Relation between androgens and cardiovascular risk factors in a young population

Association Between Sex Hormone-Binding Globulin, Atherogenic Indices of Plasma Among Young Sedentary Males

Background

Males are more likely than females to suffer from cardiovascular disease (CVD). So, sex hormones may modify these variations and affect the lipid profile. We examined the relationship between sex hormone-binding globulin (SHBG) and CVD risk factors among young males in this study.

Methods

Using a cross-sectional design, we measured total testosterone, SHBG, lipids, glucose, insulin, antioxidant parameters, and anthropometric factors in 48 young males in the age range of 18 to 40 years. Atherogenic indices of plasma were calculated. In this study, a partial correlation analysis was carried out to assess the relationship between SHBG and other variables after adjustment for confounders.

Results

According to the results of multivariable analyses adjusted for age and energy, SHBG had a negative correlation with total cholesterol (r = -.454, P =.010), low-density lipoprotein cholesterol (r = -.496, P =.005), quantitative insulin-sensitivity check index, and positive correlation with high-density lipoprotein cholesterol (r = .463, P =.009). No significant correlation was observed between SHBG and triglycerides (P >.05). Several atherogenic indices of plasma have a negative correlation with SHBG levels. These include Atherogenic Index of Plasma (r = -.474, P = .006), Castelli Risk Index (CRI)1 (r = -.581, P < .001), CRI2 (r = -.564, P = .001), and Atherogenic Coefficient (r = -.581, P < .001).

Conclusion

Among young men, high plasma SHBG was associated with reduced CVD risk factors, modified lipid profile and atherogenic ratios, and better glycemic markers. Therefore, reduced SHBG concentrations could be a prognostic marker of CVD among young sedentary males.

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

CONTEXT

Sex hormone-binding globulin (SHBG) levels are associated with cardiovascular disease (CVD) risk factors. However, prospective data on the association between SHBG levels and CVD events are sparse, with conflicting results.

OBJECTIVES

To examine associations between serum SHBG, total testosterone (TT), and incident CVD and CVD-related mortality in middle-aged to elderly men.

DESIGN AND METHODS

Data on 2563 community-dwelling men (35 to 80 years) were obtained from participants in the Men Androgen Inflammation Lifestyle Environment and Stress cohort. The analytic sample included 1492 men without baseline (2002 to 2007) CVD and with fasted morning serum SHBG and TT available at both baseline and follow-up (2007 to 2010) and without medications affecting TT or SHBG. Associations of baseline SHBG and TT, with incident CVD and CVD mortality, were analyzed using logistic regression for incident CVD and Cox proportional hazard regression for CVD mortality, adjusting for established CVD risk factors.

RESULTS

In multivariable models, elevated baseline SHBG and lower baseline TT were independently associated with incident CVD (SHBG: OR, 1.54; 95% CI, 1.15 to 2.06 per SD increase in SHBG, P = 0.003; TT: OR, 0.71; 95% CI, 0.52 to 0.97 per SD decrease in TT; P = 0.03). A decrease in TT between time points was associated with incident CVD (OR, 0.72; 95% CI, 0.56 to 0.92; P = 0.01). Neither SHBG nor TT was significantly associated with all-age CVD mortality [hazard ratio (HR), 0.69; 95% CI, 0.29 to 1.63; P = 0.40; and HR, 0.60; 95% CI, 0.28 to 1.26; P = 0.18, respectively].

CONCLUSIONS

Among all men and men >65 years, elevated SHBG and lower TT were independently associated with both a greater risk of CVD and an increased CVD mortality risk.

Associations of Dehydroepiandrosterone Sulfate With Cardiometabolic Risk Factors in Prepubertal Children

CONTEXT

Premature adrenarche (PA) has been associated with overweight and insulin resistance, but the associations of serum dehydroepiandrosterone sulfate (DHEAS) concentration with other cardiometabolic risk factors are uncertain.

OBJECTIVE

To examine the associations of serum DHEAS concentration with several cardiometabolic risk factors in children.

DESIGN

Cross-sectional data from the Physical Activity and Nutrition in Children Study.

PARTICIPANTS

Population sample of 207 girls and 225 boys aged 7.6 ± 0.4 years.

MAIN OUTCOME MEASURES

Cardiometabolic risk factors by serum DHEAS concentration.

RESULTS

DHEAS correlated positively with body mass index standard deviation score, body fat percentage, lean body mass, high-sensitivity C-reactive protein (hs-CRP), and alanine aminotransferase (ALT) when adjusted for age and sex. The associations of DHEAS with hs-CRP and ALT disappeared when adjusted also for body fat percentage. When further adjusted for birth weight SD score, DHEAS correlated negatively with low-density lipoprotein (LDL) cholesterol and LDL/high-density lipoprotein (HDL) cholesterol ratio. LDL cholesterol was lower in children with DHEAS ≥40 µg/dL than in those with DHEAS <40 µg/dL, adjusted for age, sex, and body fat percentage (86.5 vs 92.3 mg/dL, P = 0.029). This association strengthened after further adjustment for birth weight SD score (85.3 vs 92.3 mg/dL, P = 0.012).

CONCLUSION

Higher DHEAS is not associated with an increased cardiometabolic risk in prepubertal children. Instead, it may be protective, evidenced by an association with lower LDL cholesterol and LDL/HDL cholesterol ratio. The increased cardiometabolic risk in PA shown in many studies may be due to low birth weight and childhood overweight associated with PA.

Circulating steroid levels as correlates of adipose tissue phenotype in premenopausal women

Background Obesity-related alterations in the circulating steroid hormone profile remain equivocal in women. Our objective was to identify circulating steroid levels that relate to increased adiposity and altered adipose phenotype in premenopausal women. Materials and methods In a sample of 42 premenopausal women [age 46 ± 3 years; body mass index (BMI) 27.1 ± 4.2 kg/m2], 19 plasma steroids were quantified by electrospray ionization-liquid chromatography-tandem mass spectroscopy (ESI-LC-MS/MS). Body composition and fat distribution were assessed by dual-energy X-ray absorptiometry (DXA) and computed tomography (CT), respectively. Markers of adipose tissue function including adipocyte size distributions, radiological attenuation and macrophage infiltration were also analyzed in surgically obtained visceral and subcutaneous fat samples. Results Many negative correlations were observed between adiposity measurements such as BMI, body fat percentage or total abdominal adipose tissue area and plasma levels of androstenedione (Δ4) (r = -0.33 to -0.39, p ≤ 0.04), androsterone (ADT) (r = -0.30 to -0.38, p ≤ 0.05) and steroid precursor pregnenolone (PREG) (r = -0.36 to -0.46, p ≤ 0.02). Visceral adipocyte hypertrophy was observed in patients with low PREG concentrations (p < 0.05). Visceral adipose tissue radiologic attenuation, a potential marker of adipocyte size, was also positively correlated with PREG levels (r = 0.33, p < 0.05). Low levels of PREG were related to increased number of macrophages infiltrating visceral and subcutaneous adipose tissue (p < 0.05). Conclusion Plasma levels of androgens and their precursors are lower in women with increased adiposity and visceral adipocyte hypertrophy. Low circulating PREG concentration may represent a marker of adipose tissue dysfunction.

Genetically predicted testosterone and systemic inflammation in men: a separate-sample Mendelian randomization analysis in older Chinese men

Objectives

Observationally, testosterone is negatively associated with systemic inflammation, but this association is open to both residual confounding and reverse causality. Large-scale randomized controlled trials (RCTs), assessing exogenous effects, are presently unavailable. We examined the association of endogenous testosterone with well-established systemic inflammatory markers (white blood cell, granulocyte, lymphocyte and high-sensitivity C-reactive protein (hsCRP)) using a separate-sample Mendelian randomization analysis to minimize reverse causality.

Methods

A genetic prediction rule for serum testosterone was developed in 289 young Chinese men with mean age of 21.0, using selected testosterone-related SNPs (rs10046, rs1008805 and rs1256031). Multivariable linear regression was used to examine the association of genetically predicted serum testosterone with inflammatory markers among 4,212 older Chinese men from the Guangzhou Biobank Cohort Study.

Results

Genetically predicted testosterone was unrelated to white blood cell count (-0.01 109/L per nmol/L testosterone, 95% confidence interval (CI) -0.05 to 0.04), granulocyte count (-0.02 109/L, 95% CI -0.06 to 0.02), lymphocyte count (0.005 109/L, 95% CI -0.01 to 0.02) and hsCRP (-0.05 mg/L, 95% CI -0.15 to 0.06).

Conclusion

Our findings did not corroborate any anti-inflammatory effects of testosterone or corresponding potentially protective effects of testosterone on chronic diseases resulting from reduced low-grade systemic inflammation.

Association between sex hormone-binding globulin (SHBG) and metabolic syndrome among men

CONTEXT AND OBJECTIVE

Metabolic syndrome consists of a set of factors that imply increased risk of cardiovascular diseases. The objective here was to evaluate the association between sex hormone-binding globulin (SHBG), sex hormones and metabolic syndrome among men.

DESIGN AND SETTING

Retrospective analysis on data from the study "Endogenous oestradiol but not testosterone is related to coronary artery disease in men", conducted in a hospital in São Paulo.

METHODS

Men (aged 40-70) who underwent coronary angiography were selected. The age, weight, height, waist circumference, body mass index and prevalence of dyslipidemia, hypertension and diabetes of each patient were registered. Metabolic syndrome was defined in accordance with the criteria of the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (NCEP-ATPIII). Serum samples were collected to assess the levels of glucose, total cholesterol, HDL-cholesterol (high density lipoprotein), triglycerides, albumin, SHBG, estradiol and total testosterone (TT). The levels of LDL-cholesterol (low density lipoprotein) were calculated using Friedewald's formula and free testosterone (FT) and bioavailable testosterone (BT) using Vermeulen's formula.

RESULTS

141 patients were enrolled in the study. The prevalence of metabolic syndrome was significantly higher in the first SHBG tercile than in the second and third terciles. A statistically significant positive association between the SHBG and TT values was observed, but no such association was seen between SHBG, BT and FT.

CONCLUSION

Low serum levels of SHBG are associated with higher prevalence of metabolic syndrome among male patients, but further studies are required to confirm this association.

Relationship of adiponectin with sex hormone levels in adolescents

BACKGROUND/AIMS

Adiponectin is an adipose tissue-derived adipocytokine which, starting at puberty, is present in lower levels in males than in females. In adults, a relationship between adiponectin levels and sexual hormones has been suggested, but this association remains unclear in children. Our study aimed to analyze the relationship of adiponectin with dehydroepiandrosterone sulfate, testosterone, estradiol, and sex hormone-binding globulin (SHBG) in adolescents.

METHODS

The population-based sample included 785 healthy 12- to 16-year-old children. Testosterone, estradiol, and dehydroepiandrosterone sulfate levels were assessed by radioimmunoassay. SHBG was measured by immunoradiometric assay. Adiponectin concentrations were measured by ELISA.

RESULTS

Adiponectin levels were positively correlated with SHBG and negatively correlated with the free androgen index independently of body mass index (BMI) and fat mass. No significant correlations were observed between adiponectin and total testosterone or estradiol. Multiple linear regression analysis showed that, after adjustment for BMI, SHBG appears as the primary predictor of adiponectin levels in both sexes, accounting for 5.7% of the variation in adiponectin levels in boys and 7.5% in girls.

CONCLUSION

Adiponectin is related to free androgen index and SHBG levels in adolescents after adjusting for BMI and fat mass, thus suggesting an association between adiponectin levels and androgen bioavailability that would explain the sex-based differences in adiponectin levels through life.

Androgen activity and markers of inflammation among men in NHANES III

OBJECTIVES

Inflammation contributes to chronic diseases. Lower serum testosterone among men is associated with less inflammation, yet immune defense is thought to trade-off against reproduction with androgens adversely affecting immune function. Anti-androgens are effective at castrate levels of serum testosterone, suggesting serum testosterone may not capture all androgen activity. The association of two androgen biomarkers with key markers of inflammation was examined.

METHODS

The adjusted association of serum testosterone and androstanediol glucuronide with C-reactive protein, white blood cell, granulocyte and lymphocyte count, fibrinogen, and hemoglobin, as a control outcome because testosterone administration raises hemoglobin, were examined in a nationally representative sample of 1,490 US men from the National Health and Nutrition Examination Survey III phase 1 (1988-1991) using multivariable linear regression.

RESULTS

Serum testosterone and androstanediol glucuronide were weakly correlated (0.13). Serum testosterone was associated with lower white blood cell count [-0.26 × 10(-9) per standard deviation, 95% confidence interval (CI) -0.37 to -0.14] and granulocyte count (-0.21 × 10(-9) , 95% CI -0.29 to -0.13) but not with hemoglobin (0.02 g/l, 95% CI -0.89 to 0.92), adjusted for age, education, race/ethnicity, smoking, and alcohol. Similarly adjusted, androstanediol glucuronide was not associated with white blood cell count (0.10 × 10(-9) , 95% CI -0.05 to -0.25), granulocyte count (0.12 × 10(-9) , 95% CI -0.02 to 0.25), or fibrinogen (0.05 g/l, 95% CI -0.004 to 0.11), but was with hemoglobin (0.70 g/l, 95% CI 0.07 to 1.32).

CONCLUSIONS

Different androgen biomarkers had different associations with inflammatory markers, highlighting the need to consider several androgen biomarkers. The possibility remains that androgens may generate inflammatory processes with implications for chronic diseases.

The impact of type 2 diabetes mellitus on mortality in hospitalized female cancer patients in Taiwan

INTRODUCTION

The goal of this study was to determine the relationships among type 2 diabetes mellitus (DM), specific cancer histological types and mortality in hospitalized women.

METHODS

Patients over 19 years of age were included if the indication for hospital admission was a diagnosis of type 2 DM or a malignancy. In total, 67,660 female patients with a mean age 62.76 ± 14.48 years were enrolled. These patients were categorized into the following three groups: patients with cancer but without type 2 DM (group A); patients with cancer and type 2 DM (group B) and patients with type 2 DM but without cancer (group C). Attributable fractions (AF) were calculated as ([hazard ratio - 1]/hazard ratio) × 100 to evaluate the impact of type 2 DM on mortality for specific cancers.

RESULTS

Of the study participants, 37,204 (55%) were diagnosed with type 2 DM. The patients were categorized as follows: group A, 30,456 patients; group B, 5992 patients and group C, 31,212 patients. Group B patients had high frequencies of pancreatic, liver and renal cancers and low frequencies of thyroid, breast and ovarian cancers. Of the 36,448 cancer patients, 2906 (8%) died. The mortality rate in group B (10 %) was significantly higher than that in groups A and C. Type 2 DM was associated with increased mortality and AF for thyroid, nasopharyngeal, urinary tract, ovarian, breast and cervical cancers (hazard ratio over 1.50).

CONCLUSION

The incidence of type 2 DM in patients with different histological types of cancer varied widely, ranging from 8-34%. Among the cancer patients, type 2 DM had a significantly greater impact on the mortality rates of patients with cancers associated with relatively low mortality.

Endogenous sex hormones and C-reactive protein in healthy Chinese men

OBJECTIVE

To examine the association of endogenous sex hormones and sex hormone-binding globulin (SHBG) with C-reactive protein (CRP) in Chinese men.

DESIGN AND PARTICIPANTS

The study population comprised 1989 men at baseline recruitment of a population-based cohort in China. Participant information on risk factors was collected by a face-to-face interview and clinical examination. All subjects in the study were without taking any kind of medication for anti-inflammation purpose or treatment of hypogonadism and with CRP value less than 10 mg/l. Data were analysed using linear regression analyses.

RESULTS

Higher levels of total testosterone (TT, β = -0.114, 95%CI, -0.162 to -0.065), free testosterone (β = -0.059, 95%CI, -0.106 to -0.012) and SHBG (β = -0.116, 95%CI, -0.169 to -0.063) were statistically significantly related to lower levels of CRP, after adjustment for age, waist circumference (WC), triglycerides, high-density lipoprotein cholesterol, fasting glucose, insulin, smoking status, hypertension, diabetes and family history of hypertension or diabetes. In the subgroup of men with body mass index ≥ 27.5 kg/m(2) or with metabolic syndrome, findings for TT and SHBG were more pronounced, whereas the associations of TT with CRP were attenuated and nonstatistically significant among subjects with WC ≥ 90 cm or with insulin resistance. No associations were observed between estradiol, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and CRP.

CONCLUSIONS

We have confirmed the association of androgens with reduced inflammation as measured by CRP in Chinese men. This is independent of conventional cardiovascular risk factors and is explained in part by markers of central obesity and insulin resistance, rather than metabolic syndrome.

Abdominal aorta intima media thickness in obese children

The aim of this study is to investigate whether abdominal aorta intima media thickness (aIMT), increases in obese children and to determine risk factors. Ninety-six children aged 5-16 (51 obese and 45 non-obese) were enrolled in this prospective and cross-sectional study. Age, gender, and relative body mass index (BMI) were recorded. Their serum lipids, thyrotropin, fasting glucose and insulin levels were analyzed. The homeostasis model assessment (HOMA-IR) score was calculated for insulin resistance. Anthropometric and biochemical data were assessed along with aIMT. Findings in obese children were compared with those of non-obese control subjects. The aIMT was significantly greater in obese children. Similar trends were observed in both prepubertal children and adolescents. In obese children, the mean aIMT (mm) was 0.021 (years of age) +0.519. In non-obese children, the mean aIMT (mm) was 0.017 (years of age) +0.381. Our data suggests a relationship between glucose metabolism and aIMT in obese children. BMI was an independent risk factor for increasing aIMT. In conclusion, when compared with non-obese controls, obese children demonstrated significantly increased aIMT. Higher BMI, insulin, HOMA-IR and increased systolic blood pressure seem to be the main factors contributing to increased aIMT and risk for developing vascular disease. Childhood obesity contributes to the development of an increased aIMT.