Sex hormone-binding globulin and insulin resistance in African-American women

First Trimester Placental Biomarkers for Pregnancy Outcomes

The placenta plays a key role in several adverse obstetrical outcomes, such as preeclampsia, intrauterine growth restriction and gestational diabetes mellitus. The early identification of at-risk pregnancies could significantly improve the management, therapy and prognosis of these pregnancies, especially if these at-risk pregnancies are identified in the first trimester. The aim of this review was to summarize the possible biomarkers that can be used to diagnose early placental dysfunction and, consequently, at-risk pregnancies. We divided the biomarkers into proteins and non-proteins. Among the protein biomarkers, some are already used in clinical practice, such as the sFLT1/PLGF ratio or PAPP-A; others are not yet validated, such as HTRA1, Gal-3 and CD93. In the literature, many studies analyzed the role of several protein biomarkers, but their results are contrasting. On the other hand, some non-protein biomarkers, such as miR-125b, miR-518b and miR-628-3p, seem to be linked to an increased risk of complicated pregnancy. Thus, a first trimester heterogeneous biomarkers panel containing protein and non-protein biomarkers may be more appropriate to identify and discriminate several complications that can affect pregnancies.

The association between triglyceride glucose-body Mass Index and in vitro fertilization outcomes in women with polycystic ovary syndrome: a cohort study

BACKGROUND

Polycystic Ovary Syndrome (PCOS) is a common reproductive disorder that frequently affects fertility. The TyG-BMI (Triglyceride glucose-body mass) index is a newly explored parameter that may be linked to reproductive results in individuals with PCOS. Nevertheless, its connection with outcomes in In Vitro Fertilization (IVF) procedures remains uncertain.

METHODS

This study included a total of 966 females who underwent IVF treatments for PCOS. At the baseline, the participants were categorized into four groups according to the quartiles of TyG-BMI measured prior to oocyte retrieval. Subsequently, the study compared the differences in clinical and laboratory outcomes among these four groups.

RESULTS

Patients in higher TyG-BMI quartiles exhibited a decreased number of retrieved oocytes, 2PN embryos, and available/high-quality embryos (P < 0.05 for Q1-Q4). Additionally, the multivariable regression analysis revealed that individuals in the top quartile of TyG-BMI had a lower count of accessible embryos (β = -0.224, P = 0.257) and a decreased number of high-quality embryos (β = -0.352, P = 0.028) in comparison to those in the lowest quartile. Nevertheless, there were no notable variances detected in the rates of pregnancy or live births among these quartiles. Furthermore, a linear correlation was noted between the TyG-BMI index and the quantity of accessible embryos (P-non-linear = 0.6, P-overall < 0.001), along with high-quality embryos (P-nonlinear = 0.026, P-overall = 0.006). In contrast, there was no notable linear correlation found between the TyG-BMI index and the available embryo rate (P-nonlinear = 0.60, P-overall = 0.8).

CONCLUSIONS

The results of this research emphasize the notable correlation between TyG-BMI and IVF results in females diagnosed with PCOS. The interplay of insulin resistance and disorders of lipid metabolism may indeed play a pivotal role in influencing the assisted reproductive outcomes of patients with PCOS. Considering these findings, TyG-BMI proves to be a valuable indicator for exploring this potential association.

First trimester sex hormone-binding globulin predicts gestational diabetes mellitus in a population of Nigerian women

There has been a steady rise in the disease burden of Gestational Diabetes Mellitus (GDM) in the sub-Saharan African region over time. Diagnostic testing for GDM is currently recommended at 24 - 28 weeks of gestation, leaving a narrow window for intervention before delivery. Hence the need for early prediction and preventive intervention. The performance of first trimester serum sex hormone-binding globulin (SHBG) assay as a predictor of GDM was determined by binary logistic regression. Women with GDM (n = 49) had a significantly lower mean first trimester SHBG level (104.7 ± 61.6 nmol/L) than did those without GDM (n = 180; 265.2 ± 141.5 nmol/L; p < .001). First trimester SHBG was significantly negatively correlated (r_pb = -0.460, p value = <.001) with subsequent development of GDM and an area under receiver operator characteristics (ROC) curve of 0.874 (p < .001). A cut-off value of 158.0 nmol/L predictive of GDM had a diagnostic sensitivity of 81.5%, a specificity of 80.1%, and an overall diagnostic efficiency of 80.3%.IMPACT STATEMENTWhat is already known on this subject? GDM is associated with high risk of various complications and is commonly diagnosed at 24-28 weeks of gestation, leaving a narrow window for intervention. The performance of current maternal clinical and demographic risk factor-based prediction approaches is unreliable. Thus, more favourable prediction approaches need to be developed. Previous studies have suggested that SHBG, a readily assessable marker, has potential to predict GDM; however, these studies have mostly involved Caucasian and other non-African populations.What the results of this study add? SHBG may serve as a reliable first trimester screening tool for GDM development in Nigerian women with singleton pregnancies. This study demonstrates that first trimester SHBG can predict GDM development in sub-Saharan African women despite racial, ethnic and geographical differences.What are the implications of these findings for clinical practice and/or further research? Effective first trimester prediction of GDM using SHBG may enable preventive interventions, thereby mitigating the high burden of the disease in the sub-Saharan African region. It may also provide relevant information that may guide adaptation of current management guidelines to ensure effective management of GDM in the region.

Identification of predictors of the ovarian response to clomiphene citrate in infertile women with polycystic ovary syndrome: a prospective cohort study

Objective

To identify predictors of the ovarian response to clomiphene citrate (CC) in infertile patients with polycystic ovary syndrome (PCOS).

Methods

We performed a prospective cohort study of infertile patients with PCOS. The participants underwent assessments of their physical, endocrine, and metabolic characteristics, and treatment with CC at an initial dose of 50 mg/day and a maximum of 100 mg/day between days 3 and 7 of their menstrual cycles. Participants who ovulated were identified as responders and those who did not as non-responders.

Results

Of the 72 participants, 48 (66.7%) were identified as responders and 24 as non-responders. Sex hormone-binding globulin (SHBG) (odds ratio 1.022, 95% confidence interval: 1.000–1.045) was found to be associated with the ovarian response to CC using logistic multivariate regression analysis. Receiver operating characteristic analysis also showed that SHBG was a significant predictor of the response to CC (area under the curve 0.799).

Conclusion

We have shown that SHBG is the best prognostic indicator of an ovulatory response to CC. However, larger prospective studies, in which more variables are assessed, are required to confirm this finding and to identify appropriate cut-off values.

The relationship between components of metabolic syndrome and plasma level of sex hormone-binding globulin

Plasma concentration of sex hormone-binding globulin (SHBG), as an androgen binding protein, is impressed by many physiological and environmental factors. Recent studies have shown that plasma level of SHBG is related to some components of metabolic syndrome (MetS); however, in contrast, few articles failed to show any associations between SHBG and MetS. So, this study was conducted to investigate the relationship between Components of Metabolic Syndrome and Plasma Level of Sex Hormone-Binding Globulin. In this study, after measuring the plasma level of SHBG in 84 individuals, the relation between MetS and the plasma level of SHBG was investigated. After evaluating the plasma level of SHBG and metabolic abnormalities in men and women, we investigated the factors which mentioned above in two groups including patients with and without MetS. Also, the metabolic abnormalities which evaluated in this study including plasma level of 25-hydroxyvitamin D, serum uric acid (SUA), Albumin, lipid profiles and etc. according to five components of MetS. Our result shows that SHBG could contributed to some laboratory parameters such as LDL-C (P<0.05), total cholesterol (P<0.05), triglycerides (P<0.05) and etc. in men, but not in women. On the other hand, we observed that concentration of SHBG is higher in patients with MetS (P<0.05); however, results from our experiment showed that there is no relation between lower level of SHBG and five components of MetS such as central obesity, raised fasting plasma glucose (FPG) (P>0.05), reduced HDL-C (P>0.05), raised triglycerides (P>0.05) and raised blood pressure (P>0.05) in both men and women. There is a significant association between SHBG and Log-Hip Circumference (P<0.05), Non-HDL-C (P<0.05) and Log-25(OH)D (P<0.05) was seen in this cross-section study in both men and women. Results obtained from our study suggest that SHBG is not a powerful enough factor to use as a predictor of MetS alone and there is no association between plasma level of SHBG and development of five components of MetS, however, lower SHBG level may contributed to lipid profiles.

SHBG expression is correlated with PI3K/AKT pathway activity in a cellular model of human insulin resistance

Decreased sex hormone-binding globulin (SHBG) expression is an independent risk factor for gestational diabetes mellitus(GDM).However, the mechanisms that link low SHBG expression and insulin resistance in GDM is unclear. In this study, we investigated the placenta SHBG in the PI3K/AKT pathway to reveal the mechanism that links decreased SHBG to insulin resistance. A insulin resistance cells model was established by the method of insulin stimulation. Two groups were set up, HTR8/Svneo cells and insulin-resistance cells of HTR8/SVneo. The expression of SHBG and PI3K/AKT associated factors were detected using real-time PCR and western blotting and their correlations were analyzed. The results showed that SHBG protein and mRNA levels in insulin resistance cells were both significantly lower. Along with decreased SHBG expression, the mRNA and protein levels of IRS-1, IRS-2, PI3Kp85α and GLUT-3, GLUT-4 decreased significantly. However, the expression of GLUT-1 increased significantly. Pearson correlation analysis showed that SHBG mRNA expression was positively correlated with IRS-1, IRS-2 and PI3Kp85α mRNA levels. According to the results, low SHBG expression not only participates in the development of local insulin resistance, but may also play an important role in PI3K/AKT pathway-mediated systemic insulin resistance and gestational diabetes.

Metabolic Syndrome and Breast Cancer Risk

Objective

The study was meant to estimate the prevalence of metabolic syndrome in patients with breast cancer and to establish its role as an independent risk factor on occurrence of breast cancer.

Materials and Methods

Fifty women aged between 40 and 80 years with breast cancer and fifty controls of similar age were assessed for metabolic syndrome prevalence and breast cancer risk factors, including age at menarche, reproductive status, live births, breastfeeding, and family history of breast cancer, age at diagnosis of breast cancer, body mass index, and metabolic syndrome parameters.

Results

Metabolic syndrome prevalence was found in 40.0% of breast cancer patients, and 18.0% of those in control group (P = 0.02). An independent and positive association was seen between metabolic syndrome and breast cancer risk (odds ratio = 3.037; 95% confidence interval 1.214-7.597).

Conclusions

Metabolic syndrome is more prevalent in breast cancer patients and is an independent risk factor for breast cancer.

Risk factors for preeclampsia in infertile Chinese women with polycystic ovary syndrome: A prospective cohort study

To explore preconception risk factors for preeclampsia (PE) in women with polycystic ovary syndrome (PCOS), a prospective cohort study was conducted in 92 infertile Chinese women with PCOS who had a singleton pregnancy by ovulation induction and were followed up for 6 weeks after delivery. The patients underwent assessment of physical, endocrine, and metabolic features before ovulation induction. Fifteen (16.3%) patients were diagnosed with PE. Logistic regression analysis showed that preconception sex hormone–binding globulin (SHBG), insulin level at 120 minutes, and body mass index were three independent risk factors for PE (odds ratio [OR], 0.981; 95% confidence interval [CI], 0.964–0.998 [P=.027]; OR, 1.011; 95% CI, 1.000–1.021 [P=.048]; and OR, 1.249; 95% CI, 0.992–1.572 [P=.059], respectively). Receiver operator characteristic analysis indicated the risk value of prepregnancy SHBG, insulin level at 120 minutes, and body mass index (area under the curve=.788, .686, and .697, respectively). Preconception low SHBG levels, overweight/obesity, and hyperinsulinism might be correlated with the subsequent development of PE in patients with PCOS.

Metabolic syndrome and breast cancer risk: a case-cohort study nested in a multicentre italian cohort

Background

Metabolic syndrome (defined as at least three among abdominal obesity, high blood triglycerides, low high-density lipoprotein cholesterol, high blood glucose, and high blood pressure) is emerging as a risk factor for breast cancer; however few studies – most confined to postmenopausal women – have investigated associations between breast cancer risk and metabolic syndrome. The purpose of this study was to examine the association between metabolic syndrome and its components, and risk of breast cancer in postmenopausal and premenopausal women.

Methods

We performed a case-cohort study on 22,494 women recruited in 1993-1998 to four Italian centres (Turin, Varese, Naples, Ragusa) of the European Prospective Investigation into Cancer and Nutrition (EPIC) and followed-up for up to 15 years. A random subcohort of 565 women was obtained and 593 breast cancer cases were diagnosed. Hazard ratios (HR) with 95% confidence intervals (CI), adjusted for potential confounders, were estimated by Prentice-weighted Cox proportional hazards models.

Results

Presence of metabolic syndrome was associated with significantly increased breast cancer risk in all women (HR 1.52, 95%CI 1.14-2.02). When the analyses were repeated separately for menopausal status, the association was limited to postmenopausal women (HR 1.80, 95%CI 1.22-2.65) and absent in premenopausal women (HR 0.71, 95%CI 0.43-1.16); P for interaction between metabolic syndrome and menopausal status was 0.001. Of metabolic syndrome components, only high blood glucose was significantly associated with increased breast cancer risk in all women (HR 1.47, 95%CI 1.13-1.91) and postmenopausal women (HR 1.89, 95%CI 1.29-2.77), but not premenopausal women (HR 0.80, 95%CI 0.52-1.22; P interaction=0.004).

Conclusions

These findings support previous data indicating that metabolic syndrome is an important risk factor for breast cancer in postmenopausal women, but not in premenopausal women, and suggest that prevention of metabolic syndrome through lifestyle changes could confer protection against breast cancer.

Metabolic syndrome is associated with increased breast cancer risk: a systematic review with meta-analysis

Background. Although individual metabolic risk factors are reported to be associated with breast cancer risk, controversy surrounds risk of breast cancer from metabolic syndrome (MS). We report the first systematic review and meta-analysis of the association between MS and breast cancer risk in all adult females. Methods. Studies were retrieved by searching four electronic reference databases [PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, and ProQuest through June 30, 2012] and cross-referencing retrieved articles. Eligible for inclusion were longitudinal studies reporting associations between MS and breast cancer risk among females aged 18 years and older. Relative risks and 95% confidence intervals were calculated for each study and pooled using random-effects models. Publication bias was assessed quantitatively (Trim and Fill) and qualitatively (funnel plots). Heterogeneity was examined using Q and I² statistics. Results. Representing nine independent cohorts and 97,277 adult females, eight studies met the inclusion criteria. A modest, positive association was observed between MS and breast cancer risk (RR: 1.47, 95% CI, 1.15–1.87; z = 3.13; p = 0.002; Q = 26.28, p = 0.001; I² = 69.55%). No publication bias was observed. Conclusions. MS is associated with increased breast cancer risk in adult women.

Androgenic sex steroids contribute to metabolic risk beyond intra-abdominal fat in overweight/obese black and white women

OBJECTIVE

To determine the independent contribution of androgenic sex hormones beyond visceral adipose tissue (VAT) on metabolic risk.

DESIGN AND METHODS

A cross-sectional evaluation of 66 (36 white and 30 black) premenopausal overweight/obese women using multiple regression analyses to determine the independent effects of sex hormone-binding globulin (SHBG), total testosterone (TT), and free testosterone using the free androgen index (FAI) on metabolic variables above VAT.

RESULTS

SHBG contributed to the variance in insulin (P = 0.003), insulin resistance using HOMA-IR (P = 0.006), and high-density lipoprotein cholesterol2 (P = 0.029). TT contributed to the variance in systolic and diastolic blood pressure (P < 0.001), total cholesterol (P = 0.003), low-density lipoprotein cholesterol (P = 0.003), and apolipoprotein B (P = 0.004). FAI contributed to the variance in the greatest number of metabolic variables beyond VAT. There was also a significant race-FAI interaction for fasting glucose (P = 0.013). A Pearson's correlation coefficient showed a significant relationship between FAI and glucose in white women (r = 0.48, P = 0.003) while showing no relationship in black women (r = -0.01, P = 0.941).

CONCLUSIONS

Our study showed that androgenic sex steroids contributed significantly to the variance in metabolic variables associated with health risk. However, they do not provide sufficient information relevant to glucose status in black women.

Impact of five nights of sleep restriction on glucose metabolism, leptin and testosterone in young adult men

BACKGROUND

Sleep restriction is associated with development of metabolic ill-health, and hormonal mechanisms may underlie these effects. The aim of this study was to determine the impact of short term sleep restriction on male health, particularly glucose metabolism, by examining adrenocorticotropic hormone (ACTH), cortisol, glucose, insulin, triglycerides, leptin, testosterone, and sex hormone binding globulin (SHBG).

METHODOLOGY/PRINCIPAL FINDINGS

N = 14 healthy men (aged 27.4±3.8, BMI 23.5±2.9) underwent a laboratory-based sleep restriction protocol consisting of 2 baseline nights of 10 h time in bed (TIB) (B1, B2; 22:00-08:00), followed by 5 nights of 4 h TIB (SR1-SR5; 04:00-08:00) and a recovery night of 10 h TIB (R1; 22:00-08:00). Subjects were allowed to move freely inside the laboratory; no strenuous activity was permitted during the study. Food intake was controlled, with subjects consuming an average 2000 kcal/day. Blood was sampled through an indwelling catheter on B1 and SR5, at 09:00 (fasting) and then every 2 hours from 10:00-20:00. On SR5 relative to B1, glucose (F(1,168) = 25.3, p<0.001) and insulin (F(1,168) = 12.2, p<0.001) were increased, triglycerides (F(1,168) = 7.5, p = 0.007) fell and there was no significant change in fasting homeostatic model assessment (HOMA) determined insulin resistance (F(1,168) = 1.3, p = 0.18). Also, cortisol (F(1,168) = 10.2, p = 0.002) and leptin (F(1,168) = 10.7, p = 0.001) increased, sex hormone binding globulin (F(1,167) = 12.1, p<0.001) fell and there were no significant changes in ACTH (F(1,168) = 0.3, p = 0.59) or total testosterone (F(1,168) = 2.8, p = 0.089).

CONCLUSIONS/SIGNIFICANCE

Sleep restriction impaired glucose, but improved lipid metabolism. This was associated with an increase in afternoon cortisol, without significant changes in ACTH, suggesting enhanced adrenal reactivity. Increased cortisol and reduced sex hormone binding globulin (SHBG) are both consistent with development of insulin resistance, although hepatic insulin resistance calculated from fasting HOMA did not change significantly. Short term sleep curtailment leads to changes in glucose metabolism and adrenal reactivity, which when experienced repeatedly may increase the risk for type 2 diabetes.

Relationships of total adiponectin and molecular weight fractions of adiponectin with free testosterone in African men and premenopausal women

Adiponectin, a protein secreted by adipose tissue, has anti-inflammatory, antithrombogenic, and antidiabetogenic effects. Lower plasma adiponectin levels are present in diabetes, obesity, and the metabolic syndrome. Adiponectin levels are higher in women compared with men. The purpose of this study was to determine whether there is a relationship between total adiponectin, or the molecular weight fractions of adiponectin, and testosterone levels in African American men and premenopausal women. A sample (N=48) of men and premenopausal women was selected based on high and low serum-free testosterone level. All patients had data on blood pressure, metabolic risk factors, and sex hormone levels. Stored plasma samples were assayed for total adiponectin. Molecular weight fractions of adiponectin were separated by gel electrophoresis and quantified by Western blot. Data analysis compared adiponectin (total and fractions) levels with androgen status in both sexes. Among men with high testosterone levels, all fractions of adiponectin were significantly lower than those in men with low testosterone (P<.05). In women with high testosterone, total adiponectin (P=.02) and all fractions of molecular weight adiponectin (P<.05) were lower compared with those in women with low testosterone. Plasma adiponectin levels are lower in both men and premenopausal women with relatively higher testosterone levels.

Racial Disparities between the Sex Steroid Milieu and the Metabolic Risk Profile

Aims and Method. The present study examined the relationship between the metabolic risk profile (MRP) and total testosterone (TT) and free testosterone using the free androgen index (FAI) and sex hormone binding globulin (SHBG) in 36 Caucasian American (CA) and 30 African-American (AA) women volunteering for a weight loss study. Results. After controlling for age, significant relationships were found between TT and diastolic blood pressure (P = .004 and P = .015 in CA and AA women, resp.). Additionally, total cholesterol (P = .003), low density lipoprotein cholesterol (P = .004), apolipoprotein B (P = .006), and the total cholesterol/high density lipoprotein cholesterol (P = .027) were significantly related to TT in AA women only. In CA women, similar measures of glucose/insulin status related to FAI, were also related to SHBG. In both CA and AA women, SHBG was related to waist (P = .031 and P = .022 resp.). Conclusion. Our findings showed racial disparities in the relationship between the sex steroid milieu and the MRP in overweight/obese CA and AA women.

Metabolic syndrome and postmenopausal breast cancer in the ORDET cohort: a nested case-control study

BACKGROUND AND AIMS

The increase in breast cancer incidence over recent decades has been accompanied by an increase in the frequency of metabolic syndrome. Several studies suggest that breast cancer risk is associated with the components of metabolic syndrome (high serum glucose and triglycerides, low HDL-cholesterol, high blood pressure, and abdominal obesity), but no prospective study has investigated risk in relation to the presence of explicitly defined metabolic syndrome. We investigated associations between metabolic syndrome, its components, and breast cancer risk in a nested case-control study on postmenopausal women of the ORDET cohort.

METHODS AND RESULTS

After a median follow-up of 13.5 years, 163 women developed breast cancer; metabolic syndrome was present in 29.8%. Four matched controls per case were selected by incidence density sampling, and rate ratios were estimated by conditional logistic regression. Metabolic syndrome (i.e. presence of three or more metabolic syndrome components) was significantly associated with breast cancer risk (rate ratio 1.58 [95% confidence interval 1.07-2.33]), with a significant risk increase for increasing number of components (P for trend 0.004). Among individual metabolic syndrome components, only low serum HDL-cholesterol and high triglycerides were significantly associated with increased risk.

CONCLUSIONS

This prospective study indicates that metabolic syndrome is an important risk factor for breast cancer in postmenopausal women. Although serum HDL-cholesterol and triglycerides had the strongest association with breast cancer, all components may contribute to increased risk by multiple interacting mechanisms. Prevention or reversal of metabolic syndrome by life-style changes may be effective in preventing breast cancer in postmenopausal women.

The change in sex hormone binding globulin and the influence by gestational diabetes mellitus in fetal period

OBJECTIVE

To investigate the influence of gestational diabetes mellitus (GDM) on the change of SHBG in fetus.

METHOD

Forty-eight pregnant women with GDM and 86 women with normal pregnancy were included in the study. The following were measured in the serums of pregnant women, amniotic fluids, and umbilical cord serums: glucose, insulin, peptide-C, SHBG, and sex hormones.

RESULTS

SHBGs in pregnant women's serums were, when compared with the control group: in male fetuses 308.06 +/- 55.64 vs. 445.21 +/- 50.07 (p < 0.01) and in female fetuses 312.38 +/- 56.61 vs. 451.05 +/- 52.87 (p < 0.01). When comparing the levels of SHBGs in amniotic fluids, inclusive of the control group, the following were in male fetuses 8.35 +/- 1.07 vs. 8.41 +/- 1.09 (p = NS) and in female fetuses 8.31 +/- 0.97 vs. 8.39 +/- 0.94 (p = NS). For the levels of SHBGs in umbilical cord serums and comparison to the control group were: in male fetuses 41.44 +/- 8.83 vs. 40.24 +/- 7.50 (p = NS) and in female fetuses 39.93 +/- 7.04 vs. 39.69 +/- 7.16 (p = NS). The concentration of SHBG in amniotic fluid had no significant relationship to glucose, dehydroepiandrosterone (DHEAS), estradiol, and total and free testosterone, but had an extremely negatively correlated to insulin and peptide-C (p < 0.01) in GDM group.

CONCLUSION

Although the concentration of SHBG does not change in fetus when pregnant woman is complicated with GDM, it is already influenced by the fetal regulation on hyperinsulinemia.

Novel biomarkers for predicting preeclampsia

Preeclampsia is a major cause of maternal morbidity and mortality worldwide. Despite decades of research into the condition, the ability of clinicians to predict preeclampsia prior to the onset of symptoms has not improved significantly. In this review, we will examine the pathophysiology underlying preeclampsia and will look at potential biomarkers for early prediction and diagnosis. In addition, we will explore potential future areas of research into the condition.

Adiposity, the metabolic syndrome, and breast cancer in African-American and white American women

Breast cancer, the second most common cause of cancer-related deaths in American women, varies substantially in incidence and mortality according to race and ethnicity in the United States. Although the overall incidence of breast cancer among African-American (AA) women is lower than in white American women, this cancer is more common in young premenopausal AA women, and AA breast cancer patients of all ages are more likely to have advanced disease at diagnosis, higher risk of recurrence, and poorer overall prognosis. Epidemiological studies indicate that these differences may be attributable in part to variation in obesity and body fat distribution. Additionally, AA women more frequently exhibit breast cancer with an aggressive and metastatic phenotype that may also be attributable to the endocrine and metabolic changes associated with upper body obesity. These changes include both elevated estrogen and androgen bioactivity, hyperinsulinemia, and perturbations of the adipokines. Type 2 diabetes and the metabolic syndrome, which are more common in AA women, have also been associated with breast cancer risk. Moreover, each of the individual components of the syndrome has been associated with increased breast cancer risk, including low levels of the adipocytokine, adiponectin. This review explores the specific roles of obesity, body fat distribution (particularly visceral and sc adipose tissue), type 2 diabetes, metabolic syndrome, and adipocytokines in explaining the differential patterns of breast cancer risk and prognosis between AA and white American women.

Associations of adiponectin with sex hormone-binding globulin levels in aging male and female populations

BACKGROUND

Changes with aging in serum gonadal hormones, sex hormone-binding globulin (SHBG) and adiponectin, which are involved in insulin resistance and metabolic syndrome, are different in men and women. We examined the relationships of serum adiponectin concentrations with serum concentrations of hormones and SHBG in men and women.

METHODS

One hundred fifty-four men and 180 women aged from 50 to 85 years were included in the cross-sectional study. Serum concentrations of testosterone, estradiol, dehydroepiandrosterone-sulfate, SHBG and adiponectin were measured in men and women.

RESULTS

Serum adiponectin concentration showed a significant positive correlation with serum SHBG concentration in men and women (r=0.404, p<0.0001 and r=0.348, p<0.0001, respectively). Multiple regression analysis also showed that SHBG was the significant predictor for adiponectin in men and women. Serum adiponectin concentration in men showed a significant positive correlation with total testosterone concentration, but that in women was not significantly correlated with total testosterone concentration. Both adiponectin and SHBG concentrations in men (r=-0.222, p=0.0051 and r=-0.334, p<0.0001, respectively) and women (r=-0.281, p=0.0014 and r=-0.251, p=0.0048, respectively) showed significant negative correlations with the homeostasis model assessment (HOMA) index.

CONCLUSION

Correlations between adiponectin and SHBG were significantly positive in both men and women, and both adiponectin and SHBG might be involved in insulin resistance in both sexes.

Adiposity, type 2 diabetes and the metabolic syndrome in breast cancer

Upper body obesity and the related metabolic disorder type 2 diabetes have been identified as risk factors for breast cancer, and associated with late-stage disease and a poor prognosis. Components of the metabolic syndrome, including visceral adiposity, insulin resistance, hyperglycemia and hyperinsulinemia, with or without clinically manifest diabetes mellitus, low serum high-density lipoprotein cholesterol and hypertension have all been related to increased breast cancer risk. The biochemical mechanisms include extraglandular oestrogen production, reduced sex hormone-binding globulin with consequent elevation of the bioactive plasma free oestradiol and increased insulin biosynthesis, all of which exert mitogenic effects on both untransformed and neoplastic breast epithelial cells. Obesity, type 2 diabetes and the metabolic syndrome also have in common an increased production of leptin and a decreased production of adiponectin by adipose tissue, with consequent elevations and reductions, respectively, in the circulating levels of these two adipokines. These changes in plasma leptin and adiponectin, acting through endocrine and paracrine mechanisms, have been associated in several studies with an increase in breast cancer risk and, perhaps, to more aggressive tumours; studies in vitro showed that leptin stimulates, and adiponectin inhibits, tumour cell proliferation and the microvessel angiogenesis which is essential for breast cancer development and progression.

Do sex hormones influence features of the metabolic syndrome in middle-aged women? A population-based study of Swedish women: the Women's Health in the Lund Area (WHILA) Study

OBJECTIVE

To outline perceived associations between various sex hormones and risk markers for cardiovascular disease in middle-aged women, with an emphasis on features of the metabolic syndrome (MS).

DESIGN

Cross-sectional analysis.

SETTING

Women's Health in the Lund Area Study.

PATIENT(S)

Population-based cohort.

INTERVENTION(S)

A generic questionnaire, physical examinations, and laboratory assessments were completed by 6,917 women aged 50-59 years living in the Lund area of southern Sweden. Women at or above defined cutoff limits for the MS were considered positively screened. After exclusion of women using hormone therapy (HT), 2,038 women with (MS+) and 2,054 women without features of the MS (MS-) were included. The ELISA techniques were used for the determination of serum androstendione (A), E2, T, sex hormone-binding globulin (SHBG), cortisol, insulin, and leptin levels. Serum lipids and lipoproteins were determined by conventional methods. Multiple linear regression analyses were performed, controlling for age, body mass index (BMI), and smoking habits.

MAIN OUTCOME MEASURE(S)

Features of the MS, sex steroids, cardiovascular risk markers.

RESULT(S)

In the MS+ group, a positive association was seen between A and systolic blood pressure. Estradiol was negatively associated with total cholesterol and diastolic blood pressure. The SHBG was negatively associated with triglycerides, blood glucose, and diastolic blood pressure and positively with high-density lipoprotein (HDL). In the MS- group, there were positive associations between A, blood glucose, and systolic blood pressure. Testosterone was positively associated with HDL. Estradiol was negatively associated with total cholesterol and positively with systolic blood pressure. The SHBG was positively associated with HDL and negatively with triglycerides and diastolic blood pressure. There were positive associations between cortisol, low-density lipoprotein (LDL) cholesterol, blood glucose, and systolic blood pressure and a negative association with triglycerides in both MS+ and MS- groups.

CONCLUSION(S)

Androstendione, E2, and T levels were associated with cardiovascular risk factors in middle-aged women. Effects by sex steroids on cardiovascular risk markers seem to be different in women with or without features of the MS.

First trimester sex hormone-binding globulin and subsequent development of preeclampsia or other adverse pregnancy outcomes

OBJECTIVE

To investigate whether first trimester maternal serum sex hormone-binding globulin (SHBG) concentrations are altered in women who subsequently develop preeclampsia or other pregnancy complications.

POPULATION

Women undergoing first trimester combined ultrasound and biochemical screening for chromosomal anomalies. We searched the database and identified 32 pregnancies resulting in miscarriage, 64 pregnancies with preexisting or gestational diabetes mellitus, 107 with fetal growth restriction, 103 with preeclampsia, 64 with pregnancy-induced hypertension, and 26 with spontaneous preterm delivery. We also selected 400 controls from among the population of pregnancies that had a delivery of a normal baby with no pregnancy complications.

METHODS

Maternal serum SHBG concentrations were measured retrospectively using a competitive chemiluminescent immunoassay. The levels between those with normal outcome and those resulting in adverse outcome were compared.

RESULTS

The median maternal serum SHBG concentration was not significantly different from controls, in those that subsequently developed preeclampsia (median MoM 1.05), non-proteinuric hypertension (median MoM 0.94) or preterm delivery (median MoM 1.15). The levels were significantly lower in those with diabetes (median MoM, 0.81 p=0.0005) and those pregnancies resulting in miscarriage (median MoM 0.80, p=0.008).

CONCLUSION

First trimester maternal serum SHBG concentrations are no different from controls in women who subsequently develop preeclampsia, pregnancy-induced hypertension, fetal growth restriction, or preterm delivery. Levels are reduced in those who subsequently miscarry or in those presenting with diabetes.

Is sex hormone-binding globulin associated with glucose tolerance?

BACKGROUND/AIM

Women with a reduced concentration of sex hormone-binding globulin (SHBG) in the first trimester of pregnancy are at increased risk of developing gestational diabetes. Furthermore, a lower concentration of SHBG in women with gestational diabetes identifies women at increased likelihood of requiring insulin treatment. The aim of this study was to explore the relationship of SHBG concentration in pregnancy to insulin resistance and glucose tolerance.

METHODS

Prospective cohort study of 220 pregnant women who attended The Royal North Shore Hospital in Sydney, Australia between August 2002 and June 2003 for their 75-g glucose tolerance test. All tests were performed in the morning after the women had fasted for at least 10 h. To test for differences between patients with or without gestational diabetes, t-tests and chi-square tests were used. Stepwise linear regression was used to determine the independent predictors of SHBG.

RESULTS

The mean concentration of SHBG increased linearly with gestational age. Statistically significant predictors of SHBG from the stepwise regression were gestational age (P < 0.001), insulin resistance (P < 0.001) and body mass index (P = 0.003). Glucose tolerance as assessed by either a fasting or 2-h glucose tolerance test did not predict SHBG concentration in this population. In addition, there was no significant difference in the concentration of SHBG between patients categorized as normal glucose tolerance or gestational diabetes (P = 0.77). This remained the case when SHBG was expressed as SHBG/insulin ratio as suggested by Bartha et al. (Sex hormone-binding globulin in gestational diabetes. Acta Obstet Gynecol Scanda 2000; 79: 839-845) (P = 0.10).

CONCLUSION

In a cross-sectional study of pregnant women, we find no association between SHBG concentration and glucose tolerance.

Candidate-based proteomics in the search for biomarkers of cardiovascular disease

The key concept of proteomics (looking at many proteins at once) opens new avenues in the search for clinically useful biomarkers of disease, treatment response and ageing. As the number of proteins that can be detected in plasma or serum (the primary clinical diagnostic samples) increases towards 1000, a paradoxical decline has occurred in the number of new protein markers approved for diagnostic use in clinical laboratories. This review explores the limitations of current proteomics protein discovery platforms, and proposes an alternative approach, applicable to a range of biological/physiological problems, in which quantitative mass spectrometric methods developed for analytical chemistry are employed to measure limited sets of candidate markers in large sets of clinical samples. A set of 177 candidate biomarker proteins with reported associations to cardiovascular disease and stroke are presented as a starting point for such a 'directed proteomics' approach.

Is there any link between insulin resistance and inflammation in established preeclampsia?

Both insulin resistance and inflammation may contribute to the onset of preeclampsia. They also could be interrelated. We studied the relationship between inflammatory cytokines and markers of insulin resistance. During their third trimester, 22 proteinuric preeclamptic women and 16 normotensive controls underwent intravenous glucose tolerance test (minimal model). Preeclamptic women were more insulin-resistant (P = .009), and they had higher levels of serum soluble tumor necrosis alpha receptor II (TNFalpha RII) (P = .002), triglycerides (P = .006), uric acid (P = .001), and leptin (P = .002) than did the controls. However, the study groups did not differ in serum TNFalpha, C-reactive protein (CRP), interleukin-6 (IL-6), sex hormone-binding globulin (SHBG), and high-density lipoprotein-2 (HDL(2))-cholesterol. In multiple regression analysis only SHBG (P = .01) and triglycerides (P = .0036) were associated with insulin sensitivity independently of body mass index (BMI), weight gain, HDL(2)-cholesterol, CRP, TNFalpha, and TNFalpha RII, IL-6, and leptin. We conclude that insulin resistance and the inflammatory markers studied were not associated in established preeclampsia.

Insulin resistance and alterations in angiogenesis: additive insults that may lead to preeclampsia

Altered angiogenesis and insulin resistance, which are intimately related at a molecular level, characterize preeclampsia. To test if an epidemiological interaction exists between these two alterations, we performed a nested case-control study of 28 women who developed preeclampsia and 57 contemporaneous controls. Serum samples at 12 weeks of gestation were measured for sex hormone binding globulin (SHBG; low levels correlate with insulin resistance) and placental growth factor (PlGF; a proangiogenic molecule). Compared with controls, women who developed preeclampsia had lower serum levels of SHBG (208+/-116 versus 256+/-101 nmol/L, P=0.05) and PlGF (16+/-14 versus 67+/-150 pg/mL, P<0.001), and in multivariable analysis, women with serum levels of PlGF < or =20 pg/mL had an increased risk of developing preeclampsia (odds ratio [OR] 7.6, 95% CI 1.4 to 38.4). Stratified by levels of serum SHBG (< or =175 versus >175 mg/dL), women with low levels of SHBG and PlGF had a 25.5-fold increased risk of developing preeclampsia (P=0.10), compared with 1.8 (P=0.38) among women with high levels of SHBG and low levels of PlGF. Formal testing for interaction (PlGFxSHBG) was significant (P=0.02). In a model with 3 (n-1) interaction terms (high PlGF and high SHBG, reference), the risk for developing preeclampsia was as follows: low PlGF and low SHBG, OR 15.1, 95% CI 1.7 to 134.9; high PlGF and low SHBG, OR 4.1, 95% CI 0.45 to 38.2; low PlGF and high SHBG, OR 8.7, 95% CI 1.2 to 60.3. Altered angiogenesis and insulin resistance are additive insults that lead to preeclampsia.

First-trimester sex hormone binding globulin and subsequent gestational diabetes mellitus

OBJECTIVE

We sought to examine the association between early pregnancy levels of sex hormone binding globulin and subsequent gestational diabetes mellitus, an association that has not been studied previously.

STUDY DESIGN

We conducted a nested case-control study of 44 patients with gestational diabetes mellitus and 94 women with negative third-trimester screening for gestational diabetes mellitus. Sex hormone binding globulin levels were measured from serum samples that had been collected in the first trimester, and clinical data were ascertained from prospectively collected electronic medical records.

RESULTS

Compared with women without gestational diabetes mellitus, first-trimester sex hormone binding globulin levels were lower among women in whom gestational diabetes mellitus subsequently developed (187 +/- 82 nmol/L vs 233 +/- 92 nmol/L, P <.01). In logistic regression analysis that was adjusted for body mass index, age, race, smoking, blood pressure, serum testosterone and estradiol levels, and gestational age at serum collection, sex hormone binding globulin levels remained independently associated with subsequent gestational diabetes mellitus. For every 50-nmol/L increase in sex hormone binding globulin, the odds of gestational diabetes mellitus fell by 31% (odds ratio, 0.69; 95% CI: 0.48, 0.99).

CONCLUSION

Sex hormone binding globulin offers a potential early marker to target women who are at risk for gestational diabetes mellitus.

Relationship between sex hormone-binding globulin levels and features of the metabolic syndrome

Previous studies have demonstrated that reduced plasma levels of sex hormone-binding globulin (SHBG) are related to alterations in several features of the metabolic syndrome in both men and women. We investigated whether SHBG level was a global predictor of the metabolic syndrome in a sample of 203 men, 173 premenopausal, and 46 postmenopausal women for whom we also obtained a detailed assessment of the metabolic profile, including body composition (hydrostatic weighing), abdominal adipose tissue areas (computed tomography), plasma lipid-lipoprotein levels, and glucose homeostasis (oral glucose challenge). Low SHBG levels were associated with increased total and abdominal adiposity in men as well as in pre- and postmenopausal women. Low SHBG levels were also associated with an altered metabolic profile, especially in premenopausal women. Subjects were subdivided according to the presence of 0, 1 to 2, or 3 or more features of the metabolic syndrome. Twenty-five percent of men were characterized by 3 features or more, whereas most premenopausal women (61.3%) had a healthy metabolic profile (0 features) and 6.9% were characterized by 3 or more features. Most postmenopausal women (54.3%) were characterized by 1 to 2 components of the metabolic syndrome, and 13.0% were characterized by 3 or more components. The proportion of subjects characterized by the metabolic syndrome (3 components or more) was lower in subjects with SHBG values in the upper tertile compared with the lower tertile in both men and premenopausal women (17.7% v 28.4% and 1.7% v 14.0%, respectively). Logistic regression analyses indicated that an SHBG level in the upper tertile was associated with a significant reduction in the probability of being characterized by the metabolic syndrome (odds ratios of 0.35, P =.02 for men and.11, P =.05 for premenopausal women, with the lower tertile as a reference). The logistic regression was not significant in postmenopausal women. These results suggest that plasma SHBG level may represent a significant predictor of the metabolic syndrome in men and premenopausal women.

Androgens and coronary artery disease

A significant and independent association between endogenous testosterone (T) levels and coronary events in men and women has not been confirmed in large prospective studies, although cross-sectional data have suggested coronary heart disease can be associated with low T in men. Hypoandrogenemia in men and hyperandrogenemia in women are associated with visceral obesity; insulin resistance; low high-density lipoprotein (HDL) cholesterol (HDL-C); and elevated triglycerides, low-density lipoprotein cholesterol, and plasminogen activator type 1. These gender differences and confounders render the precise role of endogenous T in atherosclerosis unclear. Observational studies do not support the hypothesis that dehydroepiandrosterone sulfate deficiency is a risk factor for coronary artery disease. The effects of exogenous T on cardiovascular mortality or morbidity have not been extensively investigated in prospective controlled studies; preliminary data suggest there may be short-term improvements in electrocardiographic changes in men with coronary artery disease. In the majority of animal experiments, exogenous T exerts either neutral or beneficial effects on the development of atherosclerosis. Exogenous androgens induce both apparently beneficial and deleterious effects on cardiovascular risk factors by decreasing serum levels of HDL-C, plasminogen activator type 1 (apparently deleterious), lipoprotein (a), fibrinogen, insulin, leptin, and visceral fat mass (apparently beneficial) in men as well as women. However, androgen-induced declines in circulating HDL-C should not automatically be assumed to be proatherogenic, because these declines may instead reflect accelerated reverse cholesterol transport. Supraphysiological concentrations of T stimulate vasorelaxation; but at physiological concentrations, beneficial, neutral, and detrimental effects on vascular reactivity have been observed. T exerts proatherogenic effects on macrophage function by facilitating the uptake of modified lipoproteins and an antiatherogenic effect by stimulating efflux of cellular cholesterol to HDL. In conclusion, the inconsistent data, which can only be partly explained by differences in dose and source of androgens, militate against a meaningful assessment of the net effect of T on atherosclerosis. Based on current evidence, the therapeutic use of T in men need not be restricted by concerns regarding cardiovascular side effects. Available data also do not justify the uncontrolled use of T or dehydroepiandrosterone for the prevention or treatment of coronary heart disease.

Insulin resistance but not inflammation is associated with gestational hypertension

Hypertensive disorders of pregnancy, including gestational hypertension and preeclampsia, are leading causes of pregnancy-associated morbidity. Although insulin resistance and inflammation contribute to preeclampsia, prospective data regarding mechanisms of gestational hypertension are sparse. We conducted a prospective, nested case-control study to test the hypotheses that insulin resistance, marked by reduced sex hormone-binding globulin (SHBG) levels, and inflammation, marked by increased C-reactive protein levels, are similarly associated with gestational hypertension. We measured first-trimester C-reactive protein and SHBG levels in 51 women who subsequently developed gestational hypertension and 102 randomly selected normotensive pregnant controls. Compared with controls, first-trimester SHBG levels were significantly reduced among women who later developed gestational hypertension (176+/-73 versus 203+/-79 nmol/L; P=0.03), but there was no difference in C-reactive protein levels. There was statistically significant interaction among nulliparity, first-trimester SHBG levels, and risk of gestational hypertension, such that increasing SHBG levels were associated with significantly reduced risk of gestational hypertension among nulliparous women (odds ratio, 0.64 per 50-nmol/L increase; 95% confidence interval, 0.46, 0.90; P<0.01) but not among multiparous women. This association remained significant after adjusting for potential confounders (odds ratio, 0.55; 95% confidence interval, 0.31, 0.98; P=0.04). We conclude that insulin resistance, but not inflammation, is an independent risk factor for gestational hypertension among nulliparous women. Furthermore, important mechanistic differences exist in the pathogenesis of gestational hypertension comparing nulliparous and multiparous women.

First trimester insulin resistance and subsequent preeclampsia: a prospective study

Insulin resistance is implicated in the pathogenesis of preeclampsia, but prospective data are limited. SHBG, a marker of insulin resistance among nonpregnant individuals, has not been studied in detail during pregnancy. We conducted a prospective, nested, case-control study to test the hypothesis that increased insulin resistance, marked by reduced first trimester SHBG levels, is associated with increased risk of subsequent preeclampsia. First trimester SHBG levels were measured in 45 nulliparous women who subsequently developed preeclampsia (blood pressure, > or =140/90 mm Hg; proteinuria, either > or =2+ by dipstick or > or =300 mg/24 h, after 20 wk gestation) and in 90 randomly selected normotensive nulliparous controls. Compared with controls, women who developed preeclampsia had significantly reduced first trimester SHBG levels (302 +/- 130 vs. 396 +/- 186 nmol/liter; P < 0.01). Every 100 nmol/liter increase in SHBG was associated with a 31% reduced risk of preeclampsia [odds ratio (OR), 0.69; 95% confidence interval (CI), 0.55, 0.88; P < 0.01]. After adjusting for covariates in a multiple logistic regression model, the association between first trimester SHBG and preeclampsia remained significant (per 100 nmol/liter increase; OR, 0.66; 95% CI, 0.47, 0.92; P = 0.01). When subjects were stratified by body mass index (lean: body mass index, < 25 kg/m(2); overweight: body mass index, > or =25 kg/m(2)), overweight women had lower SHBG levels than lean women (286 +/- 156 vs. 410 +/- 166 nmol/liter; P < 0.01), and within each stratum, women with preeclampsia had lower SHBG levels than their respective controls. In a multivariable analysis, the association between SHBG and preeclampsia strengthened among lean women, such that every 100 nmol/liter increase in serum SHBG was associated with a 55% reduction in the risk of preeclampsia (OR, 0.45; 95% CI, 0.27, 0.77; P < 0.01), whereas in overweight women, the association was mitigated (OR, 1.02; 95% CI, 0.62, 1.69; P = 0.9). We conclude that increased early pregnancy insulin resistance is independently associated with subsequent preeclampsia. First trimester SHBG levels may be a useful biomarker for preeclampsia, especially among lean women who otherwise would be perceived to be at low risk.

Racial disparities in metabolism, central obesity, and sex hormone-binding globulin in postmenopausal women

Increased total and intraabdominal fat (IAF) obesity as well as other metabolic conditions associated with the insulin resistance syndrome (IRS) are related to low levels of sex hormone-binding globulin (SHBG) in young and older Caucasian (CAU) and young African-American (AA) women. We examined whether postmenopausal AA women, a population with a high incidence of obesity and IRS despite low IAF, would have higher levels of circulating SHBG compared with CAU women, and whether there would be negative relationships between indexes of obesity and risk factors associated with IRS and SHBG levels. We measured body composition, SHBG, free testosterone, leptin, glucose tolerance, insulin, and lipoprotein lipids in 55 CAU (mean +/- SD, 59 +/- 7 yr) and 35 AA (57 +/- 6 yr) sedentary women of comparable obesity (48% body fat, by dual energy x-ray absorptiometry). Compared with CAU women, AA women had larger waist (101 vs. 96 cm), larger fat mass (44.9 +/- 8.8 vs. 39.9 +/- 8.1 kg), larger sc fat area (552 +/- 109 vs. 452 +/- 109 cm(2)), and lower IAF/SC ratio (0.28 +/- 0.12 vs. 0.38 +/- 0.15; P < 0.01), but similar waist to hip ratio (0.83). Both groups had similar SHBG (117 vs. 124 nmol/L) and free testosterone (3.7 vs. 3.4 pmol/L) levels, but AA women had a 35% higher leptin, 34% higher fasting insulin, and 39% greater insulin response to a glucose load (P < 0.05) compared with CAU women. In CAU, but not AA, women SHBG correlated negatively with body mass index (r = -0.28; P < 0.05), waist (r = -0.36; P = 0.01), IAF (r = -0.34; P = 0.01), and insulin response to oral glucose (r = -0.37; P < 0.05) and positively with high density lipoprotein cholesterol (r = 0.30; P = 0.03). The relationship between insulin area and SHBG in CAU women disappeared after adjusting for IAF, whereas the relationship between high density lipoprotein cholesterol and SHBG persisted after adjusting for IAF, but not for fat mass. Leptin was positively related to fat mass (P < 0.05) in both groups, but it was related to insulin only in the Caucasian women (P< 0.01). There was a racial difference in the slopes (P< 0.05) of the relationships of leptin to fat mass (P < 0.05). Racial differences in leptin disappeared after adjustment for fasting insulin. These results suggest that the metabolic relationships between total and regional obesity, glucose, and lipid metabolism with SHBG in CAU women are different from those in postmenopausal obese AA women.

Sex hormone binding globulins and atherosclerotic risk in systemic lupus

Sex hormone binding globulin (SHBG) is a transport protein in human plasma which regulates the bioavailability of sex hormones, mediates membrane receptor signaling and may affect inflammatory processes, suggesting a regulatory role for this protein in the prevention of atherosclerosis. The current report summarizes literature implicating several members of the SHBG family in the regulation of hormonal and inflammatory processes which may be pertinent to the accelerated atherosclerosis seen in systemic lupus.

Benefits and risks of oral contraceptives

The major benefits of modern low-dose oral contraceptives include relative safety and a high degree of efficacy, decreasing the need for abortion or surgical sterilization; reduced risks of bacterial (but not viral) pelvic inflammatory disease and of endometrial and ovarian cancer; improved menstrual regularity, with less dysmenorrhea and blood flow; and, when low-dose combination (not progestogen-only) oral contraceptives are used, reduced acne and hirsutism. Major risks are cardiovascular. Preliminary data from nonrandomized studies suggest that oral contraceptives containing third-generation progestogens are associated with increased risk of venous thromboembolism, particularly in carriers of the coagulation factor V Leiden mutation. The risk of arterial thrombosis, such as myocardial infarction or stroke, may be directly related to estrogen dose, particularly in women who have hypertension, smoke, or are >35 years old. Considering that only users aged >/=30 years who smoke >/=25 cigarettes/d have a higher estimated mortality rate than that of pregnant women, the benefits of oral contraceptives appear to outweigh their risks.

Hyperinsulinism and sex hormones in young adult African Americans

Hyperinsulinemia is a risk factor for cardiovascular disease, and is linked with non-insulin-dependent diabetes mellitus (NIDDM), hyperlipidemia, obesity, and hypertension. Sex hormones also play a role in the metabolic alterations associated with the risk for cardiovascular disease. A reduction in sex hormone-binding globulin (SHBG) may be predictive of future NIDDM particularly in women. The postmenopausal decline in estrogen is also associated with an increase in risk factor expression in women. Since African Americans experience a greater prevalence of NIDDM, obesity, and hypertension, conditions associated with hyperinsulinemia, the purpose of this study was to determine if alterations in sex hormone levels are associated with the plasma insulin concentration in young adult African Americans, and to determine if there are sex differences in the effect of insulin on lipids and sex hormones. In a sample of 221 nondiabetic African American men (n = 105) and women (n = 116) with a mean age of 31 years, we examined the relationship of the plasma insulin concentration with the body mass index (BMI), blood pressure, plasma lipids, and sex hormones, including free testosterone, estradiol, and SHBG. Plasma insulin increased with the BMI and other measures of adiposity (P<.001) in men and women. Significant correlations of insulin with plasma lipids were also present in both sexes. There was a significant inverse correlation of insulin with SHBG in both men (r = .28, P = .007) and women (r = .27, P = .02). There was a significant direct correlation of insulin with free testosterone in women (r = .032, P<.001). Stepwise multiple regression analyses with insulin as the dependent variable detected the BMI, triglyceride, and apolipoprotein A1 as significant contributors to the plasma insulin concentration in men. In women, the multiple regression model detected percent body fat, low-density lipoprotein (LDL) cholesterol, and free testosterone as significant contributors to plasma insulin. These data on young African Americans demonstrate a significant relationship between hyperinsulinemia and obesity, atherogenic lipid status, and lower SHBG. In the premenopausal women, the lower SHBG is linked with higher free testosterone, favoring a condition of relative androgen excess.