Higher Serum Sex Hormone-binding Globulin Research Articles

Genetically predicted high serum sex hormone-binding globulin levels are associated with lower ischemic stroke risk: A sex-stratified Mendelian randomization study

ObjectiveCross-sectional and cohort studies have found insufficient evidence of a causal relationship between sex hormone-binding globulin and ischemic stroke, only associations. Here, we performed a sex-stratified, bidirectional, two-sample Mendelian randomization analysis to evaluate whether a causal relationship exists between sex hormone-binding globulin and ischemic stroke. MethodsSingle-nucleotide polymorphisms associated with sex hormone-binding globulin and ischemic stroke were screened from genome-wide association studies summary data as instrumental variables to enable a bidirectional, two-sample Mendelian randomization study design. Inverse-variance weighted analysis was used as the main method to evaluate potential causality, and additional methods, including the weighted median and MR-Egger tests, were used to validate the Mendelian randomization results. Cochran's Q statistic, MR-Egger intercept test, and Mendelian Randomization-Pleiotropy Residual Sum and Outlier global test were used as sensitivity analysis techniques to assure the reliability of the results. Multivariable analysis was used to show the robustness of the results with key theorized confounders. ResultsInverse-variance weighted analysis showed that genetically predicted higher serum sex hormone-binding globulin levels were associated with significantly decreased risk of ischemic stroke in males (odds radio = 0.934, 95 % confidence interval = 0.885-0.985, P = 0.012) and females (odds radio = 0.924, 95 % confidence interval = 0.868-0.983, P = 0.013). In an analysis of ischemic stroke subtypes, genetically predicted higher serum sex hormone-binding globulin levels were also associated with significantly decreased risk of small-vessel occlusion in both males (odds radio = 0.849, 95 % confidence interval = 0.759-0.949, P = 0.004) and females (odds radio = 0.829, 95 % confidence interval = 0.724-0.949, P = 0.006). The association remained in sensitivity analyses and multivariable analyses. The reverse analysis suggested an association between genetically predicted risk of cardioembolism and increased serum sex hormone-binding globulin in females (Beta = 0.029 nmol/L, Standard Error = 0.010, P = 0.003). ConclusionOur findings provide new insight into the etiology of ischemic stroke and suggest that modulating serum sex hormone-binding globulin may be a therapeutic strategy to protect against ischemic stroke.

Abstract 3434: Effect modification by levels of sex hormones in the association between adiposity and cancer incidence in the UK Biobank

Abstract Introduction: The association between adiposity and cancer risk differs between sexes for some cancer types. Methods: We prospectively examined adiposity in relation to cancer incidence according to sex hormones in the UK Biobank. Adiposity was assessed by body mass index (BMI) and visceral adipose tissue (VAT), the latter predicted using determinants of age, height, weight, hip circumference, waist circumference, and race. Serum sex hormone binding globulin (SHBG), testosterone, and estradiol were measured using a biochemistry assay and were classified as high or low based on median levels. Cancer incidence was ascertained using ICD-10 codes through cancer registry linkage. For cancer types showing a sex difference in the association between adiposity and cancer incidence, we assessed multiplicative and additive interaction with sex hormones in men and women separately and corrected for multiple testing using false discovery rate. We used Cox regression to calculate the multivariable hazard ratio (HR) of cancer per increase between the 90th to 10th percentile of adiposity (BMI or predicted VAT). Results: During a median follow-up of 13.1 years, we documented 23,964 and 21,045 incident cancer cases among 217,460 men and 256,163 women, respectively. Adiposity showed a much stronger association with higher risk of colorectal, esophageal, and liver cancers in men than women. In men, BMI was more strongly associated with higher risk of colorectal cancer in low vs. high levels of SHBG (HR (95%CI) of 1.47 (1.31-1.64) vs. 1.12 (0.94-1.33) (adjusted Pinteraction = 0.027). In contrast, BMI showed a stronger association in high vs. low levels of SHBG with esophageal (HR = 2.39 vs. 1.62) and liver cancers (HR = 3.24 vs 1.96) in men (adjusted Pinteraction = 0.038 and 0.027, respectively). Among women, BMI was associated with a higher risk of esophageal cancer in those with low SHBG (HR=1.68) but not in those with high SHBG (HR=0.64) (adjusted Pinteraction = 0.025). Similar patterns were observed for predicted VAT. Men with high SHBG levels and high adiposity (BMI and predicted VAT) had 7.63 (5.08-11.46) and 8.92 (5.72 to 13.90), respectively, times higher risk of liver cancer compared to men with low SHBG levels and low adiposity. No effect modification by estradiol or testosterone was detected for any of the cancers studied. Conclusions: The association between adiposity and colorectal, esophageal, and liver cancer differed by sex. SHBG may be an important factor underlying these differences. Citation Format: LeeAnn Lucas, Yujia Lu, Edward L. Giovannucci, Mingyang Song. Effect modification by levels of sex hormones in the association between adiposity and cancer incidence in the UK Biobank [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3434.

Ovarian Hyperandrogenism and Response to Gonadotropin-releasing Hormone Analogues in Primary Severe Insulin Resistance.

ContextInsulin resistance (IR) is associated with polycystic ovaries and hyperandrogenism, but underpinning mechanisms are poorly understood and therapeutic options are limited.ObjectiveTo characterize hyperandrogenemia and ovarian pathology in primary severe IR (SIR), using IR of defined molecular etiology to interrogate disease mechanism. To extend evaluation of gonadotropin-releasing hormone (GnRH) analogue therapy in SIR.MethodsRetrospective case note review in 2 SIR national referral centers. Female patients with SIR with documented serum total testosterone (TT) concentration.ResultsAmong 185 patients with lipodystrophy, 65 with primary insulin signaling disorders, and 29 with idiopathic SIR, serum TT ranged from undetectable to 1562 ng/dL (54.2 nmol/L; median 40.3 ng/dL [1.40 nmol/L]; n = 279) and free testosterone (FT) from undetectable to 18.0 ng/dL (0.625 nmol/L; median 0.705 ng/dL [0.0244 nmol/L]; n = 233). Higher TT but not FT in the insulin signaling subgroup was attributable to higher serum sex hormone–binding globulin (SHBG) concentration. Insulin correlated positively with SHBG in the insulin signaling subgroup, but negatively in lipodystrophy. In 8/9 patients with available ovarian tissue, histology was consistent with polycystic ovary syndrome (PCOS). In 6/6 patients treated with GnRH analogue therapy, gonadotropin suppression improved hyperandrogenic symptoms and reduced serum TT irrespective of SIR etiology.ConclusionSIR causes severe hyperandrogenemia and PCOS-like ovarian changes whether due to proximal insulin signaling or adipose development defects. A distinct relationship between IR and FT between the groups is mediated by SHBG. GnRH analogues are beneficial in a range of SIR subphenotypes.

Higher Serum Sex Hormone-Binding Globulin Levels Are Associated With Incident Cardiovascular Disease in Men.

Sex hormone-binding globulin (SHBG) levels are associated with cardiovascular disease (CVD) risk factors. However, prospective data on the association between SHBG levels and CVD events are sparse, with conflicting results. To examine associations between serum SHBG, total testosterone (TT), and incident CVD and CVD-related mortality in middle-aged to elderly men. Data on 2563 community-dwelling men (35 to 80 years) were obtained from participants in the Men Androgen Inflammation Lifestyle Environment and Stress cohort. The analytic sample included 1492 men without baseline (2002 to 2007) CVD and with fasted morning serum SHBG and TT available at both baseline and follow-up (2007 to 2010) and without medications affecting TT or SHBG. Associations of baseline SHBG and TT, with incident CVD and CVD mortality, were analyzed using logistic regression for incident CVD and Cox proportional hazard regression for CVD mortality, adjusting for established CVD risk factors. In multivariable models, elevated baseline SHBG and lower baseline TT were independently associated with incident CVD (SHBG: OR, 1.54; 95% CI, 1.15 to 2.06 per SD increase in SHBG, P = 0.003; TT: OR, 0.71; 95% CI, 0.52 to 0.97 per SD decrease in TT; P = 0.03). A decrease in TT between time points was associated with incident CVD (OR, 0.72; 95% CI, 0.56 to 0.92; P = 0.01). Neither SHBG nor TT was significantly associated with all-age CVD mortality [hazard ratio (HR), 0.69; 95% CI, 0.29 to 1.63; P = 0.40; and HR, 0.60; 95% CI, 0.28 to 1.26; P = 0.18, respectively]. Among all men and men >65 years, elevated SHBG and lower TT were independently associated with both a greater risk of CVD and an increased CVD mortality risk.

Sex hormone-binding globulin and thrombin generation in women using hormonal contraception

Objectives: We investigated the impact of serum sex hormone-binding globulin (SHBG) on thrombin generation (TG) in women according to hormonal contraception.Patients and methods: A cross-sectional study of SHBG and TG measured via calibrated automated thrombography was conducted in 150 healthy women, including 75 users of combined oral contraceptives (COC), 22 users of progestin-only contraceptives (POC) and 53 nonusers.Results: COC but not POC-users had significantly higher SHBG levels compared with nonusers. In hormonal contraceptive users, SHBG was positively associated with both activated protein C (APC) resistance and baseline TG, and protein S and prothrombin were important mediators.Conclusion: These data provide further evidence that SHBG may be used as a biomarker in assessing prothrombotic profile of hormonal contraception.

High Serum SHBG Predicts Incident Vertebral Fractures in Elderly Men.

ABSTRACTPrevious prospective cohort studies have shown that serum levels of sex steroids and sex hormone‐binding globulin (SHBG) associate with nonvertebral fracture risk in men. The predictive value of sex hormones and SHBG for vertebral fracture risk specifically is, however, less studied. Elderly men (aged ≥65 years) from Sweden and Hong Kong participating in the Osteoporotic Fractures in Men (MrOS) study had baseline estradiol and testosterone analyzed by gas chromatography–mass spectrometry (GC‐MS) and SHBG by immunoradiometric assay (IRMA). Incident clinical vertebral fractures (n = 242 cases) were evaluated in 4324 men during an average follow‐up of 9.1 years. In a subsample of these men (n = 2256), spine X‐rays were obtained at baseline and after an average follow‐up of 4.3 years to identify incident radiographic vertebral fractures (n = 157 cases). The likelihood of incident clinical and radiographic vertebral fractures was estimated by Cox proportional hazards models and logistic regression models, respectively. Neither serum estradiol (hazard ratio [HR] per SD increase = 0.93, 95% confidence interval [CI] 0.80–1.08) nor testosterone (1.05, 0.91–1.21) predicted incident clinical vertebral fractures in age‐adjusted models in the combined data set. High serum SHBG, however, associated with increased clinical vertebral fracture risk (1.24, 1.12–1.37). This association remained significant after further adjustment for FRAX with or without bone mineral density (BMD). SHBG also associated with increased incident radiographic vertebral fracture risk (combined data set; odds ratio [OR] per SD increase = 1.23, 95% CI 1.05–1.44). This association remained significant after adjustment for FRAX with or without BMD. In conclusion, high SHBG predicts incident clinical and radiographic vertebral fractures in elderly men and adds moderate information beyond FRAX with BMD for vertebral fracture risk prediction. © 2015 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

The relationship of sex hormone-binding globulin (SHBG) gene polymorphisms with serum SHBG level and metabolic syndrome in Chinese Han males

Epidemiological studies have shown that circulating sex hormone-binding globulin (SHBG) levels are lower in metabolic syndrome (MetS) patients than in non-MetS individuals. In this study, we investigated the relationship of polymorphisms in the SHBG gene with the serum SHBG levels and MetS in Han Chinese. We performed a cross-sectional study of 316 subjects who were recruited from a health checkup population at Zhongshan Hospital, Fudan University. Anthropometric measurements, blood pressure, fasting plasma glucose, lipid levels, total testosterone, and SHBG levels were obtained in addition to the seven SHBG single-nucleotide polymorphisms (SNPs). The variant allele (AG or AA) carriers in rs6259, compared to the wild-type allele carriers (GG), have a lower risk for MetS [OR 0.56, 95% confidence interval (CI) 0.33-0.96] and higher serum SHBG and TT levels (P = 0.016, 0.004). CT or TT allele carriers in rs3760213, compared to CC allele carriers, also have a lower risk for MetS (OR 0.59, 95 % CI 0.34-1.00) and significantly higher SHBG and TT levels (P = 0.029, 0.009). Carriers having both of the variant alleles had the lowest risk of MetS (OR 0.51, 95 % CI 0.275-0.950) and the highest SHBG levels. The risk of MetS rose with the decrease in serum SHBG levels for rs6259 and rs376021 carriers. rs6259 and rs3760213 SNPs are associated with the risk of MetS and lower serum SHBG level in Chinese Han males.

Importancia de la testosterona libre calculada en el diagnóstico del síndrome de déficit de testosterona

Objective To demonstrate that calculated free testosterone is the optimal parameter for early diagnosis of testosterone deficiency syndrome and should be determined at the first visit. Material and methods From August 2007 to December 2009, we evaluated 203 patients with sexual health problems. In all patients, total testosterone, sex hormone-binding globulin (SHBG) and albumin serum-levels were measured at the first visit to calculate free testosterone levels. Results A total of 203 patients were studied. Calculated serum free testosterone levels were below 250 pmol/L in 80 patients who were candidates for testosterone replacement therapy. Among these, total serum testosterone levels were higher than 12 nmol/L in 24 patients (30%), between 8 and 12 nmol/L in 37 patients (46.3%) and below 8 nmol/L in 19 patients (23.8%). Interestingly, patients with a total serum testosterone level higher than 12 nmol/L had a calculated free testosterone level below 250 pmol/L due to high serum SHBG levels (mean value: 53.5 nmol/L). Conclusions This study indicates that calculated free testosterone level is more effective than total testosterone level for the early diagnosis of testosterone deficiency syndrome. Consequently, we propose that total testosterone, SHBG and albumin levels be measured at the first visit in order to determine free testosterone levels.

Associations between the CYP17, CYPIB1, COMT and SHBG polymorphisms and serum sex hormones in post-menopausal breast cancer survivors

Several polymorphisms have been identified in genes that code for enzymes involved with estrogen biosynthesis and metabolism. Little is known about the functional relevance of these polymorphisms on sex hormones in vivo. We examined the association between CYP17, CYP1B1, COMT or SHBG genotypes and serum concentrations of estrone, estradiol, free estradiol, sex hormone-binding globulin (SHBG), testosterone, free testosterone and dehyroepiandrosterone in 366 post-menopausal breast cancer survivors in New Mexico, California and Washington. Hormone levels were determined by high performance liquid chromatography and radioimmunoassay in blood drawn approximately 2 years post-diagnosis. We used generalized linear regression to calculate mean hormone levels by genotype, adjusting for age, race/ethnicity, stage, study site, tamoxifen use, number of remaining ovaries, hormone therapy use, marital status and BMI. No associations were observed between any of the genotypes and sex hormones when analyzing the main effects. In subgroup analyses, androgen levels of Hispanic women with the variant (A2) CYP17 genotype were 46-87% higher than those of women with the wild-type; androgen levels were 13-20% lower in non-Hispanic whites with the variant genotype; no difference by genotype was observed for African-American women. Current tamoxifen users with the variant asn(327) SHBG genotype had 81% higher serum SHBG and 39% lower free testosterone concentrations than women with the wild-type genotype. Non-tamoxifen users with the variant SHBG allele had elevated free estradiol levels. These results provide little evidence that the CYP17, CYP1B1, and COMT polymorphisms are associated with different sex hormone levels in post-menopausal breast cancer survivors.

Prostate Cancer Risk: The Significance of Differences in Age Related Changes in Serum Conjugated and Unconjugated Steroid Hormone Concentrations Between Arab and Caucasian Men

Factors responsible for the low incidence of clinical prostate cancer (3-8/100,000 men/year) in the Arab population remain unclear, but may be related to changes in steroid hormone metabolism. We compared the levels of serum conjugated and unconjugated steroids between Arab and Caucasian populations, to determine if these can provide a rational explanation for differences in incidence of prostate cancer between the two populations. Venous blood samples were obtained from 329 unselected apparently healthy indigenous Arab men (Kuwaitis and Omanis) aged 15-80 years. Samples were also obtained from similar Arab men with newly diagnosed prostate cancer or benign prostatic hyperplasia (BPH). The samples were taken between 8:00 am and 12:00 noon. Serum levels of total testosterone, (TT), sex hormone binding globulin (SHBG), free androgen index (FAI); adrenal C19-steroids, dehydroepiandrosterone sulphate (DHEAS) and androstenedione (ADT) were determined using Immulite kits (Diagnostic Systems Laboratories Inc, Webster Texas, USA). The results obtained in Arab men were compared with those reported for similarly aged Chinese, German and White USA men. In all four ethnic groups, median TT and FAI declined with age, while SHBG increased with age. However, the mean TT and SHBG was significantly lower (p < 0.01) and the FAI significantly higher in Arab men (p < 0.01) compared to German men only in 21-30 years age group. In the other age groups the levels of TT and SHBG were higher in the Germans but the differences were not statistically significant. In all the racial groups serum levels of DHEAS and ADT reached a peak by about 20 years of life, and then declined progressively. The mean DHEAS in American Caucasians aged 20-29 years was 11.4 micromol/l compared to 6.22 micromol/l in the Arabs (p < 0.001). The mean DHEAS in USA Caucasians aged 70-79 years was 2.5 micromol/l compared to 1.8 micromol/l (p < 0.03) in the Arabs. There was no significant difference in mean serum levels of DHEAS between German and USA men. Similarly, there was no significant difference in the level of the hormones between Arab and Chinese men. Arab men with newly diagnosed prostate cancer had high serum TT, SHBG and DHEAS compared to those without the disease. The mean TT and SHBG was significantly lower in Arab men compared to Caucasian men especially in early adulthood. Caucasians have significantly higher serum levels of the precursor androgens DHEAS and ADT especially in early adulthood compared to Arab men. These observations of low circulating androgens and their adrenal precursors in Arab men may partially account for the decreased risk for prostate cancer among Arab men.

Serum estradiol and sex hormone-binding globulin and the risk of hip fracture in elderly women: the EPIDOS study.

It has been suggested that low serum 17beta-estradiol (E2) and sex hormone-binding globulin (SHBG) may predict hip fracture in postmenopausal women. We have investigated the predictive value of serum E2 and SHBG concentrations and urinary deoxypyridinoline (D-Pyr) and type I collagen breakdown products (CTX) in a large prospective cohort of 7,598 healthy elderly ambulatory women (EPIDOS study), aged 75 years or more. We performed a nested case control study, by matching 212 patients with incident hip fracture with 636 controls. Mean follow-up was 3.3 years (maximum, 4.9 years). Women having serum E2 below the limit of detection (3 pg/ml), that is, 2% of the population, were not at higher risk, with a relative hazard (RH) of 1.59 (95% CI = 0.45-5.55). Women having serum E2 below 5, 6, 7, or 8 pg/ml, in the lowest quartile, or below the median had no increased risk of hip fracture. In contrast, women having serum E2 in the highest quartile (i.e., > or = 10 pg/ml) were protected, with an RH of 0.66 (0.44-0.98) that did not remain significant after adjustment for weight (RH = 0.71 [0.47-1.06]). High serum SHBG values with different cut-offs tended to be associated with an increased risk of hip fracture. Women in the highest quartile had an RH of 2.5 (1.37-4.61), compared with those in the lowest quartile, that decreased markedly after adjustment for body weight (1.61 [0.99 -2.62]). The highest quartile of the ratio E2/SHBG, which is an index of free E2, was associated with a lower hip fracture risk (RH = 0.6 [0.4-0.91]) that was no longer significant after adjustment for weight. In contrast, urinary D-Pyr and CTX, when elevated above the upper limit of premenopausal values, were predictive of hip fracture, with an RH of 2.07 (1.49-2.9) and 1.67 (1.19-2.32), respectively, even after adjustment for body weight, serum E2, and SHBG. We conclude that in healthy elderly French women over 75 years of age, serum E2 and E2/SHBG in the highest quartile are associated with a lower risk of hip fracture and that this association is explained by a higher body weight. In addition, serum levels of E2 and SHBG do not account for the increased risk of hip fracture associated with high levels of bone resorption markers.

Biochemical markers of bone turnover, endogenous hormones and the risk of fractures in postmenopausal women: the OFELY study.

The mechanisms leading to increased bone loss and skeletal fragility in women with postmenopausal osteoporosis are still poorly understood. Increased bone resorption, low serum estradiol and high serum sex-hormone-binding globulin (SHBG) recently have been reported as predictors of vertebral and hip fractures in elderly women. In a cohort of healthy untreated younger postmenopausal women aged 50-89 years (mean, 64 years), we compared baseline levels of bone markers and endogenous hormones in 55 women who subsequently had a fracture (20 vertebral and 35 peripheral fractures) with levels in the 380 women who did not fracture during a mean 5 years of follow-up. Women with levels in the highest quartile of four bone resorption markers including urinary-free deoxypyridinoline (D-Pyr), urinary type I collagen N-telopeptides (NTX), and urinary and serum type I collagen C-telopeptides (CTX) had about a 2-fold increased risk of fractures compared with women with levels in the three lowest quartiles with relative risk (RR) and 95% CI of 1.8 (1.0-3.4) for free D-Pyr, 1.7 (0.9-3.2) for urinary NTX, 2.3 (1.3-4.1) for urinary CTX, and 2.1 (1.2-3.8) for serum CTX. Serum levels of bone alkaline phosphatase (BAP) in the highest quartile were associated with an RR of fracture of 2.4 (1.3-4.2). Women with serum levels of estradiol and dehydroepiandrosterone (DHEA) sulfate in the lowest quartile had an RR of fracture of 2.2 (1.2-4.0) and 2.1 (1.2-3.8), respectively. Increased levels of SHBG and intact parathyroid hormone (PTH) were moderately associated with an increased risk of fracture. Similar results were obtained when the analysis was restricted to symptomatic vertebral and nonvertebral fractures. Adjustment of biochemical markers by hormone levels did not significantly alter the results. Women with both high bone resorption markers and low estradiol (or low DHEA sulfate) had a higher risk of fracture with RRs of 3.0-3.3 (p < 0.001). After adjustment for bone mineral density (BMD) of the hip, spine, radius, or total body, bone markers and hormones were still predictive of fracture risk with similar RRs. We conclude that high levels of some biochemical markers of bone turnover, low serum estradiol, low DHEA sulfate, high SHBG, and high PTH are associated with increased risk of osteoporotic fracture in postmenopausal women, independently of each other and of BMD. The mechanism by which some postmenopausal women have an increased rate of bone turnover leading to an increased risk of fracture remains to be elucidated.

Mechanism of feminization in male patients with non-alcoholic liver cirrhosis: Role of sex hormone-binding globulin

We measured serum sex hormone-binding globulin (SHBG) using a radioimmunoassay developed by us, testosterone (T), estradiol (E2), free T and free E2 in 50 male patients with non-alcoholic liver cirrhosis (compensated: 30, decompensated; 20) and age-matched healthy male subjects, SHBG was significantly increased in patients with liver cirrhosis compared with healthy subjects. The high serum SHBG level in male compensated cirrhotic patients tended to decrease with progression to the decompensated state. Serum cholinesterase showed a positive correlation with SHBG in liver cirrhosis. Serum free T and the T/SHBG ratio decreased, while serum E2, free E2, and the E2/T and the free E2/free T ratios increased in liver cirrhosis, resulting in estrogen predominance and feminization of male patients. These changes were more marked in decompensated than compensated liver cirrhosis. An increased free E2/free T ratio was observed in patients with gynecomastia, palmar erythema or vascular spider. The T/SHBG ratio showed a positive correlation with serum free T, suggesting that it can be used as a free T index in liver cirrhosis. From these observations, it is suggested that serum SHBG plays an important role, by regulating the serum free T level in the occurrence of feminization in male patients with non-alcoholic liver cirrhosis.

Serum Steroid Hormones and Pituitary Function in Female Epileptic Patients During Carbamazepine Therapy

Ten regularly menstruating women with epilepsy were studied in a 12-month prospective follow-up study to evaluate the short-term effects of carbamazepine (CBZ) on serum sex hormone balance and pituitary function. Thirteen female epilepsy patients receiving long-term CBZ monotherapy (mean medication duration 5.3 years) were also studied. Controls were 17 regularly menstruating healthy volunteers. Untreated patients had higher free testosterone (FT) and luteinizing hormone (LH) serum concentrations than control subjects, whereas the other parameters did not differ between these two groups. However, serum sex hormone binding globulin (SHBG) levels increased and dehydroepiandrosterone sulfate (DHEAS) levels decreased during CBZ treatment. Although calculated free androgen index (FAI) decreased during CBZ therapy, the directly measured FT levels remained unaltered. These changes were found after 2 months and continued after 12 months of CBZ treatment. Moreover, patients with long-term CBZ also had high SHBG levels, low serum DHEAS levels, and low FAI values. Basal LH serum levels decreased during the first year of CBZ treatment and luteinizing hormone-releasing hormone (LH-RH)-stimulated LH concentrations were lower after 2 months of CBZ treatment. Although the serum basal follicle-stimulating hormone (FSH) and prolactin (PRL) levels were unaffected during the first year of CBZ therapy, the LH-RH-stimulated FSH concentrations and metoclopramide (MC)-stimulated PRL concentrations were lower after 12 months of CBZ treatment than before CBZ. Both basal and stimulated gonadotropin and PRL serum levels of long-term CBZ patients were unaffected. No changes were found in estradiol (E2), testosterone (T), or cortisol (C) serum concentrations during short or long-term CBZ treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Androgens and estrogens in postmenopausal insulin-treated diabetic women.

Diabetic women may have an increased risk of developing endometrial carcinoma. Ovarian and adrenal activity seem to be factors in the genesis of this cancer. We have measured serum sex hormone-binding globulin (SHBG), free and bound fractions of estrogens and androgens, and gonadotropins in 20 consecutive postmenopausal insulin-treated diabetic women and 16 normal postmenopausal women. The diabetics were nonketoacidotic, without nephropathy and without proliferative retinopathy. The groups were comparable regarding age and percent ideal body weight. The diabetic group had significantly increased serum levels of estrone (P less than 0.001), estrone sulfate (P less than 0.05), 17 beta-estradiol (P less than 0.02), and SHBG (P less than 0.001). Levels of testosterone, delta 4-androstenedione, and dehydroepiandrosterone sulfate tended to be higher (not significantly) in the diabetics. FSH and LH levels were similar in the two groups, while serum PRL was significantly lower in the diabetic group (P less than 0.02). The hormonal changes in the diabetics were not related to control of the diabetes. We conclude that total estrogen levels are increased in postmenopausal women with insulin-treated diabetes mellitus. High SHBG levels in these patients tend to keep the free fractions of sex hormones within normal limits.

High serum sex hormone-binding globulin (SHBG) and low serum non-SHBG-bound testosterone in boys with idiopathic hypopituitarism: effect of recombinant human growth hormone treatment.

We measured serum sex hormone-binding globulin (SHBG), total testosterone (T), non-SHBG-bound T, albumin-bound T, free T, and SHBG-bound T in 19 prepubertal boys with hypopituitarism. Serum SHBG decreased with age with a slope similar to that in 91 normal prepubertal boys at higher level, and therefore, it reached similar values at a later age. Serum SHBG was significantly higher in hypopituitary prepubertal boys [mean, 123 +/- 12 (+/- SE) nmol/L] than in normal prepubertal boys (76 +/- 4; P less than 0.001) despite the fact that their mean age was also higher (10.0 +/- 4 vs. 7.1 +/- 4.1 yr; P less than 0.001). In 4 boys with isolated hypogonadotropic hypogonadism (Kallman's syndrome), aged 15.6 +/- 1.5 yr, serum SHBG was 21 +/- 14 nmol/L, a value below the 95% confidence limit of the regression line in GH-deficient boys. The affinity constants of association of the SHBG-DHT complex were similar in hypopituitary and normal boys. Eleven of the 19 hypopituitary boys (mean chronological age, 8.3 +/- 2.5 yr; mean bone age, 4.1 +/- 2.1 yr) were treated with recombinant hGH (0.5 U/kg BW.week) for 1 yr. Their mean serum SHBG level before treatment was 154 +/- 14 nmol/L, and it decreased gradually to 106 +/- 5 nmol/L (P less than 0.01) after 12 months of treatment. The tendency toward normalization of serum SHBG during treatment suggested that GH deficiency was responsible for the high serum SHBG levels. Serum SHBG correlated negatively with age in both treated hypopituitary and normal boys, but the slope of the regression line was significantly steeper in treated hypopituitary boys (P less than 0.01). On the other hand, the mean serum non-SHBG-bound T level was 0.10 +/- 0.02 (+/- SE) nmol/L in hypopituitary boys, significantly lower than that in normal boys (0.21 +/- 0.02 nmol/L; P less than 0.02). Since serum total T concentrations were similar in the two groups, the higher serum SHBG concentration resulted in lower serum bioavailable T levels in the hypopituitary boys. These changes might explain the poor response to T treatment reported in GH-deficient patients. The lower serum non-SHBG-bound T concentrations in the GH-deficient boys suggest there may be delayed exposure of central nervous system structures to increased levels of sex hormones, which, in turn, may slow body maturation. This mechanism might play a role in the delay of puberty that occurs in patients with isolated GH deficiency.