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

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.

High C-reactive protein is associated with increased risk of biochemical hypogonadism: a population-based cohort study

CONTEXT

Obesity seems to decrease levels of testosterone. It is still unknown what role inflammation plays in the secretion of testosterone in men.

OBJECTIVE

The objective is to study the association between levels of C-reactive protein and testosterone and its role in predicting biochemical hypogonadism in men.

DESIGN

This was a longitudinal observational study between 2002 and 2014 in Sweden.

PATIENTS OR OTHER PARTICIPANTS

At the first visit, a random population sample of 1400 men was included, and 645 men fulfilled a similar protocol at a 10-year follow-up visit. After exclusion, 625 men remained to be included in the final analyses.

MAIN OUTCOME MEASURE(S)

Serum concentrations of testosterone and C-reactive protein (CRP) were measured at both visits. Bioavailable testosterone was calculated. Biochemical hypogonadism was defined as total testosterone levels <8 nmol/L.

RESULTS

At the first visit and in the longitudinal analyses, a strong association was found between high levels of CRP and low levels of calculated bioavailable testosterone even after adjustments for age, waist-hip ratio, hypertension, smoking, type 2 diabetes, and leisuretime physical activity (B = -0.31, 95% CI -0.49 to -0.13, P = 0.001, B = -0.26, 95% CI -0.41 to -0.11, P = 0.001). Similarly, increase with one s. d. in CRP was associated with increased risk of having hypogonadism after adjustment in the final model (odds ratio (OR) 1.76, 95% CI 1.12-2.78, P = 0.015, OR 1.80, 95% CI 1.16-2.78, P =0.008).

CONCLUSIONS

In this representative cohort of men in southwestern Sweden, high levels of CRP were longitudinally associated with low concentrations of calculated bioavailable testosterone and increased risk of biochemical hypogonadism.

Novel predictive risk factor for erectile dysfunction: Serum high-sensitivity C-reactive protein

BACKGROUND

C-reactive protein (CRP), as a marker of inflammation, may be closely related to erectile dysfunction (ED), however, there is no meta-analysis exists for it.

OBJECTIVES

We aimed to verify the relationship between CRP and erectile dysfunction and to explore the changes of CRP levels in ED patients after first-line treatment.

MATERIALS AND METHODS

We searched databases including the Cochrane Library, PubMed, and MEDLINE to identify studies up to January 1, 2022. We performed a comprehensive analysis of the included studies by STATA software and calculated standardized mean differences (SMDs) and their corresponding 95% confidence intervals.

RESULTS

A total of 12 studies were included and the analysis showed that CRP levels were higher significantly in patients with erectile dysfunction than the healthy controls (P < 0.001) and decreased by a mean of 0.38 mg/L after first-line PDE5i drug treatment (P = 0.001).

DISCUSSION AND CONCLUSION

This novel meta-analysis suggests that CRP is statistically significantly associated with erectile dysfunction and may be a predictor or risk factor for the assessment of ED. However, further original studies with large sample sizes are needed to validate this. This article is protected by copyright. All rights reserved.

Association of testosterone therapy with disease progression in older males with COVID-19

Importance

Low testosterone levels in males have been linked with increase in proinflammatory cytokines—a primary culprit in COVID‐19 disease progression—and with adverse COVID‐19 outcomes. To date, however, no published studies have assessed the effect of testosterone therapy on COVID‐19 outcomes in older men.

Objective

To examine whether testosterone therapy reduced disease progression in older men diagnosed with COVID‐19.

Design, setting, and participants

Nested within a national cohort of older (aged ≥50 years) male patients diagnosed with COVID‐19 between January 1, 2020 and July 1, 2021 from the Optum electronic health record COVID‐19 database, two matched case–control studies of COVID‐19 outcomes were conducted. Cases—defined, respectively, as persons who (a) were hospitalized ≤30 days after COVID‐19 diagnosis (n = 33,380), and (b) were admitted to the intensive care unit or received mechanical ventilation during their COVID‐19 hospitalization (n = 10,273)—were matched 1:1 with controls based on demographic and clinical factors.

Exposures

Testosterone therapy was defined based on receipt of prescription at ≤60, ≤90, or ≤120 days before COVID‐19 diagnosis.

Main outcomes and measures

Adjusted odds ratios (ORs) for the risk of hospitalization within 30 days of COVID‐19 diagnosis and intensive care unit admission/mechanical ventilation during COVID‐19 hospitalization.

Results

The use of testosterone therapy was not associated with decreased odds of hospitalization (≤60 days: OR = 0.92, 95% confidence interval [CI] = 0.70–1.20; ≤90 days: OR = 0.87, 95% CI = 0.68–1.13; ≤120 days: OR = 0.97, 95% CI = 0.72–1.32) or intensive care unit admission/mechanical ventilation (≤60 days: OR = 0.67, 95% CI = 0.37–1.23; ≤90 days: OR = 0.63, 95% CI = 0.36–0.11; ≤120 days: OR = 0.58, 95% CI = 0.29–1.19).

Conclusions and relevance

This study showed that testosterone therapy was not associated with decreased risks of COVID‐19 adverse outcomes. These findings may provide clinically relevant information regarding testosterone treatment in older men with COVID‐19 and other respiratory viral infections with similar pathogenesis.

Lowered Serum Testosterone Concentration Is Associated With Enhanced Inflammation and Worsened Lipid Profile in Men

The negative relationship between testosterone and inflammatory cytokines has been reported for decades, although the exact mechanisms of their interactions are still not clear. At the same time, little is known about the relation between androgens and acute phase proteins. Therefore, in this investigation, we aimed to study the relationship between androgen status and inflammatory acute phase reactants in a group of men using multi-linear regression analysis. Venous blood samples were taken from 149 men ranging in age from 18 to 77 years. Gonadal androgens [testosterone (T) and free testosterone (fT)], acute phase reactants [C-reactive protein (CRP), ferritin (FER), alpha-1-acid glycoprotein (AAG), and interleukin-6 (IL-6)], cortisol (C), and lipid profile concentrations were determined. It was demonstrated that the markers of T and fT were negatively correlated with all acute phase proteins (CRP, FER, and AAG; p < 0.02) and the blood lipid profile [total cholesterol (TC), low-density lipoprotein (LDL), and triglycerides (TG); p < 0.03]. Multivariate analysis showed that T, fT, and the fT/C ratio were inversely correlated with the CRP, AAG, and FER concentrations independently of age and blood lipids. When adjustment for BMI was made, T, fT, and the fT/C ratio were negatively correlated with the AAG concentrations only. In addition, it was demonstrated that gonadal androgens were positively correlated with physical activity level (p < 0.01). We have concluded that a lowered serum T concentration may promote inflammatory processes independently of adipose tissue and age through a reduced inhibition of inflammatory cytokine synthesis, which leads to enhanced acute phase protein production. Therefore, a low serum T concentration appears to be an independent risk factor in the development of atherosclerosis and cardiovascular diseases. Moreover, the positive correlation between testosterone and physical activity level suggests that exercise training attenuates the age-related decrease in gonadal androgens and, in this way, may reduce the enhancement of systemic low-grade inflammation in aging men.

Sex steroid hormones, leptin, and high-sensitivity C-reactive protein levels in adolescents

BACKGROUND

The association of sex hormones with C-reactive protein (CRP) levels has been reported. However, this association remains unexplored in children in whom important anthropometric and hormonal changes are taking place.

OBJECTIVES

To analyze the association between high-sensitivity CRP (hs-CRP) and testosterone, estradiol and sex hormone-binding globulin (SHBG) levels in a population-based sample of adolescents, and to evaluate the influence of leptin levels on this association.

MATERIALS AND METHODS

The sample population of this cross-sectional study was comprised of 338 male and 385 female adolescents, aged 12-16 years. Information on anthropometric variables, hormone, leptin, and hs-CRP levels was available.

RESULTS

In male adolescents in our study, higher age is significantly associated with higher testosterone levels and with lower leptin and SHBG concentrations across the range of age studied. No significant changes in leptin and SHBG levels by age are observed in females. In males, leptin correlates negatively with testosterone levels (-0.263, p < 0.001), showing a stronger correlation after adjusting by body mass index (BMI) (-0.424, p < 0.001). A significant correlation between hs-CRP and testosterone levels is observed in males after adjusting by BMI, but the correlation disappears after adjusting by leptin. No association between testosterone and hs-CRP was observed in females. The negative association between hs-CRP levels and SHBG remains significant after adjusting by leptin in both sexes but disappears in males after adjusting by BMI.

CONCLUSION

The negative association between hs-CRP and testosterone concentrations observed in 12- to 16-year-old males seems to be related to leptin levels which are closely negatively related to testosterone levels in males independently of BMI.

Testosterone therapy in hypogonadal patients and the associated risks of cardiovascular events

Since the male secondary sex characters, libido and fertility are attributed to their major androgen hormone testosterone, the sub-optimum levels of testosterone in young adults may cause infertility and irregularities in their sexual behaviour. Such deficiency is often secondary to maladies involving testes, pituitary or hypothalamus that could be treated with an administration of exogenous testosterone. In the last few decades, the number of testosterone prescriptions has markedly increased to treat sub-optimal serum levels even though its administration in such conditions is not yet approved. On account of its associated cardiovascular hazards, the food and drug authority in the United States has issued safety alerts on testosterone replacement therapy (TRT). Owing to a great degree of conflict among their findings, the published clinical trials seem struggling in presenting a decisive opinion on the matter. Hence, the clinicians remain uncertain about the possible cardiovascular adversities while prescribing TRT in hypogonadal men. The uncertainty escalates even further while prescribing such therapy in older men with a previous history of cardiovascular ailments. In the current review, we analysed the pre-clinical and clinical studies to evaluate the physiological impact of testosterone on cardiovascular and related parameters. We have enlisted studies on the association of cardiovascular health and endogenous testosterone levels with a comprehensive analysis of epidemiological studies, clinical trials, and meta-analyses on the cardiovascular risk of TRT. The review is aimed to assist clinicians in making smart decisions regarding TRT in their patients.

Testosterone replacement therapy and cardiovascular risk

Testosterone is the main male sex hormone and is essential for the maintenance of male secondary sexual characteristics and fertility. Androgen deficiency in young men owing to organic disease of the hypothalamus, pituitary gland or testes has been treated with testosterone replacement for decades without reports of increased cardiovascular events. In the past decade, the number of testosterone prescriptions issued for middle-aged or older men with either age-related or obesity-related decline in serum testosterone levels has increased exponentially even though these conditions are not approved indications for testosterone therapy. Some retrospective studies and randomized trials have suggested that testosterone replacement therapy increases the risk of cardiovascular disease, which has led the FDA to release a warning statement about the potential cardiovascular risks of testosterone replacement therapy. However, no trials of testosterone replacement therapy published to date were designed or adequately powered to assess cardiovascular events; therefore, the cardiovascular safety of this therapy remains unclear. In this Review, we provide an overview of epidemiological data on the association between serum levels of endogenous testosterone and cardiovascular disease, prescription database studies on the risk of cardiovascular disease in men receiving testosterone therapy, randomized trials and meta-analyses evaluating testosterone replacement therapy and its association with cardiovascular events and mechanistic studies on the effects of testosterone on the cardiovascular system. Our aim is to help clinicians to make informed decisions when considering testosterone replacement therapy in their patients.

Association between serum high-sensitivity C-reactive protein levels and erectile dysfunction: a cross-sectional study of Chinese male population

Inflammation has been known to affect endothelial function and is involved in the progression of erectile dysfunction (ED). Thus, our present study was conducted to investigate the association between inflammatory marker high-sensitivity C-reactive protein (hs-CRP) and ED in a Chinese male population. A total of 1515 participants with anthropometric measurements, serum analyses and hs-CRP values available were included in our cross-sectional study. Data involving socioeconomic and lifestyle factors were also collected. ED was assessed by the 5-item International Index Erectile Function (IIEF-5), and hs-CRP levels were measured by the immunoturbidimetric assay. Logistic regression was applied to estimate the association between the serum hs-CRP and the risk of ED, and receiver operating characteristics (ROC) curve analysis was performed to identify the predictive value of hs-CRP. Serum hs-CRP levels were significantly higher in ED patients, and increased progressively with the incremental severity of ED (P < 0.001 for trend). In the multivariate-adjusted model, men in the highest quartile of hs-CRP level versus those in the lowest quartile had a 50% increased likelihood for ED (OR = 1.50; 95% CI = 1.08–2.08). When subjects were stratified by age, the risk of ED was more prominently in the middle-aged and elderly men. Based on the ROC analysis, serum hs-CRP has a poor diagnostic value for ED with an AUC of 0.58 (95% CI: 0.56–0.61) but has a good diagnostic performance for differentiating severe ED (AUC: 0.79; 95% CI: 0.77–0.81). Our study indicates that increased serum hs-CRP levels are associated with the severity of ED and an increased ED risk in a Chinese male population. These findings suggest that hs-CRP may be of value as an inflammatory marker for the assessment of ED risk and may play an important role in the etiology of ED.

Do Androgens Modulate the Pathophysiological Pathways of Inflammation? Appraising the Contemporary Evidence

The role of testosterone in the pathophysiology of inflammation is of critical clinical importance; however, no universal mechanism(s) has been advanced to explain the complex and interwoven pathways of androgens in the attenuation of the inflammatory processes. PubMed and EMBASE searches were performed, including the following key words: "testosterone", "androgens", "inflammatory cytokines", "inflammatory biomarkers" with focus on clinical studies as well as basic scientific studies in human and animal models. Significant benefits of testosterone therapy in ameliorating or attenuating the symptoms of several chronic inflammatory diseases were reported. Because anti⁻tumor necrosis factor therapy is the mainstay for the treatment of moderate-to-severe inflammatory bowel disease; including Crohn's disease and ulcerative colitis, and because testosterone therapy in hypogonadal men with chronic inflammatory conditions reduce tumor necrosis factor-alpha (TNF-α), IL-1β, and IL-6, we suggest that testosterone therapy attenuates the inflammatory process and reduces the burden of disease by mechanisms inhibiting inflammatory cytokine expression and function. Mechanistically, androgens regulate the expression and function of inflammatory cytokines, including TNF-α, IL-1β, IL-6, and CRP (C-reactive protein). Here, we suggest that testosterone regulates multiple and overlapping cellular and molecular pathways involving a host of immune cells and biochemical factors that converge to contribute to attenuation of the inflammatory process.

The Anti-Inflammatory Effects of Testosterone

Low plasma testosterone (T) levels correlated with metabolic syndrome, cardiovascular diseases, and increased mortality risk. T exerts a significant effect on the regulation of adipose tissue accumulation, and in the glucose and lipids metabolism. Adipocytes are the primary source of the most important adipokines responsible for inflammation and chronic diseases. This review aims to analyze the possible effect of T on the regulation of the proinflammatory cytokines secretion.

A systematic literature search on MEDLINE, Google Scholar, and Cochrane using the combination of the following keywords: “testosterone” with “inflammation,” “cytokines,” “adiponectin, CRP, IL-1B, IL-6, TNFα, leptin” was conducted. Sixteen articles related to the effect of low T level and 18 to the effect of T therapy on proinflammatory cytokine were found.

T exerts a significant inhibitory effect on adipose tissue formation and the expression of various adipocytokines, such as leptin, TNF-α, IL-6, IL-1, and is positively correlated with adiponectin level, whereas a low T level is correlated with increased expression of markers of inflammation. Further studies are necessary to investigate the role of T, integrated with weight loss and physical activity, on its action on the mechanisms of production and regulation of proinflammatory cytokines.

Metabolic Changes in Androgen-Deprived Nondiabetic Men With Prostate Cancer Are Not Mediated by Cytokines or aP2

Context

Androgen deprivation therapy (ADT) remains the cornerstone of management of prostate cancer (PCa). Previous studies have shown that men undergoing ADT develop insulin resistance and diabetes, but the mechanisms behind ADT-induced metabolic abnormalities remain unclear.

Objective

To evaluate the role of inflammatory cytokines and adipocyte protein-2 (aP2) in ADT-induced metabolic dysfunction.

Participants and Interventions

This 6-month prospective cohort study enrolled nondiabetic men with PCa about to undergo ADT (ADT group) and a control group of nondiabetic men who had previously undergone prostatectomy for localized PCa and were in remission (non-ADT group); all participants had normal testosterone at study entry. Fasting blood samples were collected at baseline and at 6, 12, and 24 weeks after initiation of ADT and at the same intervals in the non-ADT group. Glucose, insulin, lipids, inflammatory cytokines, and C-reactive protein were measured. We also measured serum aP2, an adipocyte-secreted protein that promotes hepatic glucose production. Homeostatic model assessment of insulin resistance (HOMA-IR) was calculated.

Results

Seventy-three participants formed the analytical sample (33 ADT, 40 non-ADT). HOMA-IR increased in the ADT group (estimated change = 0.25; P = 0.05), but was unchanged in the non-ADT group (0.11; P = 0.342). Serum concentrations of inflammatory cytokines or aP2 did not change significantly. There was a treatment-associated increase in total (16 mg/dL; P < 0.001), high-density lipoprotein (8 mg/dL; P < 0.001), and low-density lipoprotein (7 mg/dL; P = 0.02) cholesterol.

Conclusion

ADT-induced metabolic abnormalities were not associated with changes in circulating inflammatory cytokines or aP2 levels.

Cross-sectional and longitudinal determinants of serum sex hormone binding globulin (SHBG) in a cohort of community-dwelling men

Despite its widespread clinical use, there is little data available from population-based studies on the determinants of serum sex hormone binding globulin (SHBG). We aimed to examine multifactorial determinants of circulating SHBG levels in community-dwelling men. Study participants comprised randomly selected 35–80 y.o. men (n = 2563) prospectively-followed for 5 years (n = 2038) in the Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) study. After excluding men with illness or medications known to affect SHBG (n = 172), data from 1786 men were available at baseline, and 1476 at follow-up. The relationship between baseline body composition (DXA), serum glucose, insulin, triglycerides, thyroxine (fT4), sex steroids (total testosterone (TT), oestradiol (E2)), and pro-inflammatory cytokines and serum SHBG level at both baseline & follow-up was determined by linear and penalized logistic regression models adjusting for age, lifestyle & demographic, body composition, metabolic, and hormonal factors. Restricted cubic spline analyses was also conducted to capture possible non-linear relationships. At baseline there were positive cross-sectional associations between age (β = 0.409, p<0.001), TT (β = 0.560, p<0.001), fT4 (β = 0.067, p = 0.019) and SHBG, and negative associations between triglycerides (β = -0.112, p<0.001), abdominal fat mass (β = -0.068, p = 0.032) and E2 (β = -0.058, p = 0.050) and SHBG. In longitudinal analysis the positive determinants of SHBG at 4.9 years were age (β = 0.406, p = <0.001), TT (β = 0.461, p = <0.001), and fT4 (β = 0.040, p = 0.034) and negative determinants were triglycerides (β = -0.065, p = 0.027) and abdominal fat mass (β = -0.078, p = 0.032). Taken together these data suggest low SHBG is a marker of abdominal obesity and increased serum triglycerides, conditions which are known to have been associated with low testosterone and low T4.

Benefits and Health Implications of Testosterone Therapy in Men With Testosterone Deficiency

INTRODUCTION

Testosterone (T) deficiency (TD; hypogonadism) has deleterious effects on men's health; negatively affects glycometabolic and cardiometabolic functions, body composition, and bone mineral density; contributes to anemia and sexual dysfunction; and lowers quality of life. T therapy (TTh) has been used for the past 8 decades to treat TD, with positive effects on signs and symptoms of TD.

AIM

To summarize the health benefits of TTh in men with TD.

METHODS

A comprehensive literature search was carried out using PubMed, articles relevant to TTh were accessed and evaluated, and a comprehensive summary was synthesized.

MAIN OUTCOME MEASURES

Improvements in signs and symptoms of TD reported in observational studies, registries, clinical trials, and meta-analyses were reviewed and summarized.

RESULTS

A large body of evidence provides significant valuable information pertaining to the therapeutic value of TTh in men with TD. TTh in men with TD provides real health benefits for bone mineral density, anemia, sexual function, glycometabolic and cardiometabolic function, and improvements in body composition, anthropometric parameters, and quality of life.

CONCLUSION

TTh in the physiologic range for men with TD is a safe and effective therapeutic modality and imparts great benefits on men's health and quality of life. Traish AM. Benefits and Health Implications of Testosterone Therapy in Men With Testosterone Deficiency. Sex Med Rev 2018;6:86-105.

Hypogonadism and the risk of rheumatic autoimmune disease

Testosterone deficiency has been linked with autoimmune disease and an increase in inflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor, and interleukin-6 (IL-6). However, no large-scale longitudinal studies have examined this association. We examined whether untreated hypogonadism was associated with an increased risk of rheumatic autoimmune disease in a large nationally representative cohort. Using one of the nation's largest commercial insurance databases, we conducted a retrospective cohort study in which we identified 123,460 men diagnosed with hypogonadism between January 1, 2002 and December 31, 2014 and with no prior history of rheumatic autoimmune disease. We matched this cohort to 370,380 men without hypogonadism, at a 1 to 3 ratio, on age and index/diagnosis date. All patients were followed until December 31, 2014 or until they lost insurance coverage or were diagnosed with a rheumatic autoimmune disease. Cox proportional hazards regression was used to calculate adjusted hazard ratios (aHRs). Untreated hypogonadism was associated with an increased risk of developing any rheumatic autoimmune disease (HR = 1.33, 95 % CI = 1.28, 1.38), rheumatoid arthritis (HR = 1.31, 95 % CI = 1.22, 1.44), and lupus (HR = 1.58, 95 % CI = 1.28, 1.94). These findings persisted using latency periods of 1 and 2 years. Hypogonadism was not associated with the control outcome, epilepsy (HR = 1.04, 95 % CI = 0.96, 1.15). Patients diagnosed with hypogonadism who were not treated with testosterone had an increased risk of developing any rheumatic autoimmune disease, rheumatoid arthritis, and lupus. Future research should further examine this association, with particular attention to underlying mechanisms.

Elevated serum complement factors 3 and 4 are strong inflammatory markers of the metabolic syndrome development: a longitudinal cohort study

An epidemiological design, consisting of cross-sectional (n = 2376) and cohort (n = 976) studies, was adopted to investigate the association between complement factors 3 (C3) and 4, and the metabolic syndrome (MetS) development. In the cross-sectional study, the C3 and C4 concentrations in the MetS group were higher than those in the non-MetS group (all P < 0.001), and the levels of immune globulin M (IgM), IgA, IgE, and IgG exhibited no significant differences between MetS and non-MetS (all P > 0.050). After multi-factor adjustment, the odds ratios (ORs) in the highest quartile of C3 and C4 concentrations were 7.047 (4.664, 10.648) and 1.961 (1.349, 2.849), respectively, both P_trend < 0.050. After a 4 years follow-up, total 166 subjects were diagnosed with MetS, and the complement baseline levels from 2009 were used to predict the MetS risk in 2013. In the adjusted model, the relative risks (RRs) in the highest quartile of C3 and C4 levels were 4.779 (2.854, 8.003) and 2.590 (1.567, 4.280), respectively, both P_trend < 0.001. Activation of complement factors may be an important part of inflammatory processes, and our results indicated that the elevated C3 and C4 levels were independent risk factors for MetS development.

Obesity and sex interact in the regulation of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder, for which a number of genetic, environmental, and lifestyle risk factors have been identified. A significant modifiable risk factor is obesity in mid-life. Interestingly, both obesity and AD exhibit sex differences and are regulated by sex steroid hormones. Accumulating evidence suggests interactions between obesity and sex in regulation of AD risk, although the pathways underlying this relationship are unclear. Inflammation and the E4 allele of apolipoprotein E have been identified as independent risk factors for AD and both interact with obesity and sex steroid hormones. We review the individual and cooperative effects of obesity and sex on development of AD and examine the potential contributions of apolipoprotein E, inflammation, and their interactions to this relationship.

Adverse health effects of testosterone deficiency (TD) in men

Testosterone and its metabolite, 5α-dihydrotestosterone are critical metabolic and vascular hormones, which regulate a host of biochemical pathways including carbohydrate, lipid and protein metabolism and modulate vascular function. Testosterone deficiency (TD) is a well-recognized medical condition with important health implications. TD is associated with a number of co-morbidities including increased body weight, adiposity and increased waist circumference, insulin resistance (IR) and type 2 diabetes mellitus (T2DM), hypertension, inflammation, atherosclerosis and cardiovascular disease, erectile dysfunction (ED) and increased incidence of mortality. In this review, we summarize the data in the literature on the prevalence of TD and its association with the various co-morbidities and suggest that T therapy is necessary to improve health outcomes in men with TD.

Association between endogenous sex steroid hormones and inflammatory biomarkers in US men

Sex steroid hormones and inflammatory biomarkers are both associated with the development and progression of chronic diseases, but their interrelationship is relatively uncharacterized. We examined the association of sex hormones and sex hormone-binding globulin (SHBG) with biomarkers of inflammation, C-reactive protein (CRP) and white blood cell (WBC) count. The study included data from 809 adult men in the National Health and Nutrition Examination Survey 1999-2004. Geometric means and 95% confidence intervals were estimated separately for CRP and WBC concentrations by sex steroid hormones and SHBG using weighted linear regression models. Higher concentrations of total (slope per one quintile in concentration, -0.18; p-trend, 0.001) and calculated free (slope, -0.13; p-trend, 0.03) testosterone were statistically significantly associated with lower concentrations of CRP, but not with WBC count. Men in the bottom quintile of total testosterone (≤3.3 ng/mL), who might be considered to have clinically low testosterone, were more likely to have elevated CRP (≥3 mg/L) compared with men in the top four quintiles (OR, 1.61; 95% CI, 1.00-2.61). Total and calculated free estradiol (E2) were positively associated with both CRP (Total E2: slope, 0.14; p-trend, <0.001; Free E2: slope, 0.15; p-trend, <0.001) and WBC (Total E2: slope, 0.02; p-trend, 0.08; Free E2: slope, 0.02; p-trend, 0.02) concentrations. SHBG concentrations were inversely associated with WBC count (slope, -0.03; p-trend, 0.04), but not with CRP. These cross-sectional findings are consistent with the hypothesis that higher androgen and lower oestrogen concentrations may have an anti-inflammatory effect in men.

Sex and inflammation in respiratory diseases: a clinical viewpoint

This review discusses sex differences in the prognosis of acute or chronic inflammatory diseases. The consequences of severe inflammation vary in relation to sex, depending on illness duration. In the majority of acute diseases, males present higher mortality rates, whereas continuous chronic inflammation associated with tissue damage is more deleterious in females. The recruitment of cells, along with its clinical expression, is more significant in females, as reflected by higher inflammatory markers. Given that estrogens or androgens are known to modulate inflammation, their different levels in males and females cannot account for the sexual dimorphism observed in humans and animals from birth to death with regard to inflammation. Numerous studies evaluated receptors, cytokine production, and clinical outcomes in both animals and humans, revealing that estrogens clearly modulate the immune response, but the results are contradictory and difficult to link to hormone concentrations. Even in prepubescent children, the presentation of acute pneumonia or chronic diseases mimics the adult pattern. Several genes located on the X chromosome have been shown to encode molecules involved in inflammation. Moreover, 10% to 15% of the genes from silenced X chromosome may escape inhibition. Females are also a mosaic of cells with genes from either paternal or maternal X chromosome. Therefore, polymorphism of X-linked genes would result in the presence of two cell populations with distinct regulatory arsenals, providing females with greater diversity to fight against infectious challenges, in comparison with the uniform cell populations in hemizygous males. The similarities observed between males and Turner syndrome patients using an endotoxin stimulation model support the difference in gene expression between monosomy and disomy for the X chromosome. Considering the enhanced inflammation in females, cytokine production may be assumed to be higher in females than males. Even if all results are not clear-cut, nonetheless, many studies have reported higher cytokine levels in both male humans and animals than in females. High IL-6 levels in males correlated with poorer prognosis and shorter longevity. A sound understanding of the basic regulatory mechanisms responsible for these gender differences may lead to new therapeutic targets.

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.

Correlation of C-reactive protein level and obesity in Chinese adults and children: a meta-analysis

This meta-analysis evaluated the correlations between C-reactive protein (CRP) and obesity in Chinese adults and children. We searched three Chinese databases [Wanfang, WEIPU, and Chinese National Knowledge Infrastructure (CNKI)] in addition to PubMed. The search was restricted to only Chinese studies published online before January 9, 2013. Data from 28 articles were independently abstracted by two reviewers. The articles' characteristics were abstracted as follows: 1) first author name; 2) year of publication; 3) study population; 4) sample size; 5) sex, age, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and CRP level of the study population; 6) Pearson correlation coefficients, Spearman correlation coefficients, or odds ratios between CRP level and obesity. The metaanalysis was conducted to pool the Pearson correlation coefficients using a random-effects model. The pooled Pearson correlation coefficient between CRP and BMI was 0.45 [95% confidence interval (CI): 0.33-0.56] in Chinese adults and 0.46 (95% CI: 0.31-0.62) in Chinese children, and the pooled Pearson correlation coefficient was 0.32 (95% CI: 0.24-0.40) in the general Chinese population and 0.53 (95% CI: 0.42-0.64) in the obese Chinese population. Significant correlation was thus found between CRP and obesity in Chinese adults and children.