clinical, endometrial and metabolic response

OBJECTIVE

The clinical and endometrial efficacy and lipid response of two different doses of intrauterine levonorgestrel were assessed in comparison with sequential oral medroxyprogesterone acetate in postmenopausal women receiving continuous oral E2-valerate.

DESIGN

One-year prospective multicentre randomised control trial.

SETTING

Four outpatient clinics in Oulu, Helsinki and Jyväskylä, Finland.

POPULATION

A total of 163 healthy volunteer postmenopausal women with climacteric complaints or already using hormone replacement therapy (HRT).

INTERVENTIONS

Subjects were randomly allocated to receive a new intrauterine system releasing 10 microg of levonorgestrel daily or an established intrauterine system (Mirena) releasing 20 microg of levonorgestrel daily or sequential oral medroxyprogesterone acetate (5mg/day, 14/30 days). All three regimens were combined with an oral daily dose of 2mg of E2-valerate.

MAIN OUTCOME MEASURES

Bleeding patterns were assessed by diaries kept by the subjects. Endometrial effects were evaluated by histologic biopsies taken at the baseline and after six and 12 months of therapy. Serum concentrations of total, HDL and LDL cholesterol, triglycerides and lipoprotein(a) were determined at the baseline and after six and 12 months of therapy.

RESULTS

Insertion of the smaller 10 microg levonorgestrel system was easy in 70% and difficult in 4% and that of Mirena was easy in 46% and difficult in 21% of the subjects. After six months of therapy, 43 (95.6%) of the 47 subjects receiving 10 microg levonorgestrel and 54 (98.2%) of the 55 subjects receiving 20 microg levonorgestrel had no bleeding, while the sequential medroxyprogesterone acetate regimen produced typical cyclic withdrawal bleedings. Endometrial hyperplasia was not observed in any of the treatment groups during the 12-month study. After 12 months of therapy, strong endometrial suppression was found in 46/47 and 55/55 of the subjects receiving 10 microg and 20 microg of levonorgestrel, respectively, while the endometrium was proliferative in 18/47 of the subjects in the medroxyprogesterone acetate group. Serum total cholesterol decreased in all treatment groups. HDL cholesterol increased in women receiving medroxyprogesterone acetate or the smaller intrauterine dose of levonorgestrel.

CONCLUSIONS

Both intrauterine doses of levonorgestrel provided good endometrial protection in postmenopausal women on oestrogen replacement therapy. The advantage of the 10 microg system with a smaller size is the easier insertion of the system and a minimal attenuation of the favourable effects of oral oestrogen on the serum lipid profile.

Sex hormone binding globulin and free levonorgestrel index in the first week after insertion of Norplant implants

Levonorgestrel has an inhibitory effect on sex hormone binding globulin (SHBG). This decrease in SHBG leads to an increase in the free levonorgestrel index (FLI), which has a stronger biological effect. The interaction between serum levels of levonorgestrel and SHBG in long-term users of Norplant implants has been described. This study was designed to understand the same interaction immediately after the insertion of the implants, in a group of 16 women, sampled at 0 and 6 h and at 1, 3, and 7 days after Norplant implant insertion. Peak serum levonorgestrel levels were achieved at 24 h after insertion, remaining stable on day 3 and decreasing by > 10% by day 7. SHBG did not change during the first 24 h, but decreased by 19% and 60% on days 3 and 7, respectively. FLI more than doubled from day 1 to day 7 after insertion. The large decrease in SHBG and doubling of FLI is not followed by a similar reduction in levonorgestrel, which is hard to explain without an increase in the release rate of the steroid from the capsule.

The levonorgestrel-releasing intrauterine device: a wider role than contraception

The Levonorgestrel-releasing intrauterine device (LNG IUD) provides excellent contraception; it may reduce the rate of pelvic inflammatory disease (PID) and ectopic pregnancy compared to other 'modern' copper releasing IUDs; it can safely be used in the puerperium for breast-feeding mothers, and it significantly reduces menstrual blood loss and pain. While it was developed primarily as a contraceptive, its potential role in managing heavy and painful menstruation and the symptoms of the climacteric may eventually be just as important. Amongst developed countries New Zealand and Australia have some of the highest hysterectomy rates. By the age of 50 years 1 in 4 women in New Zealand and 1 in 5 women in Australia will have had a hysterectomy (A,B). In New Zealand 90% of these are performed for heavy menstrual bleeding and fibroids (A). The LNG IUD has been shown to be effective treatment for both these conditions and its introduction to New Zealand and Australia would offer women an additional choice beyond surgery.

Effect of levonorgestrel-releasing intrauterine device on hormonal profile and menstrual pattern after long-term use

In the present study 14 women after 6 years' use of levonorgestrel-releasing IUD were investigated for the changes of LH, progesterone (P), estradiol (E2), prolactin (PRL) and serum binding globulin (SHBG) in relation to the levonorgestrel levels throughout a segment of 26-40 days with the aim of comparing the hormonal profiles with those during the first year of use of Lng-IUD. Ultrasound scanning was used to follow the development of follicles along with the RIA measurement of hormones. The results of serum LH, P and E2 showed ovulation in 11 cases with either normal menstrual cycles (5 cases), prolonged or irregular cycles (4 cases) or with amenorrhea for 2-3 years (2 cases). One case showed insufficiency of luteal function and 2 cases showed anovulation but with follicular hyperactivity. Higher percentages of ovulatory cycles (78.5%) were found after 6 years of use. No case of complete suppression of ovulation was found. Anovulatory cycles only constituted 14.3%. Clinically, the development of follicles followed by ultrasound scanning further confirmed the hormonal findings. The persistent enlargement of follicles coincided with high levels of E2. After 6 years of use, the serum levels of levonorgestrel were still maintained at mean levels of 314.26 pmol/L and 470.63 pmol/L in the ovulatory and anovulatory groups, respectively. It is concluded that over two-thirds of the cases have ovulatory cycles after long-term use of Lng-IUD; the contraceptive effect is mainly due to its local action on the endometrium, with much less effect on the ovarian function.