Endogenous sex hormones: impact on lipids, lipoproteins, and insulin

Unfavorably altered lipid profile in women with primary ovarian insufficiency

BACKGROUND

Hypoestrogenism related to the cessation of ovarian function increases the risk of metabolic disorders in postmenopausal women. Women with primary ovarian insufficiency (POI) are exposed to longer period of estrogen deficiency together with a subsequently higher risk of long-term comorbidities.

OBJECTIVE

To compare metabolic along with hormonal status among newly diagnosed women with POI with pre- and postmenopausal women. To investigate the impact of POI etiology on both metabolic and hormonal profiles.

METHODS

A case-control study with women assigned to one of the groups: 1) POI (n = 216), 2) age-matched premenopausal (n = 216), 3) postmenopausal (n = 227). Lipid profile, fasting glucose and insulin levels together with insulin resistance were determined among all participants.

RESULTS

POI women exhibited increased both total cholesterol (TC, p = 0.04) and low-density lipoprotein cholesterol (LDL-C, p < 0.01) compared to the premenopausal women and higher triglycerides (TG, p < 0.001) than postmenopausal women. POI group showed higher fasting glucose level (p = 0.04) differently to premenopausal women. The idiopathic POI group showed both lower sex hormone binding globulin (p = 0.02) and dehydroepiandrosterone sulfate (p = 0.04) along with reduced TC (p = 0.03) and TG (p = 0.01) together with increased high-density lipoprotein cholesterol (p = 0.04) levels than non-idiopathic POI women.

CONCLUSION

Women with newly diagnosed POI exhibited less favorable lipid profile than pre- or postmenopausal women. The association of negatively changed lipid profile in POI women is mostly mediated by women with unknown cause of premature ovarian cessation.

Sex and sex steroids as determinants of cardiovascular risk

There are considerable sex differences regarding the risk of cardiovascular disease (CVD), including arterial hypertension, coronary artery disease (CAD) and stroke, as well as chronic renal disease. Women are largely protected from these conditions prior to menopause, and the risk increases following cessation of endogenous estrogen production or after surgical menopause. Cardiovascular diseases in women generally begin to occur at a later age than in men (on average with a delay of 10 years). Cessation of estrogen production also impacts metabolism, increasing the risk of developing obesity and diabetes. In middle-aged individuals, hypertension develops earlier and faster in women than in men, and smoking increases cardiovascular risk to a greater degree in women than it does in men. It is not only estrogen that affects female cardiovascular health and plays a protective role until menopause: other sex hormones such as progesterone and androgen hormones generate a complex balance that differentiates heart and blood vessel function in women compared to men. Estrogens improve vasodilation of epicardial coronary arteries and the coronary microvasculature by augmenting the release of vasodilating factors such as nitric oxide and prostacyclin, which are mechanisms of coronary vasodilatation that are more pronounced in women compared to men. Estrogens are also powerful inhibitors of inflammation, which in part explains their protective effects on CVD and chronic renal disease. Emerging evidence suggests that sex chromosomes also play a significant role in shaping cardiovascular risk. The cardiovascular protection conferred by endogenous estrogens may be extended by hormone therapy, especially using bioidentical hormones and starting treatment early after menopause.

Patterns of dyslipidemia and its associated factors among prediabetic subjects. A cross-sectional study at a primary care clinic

Introduction

Diabetes is closely linked to cardiovascular diseases, with diabetic dyslipidaemia serving as an established marker of the acceleration of complications, contributing to an increased cardiovascular risk among patients. Timely detection and early characterization of lipid abnormalities can help clinicians in implementing effective preventive measures. This study aimed to determine the patterns and associated factors of dyslipidaemia among Malaysian subjects with borderline diabetes.

Methods

A retrospective study was conducted among subjects with borderline diabetes aged ≥18 years who visited a primary healthcare centre at Universiti Sains Malaysia from January 2017 to December 2018. Sociodemographic, clinical and laboratory data were obtained from electronic medical records. Data were analysed using SPSS version 25.

Results

A total of 250 participants with borderline diabetes were included in the analysis. Of them, 93.6% (n=234) had lipid abnormalities. Isolated dyslipidaemia characterised by a high low-density lipoprotein cholesterol (LDL-C) level (38.8%, n=97) was the most common pattern found, followed by combined dyslipidaemia of high LDL-C and triglyceride (TG) levels (22.8%, n=57). The male sex was found to be significantly associated with hypertriglyceridemia (adjusted odds ratio [AOR] = 1.86, 95% confidence interval [CI] =1.09-3.1)(P=0.02). Diastolic blood pressure ≥90mmHg was significantly associated with a low HDL-C level (A0R=2.09, 95% CI=1.0-4.1) (P=0.03).

Conclusion

The majority of subjects with borderline diabetes have lipid abnormalities. Specifically, isolated dyslipidaemia characterised by a high LDL-C level is alarmingly prevalent. Further large-scale robust studies are needed to confirm the present findings.

Is cholesterol a risk factor for breast cancer incidence and outcome?

Cholesterol plays important roles in many physiological processes, including cell membrane structure and function, hormone synthesis, and the regulation of cellular homeostasis. The role of cholesterol in breast cancer is complex, and some studies have suggested that elevated cholesterol levels may be associated with an increased risk of developing breast cancer, while others have found no significant association. On the other hand, other studies have shown that, for total cholesterol and plasma HDL-associated cholesterol levels, there was inverse association with breast cancer risk. One possible mechanism by which cholesterol may contribute to breast cancer risk is as a key precursor of estrogen. Other potential mechanisms by which cholesterol may contribute to breast cancer risk include its role in inflammation and oxidative stress, which have been linked to cancer progression. Cholesterol has also been shown to play a role in signaling pathways regulating the growth and proliferation of cancer cells. In addition, recent studies have shown that cholesterol metabolism can generate tumor promoters such as cholesteryl esters, oncosterone, 27-hydroxycholesterol but also tumor suppressor metabolites such as dendrogenin A. This review summarizes some of the most important clinical studies that have evaluated the role of cholesterol or its derivatives in breast cancer. It also addresses the role of cholesterol and its derivatives at the cellular level.

Associations between endogenous sex hormone levels and adipokine levels in the Multi-Ethnic Study of Atherosclerosis

Background

Differences in sex hormone levels contribute to differences in cardiovascular disease (CVD) risk. Adipokines play a role in cardiometabolic pathways and have differing associations with CVD. Adipokine levels differ by sex; however, the association between sex hormone profiles and adipokines is not well established. We hypothesized that a more androgenic sex hormone profile would be associated with higher leptin and resistin and lower adiponectin levels among postmenopausal women, with the opposite associations in men.

Methods

We performed an analysis of 1,811 adults in the Multi-Ethnic Study of Atherosclerosis who had both sex hormones and adipokines measured an average of 2.6 years apart. Sex hormones [Testosterone (T), estradiol (E2), sex hormone binding globulin (SHBG), and dehydroepiandrosterone (DHEA)] were measured at exam 1; free T was estimated. Serum adipokines (leptin, resistin, adiponectin) were measured at exams 2 or 3. We used multivariable linear regression to examine the cross-sectional associations between sex hormones and adipokines.

Results

The mean (SD) age was 63 (10) years, 48% were women; 59% non-White participants. For leptin, after adjusting for demographics only, higher free T and lower SHBG, were associated with higher leptin in women; this association was attenuated after further covariate adjustment. However in men, higher free T and lower SHBG were associated with greater leptin levels in fully adjusted models. For adiponectin, lower free T and higher SHBG were associated with greater adiponectin in both women and men after adjustment for CVD risk factors. For resistin, no significant association was found women, but an inverse association with total T and bioT was seen in men.

Conclusion

Overall, these results further suggest a more androgenic sex profile (higher free T and lower SHBG) is associated with a less favorable adipokine pattern. These findings may provide mechanistic insight into the interplay between sex hormones, adipokines, and CVD risk.

Associations between human internal chemical exposure to Persistent Organic Pollutants (POPs) and In Vitro Fertilization (IVF) outcomes: Systematic review and evidence map of human epidemiological evidence

The impact of environmental chemicals like persistent organic pollutants (POPs) on reproductive health is still poorly understood, despite the high societal and economical costs. The aim of the present study was to systematically review and evaluate the human evidence on the associations between internal levels of POPs and in vitro Fertilization (IVF) outcomes among women. We applied a protocol based on the National Toxicology Program Office of Health Assessment and Translation's guidelines for the study search, selection and quality assessment. Fifteen studies were finally retained in the present work. The results showed that main families of POPs are still pervasive in follicular fluid and serum of women undergoing IVF treatments. Globally, we found inconsistent findings across studies for specific exposure-outcome dyads, suggesting that adverse effects of POPs on IVF outcomes cannot be ruled out. Specifically, there is evidence that POPs, notably some polychlorinated biphenyls and organochlorine pesticides, may impair embryo quality and pregnancy rates. Most studies have been performed in small cohorts (n<50) and focused on PCBs and OCPs, whereas major research gaps remain for emerging compounds (e.g. perfluoroalkylated substances) and the most clinically relevant outcome, live birth rate. The overall evidence presented 'serious' or 'very serious' risk of bias, mainly due to the lack of consideration of relevant confounding variables, low sample size or underreporting of methods. Globally, we judged the level of evidence being "low". Given the high economical and societal costs associated to infertility and IVF, further well-designed research is urged to fill the highlighted gaps.

Does letrozole treatment have favorable effects on the lipid profile? A systematic review and meta-analysis of randomized clinical trials

As an aromatase inhibitor, letrozole reduces estrogen levels, affecting lipid indices because of the positive role of estrogens in modulating lipoproteins and lipids. Thus, our aim was to meta-analyze data regarding letrozole administration and its effects on the traditional lipid profile. A systematic review and meta-analysis of randomized clinical trials (RCTs) were performed based on the PRISMA guidelines. Web of Science, Scopus, PubMed/Medline, and EMBASE databases were searched until February 11, 2021. From 341 potentially relevant publications, 8 RCTs were selected. All studies used 2.5 mg/d of letrozole. Total cholesterol changed significantly by -6.28 mg/dL (95% CI: -8.73, -3.84, P < 0.001) and HDL-C by -4.40 mg/dL (95% CI: -5.30 to -3.50, p < 0.001) in letrozole group when compared to the control group. Taking into account this comparison between groups, in contrast, LDL-C (WMD: -2.50 mg/dL, 95% CI: -9.94, 4.93, p = 0.510) and triglycerides (WMD: -0.89 mg/dL, 95% CI: -6.87 to 5.07, p = 0.768) did not alter. In conclusion, letrozole administration decreased the concentrations of HDL-C and tocal cholesterol, but not of triglycerides and LDL-C.

The application value of serum 25(OH)D3, uric acid, triglyceride, and homeostasis model assessment of insulin resistance in male patients with hyperuricemia combined with hypogonadism

BACKGROUND

The purpose of this study was to investigate the application value of serum 25(OH)D3, uric acid, triglyceride (TG), and homeostasis model assessment of insulin resistance (HOMA-IR) in male patients with hyperuricemia combined with hypogonadism.

METHODS

From August 2018 to August 2020, a total of 198 male patients with primary hyperuricemia were prospectively enrolled in our hospital for inpatient treatment in the department of Metabolism and Endocrinology. They are divided into normal gonadal function group (normal group, n = 117) and hypogonadal function group (hypogonadism group, n = 81), according to free testosterone (FT) level, International Index of Erectile Function (IIEF-5), and androgen deficiency in the aging male (ADAM) questionnaires. Laboratory indexes were compared between two groups. Multivariate logistic regression was applied to analyze the influencing factors of hypogonadism.

RESULTS

Among the 198 hyperuricemia patients, 40.91 % were hypogonadism. Compared with the normal group, the BMI, waist circumference (WC), and the prevalence of non-alcoholic fatty liver disease (NAFLD), hyperlipidemia (HLP), and obesity (OB) in the hypogonadism group were higher, and the difference was statistically significant (P < 0.05, respectively). The levels of fasting plasma glucose (FPG), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR), triacylglycerol (TG), serum uric acid (SUA), alanine transaminase (ALT) of hypogonadism group were higher than those of normal group, while the levels of TT, FT, E2, 25(OH)D3 of hypogonadism group were lower than those of normal group (P < 0.05, respectively). Pearson's linear correlation was used to analyze the correlation between the indicators with significant differences in general data and laboratory indicators and hypogonadism. BMI, WC, HOMA-IR, TG, SUA, TT, FT, 25(OH)D3, E2 were positively correlated with hypogonadism (r = 0.556, 0.139, 0.473, 0.143, 0.134, 0.462, 0.419, 0.572, 0.601, P = 0.012, 0.027, 0.018, 0.019, 0.028, 0.029, 0.030, 0.009, 0.003, respectively). Taking the above indicators as independent variables and hypogonadism as the dependent variable, logistic regression analysis found that the risk factors for hypogonadism were SUA, WC, BMI, HOMA-IR, TG, TT, FT, E2, and 25(OH) D3.

CONCLUSIONS

Serum 25(OH)D3, SUA, HOMA-IR, TG levels were positively correlated with male hyperuricemia patients with hypogonadism. They have important application value in the diagnosis of male hyperuricemia patients with hypogonadism.

Gender differences in the associations among fish intake, lifestyle, and non-HDL-C level in Japanese subjects over the age of 50 years: Anti-atherosclerotic effect of fish consumption

BACKGROUND AND AIMS

Higher fish consumption may lead to the suppression of atherogenesis. The present study was aimed at investigating the gender differences in association with the frequency of fish intake, lifestyle behaviors and serum non-high-density lipoprotein cholesterol (non-HDL-C) levels.

METHODS AND RESULTS

This cross-sectional study was conducted in a cohort of 4320 (2479 males, 1570 females) healthy Japanese subjects over 50 years of age registered at the Health Planning Center of Nihon University Hospital between April 2018 and March 2019. The average weekly frequency of fish intake was 2.58 ± 1.39 days in males and 2.42 ± 1.36 days in females. In males, the serum non-HDL-C level decreased significantly as the weekly frequency of fish intake (0-1 days, 2-3 days, 4-5 days, or 6-7 days) increased (p < 0.0001). Multiple stepwise regression analysis identified the weekly frequency of fish intake (β = -0.056, p = 0.004) and habitual aerobic exercise (β = -0.063, p = 0.001) as independent determinants of the serum non-HDL-C level. On the other hand, no such associations were observed in females. However, the proportion of subjects engaging in habitual aerobic exercise increased as the frequency of fish intake increased even among females.

CONCLUSIONS

A higher frequency of fish intake may be associated with healthier lifestyle behaviors and lower non-HDL-C levels in males, but not in females. There appear to be gender differences in the relationships between the intake of fish and lifestyle behaviors on lipid metabolism.

CLINICAL TRIAL REGISTRATION

umin (http://www.umin.ac.jp/) Study ID: UMIN000035899.

Environmentally relevant concentrations of carbamazepine induced lipid metabolism disorder of Chinese rare minnow (Gobiocypris rarus) in a gender-specific pattern

Carbamazepine (CBZ), an anticonvulsant and mood stabilizer, is ubiquitous distributed in aquatic environment. Though the toxicity and endocrine disrupting effect of CBZ on non-target organisms have been studied, its lipotoxity are scarcely known. To assess the lipotoxicity of CBZ, 2-month-old Chinese rare minnow were exposed to 0, 1, 10, and 100 μg/L CBZ for 90 d. Obvious dyslipidemia was observed after 30 d and 90 d exposure, whereas overt hyperlipidemia was observed in males at 100 μg/L treatments. Severe lipid droplet accumulation in livers was observed at 10 and 100 μg/L treatments for 30 d and in females, whereas those was observed at all treatments in males. In addition, serious mitochondria damage was observed in males at 100 μg/L treatments. After 90 d exposure, the enzyme activities of FAS and ACCα were significantly increased at 10 and 100 μg/L treatments, whereas HMGCR were markedly increased at 100 μg/L treatments (p < 0.05). However, ACCβ were markedly decreased in females at 10 and 100 μg/L treatments and in males at all treatments (p < 0.05). The transcription levels of fasn, accα, hmgcrα, fdft1, idi1, plin1, plin2, caveolin1, and caveolin2 were significantly increased at 100 μg/L treatments (p < 0.05). Moreover, the body weight was obviously increased at 10 and 100 μg/L treatments in males (p < 0.05). Our results confirmed that environmental relevant concentrations CBZ induced lipid metabolism disorder and mitochondria damage of Chinese rare minnow in a gender-specific pattern, which provided a new insight into the lipotoxicity mechanism of CBZ.

CARDIOVASCULAR HEALTH MAINTENANCE IN AGING INDIVIDUALS: THE IMPLICATIONS FOR TRANSGENDER MEN AND WOMEN ON HORMONE THERAPY

OBJECTIVE

To review screening guidelines for cardiometabolic disease in aging patients and review literature describing the effect of hormone therapy (HT) on several key cardiometabolic processes to inform providers caring for older transgender individuals.

METHODS

A traditional literature review was performed using PubMed and Google Scholar databases.

RESULTS

The risk of cardiovascular disease increases with age. Exogenous sex hormones may interact with hormone-dependent metabolic pathways and affect some biochemical assays, but they do not necessarily impact clinical outcomes. While long-term HT is associated with an increased risk of some adverse cardiovascular outcomes, modern treatment regimens minimize this risk.

CONCLUSION

Screening for cardiometabolic derangements and risk reduction are important for all aging individuals. Currently, there is insufficient evidence to propose separate screening recommendations for transgender individuals on long-term HT. Aging transgender men and women should be monitored for cardiovascular disease in much the same way as their cisgender counterparts.

Sexual dimorphism in adipose tissue mitochondrial function and metabolic flexibility in obesity

OBJECTIVE

The prevalence of obesity is growing globally. Adiposity increases the risk for metabolic syndrome, type 2 diabetes and cardiovascular disease. Adipose tissue distribution influences systemic metabolism and impacts metabolic disease risk. The link between sexual dimorphisms of adiposity and metabolism is poorly defined. We hypothesise that depot-specific adipose tissue mitochondrial function contributes to the sexual dimorphism of metabolic flexibility in obesity.

METHODS

Male and female mice fed high fat diet (HFD) or standard diet (STD) from 8-18 weeks of age underwent whole animal calorimetry and high-resolution mitochondrial respirometry analysis on adipose tissue depots. To determine translatability we used RT-qPCR to examine key brown adipocyte-associated gene expression: peroxisome proliferator-activated receptor co-activator 1α, Uncoupling protein 1 and cell death inducing DFFA like effector a in brown adipose tissue (BAT) and subcutaneous adipose tissue (sWAT) of 18-week-old mice and sWAT from human volunteers.

RESULTS

Male mice exhibited greater weight gain compared to female mice when challenged with HFD. Relative to increased body mass, the adipose to body weight ratio for BAT and sWAT depots was increased in HFD-fed males compared to female HFD-fed mice. Oxygen consumption, energy expenditure, respiratory exchange ratio and food consumption did not differ between males and females fed HFD. BAT mitochondria from obese females showed increased Complex I & II respiration and maximal respiration compared to lean females whereas obese males did not exhibit adaptive mitochondrial BAT respiration. Sexual dimorphism in BAT-associated gene expression in sWAT was also associated with Body Mass Index in humans.

CONCLUSIONS

We show that sexual dimorphism of weight gain is reflected in mitochondrial respiration analysis. Female mice have increased metabolic flexibility to adapt to changes in energy intake by regulating energy expenditure through increased complex II and maximal mitochondrial respiration within BAT when HFD challenged and increased proton leak in sWAT mitochondria.

Sex hormones and stroke: Beyond estrogens

Stroke risk and poor stroke outcomes in postmenopausal women have usually beeen attributed to decreased levels of estrogen. However, two lines of evidence suggest that this hormone may not be solely responsible for elevated stroke risk in this population. First, the increased risk for CVD and stroke occurs much earlier than menopause at a time when estrogen levels are not yet reduced. Second, estrogen therapy has not successfully reduced stroke risk in all studies. Other sex hormones may therefore also contribute to stroke risk. Prior to menopause, levels of the gonadotrophin Follicle Stimulating Hormone (FSH) are elevated while levels of the gonadal peptide inhibin are lowered, indicating an overall decrease in ovarian reserve. Similarly, reduced estrogen levels at menopause significantly increase the ratio of androgens to estrogens. In view of the evidence that androgens may be unfavorable for CVD and stroke, this elevated ratio of testosterone to estrogen may also contribute to the postmenopause-associated stroke risk. This review synthesizes evidence from different clinical populations including natural menopause, surgical menopause, women on chemotherapy, and preclinical stroke models to dissect the role of ovarian hormones and stroke risk and outcomes.

Estradiol Does Not Influence Lipid Measures and Inflammatory Markers in Testosterone-Clamped Healthy Men

Context

Experimentally controlled studies of estrogenic regulation of lipid measures and inflammatory cytokines in men are rare.

Objective

To delineate the effect of estradiol (E₂) on lipids and inflammatory markers.

Design

This was a placebo-controlled, single-masked, prospectively randomized study comprising experimentally degarelix-downregulated healthy men [n = 74; age 65 years (range, 57 to 77)] assigned to four treatment groups: (1) IM saline and oral placebo; (2) IM testosterone and oral placebo; (3) IM testosterone and oral anastrozole (aromatase inhibitor); and (4) IM testosterone, oral anastrozole, and transdermal E₂ for 22 (±1) days.

Results

Mean mass spectrometry–quantified serum E₂ concentrations ranged from 1.2 to 82 pg/mL in the four treatment groups. E₂ extremes did not alter total cholesterol, triglyceride, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein cholesterol (HDL-C) , non–HDL-C, apolipoprotein B, lipoprotein (a), IL-6, or high-sensitivity C-reactive protein (hsCRP) concentrations. Higher E₂ concentrations elevated both sex hormone-binding globulin and prolactin as positive controls. LDL cholesterol, adiponectin, and leptin were higher in hypogonadal subjects without testosterone or E₂ addback (P = 0.018, 0.039, and 0.023, respectively). Abdominal visceral fat area by CT (independent variable) correlated negatively with HDL-C (P = 0.017), and positively with triglycerides (P = 0.004), hsCRP (P = 0.005), and leptin (P < 0.0001).

Conclusion

In this placebo-controlled prospectively randomized study, wide variations in circulating E₂ did not influence lipid measures and inflammatory markers when testosterone concentrations were controlled experimentally. However, medically induced central hypogonadism in older men was accompanied by increased LDL cholesterol and metabolic cytokines, adiponectin and leptin. Abdominal visceral fat correlated strongly and positively with triglycerides, hsCRP, and leptin, but negatively with HDL.

Gender impact on the correlation between thyroid function and serum lipids in patients with differentiated thyroid cancer

The present study aimed to explore the association between thyroid stimulating hormone (TSH) and serum lipids in patients with differentiated thyroid cancer (DTC), with a focus on the risk of hyperlipidemia between different genders. The study included 352 DTC patients who were ready to receive I-131 therapy as well as 352 matched normal controls. In the DTC group, 157 patients were monitored for TSH and lipid parameters prior to and after 1 month of thyroxine therapy. Results were analyzed using t-tests, Pearson bivariate correlation and binary logistic regression analyses. All participants were divided into 3 subgroups according to TSH levels: Subgroup 1 (normal TSH level), subgroup 2 (TSH between 5 and 30 µIU/ml), and subgroup 3 (TSH >30 µIU/ml). Serum total cholesterol (TC), triglycerides (TG), and low-density lipoprotein-cholesterol (LDL-C) levels were significantly higher in the DTC group than in the control group. The levels of these parameters decreased after thyroxine therapy and significant positive correlations were observed between TSH and TC, and TG and LDL-C in both genders. Binary logistic regression demonstrated that female DTC patients had higher risks of developing hyperlipidemia than male patients, and these risks increased when TSH increased. For example, the odds ratios (ORs) of high TC in subgroup 2 were 3.30 in males and 4.60 in females, respectively. However, in subgroup 3, the ORs were 9.40 in males and 13.12 in females, respectively. The results of the present study showed that after thyroidectomy, the risk of dyslipidemia markedly increased in DTC patients. More importantly, female patients had a higher risk than male patients.

Assessment of established HDL-C loci for association with HDL-C levels and type 2 diabetes in Pima Indians

AIMS/HYPOTHESIS

Epidemiological studies in Pima Indians identified elevated levels of HDL-cholesterol (HDL-C) as a protective factor against type 2 diabetes risk in women. We assessed whether HDL-C-associated single-nucleotide polymorphisms (SNPs) also associate with type 2 diabetes in female Pima Indians.

METHODS

Twenty-one SNPs in established HDL-C loci were initially analysed in 2,675 full-heritage Pima Indians. SNPs shown to associate with HDL-C (12 SNPs) were assessed for association with type 2 diabetes in 7,710 Pima Indians (55.6% female sex). The CETP locus provided the strongest evidence for association with HDL-C and was further interrogated by analysing tag SNPs.

RESULTS

Twelve of the 21 SNPs analysed had a significant association with HDL-C in Pima Indians; five SNPs representing four loci (CETP, DOCK6, PPP1R3B and ABCA1) reached genome-wide significance. Three SNPs, at CETP, KLF14 and HNF4A, associated with type 2 diabetes only in female participants with the HDL-C-lowering allele increasing diabetes risk (p values: 3.2 × 10(-4) to 7.7 × 10(-5)); the association remained significant even after adjustment for HDL-C. Additional analysis across CETP identified rs6499863 as having the strongest association with type 2 diabetes in female participants (p = 5.0 × 10(-6)) and this association remained independent of the HDL-C association.

CONCLUSIONS/INTERPRETATION

SNPs at the CETP, HNF4A and KLF14 locus are associated with HDL-C levels and type 2 diabetes (in female participants). However, since HNF4A and KLF14 are established loci for type 2 diabetes, it is unlikely that HDL-C solely mediates these associations.

Gender and Age Impact on the Association Between Thyroid-Stimulating Hormone and Serum Lipids

The relationship between thyroid-stimulating hormone (TSH) and hyperlipidemia is still a topic of debate. We aimed to explore the impact of gender and age on the association between serum TSH and lipid profile in a large cohort of Chinese.This cross-sectional study enrolled 13,915 participants (8565 male, 5350 female), who self-reported as healthy without any known previous diseases. Clinical data including anthropometric measurements, thyroid function, and other serum parameters were collected. The associations between TSH and hyperlipidemia of males and females were analyzed separately after dividing TSH and age into subgroups. Odds ratio for hyperlipidemia was calculated by binary logistic regression models.Young males had significantly higher prevalence of hypercholesterolemia, hypertriglyceridemia, and high serum low-density lipoprotein-cholesterol than females, yet after menopause, females had higher prevalence than males. TSH was positively associated with hyperlipidemia independent of thyroid hormones. Males showed more reduced risks of hyperlipidemia in low TSH concentrations, while females demonstrated more enhanced risks of hyperlipidemia in high TSH concentrations. For instance, if TSH was lower than 0.3 μIU/mL, the risks of developing hypercholesterolemia and hypertriglyceridemia in males were only 0.198 (P < 0.01) and 0.425 (P < 0.05) of the reference TSH risks (between 2.0 and 3.0 μIU/mL), while in females the risks were 0.553 (P < 0.05) and 0.642 (P > 0.05), respectively. If TSH was higher than 4.0 μIU/mL, women displayed significantly higher risks of developing hypertriglyceridemia than the reference TSH risks (P < 0.05), yet, men did not demonstrate such significances.Our results showed thyroid hormone independent positive associations between serum TSH and lipids, which were substantially influenced by gender and age. Males demonstrated more protective effects of low TSH against hyperlipidemia, while females showed more detrimental effects of high TSH on hyperlipidemia.

Lipid levels and renal function decline in pre-dialysis patients

Background

Little is known about the effect of low-density lipoprotein (LDL) cholesterol, triglyceride (TG), and high-density lipoprotein (HDL) cholesterol levels on renal function decline in patients receiving specialized pre-dialysis care.

Methods

In the prospective PREPARE-2 study, incident patients starting pre-dialysis care were included when referred to one of the 25 participating Dutch specialized pre-dialysis outpatient clinics (2004-2011). Clinical and laboratory data were collected every 6 months. A linear mixed model was used to compare renal function decline between patients with LDL cholesterol, TG, or HDL cholesterol levels above and below the target goals (LDL cholesterol: <2.50 mmol/l, TG: <2.25 mmol/l, and HDL cholesterol: ≥1.00 mmol/l). Additionally the HDL/LDL cholesterol ratio was investigated (≥0.4).

Results

In our study population (n = 306), the median age was 69 years and 70% were male. Patients with LDL cholesterol levels above the target of 2.50 mmol/l experienced an accelerated renal function decline compared to patients with levels below the target (crude additional decline: 0.10 ml/min/1.73 m²/month, 95% CI 0.00-0.20; p < 0.05). A similar trend was found for TG levels above the target of 2.25 mmol/l (0.05 ml/min/1.73 m²/month, 95% CI −0.06 to 0.16) and for a HDL/LDL cholesterol ratio below 0.4 (0.06 ml/min/1.73 m²/month, 95% CI −0.05 to 0.18). Adjustment for potential confounders resulted in similar results, and the exclusion of patients who were prescribed lipid-lowering medication (statin, fibrate, or cholesterol absorption inhibitor) resulted in a slightly larger estimated effect.

Conclusion

High levels of LDL cholesterol were associated with an accelerated renal function decline, independent of the prescription of lipid-lowering medication.

Strength and aerobic training in overweight females in Gdansk, Poland

We compared the effects of 16-week-training on rest metabolic rate, aerobic power, and body fat, and the post-exercise effects upon rest oxygen uptake and respiratory exchange ratio in overweight middle-aged females. Twenty nine overweight women (BMI 29.9 ± 1.2 kg*m^-2) participated in training (3 days a week). The subjects were divided onto groups of aerobic (AT) and strength (ST) training. The results showed that the total body mass decrease and VO₂ max increase did not differ in both groups. Decrease in waist circumference after 16 weeks was higher in the ST group. In the ST group fat-free mass increased during the first 8 weeks. Rest metabolic rate was increased significantly at 16th week compared to initial value in ST group only. Significant increase in post-exercise resting VO₂ and respiratory exchange ratio at 12 and 36 h was observed after the strength training session only. Increase in rest metabolic rate and post-exercise rest energy expenditure occurred after strength training but not after aerobic training despite the similar increase in aerobic power. The effect of 8-16 weeks of strength training on body mass decrease was higher in comparison to aerobic training.

Development of a pilot project on data sharing among partners of the Italian Hub of Population Biobanks (HIBP): association between lipid profile and socio-demographic variables

The Italian Hub of Population Biobanks (HIBP) includes both ongoing and completed studies that are heterogeneous in both their purpose and in the specimens collected. The heterogeneity in starting conditions makes sharing study data very difficult because of technical, ethical, and collection rights issues that hamper collaboration and synergy. With the aim of overcoming these difficulties and establishing the "proof-of-concept" that sharing studies is achievable among Italian collections, a data-sharing pilot project has been agreed to by HIBP members. Participants agreed to the general methodology and signed a shared Data Transfer Agreement. The biobanks involved were: EURAC (Micros study), CIG (GEHA project), CNESPS (FINE, MATISS, MONICA, OEC1998, ITR (Italian Twin Register), and IPREA studies, and MOLIBANK (Moli-Sani project). Biobank data were uploaded into a common database using a dedicated informatics infrastructure. Demographic data, and anthropometric and hematochemical parameters were shared for each record. Each biobank uploaded into the common database a dataset with a minimum of 1000 subjects, for a total of 5071 records. After a harmonization process, the final dataset included 3882 records. Subjects were grouped into three main geographic areas of Italy (North, Center, and South) and separate analyses were performed for men and women. The 3882 records were analyzed through multivariate logistic regression analysis. Results were expressed as odds ratios with 95% confidence interval. Results show several geographical differences in the lipidemic pattern, mostly regarding cholesterol-HDL, which represents a strong basis for further, deeper sample-based studies. This HIBP pilot study aimed to prove the feasibility of such collaborations and it provides a methodological prototype for future studies based on the participation in the partnership of well-established quality collections.

Serum sex hormone-binding globulin and testosterone in relation to cardiovascular disease risk factors in young men: a population-based study

OBJECTIVE

Reduced sex hormone-binding globulin (SHBG) concentration predicts insulin resistance and type 2 diabetes, but its association with cardiovascular disease (CVD) risk is unclear. We examined the association between SHBG and cardiovascular risk factors, independently of total testosterone (TT), in young men.

DESIGN

Observational, cross-sectional study.

SETTING

General community.

PARTICIPANTS

The study included 2716 men aged 31 years in the Northern Finland Birth Cohort in 1996 with clinical examination data and fasting blood samples.

OUTCOME VARIABLES

Blood pressure (BP), lipids and C-reactive protein (CRP) as biological CVD risk markers.

RESULTS

SHBG concentration was significantly and inversely related to systolic and diastolic BP, triglycerides and CRP, but positively to HDL cholesterol after adjusting for insulin, BMI, waist circumference, smoking, education and physical activity (all P<0.05). These linearly graded associations persisted with additional adjustment for TT. SHBG was significantly associated with total cholesterol only with adjustment for covariates and TT (P<0.05). The direction and magnitude of associations between TT and risk factors were variable, but further adjustment for insulin, adiposity and SHBG showed positive associations between TT and BP, total and LDL-cholesterol and triglycerides and an inverse association with CRP (all P<0.05), but its relation with HDL-cholesterol was no longer significant.

CONCLUSIONS

In this cohort of young adult men, higher SHBG concentration was associated with a more favourable CVD risk profile, independently of TT. SHBG concentration modified the associations of TT with CVD risk factors.

Beneficial and adverse effects of testosterone on the cardiovascular system in men

CONTEXT

The widespread use of T therapy, particularly in aging males, necessitates knowledge of the relationship between T and the cardiovascular system.

EVIDENCE ACQUISITION

The review is based on a 1970 to 2013 PubMed search with terms related to androgens in combination with cardiovascular disease, including T, dihydrotestosterone, trial, mortality, cardiovascular disease, myocardial infarction, blood pressure, endothelial function, dyslipidemia, thrombosis, ventricular function, and arrhythmia. Original articles, systematic reviews and meta-analyses, and relevant citations were screened.

EVIDENCE SYNTHESIS

Low T has been linked to increased blood pressure, dyslipidemia, atherosclerosis, arrhythmia, thrombosis, endothelial dysfunction, as well as to impaired left ventricular function. On the one hand, a modest association is suggested between low endogenous T and incident cardiovascular disease or cardiovascular mortality, implying unrecognized beneficial T effects, residual confounding, or a relationship with health status. On the other hand, treatments with T to restore "normal concentrations" have so far not been proven to be beneficial with respect to cardiovascular disease; neither have they definitely shown specific adverse cardiovascular effects. The cardiovascular risk-benefit profile of T therapy remains largely evasive in view of a lack of well-designed and adequately powered randomized clinical trials.

CONCLUSIONS

The important knowledge gap as to the exact relationship between T and cardiovascular disease would support a cautious, restrained approach to T therapy in aging men, pending clarification of benefits and risks by adequately powered clinical trials of sufficient duration.

The effect of androgens on lipids

PURPOSE OF REVIEW

To review recent data concerning the relationship between endogenous testosterone and lipids as well as testosterone replacement therapy and lipids. To describe the effects of sex hormones on cardiovascular disease (CVD) that may act via serum lipids.

RECENT FINDINGS

Low endogenous testosterone is associated with high low-density lipoprotein and low high-density lipoprotein in both cross-sectional and prospective observational studies. Exogenous testosterone administration is associated with decreased high-density lipoprotein coupled with beneficial decreases in low-density lipoprotein and total cholesterol. The overall impact of testosterone administration on CVD is still unclear, with mixed safety results from recent randomized controlled trials.

SUMMARY

There may be CVD risk reduction benefits, including an improved lipid profile, from testosterone administration in hypogonadal men. The overall effect of testosterone on CVD risk has not been definitively determined.

The effect of equol injection in ovo on lipid metabolism and hepatic lipogenic gene expression in broilers

This study investigated the effects of in ovo administration of equol (Eq) on post-hatch growth and hepatic lipid metabolism in broiler chickens. Fertilized eggs (146 eggs/group) were injected with 0 μg (control, Con), 20 μg (low dose, L) and 100 μg (high dose, H) Eq in the albumen on the 7th day of incubation. Except a trend increase in the weight of total fat (P = 0.09), Eq had no effect on growth or liver weight in broilers at 49 days of age. Males presented higher liver and BWs and lower total fat and relative liver weights than females (P < 0.01). However, there were no significant effects of Eq or Eq-gender interactions on growth performance or tissues weight (P > 0.05). With respect to lipid parameters in the serum, the results showed that female broilers presented higher triacyglycerol (TG) and low-density lipoprotein cholesterol concentrations than males, whereas there was no gender difference in serum total cholesterol (TC) or high-density lipoprotein cholesterol (HDLC) concentration (P > 0.05). Eq administration significantly decreased serum TG and TC but increased HDLC concentrations in serum of broilers at 49 days of age (P < 0.05), whereas there were no interactions between gender and Eq (P > 0.05). To elucidate the mechanism behind the significant changes of serum TG and TC levels, the expression of genes involved in lipid metabolism in the liver was investigated in female chickens using reverse transcription-PCR. Carnitine palmitoyl transferase I (CPTI) messenger RNA (mRNA) was significantly upregulated by 20 and 100 μg Eq (P < 0.05). High-dose Eq significantly decreased fatty acid synthase (FAS) and enhanced cholesterol-7alpha-hydroxylase (CYP7A1) mRNA levels in the liver (P < 0.05). Eq had no significant effects on acetyl-CoA carboxylase, sterol regulatory element binding protein-1c, malic enzyme, low-density lipoprotein receptor or 3-hydroxy-3-methylglutaryl coenzyme A reductase mRNA in the liver (P > 0.05). These results in female broilers suggest that Eq decreased blood TG by upregulating CPTI and downregulating FAS mRNA expression in the liver, and that high serum cholesterol levels stimulated CYP7A1 gene transcription in the liver.

Relative contributions of oligomenorrhea and hyperandrogenemia to the risk of metabolic syndrome in midlife women

CONTEXT

Young reproductive-age women with irregular menses and androgen excess are at high risk for unfavorable metabolic profile; however, recent data suggest that menstrual regularity and hyperandrogenism improve with aging in affected women approaching menopause.

OBJECTIVE

The objective of the study was to determine whether women with hyperandrogenemia (HA) and a history of oligomenorrhea (Oligo) are at an elevated risk for metabolic syndrome (MetS) at the early stages of menopausal transition.

METHODS

Baseline data from 2543 participants (mean age of 45.8 yr) in the Study of Women's Health Across the Nation were analyzed. Women with a lifetime history of more than one 3-month interval of nongestational and nonlactational amenorrhea were classified as having a history of Oligo. The highest tertile of serum testosterone was used to define HA. Women with normal serum androgens and eumenorrhea were used as the reference group. Logistic regression models generated adjusted odds ratios (AOR), controlling for age, ethnicity, body mass index, smoking, and study site.

RESULTS

Oligo was associated with MetS only when coincident with HA [AOR of 1.93 for Oligo and HA [95% confidence interval (CI) 1.17-3.17], AOR of 1.25 for Oligo and normal androgens (95% CI 0.81-1.93)]. In contrast, HA conferred a consistently significant risk for MetS, regardless of the menstrual frequency status [AOR of 1.48 for HA and eumenorrhea (95% CI 1.15-1.90)].

CONCLUSIONS

Our results suggest that HA but not history of Oligo is independently associated with the risk of prevalent MetS in pre- and perimenopausal women in their 40s.

Low testosterone levels predict all-cause mortality and cardiovascular events in women: a prospective cohort study in German primary care patients

OBJECTIVE

Although associations between testosterone and cardiovascular (CV) morbidity in women have been proposed, no large prospective study has evaluated potential associations between testosterone and mortality in women. The objective was to determine whether baseline testosterone levels in women are associated with future overall or CV morbidity and mortality.

DESIGN

Prospective cohort study with a 4.5-year follow-up period.

METHODS

From a representative sample of German primary care practices, 2914 female patients between 18 and 75 years were analyzed for the main outcome measures: CV risk factors, CV diseases, and all-cause mortality.

RESULTS

At baseline, the study population was aged 57.96±14.37 years with a mean body mass index of 26.71±5.17 kg/m(2). No predictive value of total testosterone for incident CV risk factors or CV diseases was observed in logistic regressions. Patients with total testosterone levels in the lowest quintile Q1, however, had a higher risk to die of any cause or to develop a CV event within the follow-up period compared to patients in the collapsed quintiles Q2-Q5 in crude and adjusted Cox regression models (all-cause mortality: Q2-Q5 versus Q1: crude hazard ratios (HR) 0.49, 95% confidence interval (CI) 0.33-0.74; adjusted HR 0.62, 95% CI 0.42-0.939; CV events: Q2-Q5 versus Q1: crude HR 0.54, 95% CI 0.38-0.77; adjusted HR 0.68, 95% CI 0.48-0.97). Kaplan-Meier curves revealed similar data.

CONCLUSIONS

Low baseline testosterone in women is associated with increased all-cause mortality and incident CV events independent of traditional risk factors.

Biomarkers of the metabolic syndrome and breast cancer prognosis

In spite of its public health importance, our understanding of the mechanisms of breast carcinogenesis and progress is still evolving. The metabolic syndrome (MS) is a constellation of biochemical abnormalities including visceral adiposity, hyperglycemia, hyperinsulinemia, dyslipidemia and high blood pressure. The components of the MS have all been related to late-stage disease and even to a poor prognosis of breast cancer through multiple interacting mechanisms. In this review, we aim to present a summary of recent advances in the understanding of the contribution of the MS to breast cancer with the emphasis on the role of biomarkers of the MS in the prognosis of breast cancer.

Prospective study of endogenous circulating estradiol and risk of stroke in older women

OBJECTIVE

To test the hypothesis that circulating endogenous estradiol is associated with stroke risk in older postmenopausal women. Stroke incidence increases after menopause, when endogenous estrogen levels fall, yet exogenous estrogen increases strokes in older postmenopausal women. The relation between endogenous estrogen and stroke is unclear.

DESIGN

Prospective case-control study.

SETTING

Study of Osteoporotic Fractures.

PATIENTS OR OTHER PARTICIPANTS

Women at least age 65 years (99% follow-up) who were not taking estrogen at baseline.

MAIN OUTCOME MEASURES

Free estradiol index (FEI) was calculated by dividing total estradiol by sex hormone-binding globulin concentrations measured in banked baseline serum. Using logistic regression, odds ratios were estimated for a first-ever atherothrombotic stroke associated with endogenous FEI in 196 women who had a subsequent validated stroke (median follow-up, 8 years) compared with 219 randomly selected women who did not. Potential mediators were assessed in multivariable models.

RESULTS

The age-adjusted odds of atherothrombotic stroke increased with increasing FEI quartiles (P(trend) = .007). Women in the highest FEI quartile had an age-adjusted 2.31-fold (odds ratio, 2.31; 95% confidence interval, 1.28-4.17) higher odds than women in the lowest quartile. Women with greater central adiposity had a suggestively stronger association (P = .08). Atherogenic dyslipidemia, type 2 diabetes mellitus, and C-reactive protein level were potential mediators of this relation.

CONCLUSIONS

Endogenous estradiol level is an indicator of stroke risk in older postmenopausal women, especially in those with greater central adiposity. Potential mediators, including atherogenic dyslipidemia, insulin resistance, and inflammation, might underlie this association. Whether estradiol, independent of atherogenic adiposity, influences such mediators and stroke risk needs to be determined. Estrogen-altering agents might be harmful or beneficial depending on endogenous estradiol levels, especially in women with greater central adiposity.

Relative androgen excess during the menopausal transition predicts incident metabolic syndrome in midlife women: study of Women's Health Across the Nation

OBJECTIVE

During the menopausal transition, total testosterone (T) remains unchanged, whereas estrogen decreases markedly, creating a state of relative androgen excess. We hypothesized that change in the T-to-estradiol (T/E2) ratio during the menopausal transition would be associated with incident metabolic syndrome.

METHODS

The association between incident metabolic syndrome and total E2, total T, sex hormone-binding globulin, the free androgen index, baseline total T/E2 ratio, and the change of this ratio over time was evaluated in a multiethnic cohort of 1,862 premenopausal and perimenopausal women without diabetes enrolled in the Study of Women's Health Across the Nation.

RESULTS

New cases (n = 257) of metabolic syndrome were identified in the cohort during 6,296 woman-years of follow-up. The age-adjusted total T/E2 ratio increased by 10.1% per year during the 5 years of follow-up. Neither baseline nor change in E2 was associated with incident metabolic syndrome. Low sex hormone-biding globulin, free androgen index, and high total T at baseline all increased the risk of metabolic syndrome, but their change over time did not. Both baseline total T/E2 ratio (1.41; 95% CI = 1.17-1.69; P < 0.001) and its rate of change (1.24; 95% CI = 1.01-1.52; P < 0.04) were associated with increased incident metabolic syndrome independent of ethnicity.

CONCLUSIONS

The interaction between T and E2 during the menopausal transition, rather than the individual change of each over time, is a factor in the determination of risk of developing metabolic syndrome during the menopausal transition. This relationship was independent of ethnicity and other factors associated with prevalent metabolic syndrome before the onset of the menopausal transition.

Androgens in relationship to cardiovascular risk factors in the menopausal transition

OBJECTIVE

To establish the relationship between androgens and cardiovascular disease (CVD) risk factors in the menopausal transition.

METHODS

A total of 124 women were divided into four groups: 29 premenopausal (PreM), 35 women in the menopausal transition still menstruating (MTM), 29 women in the menopausal transition with 3-6 months amenorrhea (MTA), and 31 postmenopausal women (PostM). Levels of triglycerides, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, glucose and insulin were assayed in all samples and waist circumference was measured. In a subgroup of 83 women (19 PreM, 21 MTM, 28 MTA and 15 PostM), levels of total testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS) and estradiol were determined. The free androgen index, Homeostasis Model Assessment (HOMA) index, Quantitative Insulin Sensitivity Check Index (QUICKI) and McAuley index, estradiol/total testosterone and triglyceride/HDL cholesterol ratios were calculated.

RESULTS

Androstenedione was higher in MTA vs. PostM women (p < 0.05); DHEAS was higher in PreM women vs. the other three groups (p < 0.05). Sex hormone binding globulin (SHBG) in MTM women was higher than in MTA women (p < 0.05); the free androgen index was lower in MTM women than in MTA and PostM women. SHBG and the free androgen index showed negative and positive correlations, respectively with waist circumference, insulin resistance and lipids. In a multiple regression analysis, considering waist circumference, neither free androgen index nor SHBG showed significant differences between groups. The waist circumference correlated only with SHBG (p = 0.022) and correlations between SHBG and insulin resistance markers continued to be significant, but relationships between SHBG and lipoproteins and all correlations found with free androgen index were lost.

CONCLUSIONS

An increment in the androgenic milieu that correlates with abdominal fat, insulin resistance and atherogenic lipoproteins becomes evident after the menopausal transition and suggests that evaluation of cardiovascular disease risk in these women should include androgens, considering that abdominal obesity is one of the main determinants of the relationship between androgenic parameters and cardiovascular risk factors.

Menopause and the metabolic syndrome: the Study of Women's Health Across the Nation

BACKGROUND

Cross-sectional studies suggest that prevalence of the metabolic syndrome (MetS) increases from premenopause to postmenopause in women, independent of age. Little is known about why. We hypothesized that the incidence of the MetS increases with progression through menopause and that this increase is explained by the progressive androgenicity of the hormonal milieu.

METHODS

This longitudinal, 9-year study of 949 participants in the Study of Women's Health Across the Nation investigates the natural history of the menopausal transition. Participants of 5 ethnicities at 7 geographic sites were recruited when they were premenopausal or early perimenopausal and were eligible for this study if they (1) reached menopause during the study; (2) had never taken hormone therapy, and (3) did not have diabetes mellitus or the MetS at baseline. The primary outcome was the presence of MetS using National Cholesterol Education Program Adult Treatment Panel III criteria. Secondary outcomes were the components of the MetS.

RESULTS

By the final menstrual period, 13.7% of the women had new-onset MetS. Longitudinal analyses, centered at the final menstrual period, were adjusted for age at menopause, ethnicity, study site, marital status, education, body mass index, smoking, and aging. Odds of developing the MetS per year in perimenopause were 1.45 (95% confidence interval, 1.35-1.56); after menopause, 1.24 (95% confidence interval, 1.18-1.30). These odds were significantly different (P < .001). An increase in bioavailable testosterone or a decrease in sex hormone-binding globulin levels increased the odds.

CONCLUSIONS

As testosterone progressively dominates the hormonal milieu during the menopausal transition, the prevalence of MetS increases, independent of aging and other important covariates. This may be a pathway by which cardiovascular disease increases during menopause.

Hypercholesterolemia and prostate cancer: a hospital-based case-control study

OBJECTIVE

High levels of serum cholesterol have been proposed to increase the risk of prostate cancer but the epidemiologic evidence is limited.

METHODS

We conducted a hospital-based case-control study in Fargo, ND, USA, to examine the association between hypercholesterolemia and prostate cancer. Cases were men with incident, histologically confirmed prostate cancer. Controls were men without clinical cancer who were seen at the same hospital for an annual physical exam. Demographic and clinical data were abstracted from patients' medical charts.

RESULTS

From a patient population aged 50 to 74 years old, we obtained data on 312 White cases and 319 White controls. Hypercholesterolemia was defined as total cholesterol greater than 5.17 (mmol/l). Univariate logistic regression showed a significant association between hypercholesterolemia and prostate cancer (odds ratio (OR) = 1.64, 95% confidence interval (CI): 1.19-2.27). This association changed only slightly after adjustment for age, family history of prostate cancer, body mass index, type 2 diabetes, smoking, and multivitamin use (OR = 1.58, 95% CI: 1.11-2.24). A significant association was found between low HDL and prostate cancer (OR = 1.57, 95% CI: 1.04-2.36). High LDL was associated with a 60% increased risk for prostate cancer (OR = 1.60, 95% CI: 1.09-2.34). Compared to never smokers, current smokers had an 84% increased risk for prostate cancer (OR = 1.84, 95% CI: 1.09-3.13).

CONCLUSION

This study adds to recent evidence that hypercholesterolemia may increase the risk of prostate cancer in white men.

Associations of endogenous sex hormones and sex hormone-binding globulin with lipid profiles in aged Japanese men and women

BACKGROUND

The associations of endogenous estrogen with lipid profiles and insulin resistance were conflicting in both men and women. We determined the associations of serum estradiol level and free estradiol index (FEI) with lipid profiles and insulin resistance in aged Japanese men and women.

METHODS

One hundred seventy-four men and 208 postmenopausal women aged from 50 to 85 y were included in this study. Lipid profiles, fasting glucose and insulin as well as estradiol, testosterone, dehydroepiandrosterone-sulfate (DHEA-S) and sex hormone-binding globulin (SHBG) in serum were measured.

RESULTS

Serum estradiol concentration in men showed a significant and negative correlation with high density lipoprotein-cholesterol (HDL-C) concentration and a significant and positive correlation with triglyceride (TG) after adjustment for age and body mass index (BMI). In addition, estradiol level was positively correlated with insulin and HOMA index. In women, serum levels of estradiol and testosterone were not correlated with lipid profiles and insulin resistance. SHBG concentration was negatively correlated with TG after adjustment for age and BMI in women.

CONCLUSION

Endogenous estradiol level is associated with unfavorable lipid profiles and insulin resistance in aged men. In aged women, SHBG level is associated with favorable lipid profiles.

Sex steroids and metabolic parameter levels in a seasonal breeding fish (Sparus aurata L.)

The gilthead seabream is a protandrous hermaphrodite seasonal breeding teleost with a bisexual gonad that offers an interesting model for studying the two first reproductive cycles (RCs), in which the specimens develops as males. During the first RC (RC1), 11-ketotestosterone (11-KT) and testosterone (T), the main androgens in fish, play different and specific roles in the testicular physiology as they peak at different stages of RC1. Moreover, the profiles of T serum levels during the second RC (RC2) demonstrated that this androgen is not essential in the testicular regression process that occurs during this cycle. However, changes in serum levels suggest that 17beta-estradiol (E2) orchestrates this process during both RCs. Moreover, the E2 serum levels recorded during RC2 indicate that there is a threshold level that determines the initiation of ovarian development during this cycle without promoting complete feminization. We analysed triglyceride, protein, glucose and lactate serum levels in order to establish a relationship between the mobilization and transfer of nutrients, the hormonal changes that take place during the RC and body composition, finding that in vivo serum levels of metabolites change significantly throughout the first two RCs, although the physiological relevance of such changes is still unknown. Triglyceride levels seem to be affected by the beginning of ovary development during RC2 but not by testicular recrudescence during RC1. Moreover, glucose and lactate might be important sources of energy during the resting and testicular involution stages.

Body size, hormone therapy and risk of breast cancer in Asian-American women

Historically, breast cancer rates have been low in Asia but rates have increased substantially in Asian-Americans for reasons that are not well understood. The authors conducted a population-based case-control study of breast cancer in Los Angeles County, which included 1,277 (450 Chinese, 352 Japanese, 475 Filipinos) women with incident, histologically confirmed breast cancer and 1,160 control subjects (486 Chinese, 311 Japanese, 363 Filipinos). A detailed in-person interview was conducted, which included questions on menopausal hormone therapy (HT) use, height, weight in each decade of life and reproductive factors. Breast cancer risk increased with increasing recent weight in postmenopausal women (p trend = 0.015). There was a significant 16% (95% CI = 2-35%) increase in risk per 10 kg of body weight in postmenopausal women. In both premenopausal and postmenopausal women, risk increased with increasing waist to hip ratio; this remained statistically significant after adjustment for recent weight in all subjects combined (p trend = 0.042). The increased risk associated with high recent weight in postmenopausal women was more apparent for women with high waist to hip ratio (p trend = 0.013). Use of HT was a significant risk factor; risk increased 26% per 5 years of current use of estrogen and progestin therapy (p trend = 0.017). The increased risk associated with high body weight was observed irrespective of HT use. Use of HT and high body size might have contributed to the rapid increase of breast cancer in Asian-Americans.

Sex-hormone-binding globulin and the free androgen index are related to cardiovascular risk factors in multiethnic premenopausal and perimenopausal women enrolled in the Study of Women Across the Nation (SWAN)

BACKGROUND

Recent clinical trials have shifted attention away from estrogens and toward androgens and sex hormone-binding globulin (SHBG) as potential mediators of increasing cardiovascular (CV) risk in women at midlife.

METHODS AND RESULTS

The correlation between reproductive hormones and CV risk factors was evaluated in a multiethnic (white, black, Hispanic, Chinese, and Japanese) sample of 3297 premenopausal and perimenopausal women. Testosterone and estradiol (E2) were evaluated along with SHBG and the free androgen index (FAI), the amount of testosterone not bound by SHBG. Low SHBG and high FAI were strongly and consistently related to elevated CV risk factors (higher insulin, glucose, and hemostatic and inflammatory markers and adverse lipids) even after controlling for body mass index (P<0.001 for all). Low levels of E2 were associated with elevated CV risk factors to a lesser degree. These observations were consistent across the 5 ethnic groups. Compared with whites, blacks had higher levels of SHBG and lower levels of FAI, and Chinese had lower levels of SHBG and higher levels of FAI.

CONCLUSIONS

Low SHBG and high FAI are strongly associated with CV risk factors in racially diverse women, and thus, androgens likely play a role in the CV risk profile of perimenopausal women.

Differential regulation of insulin resistance and hypertension by sex hormones in fructose-fed male rats

Differences in gender are in part responsible for the development of insulin resistance (IR) and associated hypertension. Currently, it is unclear whether these differences are dictated by gender itself or by the relative changes in plasma estrogen and/or testosterone. We investigated the interrelationships between testosterone and estrogen in the progression of IR and hypertension in vivo in intact and gonadectomized fructose-fed male rats. Treatment with estrogen significantly reduced the testosterone levels in both normal chow-fed and fructose-fed rats. Interestingly, fructose feeding induced a relative increase in estradiol levels, which did not affect IR in both intact and gonadectomized fructose-fed rats. However, increasing the estrogen levels improved insulin sensitivity in both intact and gonadectomized fructose-fed rats. In intact males, fructose feeding increased the blood pressure (140 +/- 2 mmHg), which was prevented by estrogen treatment. However, the blood pressure in the fructose-fed estrogen rats (125 +/- 1 mmHg) was significantly higher than that of normal chow-fed (113 +/- 1 mmHg) and fructose-fed gonadectomized rats. Estrogen treatment did not affect the blood pressure in gonadectomized fructose-fed rats (105 +/- 2 mmHg). These data suggest the existence of a threshold value for estrogen below which insulin sensitivity is unaffected. The development of hypertension in this model is dictated solely by the presence or absence of testosterone. In summary, the development of IR and hypertension is governed not by gender per se but by the interactions of specific sex hormones such as estrogen and testosterone.

The association of androgenic sex steroids with serum lipid levels in postmenopausal women

BACKGROUND

The aim of the present study was to examine the correlations between androgenic sex steroids and serum lipid levels in postmenopausal women. Methods. The study group included 72 postmenopausal women. Correlation analysis between serum hormone [dehydroepiandrosterone sulfate (DHEA-S), androstenedione, free testosterone and sex hormone binding globulin (SHBG)] and lipid [total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), lipoprotein (a) [Lp (a)], apolipoprotein A-1 (apo A-1) and apolipoprotein B (apo B)] levels was performed.

RESULTS

DHEA-S was found to be positively correlated with HDL-C (r = 0.231, p = 0.049) and negatively correlated with Lp (a) (r = - 0.355, p = 0.002). These correlations were statistically significant even after adjustment for age and body mass index (BMI) (r = 0.332, p = 0.005 and r = -0.362, p = 0.002, respectively). SHBG was positively correlated with HDL-C (r = 0.352, p = 0.002). There was a significant but weaker correlation between SHBG and HDL-C levels after controlling for age and BMI (r = 0.243, p = 0.041). No other correlations were found between sex hormone and lipid levels.

CONCLUSION

DHEA-S was found to be associated with a less atherogenic lipid profile in postmenopausal women.

Association between birth weight and serum lipid concentration in premenopausal Japanese women

BACKGROUND: The relationships between birth weight and serum lipid concentrations in premenopausal Japanese women were not well identified and also diet and serum hormone status in these women would be considered.

METHODS: A total of 59 premenopausal Japanese women completed a self-administered questionnaire including basic demographic information, disease histories, and menstrual and reproductive histories. They were asked to obtain information on birth weight recorded in mother-and-baby notebook issued by municipality from their mother. Diet was assessed by daily diet records from day 2 through day 10 of the menstrual cycle. Blood sample was collected on day 11 of the cycle to measure serum lipid and hormone concentrations (total and high-density lipoprotein [HDL] cholesterols, triglyceride, estrone, estradiol, and sex hormone-binding globulin).

RESULTS: Birth weight was significantly correlated with HDL cholesterol (r=0.32, p=0.03), but no with total cholesterol and triglyceride after controlling for age. Neither estrogen nor sex hormone-binding globulin was significantly correlated with serum lipid concentrations after controlling for age and the number of days prior to the next menses. The correlation between birth weight and HDL cholesterol was not affected after additional adjustment for serum estrogen and intakes of protein, calcium, and iron.

CONCLUSION: These data suggest that intrauterine growth may be associated with lipid profile.

Sex steroids and plasma lipoprotein levels in healthy women: The importance of androgens in the estrogen-deficient state

The role of endogenous estrogens and androgens and their potential interaction in atherosclerosis is not well understood. Therefore, we investigated the effects of natural menopause and endogenous sex steroids on triglycerides (TG), a major risk factor for cardiovascular disease in women. Fasting lipid and lipoprotein concentrations, postheparin lipase activities, kinetic indicators of triglyceride lipolysis, and various hormone levels, including dehydroepiandrostenedione-sulfate (DHEA-S), (bioavailable) testosterone, and androstenedione, were determined in 18 premenopausal and 18 postmenopausal women, matched for age and body composition. Fasting plasma TG were 0.69 +/- 0.29 mmol/L in postmenopausal women and 0.73 +/- 0.33 mmol/L in premenopausal women (difference not significant [NS]). Approximately 30% of all plasma TG were present in the very-low-density lipoproteins (VLDLs) in both groups. No differences were found between groups in plasma lipolytic potential of TG-rich lipoproteins. Univariate analysis revealed that VLDL-TG concentrations were strongly related to insulin (r = 0.84, P =.0001) and androstenedione (r = 0.65, P =.004) in postmenopausal women. Multivariate analysis of potential determinants of VLDL-TG showed that insulin, androstenedione, and bioavailable testosterone were independent variables, explaining 87% of the variability (r = 0.93, P =.0001) in postmenopausal women. In contrast, in premenopausal women, the only identified predictor of fasting VLDL-TG in univariate and multivariate analysis was insulin (r = 0.72, P =.001). Our results show that the association of androgens with TG varied depending on androgen concentrations, the relative androgenic potential, and most importantly on hormonal milieu. Endogenous androgens were only related to plasma VLDL-TG in the estrogen-deficient state.

Excess accumulation of body fat is related to dyslipidemia in normal-weight subjects

OBJECTIVE

To assess the relationship of fat mass (FM) and its distribution to hypertension and dyslipidemia in normal-weight Japanese individuals.

DESIGN

Cross-sectional study.

SUBJECTS

Apparently healthy Japanese subjects with a body mass index (BMI) between 20 and 23.5 kg/m(2) (265 males and 741 females, age 21-69 y).

MEASUREMENTS

BMI, waist circumference (WC), waist-hip ratio (WHR), systolic and diastolic blood pressure, serum levels of total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C) and triglyceride (TG) were measured. Low-density lipoprotein-cholesterol (LDL-C) was calculated by the Friedewald formula. Percentage fat mass (%FM) and trunk fat mass-leg fat mass ratio (FM(trunk)/FM(legs)) were obtained by dual-energy X-ray absorptiometry.

RESULTS

WC, WHR, %FM and FM(trunk)/FM(legs) were significantly correlated with TC, LDL-C, HDL-C and TG with the tendency of FM(trunk)/FM(legs) to show the strongest correlations. For %FM and FM(trunk)/FM(legs) in both sexes, odds ratios (ORs) of the third tertiles with respect to the first tertiles increased for LDL-C elevation, TG elevation and dyslipidemia. In males, ORs of the third tertiles of WC were significantly high for LDL-C elevation and dyslipidemia whereas those of WHR were high for TG elevation and dyslipidemia. ORs of the third tertiles of WC and WHR were significantly high for TG elevation in females. BMI was not associated with the risk of abnormal lipid levels. ORs for hypertension showed significant increases in none of the variables of obesity.

CONCLUSIONS

Excess accumulation of FM, especially to the upper body, was related to dyslipidemia in normal-weight subjects. Simple anthropometric variables, WC and WHR, may be useful for screening and management of dyslipidemia in these subjects.

The androgenic sex hormone profile is an essential feature of metabolic syndrome in premenopausal women: a controlled community-based study

OBJECTIVE

To evaluate sex hormones in premenopausal white women with metabolic syndrome (MBS).

DESIGN

Cross-sectional controlled community-based study.

SETTING

Pieksämäki District Health Center, Pieksämäki, Finland.

PATIENT(S)

Five hundred forty-three women, aged 34 to 54 years, were screened according to National Cholesterol Education Program criteria: waist >88 cm, hypertension >/=130/>/=85 mm Hg, hypertriglyceridemia >/=1.7 mmol/L, high-density lipoprotein (HDL)-cholesterol <1.3 mmol/L, and fasting glucose >/=6.1 mmol/L. Sixty-three women fulfilled at least three of the above-mentioned criteria and were enrolled. Eighty-eight age-matched women without MBS served as controls.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURES

Sex steroid levels in relation to insulin sensitivity and body composition.

RESULT(S)

A markedly lower insulin sensitivity index and higher free androgen index were detected in the women with MBS than in the controls. Abdominal obesity and increased diastolic blood pressure were significantly associated with high free androgen index in multiple regression analysis.

CONCLUSION(S)

A hyperandrogenic hormone profile appeared to be a typical feature of premenopausal female MBS even without polycystic ovary syndrome (PCOS).

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.

The estrogen antagonist EM-652 and dehydroepiandrosterone prevent diet- and ovariectomy-induced obesity

OBJECTIVE

EM-652 is a pure antiestrogen in human breast and uterine cancer cells that also reduces bone loss and plasma lipid levels in the rat. This study aimed to assess the ability of EM-652, alone or with dehydroepiandrosterone (DHEA), to prevent obesity and related metabolic abnormalities induced by an obesity-promoting diet and ovariectomy.

RESEARCH METHODS AND PROCEDURES

Female rats were fed a high-sucrose, high-fat (HSHF) diet, were left intact or ovariectomized (OVX), and were treated with EM-652, DHEA, or both for 20 days. Variables of energy balance and determinants of lipid metabolism and insulin sensitivity were assessed.

RESULTS

The HSHF diet (vs. chow) and OVX both increased energy intake and gain, as well as energetic efficiency. Both EM-652 and DHEA prevented diet- and OVX-induced energy gain mainly by decreasing fat deposition, without being additive. The modest EM-652-induced increase in liver triglycerides of intact rats was prevented by its combination with DHEA. EM-652, but not DHEA, decreased cholesterolemia. The HSHF diet and OVX reduced insulin sensitivity, an effect that was attenuated by EM-652 and abrogated by DHEA and EM-652+DHEA. Treatment with EM-652, DHEA, or their combination abolished the diet- and OVX-induced increase in adipose lipoprotein lipase activity that accompanied fat gain.

DISCUSSION

EM-652 is an effective agent to prevent diet- and OVX-induced obesity and its associated cardiovascular risk factors such as insulin resistance. The addition of DHEA prevents hepatic lipid accumulation and further ameliorates insulin sensitivity. The beneficial metabolic effects of such combined steroid therapy may, therefore, eventually prove to be clinically relevant.

Female rats are protected against fructose-induced changes in metabolism and blood pressure

The objective of this study was to determine whether the effects of a fructose diet, which causes hyperinsulinemia, insulin resistance, and hypertension in male rats, are dependent on sex. Blood pressure was measured via the tail-cuff method, and oral glucose tolerance tests were performed to assess insulin sensitivity. Blood pressure in female rats did not differ between fructose-fed and control rats at any time point (126 +/- 5 and 125 +/- 3 mmHg at week 9 for fructose-fed and control rats, respectively) nor was there a difference in any metabolic parameter measured. Furthermore, the vascular insulin resistance that is present in male fructose-fed rats was not observed. After ovariectomy, fructose caused a significant change in systolic blood pressure from baseline compared with fructose-fed ovary-intact rats (change of 21 +/- 5 vs. -2 +/- 4 mmHg). The results demonstrate that females do not develop hypertension or hyperinsulinemia upon fructose feeding except after ovariectomy, suggesting that female sex hormones may confer protection against the effects of a fructose diet.

Interrelationship between serum lipid profile, serum hormones and other components of the metabolic syndrome

The aim of the present study was to investigate the association between the serum lipid profile and components of the metabolic syndrome, such as central obesity (anthropometric, computed tomography and fat cell data), insulin, sex-hormone-binding-globulin (SHBG) and different hormones influencing this important syndrome, e.g. sex steroids, leptin and tumor necrosis factor-alpha (TNF-alpha). The sample consisted of 85 obese patients (30 men and 55 women) who had undergone abdominal surgery. Fasting serum lipids were analysed, as well as anthropometric and computed tomography data, perivisceral and subcutaneous fat cell size and serum glucose and hormones. Abdominal fat revealed itself as an important correlator of the adverse changes in plasma lipoprotein levels, the waist-to-hip-ratio and waist-to-thigh-ratio being the best morphological correlators in men and women, respectively. Intra-abdominal fat (VA) correlated significantly and positively to perivisceral fat cell size in women, while no correlation was found between subcutaneous fat accumulation (SA) and adipocyte size in both genders. Perivisceral fat cell size showed the greatest number of correlations with the adverse plasma lipid profile compared to that in the subcutaneous depot. SHBG and sex steroids showed a negative correlation with serum lipids considered a cardiovascular risk. In contrast, TNF-alpha and C-peptide were inversely correlated with potential protector lipids. In conclusion, abdominal obesity, adipocyte hypertrophy from visceral fat, serum TNF-alpha and C-peptide seem to be the best correlators of the lipoprotein disturbance characteristic of the metabolic syndrome, whereas SHBG and sex steroids could play a protective role regarding the lipid profile associated to this syndrome.