Mean Sex Hormone-binding Globulin Research Articles

Associations of body composition measures with circulating insulin-like growth factor-I, testosterone, and sex hormone-binding globulin concentrations in 16,000 men.

Adiposity is positively associated with risk of some cancer sites and other health conditions in men; however, it is unclear if endogenous hormones play a role in these associations. We examined how body composition, measured from magnetic resonance imaging (MRI) and common measures of adiposity (e.g., body mass index (BMI)), are related to hormone concentrations in men from the UK Biobank study. Up to 16,237 men with available body composition data (including visceral, subcutaneous, and liver fat, muscle fat infiltration (MFI), lean tissue, and common adiposity measures) and serum hormone measurements (insulin-like growth factor-I (IGF-I), total testosterone, sex hormone-binding globulin (SHBG), and calculated free testosterone) were included. Multivariable-adjusted linear regression models were used to determine the geometric mean hormone and SHBG concentrations across categories of each exposure. Common measurements of adiposity were highly correlated with MRI measures of central and total adiposity (r = 0.76-0.91), although correlations with ectopic fat (liver fat and MFI) were lower (r = 0.43-0.54). Most adiposity measurements showed an inverse U- or J-shaped association with circulating IGF-I and free testosterone; however, MFI was linearly inversely associated, and lean tissue volume was positively associated with both IGF-I and free testosterone concentrations. All body composition measures were inversely associated with total testosterone and SHBG concentrations (relative geometric mean difference between Q5 vs. Q1: 20-30%). Our results show that common adiposity and most MRI measures of adiposity relate similarly to serum hormone concentrations; however, associations with ectopic fat (particularly MFI) and lean tissue were different.

Association Between 25-hydroxyvitamin D Levels and Testosterone in Healthy, Non-Obese, Young Adult, Filipino Men.

This study seeks to determine the association between vitamin D and testosterone in healthy, adult Filipino males. This cross-sectional study included 110 healthy, non-obese, male volunteers aged 21-40. History and physical exam were taken, and blood was drawn for vitamin D, total testosterone (TT), sex hormone binding globulin (SHBG), albumin, insulin, fasting plasma glucose, and total cholesterol. Free testosterone (FT) was calculated. Vitamin D data were classified by status and TT, FT, and SHBG levels compared using the Kruskal-Wallis test. The associations of vitamin D levels with TT, FT, and SHBG were explored using multiple regression analysis. Vitamin D levels were sufficient in 3 (2.7%), insufficient in 17 (15.45%), and deficient in 90 (81.8%) of the sample. There were no significant differences in the mean TT (p = 0.7981), FT (p = 0.8768), nor SHBG (p = 0.1838) across vitamin D status. Vitamin D was not associated with TT nor FT before or after adjustment for age and age plus body mass index (BMI). Vitamin D was associated with SHBG before and after the aforementioned adjustments, but this became insignificant on sensitivity analysis. There is no association between vitamin D and TT, FT nor SHBG in our cohort with deficient vitamin D levels.

Effects of aging and the body mass index on male sex hormones: a cross-sectional study in 701 Brazilian men

Background: Some studies indicated that body mass index (BMI) is inversely proportional to serum testosterone concentrations in men. Purposes: This study aimed to analyze the effects of aging and obesity on total testosterone (TT), free testosterone (FT), bioavailable testosterone (BT), luteinizing hormone (LH), and sex hormone-binding globulin (SHBG) levels. Methods: A cross-sectional study was performed to assess the clinical and laboratory profiles of 701 patients treated at a private urology clinic in Ponta Grossa, Brazil, from January 2016 to December 2018. Results: Patients’ age ranged from 16 to 88 years (mean, 56.9 ± 13.62 years). Age did not significantly influence serum TT concentrations, except compared to patients aged >70 years. However, changes were observed in FT and BT (p < 0.05). The mean SHBG increased with age (p < 0.05). A tendency toward LH elevation was observed in older patients, but it was not statistically significant. An inverse proportional relationship between TT, FT, and BT and the testosterone deficiency rate (TT < 300 ng/dL) was observed within BMI groups (p < 0.05). The testosterone deficiency rate was 21.5% in individuals with normal BMI, 29% in overweight individuals, and 37% in obese individuals. Conclusions: Aging affected the testosterone concentrations in men and became increasingly evident using FT and BT instead of TT. SHBG increased with age. Obesity was associated with a decrease in TT, FT, and BT but also increased the rate of hypogonadism.

Concentrations of endogenous sex steroid hormones and SHBG in healthy postmenopausal women

Studies reporting age-specific reference ranges of endogenous sex steroid hormones in postmenopausal women are relatively scarce. If levels differ by age, dosing and treatment regimens should vary among postmenopausal women accordingly. Our objective was to establish reference ranges for sex steroid hormones and sex hormone binding globulin (SHBG) by age group and overall, and to investigate their association with demographic characteristics.Serum samples were obtained from 1207 healthy postmenopausal women aged 41–92, not using hormone therapy, at the baseline visit of 3 clinical trials. Estrone (E1), estradiol (E2), and total testosterone (T) were measured by radioimmunoassay with preceding purification steps; SHBG was measured by direct chemiluminescent immunoassay. Free T (FT) was calculated.Women were categorized by 5-year age groups. There was little change in the mean estrogen levels among the different age groups (E2: 9−12 pg/mL; E1: 33−35 pg/mL). Mean total T levels increased gradually with age from 19.9–26.2 ng/dL, but FT mean levels were relatively constant (3.7–4.6 pg/mL). Mean SHBG levels increased with age from 43–68 nmol/L. A generalized linear model tested the association of each demographic characteristic with the hormones and SHBG. A significant association was derived.Our study provides valuable insight into the profiles of serum sex steroid hormones and SHBG in different healthy postmenopausal women aged 41–92 years.

Longitudinal changes in serum testosterone and sex hormone-binding globulin in men aged 40-69 years from the UK Biobank.

Testosterone and sex hormone-binding globulin (SHBG) concentrations are reported to decline during male ageing, but whether these changes reflect physiological ageing or age-related comorbidities remains uncertain. We examined longitudinal changes in serum testosterone and SHBG concentrations in middle-aged to older men, concordance between baseline and follow-up valuesand relationships with concomitant changes in lifestyle and medical factors. Population-based longitudinal cohort study. Community-dwelling men aged 40-69 years. Immunoassay serum total testosterone (n = 7812) and SHBG (n = 6491) at baseline (2006-2010) and follow-up (2012-2013). Free testosterone (cFT) was calculated. Bland-Altman analyses and concordance correlation of repeated measurements were conducted. Associations of changes in hormone concentrations with lifestyle and medical factors were explored using Spearman's rank correlation. Over 4.3 years follow-up, there was a negligible mean change (±SE) in serum total testosterone concentration (+0.06 ± 0.03 nmol/L), whereas mean SHBG concentration increased (+3.69 ± 0.12 nmol/L) and cFT decreased (-10.7 ± 0.7 pmol/L). Concordance estimates were 0.67 (95% confidence interval [CI]: 0.66-0.69) for total testosterone, 0.83 (CI = 0.82-0.84) for SHBG and 0.56 (CI = 0.54-0.58) for cFT. Changes in serum total testosterone correlated with changes in SHBG (Spearman's rank ρ = 0.33, CI = 0.30-0.35), and inversely with changes in body mass index (BMI) (ρ = -0.18, CI = -0.20 to -0.16)and waist circumference (ρ = -0.13, CI = -0.15 to -0.11) and in SHBG with changes in BMI (ρ = -0.34, CI = -0.36 to -0.32) and waist circumference (ρ = -0.21, CI = -0.24 to -0.19). In relatively healthy middle-aged to older men, mean serum total testosterone concentration is stable with ageing, while mean SHBG concentration increases. Both total testosterone and SHBG concentrations were highly concordant over time.

Aging, Cardiovascular Risk, and SHBG Levels in Men and Women From the General Population.

AimsPrior studies have reported inconsistent results for the association between sex hormone-binding globulin (SHBG) and cardiovascular disease among men and women. Although it is suggested that SHBG levels change with aging, the exact trend of SHBG across age and cardiovascular risk and the underlying mechanisms of these changes remain to be elucidated.MethodsUsing data of 3264 men and women from a large population-based cohort study, we first visualized the distribution of serum SHBG levels across age. Second, we computed a cardiovascular risk factor sum score and investigated the mean SHBG levels across categories of the risk factor sum score and stratified per age-category. Next, linear regression models were used to investigate the associations between serum SHBG levels and age and potential regulators of SHBG, including body mass index (BMI), fasting insulin, sex steroids, thyroxine, and triglycerides.ResultsAmong men, a linear increase in SHBG levels with age and among women a U-shaped pattern was observed. Participants with larger number of cardiovascular risk factors had lower SHBG levels. When stratified by age, older participants had higher SHBG levels. A multivariate model including total testosterone and triglyceride levels in men and total testosterone, triglycerides, BMI, and fasting insulin in women explained, respectively, 46.2% and 31.8% of the variance in SHBG levels.ConclusionWe observed a clear sex-specific pattern for SHBG levels with age. Our findings highlight the importance of taking into account the age-related changes in SHBG levels to avoid controversial results in the assessment of the cardiovascular risk associated with SHBG.

Abstract P012: Association Between Testosterone And Sex Hormone Binding Globulin And Risk Of Ischemic Stroke: The Atherosclerosis Risk In Communities Study

Background: Sex hormones are associated with obesity, diabetes mellitus, and other stroke risk factors; however, studies on sex hormones and stroke risk report inconsistent results. We assessed the associations of testosterone and sex hormone binding globulin (SHBG) with risk of ischemic stroke among men and post-menopausal women in the Atherosclerosis Risk in Communities (ARIC) Study. Methods: A total of 4,349 men and 4,720 post-menopausal women who had SHBG and total testosterone measurements at visit 4 (1996-98) were followed through 2018 for the development of ischemic stroke. We examined log transformed SHBG and testosterone exposure as quartiles and as per 1 SD increment. We used Cox regression to estimate the hazard ratios (HR) for ischemic stroke, adjusting for demographic, behavioral and clinical variables. Analyses were stratified by sex and menopausal hormone therapy (HT) use. Results: Participants were aged 63±6 years at baseline, 52% were women (25% HT users), and 21% Black. There were 691 strokes over a median follow-up of 19.8 years. Mean log SHBG (nmol/L) and testosterone (nmol/L) were 4.3±0.7 and 3.1±0.5 for HT users, 3.6±0.7 and 3.2±0.5 for non-HT users, and 3.4±0.5 and 6.2±0.5 for men. Quartile 1 vs Q4 for SHBG and testosterone were ≤50.3 vs >121 and ≤16 vs >28 in HT users, ≤23.3 vs >55 and ≤17.9 vs >32.7 in non-HT users, and ≤23.3 vs >41.8 and ≤388 vs >657 in men. SHBG and testosterone were not significantly associated with stroke in any group (Figure). The HRs [95% confidence interval] for highest to lowest SHBG and testosterone quartiles were 1.04 [0.51-2.14] and 1.64 [0.85-3.17] in HT-users, 1.02 [0.70-1.48] and 1.16 [0.83-1.62] in HT non-users, and 0.96 [0.70-1.32] and 0.87 [0.63-1.21] in men, respectively. The HRs for stroke associated with 1 SD increase in SHBG and testosterone were 1.14 [0.88-1.46] and 1.19 [0.96-1.46] in HT users. Associations were also null among non-HT users and men. Conclusion: SHBG and testosterone were not associated with ischemic stroke risk in this cohort of older men and post-menopausal women.

Longitudinal changes over three years in sex steroid hormone levels in women aged 70years and over.

Sex steroid levels in women vary with increasing age from the age of 70years (70+). Whether this reflects change within individuals with age or a survival advantage is not known. This study aimed to determine the stability of circulating sex steroids and SHBG over time in individual women aged 70+. A prospective cohort study. 400 women, aged 70+ not using any sex steroid, anti-androgen/oestrogen or glucocorticoid therapy. Sex steroid concentrations, measured by liquid chromatography-tandem mass spectrometry and sex hormone-binding globulin (SHBG) by immunoassay, in paired blood samples drawn 3years apart and analysed together. 400 women, median (IQR) age 78.0 (8.6)years, were included in the analysis. Mean testosterone concentrations were statistically significantly higher in follow-up samples compared with baseline. The change was modest (mean change 31pmol/L, 95% confidence interval (CI) 2.4-59.8; p=.034), and an increase was not observed in all women. There was a statistically significant decline in mean body mass index (mean change -0.4kg/m2 , 95% CI 0.6 to -0.3; p<.001) and a significant increase in the mean serum SHBG concentration (mean change 4.0 nmol/L, 95% CI 2.7-5.4; p<.001). The change observed in testosterone was not explained by the observed change in SHBG. There was no significant change in the mean oestrone or dehydroepiandrosterone concentration. Testosterone concentrations in women aged 70+ were more likely to increase than decrease. Whether increasing testosterone concentrations in older women confer a survival advantage needs investigation.

Prevalence of low serum testosterone levels among men with type 2 diabetes mellitus attending two outpatient diabetes clinics in KwaZulu-Natal Province, South Africa.

The reported prevalence of low testosterone among men with type 2 diabetes mellitus (T2DM) is high. However, there is a dearth of information on the prevalence of androgen deficiency symptoms and low serum testosterone levels in men with T2DM from sub-Saharan Africa. Scanty data are available from Nigeria, Ghana and South Africa (SA). To determine the prevalence of low serum testosterone and associated risk factors and the prevalence of androgen deficiency symptoms in men with T2DM. In a cross-sectional observational study, androgen deficiency symptoms in men with T2DM attending two outpatient diabetes clinics in Durban, KwaZulu-Natal Province, SA, were assessed using the Ageing Males' Symptoms Scale (AMS) questionnaire and direct enquiry. Serum total testosterone (TT), sex hormone-binding globulin (SHBG), luteinising hormone (LH), fructosamine, serum lipids and glycated haemoglobin (HbA1c) were measured and free testosterone (FT) was calculated. TT, SHBG and FT levels were measured in control subjects with no history of diabetes. There were 148 men with T2DM in the study group and 50 control subjects in the control group. In the study group, the majority were black Africans (58.8%); Indians (39.2%) and whites (2.0%) constituted the remainder. The mean (standard deviation (SD)) age was 57.5 (11.2) years, the mean duration of diabetes 11.4 (8.9) years and the mean HbA1c 8.6% (1.9%). Of the study group, 85.8% had metabolic syndrome. Mean TT, SHBG and FT and median LH (interquartile range) in the study group were within normal ranges. However, mean (SD) serum TT and FT were lower in the study group than in the control subjects (14.5 (5.8) v. 18.8 (7.2) nmol/L; p&lt;0.001 and 265.9 (90.4) v. 351.7 (127.3) pmol/L; p&lt;0.001, respectively). The prevalence of low serum total testosterone (LSTT) and low serum free testosterone (LSFT) in the study group was 35.8% and 16.2%, respectively. The prevalence of androgen deficiency symptoms using the AMS questionnaire was 74.5% and correlated poorly with LSTT or LSFT. In multivariate analysis, LSFT was significantly associated with age (odds ratio (OR) 1.05, 95% confidence interval (CI) 1.02 - 1.218; p=0.043) and waist circumference (WC) (OR 1.033, 95% CI 0.999 - 1.068; p=0.059). LSTT was associated with body mass index (BMI) only (OR 1.138, 95% CI 1.063 - 1.218; p&lt;0.0001). TT correlated inversely with BMI, WC and the number of metabolic syndrome criteria. FT correlated inversely with BMI, WC and WHR. There was a high prevalence of LSTT, LSFT and androgen deficiency symptoms in this study. Serum TT and FT were lower in men with T2DM than in control subjects. Risk factors associated with LSFT or LSTT included higher BMI and WC and older age. The AMS score was a poor predictor of low testosterone. More research is required locally before any screening policy can be recommended.

Impact of isotretinoin treatment on testosterone and sex hormone-binding globulin in malepatients with acne vulgaris

Background: Acne vulgaris is primarily a disease of the pilosebaceous unit. Four main pathogenic factors are known to lead to its development: follicular epidermal hyperproliferation, excess sebum production, inflammation, and the activity of propionibacterium acnes. Isotretinoin (ISO) is a 13-cis-retinoic acid derivative of vitamin A. It is a highly effective therapy for severe nodulocystic acne.Objective: The aim was to measure serum total, free testosterone, and sex hormone-binding globulin (SHBG) levels, before and after treatment, in male patients suffering from acne vulgaris and taking ISO as a treatment for their acne.Patients and Methods: The authors included 113 male patients with acne vulgaris. The patients received 0.5░mg/kg/day ISO treatment. Blood samples were collected from the patients for analysis of total, free testosterone, and SHBG levels before and after 6 months of treatment.Results: After 6 months of treatment with ISO, the total lesion count was significantly lower after treatment (88.70±35.04 and 27.80±17.94, respectively, P 0.05), and the mean SHBG serum level was insignificantly higher after treatment (104.367±14.689 and105.533±16.362, respectively, P>0.05).Conclusion: This study showed that ISO treatment led to significant reduction in serum total testosterone levels, which may be beneficial for tackling the pathogenesis of acne

SAT-219 A Novel 1-Year Contraceptive Vaginal System Delivering Segesterone Acetate and Ethinyl Estradiol: Effects on Lipids and other Hepatic Proteins

Annovera™ is an FDA-approved contraceptive vaginal system (CVS) releasing 150 mcg segesterone acetate (SA), a new chemical entity, and 13 mcg ethinyl estradiol (EE) per day.1 We postulate that as a non-androgenic progestin, SA is unlikely to adversely affect lipids versus androgenic progestins. Here we review the effects of this CVS on lipids, glucose, coagulation factors and sex hormone-binding globulin (SHBG). Two pivotal, open-label, phase 3 trials and one PK trial evaluated women (18-40 years) who received the CVS for 13 cycles of 28 days over 12 months; one phase 3 study examined hepatic proteins in a substudy. The CVS was self-inserted, left in place for 21 days and removed for 7 days in each 28-day cycle. Lipids and glucose were measured at baseline and study end in the 3 trials. As previously reported, factor VIII, protein S (PS), fibrinogen, and SHBG were measured in the hepatic factors substudy.2 A total of 2308 women used the SA/EE CVS. Participants had a mean age of 26.7 years and mean BMI of 24.1 kg/m2. Most women were white (71%) and 14% were black. Women in the substudy (n=129) had similar mean ages and BMIs; 69% were white and 28% were black. In an integrated analysis of the phase 3 and PK studies, levels of total cholesterol increased by a mean +0.236 mmol/L from baseline to study end, as did HDL cholesterol (+0.162 mmol/L) and triglycerides (+0.193 mmol/L). At study end, LDL cholesterol decreased from baseline by a mean of -0.003 mmol/L. Glucose levels increased from baseline to study end by a mean +0.074 mmol/L. A prior study using the CVS showed lipid changes similar in direction and magnitude to other combined oral contraceptives (COC).3 Hepatic protein substudy results showed significant mean changes from baseline to study end for fibrinogen (+0.2±0.66 mg/mL [SD]; P=0.0052), factor VIII activity (+21%±55; P=0.0005), and PS activity (-8%±19; P=0.0043). Mean SHBG levels also significantly increased from baseline to study end by +81.7±94.3 nmol/L (P<0.0001).2 Another study comparing the CVS to an oral COC showed that the CVS had a hemostatic profile corresponding closely with that of the oral COC.4 Integrated safety data from two clinical studies, a hepatic substudy from one of the trials, and prior reports showed no clinically significant impact of the SA/EE CVS on lipids or glucose. The impact of the CVS on coagulation factors mirrored that of oral COCs. The significant increase in SHBG levels with the CVS was consistent with changes seen with other COCs containing EE and a non-androgenic progestin. The SA/EE CVS with a low dose of EE and the novel progestin, SA, has an acceptable metabolic profile with up to one year of use. 1. AnnoveraTM Prescribing Information. 2. Archer DF, et al. Contraception 2016;93(1):58-64. 3. Sitruk-Ware RL, et al. Contraception 2007;75(6):430-437. 4. Rad M, et al. Am J Obstet Gynecol 2006;195(1):72-77.

Effect of Long-term Elite Military Training and Operations on Hormonal Profile

Chronic exposure to multifactorial stress, such as that endured by elite military operators, may lead to overtraining syndrome and negatively impact hormonal regulation. In acute settings (<6 mos), military training has been shown to lead to hormonal dysfunction; however, less is known about the consequences of long-term military training. PURPOSE: The purpose of this study was to determine the chronic effects of military operations and training on the hormone profile of elite military operators. METHODS: Active-duty elite US military operators (n = 65, age = 29.8 ± 1.0 yrs, height = 178.4 ± 0.7 cm, weight = 85.1 ± 2.0 kg) concomitantly engaged in rigorous physical training were recruited to participate in the study. Basal plasma concentrations of luteinizing hormone (LH), total testosterone (TT), free testosterone (FT), sex-hormone binding globulin (SHBG), cortisol, thyroid stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) were obtained between 0600-1000 hrs. Data were analyzed for correlations and compared against normative reference values; all data are presented as mean ± SE. RESULTS: Mean LH, TT, FT, SHBG, cortisol, TSH, T3, and T4 for all subjects were: 3.4 ± 0.2 IU · L-1, 13.5 ± 0.9 nmol · L-1, 28.2 ± 1.2 pmol · L-1, 94.2 ± 6.4 nmol · L-1, 441.3 ± 26.4 nmol · L-1, 3.5 ± 0.7 mIU · L-1, 150 ± 9.0 ng · dL-1, and 7.8 ± 0.2 μg · dL-1, respectively. There was a significant positive correlation between TT and cortisol (R2 = 0.07; y = 0.0093x + 9.4364; P < 0.05). In addition, 43% of the participants (n = 28) had TT below age-based normative reference ranges. Those with lower than normal TT (8.2 ± 0.3 vs. 17.6 ± 1.3 nmol· L-1; P < 0.01), also had lower FT (24.4 ± 1.9 vs. 31.1 ± 1.4 pmol · L-1, P < 0.01), cortisol (367.4 ± 39.1 vs 497.2 ± 33.2 nmol· L-1; P < 0.05) and T3 (121.1 ± 5.4 vs. 164.0 ± 14.3 ng · dL-1; P < 0.01). CONCLUSION: These results indicate that military operations and training may place a large burden on the operators and depress or alter the hypothalamic pituitary, adrenal, gonadal and thyroid axes. Further research need be conducted to determine what, if any, consequences these differences may cause.

Serum Concentrations of Sex Hormone–binding Globulin Vary Widely in Younger and Older Men: Clinical Data from a Men’s Health Practice

BackgroundThe testosterone (T) status of a man is influenced by serum concentrations of sex hormone–binding globulin (SHBG). Specifically, tight binding of T to SHBG is believed to render the SHBG-bound T fraction biologically unavailable, meaning that interpretation of T levels in the clinical setting depends in part on knowledge of SHBG concentrations. Although SHBG levels have been reported in population studies, there is scant information for men presenting with clinical symptoms. ObjectiveTo report SHBG values for a large cohort of men presenting to a men’s health center. Design, setting, and participantsMedical records were reviewed for 1000 consecutive patients seen at our center with a reported SHBG value. SHBG concentrations were measured by a national clinical laboratory using an immunoassay run on a Beckman Coulter DXi system. Outcome measurements and statistical analysisPatients were age-stratified and data were plotted in the form of comparative histograms. Results and limitationsThe mean age (±standard deviation) of the total cohort was 53.5±13.5 yr (range 17–91). The mean SHBG was 31.8±15.2nmol/l (range 6-109), with a nearly 20-fold difference from the lowest to the highest values. SHBG was >60nmol/l in 5.6% of the men. Patients were stratified according to age. A total of 535 patients were ≤54 yr old. In this younger cohort, the mean age was 40.52±7.9 yr (range 17–54) and mean SHBG was 27.7±13.3nmol/l (range 6–88), and 2.2% of patients had SHBG >60nmol/l. A total of 465 patients were ≥55 yr old. In this older cohort, the mean age was 64.8±7.23 yr (range 55–91) and mean SHBG was 36.6±15.8 nmol/l (range 11–109), and 9% of patients had SHBG >60 nmol/l. Mean SHBG was significantly higher in the older group (p<0.001). ConclusionsA remarkably wide distribution of SHBG concentrations was observed in a clinical population of men presenting to a men’s health center, among both younger and older men. Since SHBG concentrations greatly influence test results for hormones that bind to SHBG, recognition of this large interindividual variability should be considered in the clinical interpretation of these hormone results, particularly for T. Routine SHBG testing should be considered for men suspected of T deficiency. Patient summarySex hormone–binding globulin (SHBG) levels vary widely among both older and younger men. This may impact the interpretation of test results for hormones that bind to SHBG, such as testosterone, since the portion that binds to SHBG is believed to not be biologically available.

Sex Hormone - Binding Globulin in Obese Type 2 Diabetics

Background: Obesity is one of risk factors for type 2 diabetes because of its association with insulin resistance and poor glycemic control. Sex hormone–binding globulin (SHBG) and adipose tissue hormones have a role in development of insulin resistance, hyperlipidemia and type 2 diabetes. Serum SHBG has a role in glucose homeostasis and low levels are associated with development of diabetes, cardiovascular diseases, insulin resistance and hyperinsulinemia. Aim of work: to study the relationship between serum SHBG, obesity, and metabolic parameters in type 2 diabetes in both sex. Patients and Methods: forty obese type 2 diabetic patients and ten obese non-diabetic as controls were included in this study. Blood was taking from all subjects for estimation of glucose, Lipid profile, insulin and SHBG. Results: there was highly significant decrease in mean serum SHBG concentration in diabetic group compared with control non diabetic group. There were significant negative associations between serum SHBG and age, disease duration, BMI and glucose. On the other hand, there were non significant correlations between SHBG and waist circumference, fasting insulin, HOMA-IR, cholesterol and triglyceride levels. Conclusion: Low serum SHBG is associated with hyperglycemia in both sexes, independent of insulinemia

Relationship between Testosterone and Sex Hormone Binding Globulin Concentrations with Cardiometabolic Parameters and Macrovascular Disease in Afro-Caribbean Men with Type 2 Diabetes

Introduction: Low testosterone concentrations have been reported in type 2 diabetes (T2D) and Coronary Artery Disease (CAD). Contrary to diabetes, the prevalence of CAD is lower in Afro-Caribbean (AC) from French West Indies islands than in people from mainland France. However, CAD is a frequent complication of T2D. To evaluate this paradoxical situation, we investigated the prevalence of sex steroids deficiency that might be associated with CAD in AC men with T2D and the relationships with metabolic parameters. Methods: We performed a cross-sectional study in the Department of Diabetology of the University Hospital of Guadeloupe. Clinical and biological data were collected from men with T2D. Total Testosterone (TT) and Sex Hormone Binding Globulin (SHBG) concentrations were measured using electrochemiluminescence and immunoradiometric assays. Results are expressed as mean ± SD or percentages. The data were analyzed using the Mann–Whitney and chi-squared tests, Pearson correlations and logistic regression. P values<0.05 were considered significant. Results: One hundred thirty-three AC men with T2D were included. Prevalence of testosterone deficiency was 43.5%. The mean TT and SHBG concentrations were 12.06 ± 6.24 and 35.9 ± 17.54 nmol/l respectively. Low TT concentrations were more frequently found in obese subjects compared to subjects with normal weight and low SHBG concentrations were high rather in subjects with overweight. Both sex steroids levels were higher in subjects with dyslipidemia than subjects without dyslipidemia. TT deficiency was more frequent in subjects with macrovascular disease including CAD, peripheral artery disease or stroke than subjects without macrovascular disease. Conclusion: Testosterone deficiency and low SHBG concentrations occur frequently in AC men with T2D and are associated with metabolic profile that may promote the development of macrovascular disease. In this population, it may be necessary to systematically apply a testosterone replacement in case of deficiency, to improve cardiometabolic profiles without forget the risk of prostate cancer.

Association of serum bisphenol-A concentration and male reproductive function among exposed workers.

Bisphenol-A (BPA) can alter endocrine function in animals, yet the relationship between human exposure to BPA and male reproductive function is not well understood. We collected serum samples from 281 male workers exposed to BPA and 278 controls. Serum BPA concentrations were analyzed by gas chromatography-mass spectrometry after derivatization. The serum levels of sex hormone-binding globulin (SHBG) and total testosterone (TT) were detected by radioimmunoassay and levels of inhibin B (INB) and androstenedione (AD) by enzyme-linked immunosorbent assay. We examined the association of BPA exposure and male sex hormone levels by multivariable linear regression. Both serum BPA concentrations and detection rates were greater in males exposed than those not exposed to BPA, but the two groups did not differ in levels of SHBG, TT, INB, or AD. Compared with exposure for ≤5 years, exposure for >5 years was associated with increased serum BPA and SHBG 1evels and decreased AD levels. Compared with undetectable BPA and BPA ≤ 18.75 ng/mL, BPA level >18.75 ng/mL was associated with low AD and high SHBG levels (P < 0.05). On adjusted multivariable regression, increased serum BPA level was associated with decreased mean serum AD level (0.18 ng/mL; 95% confidence interval CI -0.22 to -0.13) and increased mean serum SHBG level (2.79 nmol/L; 95% CI 2.11-3.46). Serum BPA levels were increased after occupational exposure. BPA exposure was negatively associated with serum AD level but positively associated with serum SHBG level.

In women, no significant variances of calculated free testosterone (cFT) are observed when a fixed value of albumin (Alb: 4.3 g/dL) is used instead of measured albumin values.

Calculated free testosterone (cFT) is determined from the values of total testosterone (TT), sex hormone binding globulin (SHBG), and albumin (Alb) using mathematical formulae. We evaluated any potential cFT variance when determined with fixed Alb (4.3 g/dL) compared to measured Alb, and the point at which low SHBG and Alb combinations produced significant cFT variance. We analyzed 2050 data points in 1222 women. cFT values with fixed vs. the actual measured Alb values were evaluated and contrasted. cFT levels were determined theoretically for all possible combinations of TT, SHBG, and Alb. Agreement between the two measures was assessed with Lin's concordance coefficient. Statistical analyses were performed using R software version 2.12.1. Mean Alb was 4.05 ± 0.30 g/dL. Mean SHBG 73.0 ± 53.3 nmol/L. A fixed Alb of 4.3 g/dL produced no significant variance for most evaluations of cFT. The accuracy decreased with Alb ≤ 3.5 g/dL in combination with SHBG ≤ 30 nmol/L and exists in 1.0% of the samples. A fixed Alb of 4.3 g/dL is acceptable for most clinical evaluations. If Alb is ≤ 3.5 g/dL, along with SHBG ≤ 30 nmol/L, the variance increases and a free testosterone (FT) measurement by equilibrium dialysis is warranted for better accuracy.

The association between sex hormone-binding globulin and type 2 diabetes in Nigerian men.

BackgroundEpidemiological studies have shown that sex hormone-binding globulin (SHBG) has a role in glucose homeostasis in both men and women. However, a prospective study on Japanese-American subjects concluded that SHBG was not a significant risk factor in either men or women, suggesting ethnic differences. We were not aware of any evaluation of SHBG in subjects of African ancestry.ObjectivesWe investigated the association between SHBG and insulin resistance in type 2 diabetic diabetic men in a hospital in Nigeria.MethodForty-eight male subjects with type 2 diabetes and 20 non-diabetic male subjects were recruited in this cross-sectional hospital-based study by the convenient sampling method. Height and circumferences around the waist and hip were measured to the nearest 0.5 cm and the waist–hip ratio was calculated from this measurement. Weight was measured and body mass index was calculated. Fasting plasma glucose concentration was measured by the glucose oxidase method with a between-run coefficient of variation of 3%. Insulin and SHBG were measured by means of enzyme-linked immunosorbent assay (ELISA).ResultsThere was a statistically-significant difference between test results for the diabetic and non-diabetic patients. The mean SHBG concentration was higher in the non-diabetic group (42.2 nmol/L) than the diabetic group (30.5 nmol/L). A significant inverse association between insulin resistance and SHBG was observed (r = 0.353, p < 0.015).ConclusionThis study supported earlier observations that a significant inverse correlation exists between SHBG and insulin resistance and provides evidence that the relationship may extend to type 2 diabetic men of African ancestry in Nigeria.

Are There Variances Of Calculated Free Testosterone Attributed To Variations In Albumin And Sex Hormone-Binding Globulin Concentrations In Men?

Calculated free testosterone (cFT) is determined from total testosterone (TT), sex hormone binding globulin (SHBG), and albumin (Alb) levels using mathematical formulae. Variations in cFT due to changes in SHBG or Alb have not been investigated. We evaluated potential cFT variances determined with fixed Alb (4.3 g/dL) and measured Alb, and the point at which low SHBG and Alb combinations produced significant cFT variance. We analyzed 11,176 data points from 5,797 men. cFT values with fixed versus actual Alb values were evaluated and compared. cFT levels were theoretically determined for all possible combinations of TT, SHBG, and Alb (8,343,552 combinations). Agreement between the 2 measures was assessed with Lin's concordance coefficient. Mean Alb was 4.06 ± 0.32 g/dL. Mean SHBG was 39.0 ± 23.6 nmol/L. A fixed Alb of 4.3 g/dL did not produce significant variance for most cFT evaluations. Accuracy decreased when Alb was ≤3.5 g/dL in combination with SHBG ≤30 nmol/L, and this occurred in 1.2% of all data points. A fixed Alb of 4.3 g/dL is acceptable for most clinical evaluations. If Alb is ≤3.5 g/dL and SHBG is ≤30 nmol/L, the variance increases, and a free testosterone (FT) measurement by equilibrium dialysis is warranted for better accuracy.

Diabetes mellitus abolishes the cardioprotective effect of ischemic postconditioning against ischemia/reperfusion injury in rat: Role of lipid peroxidation

The testosterone (T) status of a man is influenced by serum concentrations of sex hormone–binding globulin (SHBG). Specifically, tight binding of T to SHBG is believed to render the SHBG-bound T fraction biologically unavailable, meaning that interpretation of T levels in the clinical setting depends in part on knowledge of SHBG concentrations. Although SHBG levels have been reported in population studies, there is scant information for men presenting with clinical symptoms.To report SHBG values for a large cohort of men presenting to a men’s health center.Medical records were reviewed for 1000 consecutive patients seen at our center with a reported SHBG value. SHBG concentrations were measured by a national clinical laboratory using an immunoassay run on a Beckman Coulter DXi system.Patients were age-stratified and data were plotted in the form of comparative histograms.The mean age (± standard deviation) of the total cohort was 53.5 ± 13.5 yr (range 17–91). The mean SHBG was 31.8 ± 15.2 nmol/l (range 6-109), with a nearly 20-fold difference from the lowest to the highest values. SHBG was >60 nmol/l in 5.6% of the men. Patients were stratified according to age. A total of 535 patients were ≤54 yr old. In this younger cohort, the mean age was 40.52 ± 7.9 yr (range 17–54) and mean SHBG was 27.7 ± 13.3 nmol/l (range 6–88), and 2.2% of patients had SHBG >60 nmol/l. A total of 465 patients were ≥55 yr old. In this older cohort, the mean age was 64.8 ± 7.23 yr (range 55–91) and mean SHBG was 36.6 ± 15.8 nmol/l (range 11–109), and 9% of patients had SHBG >60 nmol/l. Mean SHBG was significantly higher in the older group (p < 0.001).A remarkably wide distribution of SHBG concentrations was observed in a clinical population of men presenting to a men’s health center, among both younger and older men. Since SHBG concentrations greatly influence test results for hormones that bind to SHBG, recognition of this large interindividual variability should be considered in the clinical interpretation of these hormone results, particularly for T. Routine SHBG testing should be considered for men suspected of T deficiency.Sex hormone–binding globulin (SHBG) levels vary widely among both older and younger men. This may impact the interpretation of test results for hormones that bind to SHBG, such as testosterone, since the portion that binds to SHBG is believed to not be biologically available.