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Sex Hormone-binding Globulin (sex + hormone-binding_globulin)

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Medical Sciences	83%

Terms modified by Sex Hormone-binding Globulin

sex hormone-binding globulin level

Selected Abstracts

Sex hormone-binding globulin and androgen levels in immigrant and British-born premenopausal British Pakistani women: Evidence of early life influences?

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 6 2006
Tessa M. Pollard
In women, raised insulin levels are associated with low sex hormone-binding globulin (SHBG) and high androgen levels, which are in turn linked to infertility. Since insulin resistance and hyperinsulinemia are major health problems for South Asians living in Western countries, we predicted that British Pakistani women would have low SHBG and raised androgen levels compared to European women. Given low birth weights in Pakistan, and known links between low birth weight and insulin resistance in later life, we also predicted that immigrant women born in Pakistan would have lower levels of SHBG and higher levels of androgens than British-born British Pakistani women. We assessed SHBG, testosterone, and the free androgen index (FAI) from a single serum sample taken on days 9,11 of the menstrual cycle from 20,40-year-old women living in the UK: 30 immigrants from Pakistan, 30 British-born British Pakistani women, and 25 British-born women of European origin. Age-adjusted analyses showed no significant differences in SHBG, testosterone, or FAI between British-born Pakistani and European-origin women. However, immigrant British Pakistani women had a significantly higher FAI than British-born British Pakistani women. Adjustment for body mass index, waist-to-hip ratio, and smoking status did not affect these results, but further adjustment for height, a marker of early environment, reduced the P -value for the difference in FAI between immigrant and British-born British Pakistani women to below significance. It is possible that the poorer early environment of immigrant British Pakistani women was at least partially responsible for their relatively high levels of free androgens. Am. J. Hum. Biol. 18:741,747, 2006. © 2006 Wiley-Liss, Inc. [source]

5,-Reductase type 2 gene variant associations with prostate cancer risk, circulating hormone levels and androgenetic alopecia

INTERNATIONAL JOURNAL OF CANCER, Issue 4 2007
Vanessa M. Hayes
Abstract Controversy exists over the significance of associations between the SRD5A2 (5,-reductase type 2) polymorphisms, A49T and V89L, and risk of prostate cancer. These potentially functional polymorphisms may alter life-long exposure to androgens with subsequent effects on male health and aging. The aim of this study was to examine the association of these variants with prostate cancer risk, plasma hormone levels and androgenetic alopecia. Subjects include 827 cases and 736 controls from an Australian population-based case,control study of prostate cancer. Information on prostate cancer risk factors and patterns of balding were collected. Plasma levels of testosterone, 3,-diol glucuronide (3,-diolG), dehydroepiandrosterone sulfate, androstenedione, sex hormone-binding globulin and estradiol were measured for controls. No associations with the V89L polymorphism were found. Carriers of the rarer A49T A allele were at a 60% higher risk of prostate cancer (OR = 1.60; 95% CI 1.09,2.36; p = 0.02) and 50% lower risk of vertex and frontal balding (p = 0.03) compared with men homozygous for the more common G allele. Although we found little evidence of association between this variant and plasma levels of 5 measured androgens, circulating 3,-diolG levels were 34% lower in A49T A allele carriers (p < 0.0001). Our study provides evidence that the SRD5A2 A49T A variant is associated with an increased risk of prostate cancer, lower levels of circulating 3,-diolG and decreased risk of baldness. These findings raise important questions with respect to previous assumptions concerning hormonal influences on prostate cancer risk in ageing males. © 2006 Wiley-Liss, Inc. [source]

Measurement-specific bioavailable testosterone using concanavalin A precipitation: Comparison of calculated and assayed bioavailable testosterone

INTERNATIONAL JOURNAL OF UROLOGY, Issue 11 2009
Kenrou Yamamoto
Objective: To assess the value of calculated bioavailable testosterone (cBT) and assayed BT (aBT) for the diagnosis of late-onset hypogonadism (LOH) in middle-aged and elderly subjects. Methods: In order to assay serum BT, sex hormone-binding globulin was precipitated with concanavalin-A and then testosterone was measured using liquid chromatography-tandem mass spectrometry. To validate the non-sex-hormone-binding-globulin-bound testosterone, gel filtration chromatography and concanavalin-A sepharose were used. Following this validation, the usefulness between aBT and cBT was evaluated in clinical samples. Results: Eighty-eight healthy male volunteers (mean age 65.6 years, range: 50,86) were recruited for this study. A significant correlation was found between cBT and aBT (R2 = 0.53, P < 0.01). Mean value ratio (cBT/aBT) was 2.48. Both cBT (R2 = 0.122) and aBT (R2 = 0.251) decreased with age. Variations in aBT were less marked than those for cBT, suggesting that aBT can be used to determine age-related reduced testosterone levels. Conclusion: aBT levels are more reliable than cBT levels for the diagnosis of LOH in middle-aged and elderly subjects. [source]

Hormonal and Biochemical Parameters and Osteoporotic Fractures in Elderly Men

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2000
Dr. Jacqueline R. Center
Abstract Low testosterone has been associated with hip fracture in men in some studies. However, data on other hormonal parameters and fracture outcome in men is minimal. This study examined the association between free testosterone (free T) estradiol (E2), sex hormone-binding globulin (SHBG), 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), insulin-like growth factor I (IGF-I), and fracture in 437 elderly community-dwelling men. Age, height, weight, quadriceps strength, femoral neck bone mineral density (FN BMD), and fracture data (1989,1997) also were obtained. Fractures were classified as major (hip, pelvis, proximal tibia, multiple rib, vertebral, and proximal humerus) or minor (remaining distal upper and lower limb fractures). Fifty-four subjects had a fracture (24 major and 30 minor). There was no association between minor fractures and any hormonal parameter. Risk of major fracture was increased 2-fold for each SD increase in age, decrease in weight and height, and increase in SHBG, and risk of major fracture was increased 3-fold for each SD decrease in quadriceps strength, FN BMD, and 25(OH)D (univariate logistic regression). Independent predictors of major fracture were FN BMD, 2.7 (1.5,4.7; odds ratio [OR]) and 95% confidence interval [CI]); 25(OH)D, 2.8 (1.5,5.3); and SHBG, 1.7 (1.2,2.4). An abnormal value for three factors resulted in a 30-fold increase in risk but only affected 2% of the population. It is not immediately apparent how 25(OH)D and SHBG, largely independently of BMD, may contribute to fracture risk. They may be markers for biological age or health status not measured by methods that are more traditional and as such may be useful in identifying those at high risk of fracture. [source]

Impact of diet and adiposity on circulating levels of sex hormone-binding globulin and androgens

NUTRITION REVIEWS, Issue 9 2008
Anne-Sophie Morisset
This review summarizes studies on the effect of various diets on circulating androgen levels and sex hormone-binding globulin (SHBG). Reduced caloric intake leading to significant weight loss increases SHBG levels regardless of diet composition, particularly in women. Cross-sectional studies show that dietary composition is generally not associated with SHBG levels independent of obesity level. No clear conclusion can be reached regarding the effect of various eating habits or dietary composition on circulating androgens. The evidence indicates that dietary effects on circulating SHBG, and possibly androgens, can be expected if body weight or fatness and/or insulin homeostasis are modulated. [source]

Sex hormone-binding globulin and androgen levels in immigrant and British-born premenopausal British Pakistani women: Evidence of early life influences?

ORIGINAL RESEARCH,ENDOCRINOLOGY: Evaluation of the Effects of Cigarette Smoking on Testosterone Levels in Adult Men

THE JOURNAL OF SEXUAL MEDICINE, Issue 6 2009
Graziele Halmenschlager MS
ABSTRACT Introduction., Cigarette smoking is highly prevalent among men. Many studies have evaluated the effect of cigarette smoking on levels of male reproductive hormones; however, the findings still remain controversial. Aim., To evaluate the influence of cigarette smoking on serum levels of total testosterone (TT), free testosterone (FT), bioavailable testosterone (BT), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Methods., A total of 255 men (90 smokers and 165 nonsmokers), aged 30 to 70 years, were investigated. Weight and height were obtained and body mass index (BMI) was calculated. Also, waist circumference and hip circumference were measured and waist-to-hip ratio was obtained. Fasting blood samples were drawn for determination of plasmatic glucose levels and serum levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c), triglycerides, albumin, prolactin, TT, SHBG, LH, and FSH. The values of low-density lipoprotein cholesterol (LDL-c) were determined by Friedwald equation and the values of FT and BT were calculated from TT, SHBG, and albumin. Statistical significance was set at P , 0.05. Main Outcome Measures., The influence of smoking on levels of TT, FT, and BT. Results., No significant difference was observed in the mean values of TT (P = 0.580), FT (P = 0.869), BT (P = 0.933), SHBG (P = 0.279), LH (P = 0.573), and FSH (P = 0.693) in the different levels of pack-years when compared to nonsmokers. Moreover, after multivariate logistic regression, no association between increased pack-years of smoking and increased odds ratio for occurrence of low hormones and SHBG levels was observed. Conclusion., In this study, smokers and nonsmokers had similar mean values of androgens, gonadotropins and SHBG. However, it is necessary to standardize pack-years of smoking in order to elucidate the influence of cigarette smoking on sex hormone levels, as well as to minimize differences among studies and to confirm our results. Halmenschlager G, Rossetto S, Lara GM, and Rhoden EL. Evaluation of the effects of cigarette smoking on testosterone levels in adult men. J Sex Med 2009;6:1763,1772. [source]

ORIGINAL RESEARCH,WOMEN'S SEXUAL HEALTH: Comparison of Androgens in Women with Hypoactive Sexual Desire Disorder: Those on Combined Oral Contraceptives (COCs) vs.

THE JOURNAL OF SEXUAL MEDICINE, Issue 5 2006
Those not on COCs
ABSTRACT Introduction., Approximately one out of four sexually active women in the United States uses some form of hormonal contraceptive method because they provide the most effective reversible method of birth control available. However, little attention has been paid to possible adverse effects of combined oral contraceptives (COCs) on sexual functioning. Aims., The aim of this study was to examine the potential effects of COCs on women with hypoactive sexual desire disorder (HSDD). It was hypothesized that female patients with generalized, acquired HSDD on COCs have lower androgen levels than those not on COCs. Methods., The patients were healthy premenopausal women with HSDD, aged 22,50 years. Subjects had a history of adequate sexual desire, interest, and functioning. Participants were required to be in a stable, monogamous, heterosexual relationship and were screened for any medication or medical or psychiatric disorders that impact desire. The patients met operational criteria for global, acquired HSDD. The 106 patients were divided into two groups: those on COCs (N = 43) and those not on COCs (N = 63). A two-tailed t -test comparison was made between the two groups comparing free and total testosterone and sex hormone-binding globulin (SHBG). Main Outcome Measures., The main outcome measures are the differences between the two groups comparing free testosterone, total testosterone, and SHBG. Results., These patients with HSDD on COCs had significantly lower free and total testosterone levels compared with those who were not on COCs. The SHBG was significantly higher in the group on COCs compared with those who were not on COCs. Conclusion., The result of this study suggests that COCs in premenopausal women with HSDD are associated with lower androgen levels than those not on COCs. Further research is required to determine if low androgen levels secondary to COCs impact female sexual desire. Warnock JK, Clayton A, Croft H, Segraves R, and Biggs FC. Comparison of androgens in women with hypoactive sexual desire disorder: Those on combined oral contraceptives (COCs) vs. those not on COCs. J Sex Med 2006;3:878,882. [source]

Testosterone and obesity in men under the age of 40 years

ANDROLOGIA, Issue 2 2009
N. P. Goncharov
Summary The study assessed anthropometric and laboratory variables, in particular testosterone (T) in a group of obese men of <40 years. Of 60 men with a body mass index (BMI) of >27 kg m,2, 34 met the criteria of the metabolic syndrome (MS). Twenty men <40 years (with a BMI <25 kg m,2) were studied for comparison. It was found that with increasing BMI, levels of serum leptin, triglycerides, insulin, the ratio high-density lipoprotein (HDL) cholesterol/low-density liporotein (LDL) cholesterol, the waist circumference (WC), the area of visceral fat and systolic/diastolic blood pressure were higher, whereas insulin sensitivity (HOMA) and serum T were lower. Obesity (BMI 27,30 kg m,2) was associated with a decline in plasma T, but not with a decline in plasma sex hormone-binding globulin (SHBG). The latter was the case in more severe obesity (>30 kg m,2) qualifying as MS. In patients with MS, 58% variability of T levels could be predicted by combination of independent factors , SHBG, ratio LDL/HDL, insulin and leptin. On the other hand, in men with MS, 80% variance of concentrations of SHBG were predicted by triglycerides, HDL, glucose, leptin and surface of visceral adipose tissue. It is concluded that plasma T is significantly correlated with a number of features of the MS and, therefore, plasma T could serve as a marker of the MS. [source]

A pilot dose-escalation study of the effects of nordihydroguareacetic acid on hormone and prostate specific antigen levels in patients with relapsed prostate cancer

BJU INTERNATIONAL, Issue 4 2008
Charles J. Ryan
OBJECTIVE To assess the tolerability of the effects of nordihydroguareacetic acid (NDGA) and its effect on prostate-specific antigen (PSA) kinetics in patients with relapsed prostate cancer, as among the many biological effects of NDGA is the inhibition of the insulin-like growth factor 1 receptor (IGF-1R) tyrosine kinase. PATIENTS AND METHODS Eligible patients were those with an increasing PSA level after definitive local therapy, in either the non-castrate (androgen-dependent prostate cancer, ADPC) or the castrate state (castration-resistant prostate cancer, CRPC) with no evidence of metastatic disease by bone scan or computed tomography of the abdomen or pelvis. Treatment consisted of continuous oral daily dosing according to a planned dose escalation of 750, 1250, 1750, 2250 and 2500 mg of NDGA. PSA levels were measured every 28 days. Serial levels of testosterone, dihydrotestosterone, oestradiol and sex hormone-binding globulin were measured at baseline and monthly while on study therapy. RESULTS Fifteen patients were enrolled, including 11 with ADPC and four with CRPC. There were asymptomatic increases in transaminase in six patients, two of which were grade 3, all occurring at ,3 months. The increases in transaminase resolved after stopping NDGA but recurred with repeated dosing. Doses of NDGA up to 2500 mg/day caused no other toxicities. A median (range) of 5.5 (1,13) cycles were delivered. Of the 11 patients with ADPC, one had a decline in PSA level of >50% of the baseline value and one a decline of <50%. Three patients with ADPC had a greater than three-fold increase in PSA doubling time while on therapy, one from 11 to 46 months (750 mg), one from 9.5 to 49.5 months (1750 mg), and one from 5.9 to 46.2 months (2500 mg). There were no reductions in PSA level in patients with CRPC. There were no significant effects on levels of testosterone, dihydrotestosterone, oestradiol or sex hormone-binding globulin. CONCLUSIONS Continuous daily dosing with NDGA is reasonably well tolerated but is associated with transaminitis in some patients, that occurs after several months on therapy. There were apparent effects on the rate of increase in PSA. Further study is required to determine the optimum pharmacokinetics and antitumour effects of this therapy. [source]

Body mass index, waist circumference and waist to hip ratio and change in sex steroid hormones: the Massachusetts Male Ageing Study

CLINICAL ENDOCRINOLOGY, Issue 1 2006
Carol A. Derby
Summary Objective, Cross-sectional data suggest that obesity, particularly central obesity, may be associated with decreased production of sex steroid hormones in men. However, longitudinal hormone data on men in relation to obesity status are limited. Previous studies have not consistently demonstrated whether sex steroids are associated specifically to body mass index or to measures of central obesity. Our objective was to examine the relation of obesity (body mass index > 30 kg/m2), and of central obesity (waist circumference > 100 cm or waist to hip ratio > 0·95) to longitudinal change in sex steroid hormones in men. Design, Prospective follow-up of a population-based sample of men in Boston. Patients, Nine hundred forty-two (942) men in the Massachusetts Male Ageing Study with complete anthropometry and hormone data at baseline (1987,1989, ages 40,70) and follow-up (1995,1997). Measurements, Free and total testosterone (FT and TT), dehydroepiandrosterone sulphate (DHEAS), and sex hormone-binding globulin (SHBG) were assessed using standardized methods. Health behaviours and medical history were obtained by structured interview. Repeated measures regression was used to describe trends in steroid hormones and SHBG in relation to obesity status, adjusting for age, smoking, alcohol, comorbidities, and physical activity. Results, Obesity was associated with decreased levels of total and free testosterone, and of SHBG at follow-up relative to baseline. For any given baseline concentration of TT, FT or SHBG, follow-up levels were lowest among men who remained obese or who became obese during follow-up. This was true for all three indices of obesity. Central adiposity was associated with lower DHEAS levels at follow-up, while elevated body mass index was not. Conclusions, Obesity may predict greater decline in testosterone and SHBG levels with age. Central adiposity may be a more important predictor of decline in DHEAS than is body mass index. [source]