Association between hormones and metabolic syndrome in older Italian men

Sex Hormone-Binding Globulin and Its Association to Cardiovascular Risk Factors in an Italian Adult Population Cohort

Abnormal sex hormone-binding globulin (SHBG) and sex hormone concentrations are the cause or the consequence of cardiometabolic diseases, however, the clinical correlates of SHBG is clearly less understood. In our study we investigate sex- and age-specific serum SHBG levels and their association with cardiovascular risk (CVR) factors and high-risk conditions in an adult cohort of Italian population. Data from 1176 men and 2236 women, aged 20–81 were analyzed and serum SHBG determined in stored samples using an immunoassay. SHBG concentrations, higher in women than in men in the younger age groups, exhibited a curvilinear increase with age in men and a U-shaped curve across the lifespan in women, with a decrease from the 2nd to the 6th decade of age and an increase after the 6th decade when SHBG concentrations were similar in both sexes. Low SHBG serum levels correlated with the traditional CVR factors diabetes, obesity, and hypertension, whereas high level of SHBG correlated with cholesterol HDL. These associations were more numerous in women than in men, in whom decreased with age. The sex- and age specific differences observed in our population-based cohort should be considered in establishing reference ranges and clinical cut-off points to improve CVR score charts and therapeutic approaches.

Association between hair cortisol concentration and metabolic syndrome

Metabolic syndrome (MetS) is a highly prevalent disorder defined as a cluster of cardiometabolic risk factors including obesity, hyperglycemia, hypertension, and dyslipidemia. It is believed that excessive cortisol secretion due to psychosocial stress-induced hypothalamic-pituitary-adrenal axis activation might be involved in the pathogenesis of MetS. We sought to explore the association between MetS and psychosocial risk factors, as well as cortisol concentration measured in different biological specimens including saliva, blood serum, and hair samples. The study was conducted on a sample of 163 young and middle-aged men who were divided into groups according to the presence of MetS. Hair cortisol concentration (HCC) was determined using high performance liquid chromatography with UV detection, while blood serum and salivary cortisol levels were measured by enzyme-linked immunoassay. Lipid metabolism biomarkers were determined using routine laboratory methods. Anthropometric and lifestyle characteristics, as well as self-reported psychosocial indicators, were also examined. Significantly higher HCC and lower social support level among participants with MetS compared with individuals without MetS were found. However, no significant differences in blood serum and salivary cortisol levels were observed between men with and without MetS. In conclusion, chronically elevated cortisol concentration might be a potential contributing factor to the development of MetS.

The Relationship of Functional Status of Cortisol, Testosterone, and Parameters of Metabolic Syndrome in Male Schizophrenics

Background

The cross-sectional study is aimed at investigating the relationship between cortisol, testosterone, and metabolic characteristics among male schizophrenics.

Methods

174 patients were grouped based on their risk of metabolic syndrome (MetS) into the non-MetS, high-risk-MetS (HR-MetS), or MetS groups. Metabolic indices (body mass index (BMI), mean arterial pressure (MAP), cholesterol, triglyceride, and fasting blood glucose (FBG)) were associated with cortisol and testosterone levels using correlation analysis. Multiple linear regression analysis was used to associate the correlations between the WHO Quality of Life–BREF (WHOQOL–BREF) score and the five metabolic indices.

Results

The WHOQOL–BREF score for the non-MetS group significantly differed from the scores of the HR-MetS and MetS groups. The triglyceride level was positively correlated with the cortisol level, while all five metabolic indices were negatively correlated with testosterone level. Stepwise regression analysis produced a model predicting WHOQOL–BREF scores with four variables including MAP, intelligence quotient (IQ), FBG, and age. The correlation analysis then showed that there was a weak linear correlation between the testosterone level and all five metabolic indices.

Conclusions

Among the five metabolic indices, the risks of hypertension and hyperglycemia are correlated with the quality of life in male schizophrenics rather than those of obesity or hyperlipidemia.

Aging and the Male Reproductive System

This narrative review presents an overview of current knowledge on fertility and reproductive hormone changes in aging men, the factors driving and modulating these changes, their clinical consequences, and the benefits and risks of testosterone (T) therapy. Aging is accompanied by moderate decline of gamete quality and fertility. Population mean levels show a mild total T decline, an SHBG increase, a steeper free T decline, and a moderate LH increase with important contribution of comorbidities (e.g., obesity) to these changes. Sexual symptoms and lower hematocrit are associated with low T and are partly responsive to T therapy. The relationship of serum T with body composition and metabolic health is bidirectional; limited beneficial effects of T therapy on body composition have only marginal effects on metabolic health and physical function. Skeletal changes are associated primarily with estradiol and SHBG. Cognitive decline is not consistently linked to low T and is not improved by T therapy. Although limited evidence links moderate androgen decline with depressive symptoms, T therapy has small beneficial effects on mood, depressive symptoms, and vitality in elderly patients with low T. Suboptimal T (and/or DHT) has been associated with increased risk of stroke, but not of ischemic heart disease, whereas an association with mortality probably reflects that low T is a marker of poor health. Globally, neither severity of clinical consequences attributable to low T nor the nature and magnitude of beneficial treatment effects justify the concept of some broadly applied "T replacement therapy" in older men with low T. Moreover, long-term safety of T therapy is not established.

Insulin-Like Growth Factor 1 in the Cardiovascular System

Non-communicable diseases, such as cardiovascular diseases, are the leading cause of mortality worldwide. For this reason, a tremendous effort is being made worldwide to effectively circumvent these afflictions, where insulin-like growth factor 1 (IGF1) is being proposed both as a marker and as a central cornerstone in these diseases, making it an interesting molecule to focus on. Firstly, at the initiation of metabolic deregulation by overfeeding, IGF1 is decreased/inhibited. Secondly, such deficiency seems to be intimately related to the onset of MetS and establishment of vascular derangements leading to atherosclerosis and finally playing a definitive part in cerebrovascular and myocardial accidents, where IGF1 deficiency seems to render these organs vulnerable to oxidative and apoptotic/necrotic damage. Several human cohort correlations together with basic/translational experimental data seem to confirm deep IGF1 implication, albeit with controversy, which might, in part, be given by experimental design leading to blurred result interpretation.

Can Low SHBG Serum Concentration Be A Good Early Marker Of Male Hypogonadism In Metabolic Syndrome?

INTRODUCTION

In men suffering from metabolic syndrome, accompanying insulin resistance may result in a lowering of sex hormone-binding globulin (SHBG) plasma levels and cause changes in their androgenic status.

AIM

The objective of the research was to assess selected androgens and SHBG plasma levels in males meeting diagnostic criteria for MS compared to healthy males.

PATIENTS AND METHODS

The group consisted of 65 men aged between 40 and 70 years old fitting IDF metabolic syndrome criteria and 84 controls. Dehydroepiandrosterone (DHEA) and its sulphate (DHEA-S), total and free testosterone and SHBG serum levels were evaluated. Calculated free and bioavailable testosterone were estimated using an algorithm proposed by the International Society for the Study of the Aging Male.

RESULTS

Men diagnosed with MS showed a statistically significant decrease in plasma levels of DHEA in comparison to healthy ones: 11.579 (8.39-15.56) vs 14.014 (9.611-17.125) ng/mL; p = 0.0350, SHBG: 47.46 (35.78-62.83) vs 71.965 (54.45-91.56) nM/L; p<0.0001 and total testosterone: 5.2 (3.8-6.5) vs 6.3 (5.4-8.25) ng/mL; p = 0.0001 (values presented as a median with Q1-Q3).

CONCLUSION

The results suggest that SHBG is a good early marker for metabolic dysregulation in MS, considering its strength of association and significance is comparable to, or better than, those of MS criteria.

Basal cortisol levels and metabolic syndrome: A systematic review and meta-analysis of observational studies

OBJECTIVE

To perform a qualitative synthesis (systematic review) and quantitative analysis (meta-analysis) to summarize the evidence regarding the relationship between basal cortisol levels and metabolic syndrome (MetS) in adults.

METHODS

A systematic search was performed in the PubMed, Embase, and PsycINFO databases for observational studies on the association between basal cortisol levels and MetS. The quality of individual studies was assessed by the Newcastle-Ottawa score. A random effects model was used to report pooled quantitative results and the I2 statistic was used to assess heterogeneity. Egger's and Begg's tests were used to evaluate publication bias.

RESULTS

Twenty-six studies (19 cross-sectional and seven case-control) met the inclusion criteria for the systematic review. The majority was classified as having a low risk of bias and used established criteria for the diagnosis of MetS. Twenty-one studies provided data on basal cortisol levels as continuous values and were included in the meta-analysis; they comprised 35 analyses and 11,808 subjects. Pooled results showed no significant difference in basal cortisol levels between subjects with and without MetS (standardized mean difference [SMD] = 0.02, 95% confidence interval [CI]=-0.11 to 0.14). There was high heterogeneity between the studies when all comparisons were considered (I2 = 83.1%;p < 0.001). Paradoxically, meta-analysis of studies evaluating saliva samples showed no significantly lower basal cortisol levels among subjects with MetS (SMD=-0.18, 95% CI=-0.37 to 0.01), whereas those studies that evaluated serum samples (SMD = 0.11, 95% CI=-0.02 to 0.24) and urine samples (SMD = 0.73, 95% CI=-0.40 to 1.86) showed no significantly higher basal cortisol levels among subjects with MetS. In the subgroup and meta-regression analyses, a significant difference in basal cortisol levels was observed according to study design, population base, age, gender, cortisol level assessment method, and study quality.

CONCLUSION

This systematic review and meta-analysis does not reveal any association between basal cortisol levels and MetS based on results of observational studies. The results of a random-effect meta-analysis showed no significant difference in basal cortisol levels between subjects with and without MetS. The present findings should be considered in order to help future studies.

Association of sex hormones with metabolic syndrome among Egyptian males

BACKGROUND

Studies have shown that testosterone and estradiol (E2) are associated with metabolic syndrome (MetS). To our knowledge, few studies, if any about the association of endogenous sex hormones with MetS have been done in Egypt.

AIM

To study the relation between endogenous sex hormones and MetS among Egyptian males.

SUBJECTS AND METHOD

For the study, 80 Egyptian males were enrolled: 40 males with MetS and 40 healthy age-matched males. Anthropometric measurements and blood pressure were taken for both groups. FBG, TC, HDL-C, TG, testosterone, and E2 levels were determined; LDL-C was calculated.

RESULTS

Males with MetS had significantly lower testosterone levels and significantly higher E2 levels compared to those without MetS (p value 0.0001). The lowest quartile of testosterone was most prevalent among males with MetS (19/40 males, 47.5%) compared to those without MetS (0/40 males, 0%, p value 0.011). Estradiol in the third quartile was most prevalent among males with MetS (19/40 males, 47.5%) compared to those without MetS (1/40 males, 2.5%, p value 0.0001). Serum testosterone and E2 levels were independent predictors of MetS with optimum cut off value (≤2.37ng/ml) for testosterone and (>16.78pg/ml) for E2.

CONCLUSION

Endogenous testosterone and estradiol are independently associated with MetS with potential utility as predictors of MetS.

Aging and sex hormones in males

Several large cohort studies have disclosed the trajectories of sex steroids changes overtime in men and their clinical significance. In men the slow, physiological decline of serum testosterone (T) with advancing age overlaps with the clinical condition of overt, pathological hypogonadism. In addition, the increasing number of comorbidities, together with the high prevalence of chronic diseases, all further contribute to the decrease of serum T concentrations in the aging male. For all these reasons both the diagnosis of late-onset hypogonadism (LOH) in men and the decision about starting or not T replacement treatment remain challenging. At present, the biochemical finding of T deficiency alone is not sufficient for diagnosing hypogonadism in older men. Coupling hypogonadal symptoms with documented low serum T represents the best strategy to refine the diagnosis of hypogonadism in older men and to avoid unnecessary treatments.

Lower SHBG level is associated with higher leptin and lower adiponectin levels as well as metabolic syndrome, independent of testosterone

In addition to testosterone (T), the emerging role of sex hormone-binding globulin (SHBG) in pathogenesis of metabolic syndrome (MetS) has been noted recently. However, reports of associations with serum adipocytokine levels are still limited. Therefore, we conducted this study to evaluate whether serum T and SHBG levels are independent predictors for the risk of MetS that are associated with adiponectin and leptin levels in 614 Taiwanese men over 40 years old collected from a free health screening. Subjects in the lowest quartile of TT and SHBG levels are exposed to a 1.58 and 3.22 times risk of developing MetS, as compared to those in the highest quartile of TT and SHBG levels. However, SHBG retains its significance independent of TT as a MetS risk predictor, but not vice versa. In addition, SHBG was significantly correlated with both adiponectin and leptin levels even after adjusting for TT levels. In conclusion, SHBG served as a major predictor for the risk of MetS and was correlated with serum adiponectin and leptin levels that are independent of T. Further studies are needed to elucidate the true role of SHBG in the pathogenesis of MetS and possible mechanisms associated with serum adiponectin and leptin levels.

Metabolic concerns in aging HIV-infected persons: from serum lipid phenotype to fatty liver

: Among HIV-infected persons, the assessment of nonalcoholic fatty liver disease (NAFLD) provides a window through which overall metabolic health can be evaluated. In this review, we summarize clinical data that support the roles of aging and metabolic dysregulation as factors contributing to fatty liver/NAFLD among HIV-infected persons.Age-related metabolic alterations include hepatic anatomic and functional changes, altered homeostasis of gastrointestinal microbiota and anthropometric changes (such as a shift of body fat depots from the subcutaneous to the visceral compartment) that are often associated with the development of insulin resistance and increased cardiovascular risk.Fatty changes in the liver occur not only with metabolic disruption but also with virus-induced injury. Chronic hepatitis C virus infection is commonly associated with fatty liver, and can be related to both hepatitis C virus genotype and host metabolic features. Similarly, HIV infection is associated with fatty liver as a result of multiple viral and host factors. Clearly, lipodystrophy, dysregulation of the gut-liver axis and HIV infection itself may each contribute simultaneously to NAFLD pathogenesis. Although lifestyle changes are the mainstay of treatment, to date no drug has specifically been approved for use in persons with NAFLD. Moreover, current guidelines provide no specific therapeutic recommendations for persons with NAFLD older than 65 years.Well-designed studies characterizing the epidemiology, pathogenesis, clinical outcomes and potential therapeutic interventions for liver disease and associated metabolic comorbidities in older HIV-infected patients are urgently needed.

Hypopituitarism in the elderly: a narrative review on clinical management of hypothalamic-pituitary-gonadal, hypothalamic-pituitary-thyroid and hypothalamic-pituitary-adrenal axes dysfunction

Hypopituitarism is an uncommon and under-investigated endocrine disorder in old age since signs and symptoms are unspecific and, at least in part, can be attributed to the physiological effects of aging and related co-morbidities. Clinical presentation is often insidious being characterized by non-specific manifestations, such as weight gain, fatigue, low muscle strength, bradipsychism, hypotension or intolerance to cold. In these circumstances, hypopituitarism is a rarely life-threatening condition, but evolution may be more dramatic as a result of pituitary apoplexy, or when a serious condition of adrenal insufficiency suddenly occurs. Clinical presentation depends on the effects that each pituitary deficit can cause, and on their mutual relationship, but also, inevitably, it depends on the severity and duration of the deficit itself, as well as on the general condition of the patient. Indeed, indications and methods of hormone replacement therapy must include the need to normalize the endocrine profile without contributing to the worsening of intercurrent diseases, such as those of glucose and bone metabolism, and the cardiovascular system, or to the increasing cancer risk. Hormonal requirements of elderly patients are reduced compared to young adults, but a prompt diagnosis and appropriate treatment of pituitary deficiencies are strongly recommended, also in this age range.

Is serum sex hormone-binding globulin a dominant risk factor for metabolic syndrome?

This multi-center, cross-sectional study investigated the association between serum testosterone (T) levels, serum sex hormone-binding globulin (SHBG) levels, and the risk of metabolic syndrome (MS) in 3332 adult Chinese men. The prevalence of MS was 34.7%, and men with MS had lower serum levels of total T (TT) and SHBG than those without MS (P < 0.001). There was no significant difference in serum free T (FT) levels between subjects with and without MS (P = 0.627). In logistic regression analysis, the association between MS and serum SHBG levels persisted after adjusting for age, body mass index (BMI), smoking and drinking status, and serum TT (odds ratio [OR] 0.962, 95% confidence interval [95% CI] 0.954-0.969, P< 0.01). However, the association between serum TT level and the risk of MS was weak after adjusting for age, BMI, SHBG level, and smoking and drinking status (OR 0.981, 95% CI 0.960-1.007). Our study reveals that both serum TT and SHBG levels, but not serum FT, are inversely associated with the prevalence of MS and that serum SHBG is an independent and dominant risk factor for MS.

Improvements in body composition, cardiometabolic risk factors and insulin sensitivity with trenbolone in normogonadic rats

Trenbolone (TREN) is used for anabolic growth-promotion in over 20 million cattle annually and continues to be misused for aesthetic purposes in humans. The current study investigated TREN's effects on body composition and cardiometabolic risk factors; and its tissue-selective effects on the cardiovascular system, liver and prostate. Male rats (n=12) were implanted with osmotic infusion pumps delivering either cyclodextrin vehicle (CTRL) or 2mg/kg/day TREN for 6 weeks. Dual-energy X-ray Absorptiometry assessment of body composition; organ wet weights and serum lipid profiles; and insulin sensitivity were assessed. Cardiac ultrasound examinations were performed before in vivo studies assessed myocardial susceptibility to ischemia-reperfusion (I/R) injury. Circulating sex hormones and liver enzyme activities; and prostate and liver histology were examined. In 6 weeks, fat mass increased by 34±7% in CTRLs (p<0.01). Fat mass decreased by 37±6% and lean mass increased by 11±4% with TREN (p<0.05). Serum triglycerides, HDL and LDL were reduced by 62%, 57% and 78% (p<0.05) respectively in TREN rats. Histological examination of the prostates from TREN-treated rats indicated benign hyperplasia associated with an increased prostate mass (149% compared to CTRLs, p<0.01). No evidence of adverse cardiac or hepatic effects was observed. In conclusion, improvements in body composition, lipid profile and insulin sensitivity (key risk factors for cardiometabolic disease) were achieved with six-week TREN treatment without evidence of adverse cardiovascular or hepatic effects that are commonly associated with traditional anabolic steroid misuse. Sex hormone suppression and benign prostate hyperplasia were confirmed as adverse effects of the treatment.

Analysis of relationships between the concentrations of total testosterone and dehydroepiandrosterone sulfate and the occurrence of selected metabolic disorders in aging men

OBJECTIVE

The evaluation of relationships between the concentrations of dehydroepiandrosterone sulfate (DHEAS) and total testosterone (TT) and the occurrence of metabolic disorders, including metabolic syndrome (MetS).

METHOD

The participants were subjected to anthropometric measurements and were tested for DHEAS, TT, lipid parameters and carbohydrate parameters.

RESULT

We observed a lower concentration of DHEAS in the men with hypertension (HT) compared to those without HT. In the men with MetS, HT, overweight and obesity, the concentration of TT was lower than in the men without these problems. We found statistically significant positive correlations (DHEAS- total cholesterol [TCh], DHEAS- low-density lipoprotein [LDL], TT- high-density lipoprotein [HDL], TT-waist-to-hip ratio [WHR]) and negative correlations (DHEAS-age, TT-body weight, TT- body mass index [BMI], TT-abdominal circumference [AC], TT-hip circumference [HC], TT- triglyceride [TG], TT- fasting plasma glucose [FPG], TT- serum insulin levels [I], TT- Homeostasis Model Assessment-Insulin Resistance [HOMA-IR]). Using logistic regression it was ascertained that lower TT levels increase the risk of HT, and were also associated with obesity.

CONCLUSION

Our research indicates relationships between TT and the occurrence of MetS and its individual components. Excess body weight in men is a factor associated with lower TT levels. It seems necessary to determine TT in men with MetS and overweight or obesity. DHEAS did not show any significant relations with MetS and its parameters. Age was the most crucial factor responsible for the decrease in DHEAS.

Testosterone supplementation therapy in the treatment of patients with metabolic syndrome

Metabolic syndrome (MetS) comprises a clinical complex of patient risk factors, including increased waist circumference, high triglyceride levels, low high-density lipoprotein cholesterol level, high blood pressure, and insulin resistance, the presence of which increases the likelihood of developing diabetes and cardiovascular disease. With a quarter of the American adult population affected, MetS and type 2 diabetes mellitus have been referred to as the most significant public health threats of the 21st century. Lifestyle modification and weight loss are recommended, however, no specific pharmacologic treatment is known. Given that low levels of testosterone have been implicated in the pathogenesis of MetS and an inverse relationship exists between circulating testosterone levels and the development of MetS, it is tempting to speculate that men with MetS may benefit from testosterone supplementation therapy. As such, our review examines the role of testosterone and the use of testosterone supplementation therapy as a treatment in men with MetS.

Mitochondrial adaptations evoked with exercise are associated with a reduction in age-induced testicular atrophy in Fischer-344 rats

Mitochondrial dysfunction in various tissues has been associated with numerous conditions including aging. In testes, aging induces atrophy and a decline in male reproductive function but the involvement of mitochondria is not clear. The purpose of this study was to examine whether the mitochondrial profile differed with (1) aging, and (2) 10-weeks of treadmill exercise training, in the testes of young (6 month) and old (24 month) Fischer-344 (F344) animals. Old animals exhibited significant atrophy (30 % decline; P < 0.05) in testes compared to young animals. However, relative mitochondrial content was not reduced with age and this was consistent with the lack of change in the mitochondrial biogenesis regulator protein, peroxisome proliferator-activated receptor gamma coactivator 1-alpha and its downstream targets nuclear respiratory factor-1 and mitochondrial transcription factor A. No effect was observed in the pro- or anti-apoptotic proteins, Bax and Bcl-2, respectively, but age increased apoptosis inducing factor levels. Endurance training induced beneficial mitochondrial adaptations that were more prominent in old animals including greater increases in relative mtDNA content, biogenesis/remodeling (mitofusin 2), antioxidant capacity (mitochondrial superoxide dismutase) and lower levels of phosphorylated histone H2AX, an early marker of DNA damage (P < 0.05). Importantly, these exercise-induced changes were associated with an attenuation of testes atrophy in older sedentary animals (P < 0.05). Our results indicate that aging-induced atrophy in testes may not be associated with changes in relative mitochondrial content and key regulatory proteins and that exercise started in late-life elicits beneficial changes in mitochondria that may protect against age-induced testicular atrophy.

Testosterone, sex hormone-binding globulin and the metabolic syndrome in men: an individual participant data meta-analysis of observational studies

Background

Low total testosterone (TT) and sex hormone-binding globulin (SHBG) concentrations have been associated with the metabolic syndrome (MetS) in men, but the reported strength of association varies considerably.

Objectives

We aimed to investigate whether associations differ across specific subgroups (according to age and body mass index (BMI)) and individual MetS components.

Data sources

Two previously published meta-analyses including an updated systematic search in PubMed and EMBASE.

Study Eligibility Criteria

Cross-sectional or prospective observational studies with data on TT and/or SHBG concentrations in combination with MetS in men.

Methods

We conducted an individual participant data meta-analysis of 20 observational studies. Mixed effects models were used to assess cross-sectional and prospective associations of TT, SHBG and free testosterone (FT) with MetS and its individual components. Multivariable adjusted odds ratios (ORs) and hazard ratios (HRs) were calculated and effect modification by age and BMI was studied.

Results

Men with low concentrations of TT, SHBG or FT were more likely to have prevalent MetS (ORs per quartile decrease were 1.69 (95% CI 1.60-1.77), 1.73 (95% CI 1.62-1.85) and 1.46 (95% CI 1.36-1.57) for TT, SHBG and FT, respectively) and incident MetS (HRs per quartile decrease were 1.25 (95% CI 1.16-1.36), 1.44 (95% 1.30-1.60) and 1.14 (95% 1.01-1.28) for TT, SHBG and FT, respectively). Overall, the magnitude of associations was largest in non-overweight men and varied across individual components: stronger associations were observed with hypertriglyceridemia, abdominal obesity and hyperglycaemia and associations were weakest for hypertension.

Conclusions

Associations of testosterone and SHBG with MetS vary according to BMI and individual MetS components. These findings provide further insights into the pathophysiological mechanisms linking low testosterone and SHBG concentrations to cardiometabolic risk.

Adiponectin, leptin, and chemerin in elderly patients with type 2 diabetes mellitus: a close linkage with obesity and length of the disease

Obesity, insulin resistance, and aging are closely associated and adipokines seem to have a crucial role in their pathophysiology. We aim to study the relationship between aging and chemerin, adiponectin, and leptin levels in type 2 diabetes mellitus (T2DM). Age correlated positively with chemerin and leptin and inversely with adiponectin. Body mass index (BMI) correlated positively with leptin (in males) and chemerin and inversely with adiponectin. The patients with ≥65 years (n = 34) showed significantly higher leptin and chemerin and lower adiponectin levels than middle-aged (38–64 years) patients (n = 39) and controls (n = 20). After statistical adjustment for length of disease, there was a loss of significance, between T2DM groups, for adiponectin and, in female, for leptin. In the older group, BMI correlated with adiponectin and with leptin, but not with chemerin. Adiponectin and leptin levels in elderly T2DM patients seem to be closely linked to obesity and to length of the disease. In elderly T2DM patients, chemerin concentrations are increased and seem to be independent of length of disease and BMI, suggesting that adipocyte dysfunction is enhanced with aging. The understanding of the glucose homeostasis impairment in the elderly is mandatory in order to achieve ways to improve their quality of life and longevity.

A 6-month observational study of energy, sexual desire, and body proportions in hypogonadal men treated with a testosterone 1% gel

AIMS AND METHODS

This was a 6-month, open label, multinational, observational study in hypogonadal men treated with daily titrated dose of 50, 75, or 100 mg 1% testosterone gel (AndroGel®) in community practice. Primary outcome was effect of treatment on hypogonadal symptoms and quality of life as assessed by Aging Males' Symptoms (AMS) scale. Secondary objectives included erectile dysfunction (International Index of Erectile Function [IIEF]), fatigue (Multidimensional Fatigue Inventory [MFI]), and surrogates for body composition (waist circumference, body mass index [BMI]).

RESULTS

Seven hundred and ninety-nine of the 1053 men enrolled had follow-up data at 6 months, 81.2% had ≥1 testosterone value in the normal range during the study. Substantial and significant improvements were observed in mean AMS score (-29%), IIEF score (+115.7%), and MFI scores (-21.5%). Further beneficial effects were significant decreases in mean BMI (-0.8 kg/m(2)) and waist circumference (-3.3 cm). Younger age quartiles showed greater improvements in AMS, MFI, BMI, and waist circumference than older quartiles. IIEF scores, however, did not differ significantly by age category.

CONCLUSIONS

Substantial improvements in hypogonadal symptoms, quality of life, fatigue, erectile dysfunction, and libido/sexual desire were observed. Adverse drug reactions were experienced by 7.5% of the safety population over the 6-month study period.

The Interplay between Magnesium and Testosterone in Modulating Physical Function in Men

The role of nutritional status as key factor of successful aging is very well recognized. Among the different mechanisms by which nutrients may exert their beneficial effects is the modulation of the hormonal anabolic milieu, which is significantly reduced with aging. Undernutrition and anabolic hormonal deficiency frequently coexist in older individuals determining an increased risk of mobility impairment and other adverse outcomes. Mineral assessment has received attention as an important determinant of physical performance. In particular, there is evidence that magnesium exerts a positive influence on anabolic hormonal status, including Testosterone, in men. In this review we summarize data from observational and intervention studies about the role of magnesium in Testosterone bioactivity and the potential underlying mechanisms of this relationship in male subjects. If larger studies will confirm these pivotal data, the combination of hormonal and mineral replacements might be adopted to prevent or delay the onset of disability in the elderly.

The relationship between lower urinary tract symptoms/benign prostatic hyperplasia and the number of components of metabolic syndrome

OBJECTIVE

To investigate the relationship between lower urinary tract symptoms (LUTS)/benign prostate hyperplasia (BPH) and a number of components of metabolic syndrome (MetS).

METHODS

A total of 1224 male police officers aged 50-59 years who had participated in a health examination were included. LUTS/BPH were assessed by prostate-specific antigen, international prostate symptom score (IPSS), total prostate volume (TPV), maximum urinary flow rate (Qmax), and postvoid residual (PVR) urine volume. Testosterone levels were also examined. MetS was defined using National Cholesterol Education Program-Adult Treatment Panel III guidelines. The subjects were classified into 4 groups according to the number of exhibited MetS components (0, 1-2, 3, and 4-5). We used the Mantel-Haenszel extension test and logistic regression analyses.

RESULTS

MetS was diagnosed in 29.0% of the patients. The BPH ratio (IPSS >7, TPV ≥30 mL, and/or Qmax <15 mL/sec), TPV ≥30 mL, and PVR ≥50 mL significantly increased with an increasing number of metabolic abnormalities. The odds ratio (OR) in relation to a TPV ≥30 mL and a PVR ≥50 mL significantly rose as the number of positive MetS components increased after adjusting for age and testosterone. Additionally, the ORs (adjusting for age and testosterone) in relation to BPH also increased as the number of positive MetS components increased, with a suggestive threshold effect associated with 4-5 positive components (BPH: IPSS >7 + TPV ≥30 mL; 4 and 5 components, 3.496, 1.805-6.769, P = .001; BPH: IPSS >7 + TPV ≥30 mL + Qmax <15 mL/sec; 4 and 5 components, 5.458, 1.777-16.764, P = .002).

CONCLUSION

According to our results, the cases of LUTS/BPH were positively associated with the number of MetS components.

Both total testosterone and sex hormone-binding globulin are independent risk factors for metabolic syndrome: results from Fangchenggang Area Male Health and Examination Survey in China

BACKGROUND

Metabolic syndrome is often beneficial from testosterone replacement therapy. Although testosterone and sex hormone-binding globulin (SHBG) are inversely associated with the risk of metabolic syndrome, it is controversial whether the association between testosterone and metabolic syndrome is independent of SHBG.

METHODS

Testosterone, SHBG and metabolic syndrome were evaluated in 2361 men aged 20-73 years, who participated in the population-based Fangchenggang Area Male Health and Examination Survey. Total testosterone, SHBG and other biochemical profiles were measured. Free testosterone and bioavailable testosterone were calculated on the basis of Vermeulen's formula. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria for Asian population. The independent associations with metabolic syndrome were determined by multivariate logistic regression analysis.

RESULTS

Men with metabolic syndrome had a lower level of total testosterone, bioavailable testosterone, free testosterone, or SHBG than those without metabolic syndrome (all p < 0.001). Both total testosterone and SHBG were inversely correlated with body mass index or homeostasis model assessment of insulin resistance (all age-adjusted p < 0.001). Men within the lowest quartile of total testosterone [odds ratio (OR) = 4.86, 95% confidence interval (CI) = 2.72-8.68], bioavailable testosterone (OR = 3.04, 95% CI = 1.81-5.10), free testosterone (OR = 3.08, 95% CI = 1.81-5.27) or SHBG (OR = 4.28, 95% CI = 2.52-7.27) had a risk of metabolic syndrome after adjusting for age, smoking, homeostasis model assessment of insulin resistance and body mass index. Total testosterone remained inversely associated with metabolic syndrome after further adjusting for SHBG (OR = 0.95, 95% CI = 0.92-0.99), while SHBG remained inversely associated with metabolic syndrome after further adjusting for total testosterone (OR = 0.99, 95% CI = 0.97-1.00).

CONCLUSION

Total testosterone and SHBG are independent risk factors of metabolic syndrome. Prospective studies are needed to explore whether the association between sex hormones and metabolic syndrome was mediated by insulin resistance or obesity.

Cortisol in hair and the metabolic syndrome

CONTEXT

Although exposure to supraphysiological levels of glucocorticoids is known to contribute to the development of the metabolic syndrome (MetS), the importance of physiological variation in basal cortisol secretion is less clear. This issue can be addressed by using hair cortisol analysis, which for the first time allows the assessment of long-term integrated hormone levels.

OBJECTIVE AND DESIGN

We used the analysis of cortisol in hair (hairF) to examine associations of long-term cortisol levels with prevalence of MetS and individual cardiometabolic parameters in a large occupational cohort. In additional exploratory analyses, we also studied cardiometabolic associations with hair cortisone levels.

PARTICIPANTS

Participants included 1258 employees of a large aerospace company (aged 16-64 years; 84.8% males) who partook in a voluntary health assessment.

MAIN OUTCOME MEASURES

The first 3 cm of scalp-near hair were analyzed for glucocorticoid concentrations using liquid chromatography tandem mass spectrometry. Relevant cardiometabolic risk factors were assessed and MetS was diagnosed (according to 2009 international task force criteria).

RESULTS

A higher prevalence of MetS was seen in individuals falling into the third (odds ratio 1.71, 95% confidence interval 1.08-2.69) or fourth hairF quartile (odds ratio 2.42, 95% confidence interval 1.55-3.75) compared with the first quartile, in fully adjusted analyses. HairF also showed positive associations with weight-related anthropometric measures (body mass index, waist to hip ratio, waist circumference) and glycated hemoglobin. The exploratory analysis of hair cortisone also indicated relevant associations with cardiometabolic parameters.

CONCLUSION

Normal physiological differences in long-term cortisol secretion, as assessed in hair, show relevant relationships with MetS and individual cardiometabolic parameters.

Serum IGF1, metabolic syndrome, and incident cardiovascular disease in older people: a population-based study

OBJECTIVE

High as well as low levels of IGF1 have been associated with cardiovascular diseases (CVD). The relationship of IGF1 with (components of) the metabolic syndrome could help to clarify this controversy. The aims of this study were: i) to investigate the association of IGF1 concentration with prevalent (components of) the metabolic syndrome; and ii) to examine the role of (components of) the metabolic syndrome in the relationship between IGF1 and incident CVD during 11 years of follow-up.

METHODS

Data were used from the Longitudinal Aging Study Amsterdam, a cohort study in a representative sample of the Dutch older population (≥65 years). Data were available in 1258 subjects. Metabolic syndrome was determined using the definition of the US National Cholesterol Education Program Adult Treatment Panel III. CVD were ascertained by self-reports and mortality data.

RESULTS

Levels of IGF1 in the fourth quintile were associated with prevalent metabolic syndrome compared with the lowest quintile (odds ratio: 1.59, 95% confidence interval (CI) 1.09-2.33). The middle up to the highest quintile of IGF1 was positively associated with high triglycerides in women. Metabolic syndrome was not a mediator in the U-shaped relationship of IGF1 with CVD. Both subjects without the metabolic syndrome and low IGF1 levels (hazard ratio (HR) 1.75, 95% CI 1.12-2.71) and subjects with the metabolic syndrome and high IGF1 levels (HR 2.28, 95% CI 1.21-4.28) demonstrated increased risks of CVD.

CONCLUSIONS

In older people, high-normal IGF1 levels are associated with prevalent metabolic syndrome and high triglycerides. Furthermore, this study suggests the presence of different pathomechanisms for both low and high IGF1 levels and incident CVD.

Cortisol, obesity, and the metabolic syndrome: a cross-sectional study of obese subjects and review of the literature

OBJECTIVE

Circulating cortisol and psychosocial stress may contribute to the pathogenesis of obesity and metabolic syndrome (MS). To evaluate these relationships, a cross-sectional study of 369 overweight and obese subjects and 60 healthy volunteers was performed and reviewed the previous literature.

DESIGN AND METHODS

Overweight and obese subjects had at least two other features of Cushing's syndrome. They underwent measurements representing cortisol dynamics (24 h urine cortisol excretion (UFC), bedtime salivary cortisol, 1 mg dexamethasone suppression test) and metabolic parameters (BMI, blood pressure (BP); fasting serum triglycerides, HDL, insulin, and glucose). Subjects also completed the Perceived Stress Scale (PSS). UFC, salivary cortisol, and weight from 60 healthy volunteers were analyzed.

RESULTS

No subject had Cushing's syndrome. UFC and dexamethasone responses were not associated with BMI or weight. However, salivary cortisol showed a trend to increase as BMI increased (P < 0.0001), and correlated with waist circumference (WC) in men (rs = 0.28, P = 0.02) and systolic BP in women (rs = 0.24, P = 0.0008). Post-dexamethasone cortisol levels were weak to moderately correlated with fasting insulin (rs = -0.31, P = 0.01) and HOMA-IR (rs = -0.31, P = 0.01) in men and systolic (rs = 0.18, P = 0.02) and diastolic BP (rs = 0.20, P = 0.009) in women. PSS results were higher in obese subjects than controls, but were not associated with cortisol or metabolic parameters. As expected, WC correlated with fasting insulin, HOMA-IR, and systolic BP (adjusted for BMI and gender; P < 0.01). Literature showed inconsistent relationships between cortisol and metabolic parameters.

CONCLUSION

Taken together, these data do not support a strong relationship between systemic cortisol or stress and obesity or MS.

The relationship between sex hormones, sex hormone binding globulin and peripheral artery disease in older persons

OBJECTIVE

The prevalence of peripheral artery disease (PAD) increases with aging and is higher in persons with metabolic syndrome and diabetes. PAD is associated with adverse outcomes, including frailty and disability. The protective effect of testosterone and sex hormone binding globulin (SHBG) for diabetes in men suggests that the biological activity of sex hormones may affect PAD, especially in older populations.

METHODS

Nine hundred and twenty-one elderly subjects with data on SHBG, testosterone (T), estradiol (E2) were selected from InCHIANTI study. PAD was defined as an Ankle-Brachial Index (ABI) < 0.90. Logistic regression models adjusted for age (Model 1), age, BMI, insulin, interleukin-6, physical activity, smoking, chronic diseases including metabolic syndrome (Model 2), and a final model including also sex hormones (Model 3) were performed to test the relationship between SHBG, sex hormones and PAD.

RESULTS

The mean age (±SD) of the 419 men and 502 women was 75.0 ± 6.8 years. Sixty two participants (41 men, 21 women) had ABI < 0.90. Men with PAD had SHBG levels lower than men without PAD (p = 0.03). SHBG was negatively and independently associated with PAD in men (p = 0.028) but not in women. The relationship was however attenuated after adjusting for sex hormones (p = 0.07). The E2 was not significantly associated with PAD in both men and women. In women, but not in men, T was positively associated with PAD, even after adjusting for multiple confounders, including E2 (p = 0.01).

CONCLUSIONS

Low SHBG and high T levels are significantly and independently associated with the presence of PAD in older men and women, respectively.

Androgens for postmenopausal women's health?

Obesity, metabolic syndrome, and diabetes are becoming a leading health concern in the developed Countries, due to their link to cardiovascular disease. These conditions are common in women in the post-menopausal period. Unfortunately, actual lifestyle change strategy fail to prevent cardiovascular events for several reasons, thus specific medications are needed. In addition, it was showed an increased cardiovascular diseases and breast cancer risk in postmenopausal women taking estrogens alone or with progestin, thus the optimal therapy for the prevention of chronic disease in women is still lacking. Androgens exert different actions on organs like adipose tissue, brain, bone, and on cardiovascular system. However, a debate still exists on the positive role of androgens on human health, especially in women. Furthermore, the vascular effects of androgens remain poorly understood and have been controversial for a long time. Sex hormones are important determinants of body composition. Aging is, often, accompanied by a decrease in free testosterone levels, a concomitant reduction in muscle mass and an increase in fat mass. Furthermore, numerous studies showed that total serum testosterone levels were inversely related to the atherosclerosis disease incidence in postmenopausal women. New therapeutic targets may, therefore, arise understanding how androgen could influence the fat distribution, the metabolic disease onset, the vascular reactivity and cardiovascular risk, in both sex.

A randomized, double-blind, placebo-controlled trial of testosterone gel on body composition and health-related quality-of-life in men with hypogonadal to low-normal levels of serum testosterone and symptoms of androgen deficiency over 6 months with 12 months open-label follow-up

INTRODUCTION

The clinical significance of low to low-normal testosterone (T) levels in men remains debated.

AIM

To analyze the effects of raising serum T on lean body mass (LBM), fat mass (FM), total body mass, and health-related quality-of-life (HRQoL).

METHODS

Randomized, double-blind, placebo-controlled study. Men, aged 50-80 years, with serum total T<15 nmol/L and bioavailable T < 6.68 nmol/L, and a Aging Males' Symptoms (AMS) total score >36, received 6 months treatment with transdermal 1% T gel (5-7.5 mg/day; n =183) or placebo gel (n =179), followed by 12 months open-label with T in all.

RESULTS

After 6 months, LBM increased in T- treated patients by 1.28 ± 0.15 kg (mean ± SE) and FM decreased by 1.16 ± 0.16 kg, with minor changes with placebo (LBM +0.02 ± 0.10 kg and FM -0.14 ± 0.12 kg; all p < 0.001, T group vs. placebo). Changes were largely similar across subgroups of age, baseline total testosterone, and baseline BMI. Total HRQoL improved compared with placebo (p < 0.05, T group vs. placebo).

CONCLUSIONS

Six months 1% T gel improved body composition and HRQoL in symptomatic men with low to low-normal T, with further improvements over the following 12 months.

Cardiovascular and metabolic comorbidities in patients with obstructive sleep apnoea syndrome

The purpose of this study was to evaluate the correlation between severity of obstructive sleep apnoea syndrome (OSAS), cardiovascular disease and metabolic syndrome. We recruited 1185 patients with OSAS who underwent a complete ENT examination, including nasolaryngeal fibre optic endoscopy with Müller's manoeuvre, overnight cardio-respiratory monitoring, Epworth Sleepiness Scale (ESS) to measure daytime sleepiness, body mass index (BMI), measurement of blood pressure and blood tests.SUBSEQUENTLY, SUBJECTS WERE DIVIDED INTO THREE SUBGROUPS ACCORDING TO THE APNOEA HYPOPNOEA INDEX (AHI): mild OSAS (AHI 5-15), moderate OSAS (AHI 15-30) and severe OSAS (AHI > 30). In the sample collected, 347 (262 males and 85 females) of 1185 patients suffered from mild OSAS, 363 (269 males and 94 females) from moderate OSAS and 475 (330 males and 145 females) from severe OSAS. In the group suffering from mild OSAS, we found: 127 patients affected by hypertension, 48 with diabetes, 11 with dyslipidaemia and 32 with metabolic syndrome. In the group with moderate OSAS there were 157 patients with hypertension, 63 with diabetes, 72 with dyslipidaemia and 47 with metabolic syndrome. In the group suffering from severe OSAS there were 244 patients with hypertension, 138 with diabetes, 47 with dyslipidaemia and 90 with metabolic syndrome. For data analysis, we used the Spearman correlation test adjusted according to Sidak between the dependent variable AHI and the independent variables BMI, ESS, average SO2 (SO(2med)), hypertension, diabetes mellitus, dyslipidaemia and metabolic syndrome. The results show different patterns of correlation in terms of statistical significance: BMI ρ(s) = 0.26, SO(2med) ρ(s) = -0:51, hypertension ρ(s) = -0.05, dyslipidaemia ρ(s) = 0.22 for women, and BMI ρ(s) = 0.53, ESS ρ(s) = 0.28, SO(2med) ρ(s) = -0.50, hypertension ρ(s) = 0.17, diabetes mellitus ρ(s) = 0.28 and metabolic syndrome ρ(s) = 0.26 for men. The results of the study confirm the existence of a statistically significant correlation between the severity of OSAS and BMI, ESS, average SO2, hypertension, diabetes mellitus, dyslipidaemia and metabolic syndrome.

Testosterone and metabolic syndrome: The link

Metabolic syndrome (MetS) or "Syndrome X" which is a constellation of insulin resistance, hyperglycemia, hypertension, low high-density lipoprotein cholesterol (HDL-C), and increased very-low-density lipoprotein (VLDL) and triglyceride (TG) levels. It is one of the main threats for public health in the 21st century with its associated risk of cardiovascular disease. This condition affects a major chunk of mankind. International Diabetes Federation (IDF) estimated that around 20-25% of the adult population of the world has MetS. Several definitions have been put forward by different expert bodies leading to confusion. To overcome this, joint new statement of many expert group have been issued. Serum testosterone (T) has been shown to be associated with MetS. Several studies have shown a higher prevalence of MetS in subjects with low testosterone. There are also several studies showing a significant difference in serum T between those with MetS and those without. Serum T has also been shown to be associated with components of MetS and testosterone replacement therapy (TRT) improves various metabolic and anthropometric parameters in MetS. Patients with androgen deprivation for treatment of various cancers have also been reported to have higher prevalence of MetS. But the evidence of association is not sufficient evidence for the causation of MetS by low testosterone and long-term studies are needed to confirm whether T deficiency is the cause or is a feature of MetS.

Association of baseline sex hormone levels with baseline and longitudinal changes in waist-to-hip ratio: Multi-Ethnic Study of Atherosclerosis

Objective

Waist-to-hip ratio (WHR) is strongly associated with prevalent atherosclerosis. We analyzed the associations of baseline serum levels of testosterone (T), estradiol (E2), sex hormone binding globulin (SHBG), and dehydroepiandrosterone (DHEA) with WHR in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort.

Subjects

Baseline data was available for 3144 men and 2038 postmenopausal women, who were non-users of hormone therapy, who were 45–84 years of age, and of White, Chinese, Black or Hispanic racial/ethnic groups. Of these, 2708 men and 1678 women also had longitudinal measurements of WHR measured at the second and/or the third study visits (median follow-up 578 days, and 1135 days, respectively).

Results

In cross-sectional analyses adjusted for age, race, and cardiovascular disease risk factors, T was negatively associated with baseline WHR in men, while in both sexes, E2 was positively associated and SHBG was negatively associated with WHR (all p<0.001). In longitudinal analyses, further adjusted for follow-up time and baseline WHR, baseline T was negatively associated with WHR at follow-up (p=0.001) in men, while in both sexes, E2 was positively associated (p=0.004), and SHBG was negatively associated with WHR (p<0.001). The longitudinal association of E2, but not T, was independent of SHBG. In both cross-sectional or longitudinal analyses, there were no associations between DHEA and WHR in either men or women.

Conclusion

Sex hormones are associated with WHR at baseline and also during follow-up above and beyond their baseline association. Future research is needed to determine if manipulation of hormones is associated with changes in central obesity.

Relationship between testosterone deficiency and cardiovascular risk and mortality in adult men

Classic male hypogonadism is associated with known adverse effects including decreased libido, erectile dysfunction, osteoporosis, and changes in body composition. Recently, we have come to appreciate that reduction in serum testosterone (T) levels resulting from aging or chronic disease or androgen deprivation therapy (ADT) have consequences similar to those seen in classic male hypogonadism which include increased fat mass, decreased lean body mass, decreased muscle strength, and sexual dysfunction. These data suggest that low T levels may represent a newly recognized cardiometabolic risk factor. Therefore, we carried out a careful review of the literature, focusing on major turning points of research and studies which gave more important and controversial contribution to the cardiovascular role of T. Observational studies and clinical trials investigating the relationship between T levels and cardiovascular disease and mortality were identified byMedline search. The results were synthesized, tabulated, and interpreted. The aim of this review is to discuss the association between low T levels and adverse metabolic profile such as insulin resistance, metabolic syndrome, and diabetes. We will also investigate the potential mechanisms by which male hypogonadism, especially age related or induced by ADT, may increase cardio-metabolic risk. Finally we will detail the emerging relationship between low T and mortality in men addressing also the reverse hypothesis that low T has a protective role by turning off T-dependent functions.

Men's health: sexual dysfunction, physical, and psychological health--is there a link?

INTRODUCTION

Sexual dysfunction in men, such as erectile dysfunction, hypogonadism, and premature ejaculation, generates considerable attention. Its association with physical and psychological health is an issue which should be addressed seriously.

AIM

A review of the literature pertaining to the correlation between sexual dysfunction and physical and psychological health.

METHODS

PubMed search for relevant publications on the association between sexual dysfunction in men and physical and psychological health.

MAIN OUTCOME MEASURE

Clinical and epidemiological evidence that demonstrates the association between sexual dysfunction in men and physical and psychological health.

RESULTS

Sexual dysfunction, i.e., erectile dysfunction, hypogonadism, and premature ejaculation, has been shown to be associated with physical and psychological health. There is a strong correlation between sexual dysfunction and cardiovascular disease, metabolic syndrome, quality of life, and depression.

CONCLUSION

The association between men's sexual dysfunction and physical and psychological health is real and proven. Therefore, it should not be taken lightly but instead treated as a life-threatening medical problem.

The insulin-like growth factor system, metabolic syndrome, and cardiovascular disease risk

The metabolic syndrome is a combination of metabolic and clinical features that aggregate in individuals and increase cardiovascular disease (CVD) risk considerably. It is believed, although sometimes controversially, that the underlying basis for this syndrome is insulin resistance (IR) and accompanying compensatory hyperinsulinemia. Insulin and insulin-like growth factors (IGFs) have significant homology and interact with differing affinity with the same receptors. Therefore, their actions can be complementary, and this becomes particularly significant clinico-pathologically when their circulating levels are altered. This review of currently available information attempts to answer the following questions: (1) Is there any evidence for changes in the components of the IGF system in individuals with established CVD or with increased CVD risk as with the metabolic syndrome? (2) What are the underlying mechanisms for interactions, if any, between insulin and the IGF system, in the genesis of CVD? (3) Can knowledge of the pathophysiological changes in the IGF system observed in macrosomic newborn infants and growth hormone (GH)-treated children and adults explain some of the observations in relation to the IGF system and the metabolic syndrome? (4) Can the experimental and clinical evidence adduced from the foregoing be useful in designing novel therapies for the prevention, treatment, and assignment of prognosis in metabolic syndrome-associated disease, particularly ischemic heart disease? To answer these questions, we have performed a literature review using bibliographies from PubMed, Medline, and Google Scholar published within the last 10 years. We suggest that IGF-1 levels are reduced consistently in individuals with the metabolic syndrome and its components and in those with ischemic CVD. Such changes are also seen with GH deficiency in which these changes are partially reversible with GH treatment. Furthermore, changes are seen in levels and interactions of IGF-binding proteins in these disorders, and some of these changes appear to be independent of IGF-binding capability and could potentially impact on risk for the metabolic syndrome and CVD. The promising therapeutic implications of these observations are also discussed.

Hypogonadism and metabolic syndrome

BACKGROUND

The relationship between metabolic syndrome (MetS), male hypogonadism and their possible interaction in cardiovascular (CV) risk stratification are not completely understood.

AIM

We reviewed relationships between testosterone (T) and MetS emphasizing their possible interaction in the pathogenesis of CV diseases.

MATERIALS AND METHODS

A systematic search of published evidence was performed using Medline (1969 to January 2011).

RESULTS

Cross-sectional data have shown that subjects with MetS have lower levels of total T (TT) (about 3 nmol/l), as hypogonadism is more evident in subjects with than in those without erectile dysfunction (ED) than in those without. Longitudinal evidence shows that low T is allocated with a higher risk of subsequent development of MetS, although the reverse condition is also possible. Which are the factors in MetS responsible for the low T is not completely clarified. In clinical studies, increased waist circumference is the major determinant of MetS-associated hypogonadism. Our experiments in rabbits do not support the idea that visceral fat is the main determinant of MetS-associated male hypogonadism. Only few randomized clinical trials have evaluated the impact of T replacement therapy (TRT) in patients with MetS. Available evidence suggests that TRT decreases visceral fat accumulation and ameliorates insulin sensitivity, whereas androgen deprivation increases abdominal adiposity.

CONCLUSIONS

The clinical significance of the MetS-associated hypogonadism needs further clarifications. In particular, it has not been completely clarified if low T might be considered a cause or a consequence of MetS. The benefit of TRT in term of the reduction of CV risk needs to be confirmed in larger and longer studies.

Aging and exercise training reduce testes microvascular PO2 and alter vasoconstrictor responsiveness in testicular arterioles

Testicular function and associated testosterone concentration decline with advancing age, and an impaired O₂ supply may contribute, in part, to this reduction. We hypothesized that there would be a reduced microvascular Po₂ (Po₂(m)) in the testes from aged rats, and this reduced Po₂(m) would be associated with impaired vasomotor control in isolated resistance arterioles. In addition, given the positive effect of exercise on microvascular Po₂ and arteriolar function, we further hypothesized that there would be an enhanced Po₂(m) in the testes from aged animals after aerobic exercise training. Testicular Po₂(m) was measured in vivo via phosphorescence quenching in young and aged sedentary (SED) and exercise-trained (ET; 15 m/min treadmill walking, 15-degree incline, 5 days/wk for 10 wk) male Fischer-344 rats. Vasoconstriction to α-adrenergic [norepinephrine (NE) and phenylephrine (PE)] and myogenic stimuli in testicular arterioles was assessed in vitro. In the SED animals, testicular Po₂(m) was reduced by ∼50% with old age (aged SED 11.8 ± 1.9 vs. young SED 22.1 ± 1.1 mmHg; P = 0.0001). Contrary to our hypothesis, exercise training did not alter Po₂(m) in the aged group and reduced testicular Po₂(m) in the young animals, abolishing age-related differences (young ET, 10.0 ± 0.8 vs. aged ET, 10.7 ± 0.9 mmHg; P = 0.37). Vasoconstrictor responsiveness to NE and PE was diminished in aged compared with young (NE: young SED, 58 ± 2 vs. aged SED, 47 ± 2%; P = 0.001) (PE: young SED, 51 ± 3 vs. aged SED, 36 ± 5%; P = 0.008). Exercise training did not alter maximal vasoconstriction to NE in young or aged groups. In summary, advancing age is associated with a reduced testis Po₂(m) and impaired adrenergic vasoconstriction. The diminished testicular microvascular driving pressure of O₂ and associated vascular dysfunction provides mechanistic insight into the old age-related decrease in testicular function, and a reduced Po₂(m) may contribute, in part, to reduced fertility markers after exercise training.

Metabolic depression: a chronic depressive subtype? Findings from the InCHIANTI study of older persons

OBJECTIVE

Several studies report a cross-sectional association between metabolic syndrome and depression. Possibly, metabolic syndrome promotes onset or chronicity of depression. However, such a longitudinal link has not yet been confirmed. This study examines whether metabolic syndrome or its components are associated with onset and chronicity of depression.

METHOD

Secondary analyses were performed on data from 823 participants (≥ 65 years of age) in the InCHIANTI study, a prospective, population-based cohort study of older persons. From 1998 to 2000, the study sample was randomly selected from the population registry of 2 sites in Italy using a multistage stratified sampling method. Baseline data collection consisted of a home interview and a medical evaluation at the study clinic. Follow-up for each participant occurred after 3 years and 6 years. Metabolic syndrome at baseline was defined as ≥ 3 of the following: abdominal obesity, high triglycerides, low high-density lipoprotein cholesterol, high blood pressure, and high fasting glucose. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression scale (CES-D) at baseline and after 3 and 6 years. Sample characteristics were compared between persons with and without depression at baseline using χ² and t statistics. Logistic regression analyses were conducted separately in persons with and without depression at baseline to test whether metabolic syndrome at baseline could predict onset and chronicity of depression at follow-up.

RESULTS

At baseline, 235 persons had metabolic syndrome, and 168 were depressed (CES-D score ≥ 20). Among persons not depressed at baseline, 26.0% developed depression. Higher waist circumference increased the odds of depression onset (adjusted OR per SD increase = 1.28; 95% CI, 1.05-1.56), but there was no association between other metabolic syndrome components and onset of depression. Among persons depressed at baseline, depression had a chronic character in 69.0% of persons without and 88.5% of persons with metabolic syndrome. Metabolic syndrome was associated with an almost 3-fold increase in the odds of chronicity of depression (adjusted OR = 2.66; 95% CI, 1.01-7.00), with almost every metabolic syndrome component contributing to this association.

CONCLUSION

In late life, waist circumference, but not metabolic syndrome, predicted onset of depression. Depressed persons with metabolic syndrome were more likely to have persistent or recurrent depression. The latter may suggest that depression with metabolic abnormalities, which could be labeled metabolic depression, identifies a chronic subtype of depression.

Self-referred older Asian males in a men's health clinic: the inter-relationships between androgens, metabolic parameters and quality of life measures

BACKGROUND

Current data on late-onset hypogonadism, derived from healthy males in epidemiological studies, may not reflect the profile of men seen in actual clinical practice.

OBJECTIVE

To examine androgen levels in relation to metabolic status and quality of life (QOL) measures in self-referred men at a hospital-based Men's Health clinic.

METHODS

Cross-sectional study of 238 consecutive Asian males. Fasting total testosterone (TT), sex-hormone binding globulin (SHBG), luteinising (LH) and follicle stimulating (FSH) hormones, glucose (FPG) and lipid profile were measured. Bioavailable (cBT) and free testosterone (cFT) were calculated. Waist circumference (WC) and body mass index (BMI) were collected. Subjects also answered the modified International Index of Erectile Dysfunction (IIEF-5) and Ageing Male Symptom (AMS) questionnaires.

RESULTS

Among non-diabetic males (N = 201), no change was noted for TT, although SHBG and gonadotrophins rose, while cBT and cFT declined, significantly with age. Sex hormones were negatively related with WC, BMI and FPG. SHBG displayed a stronger association with metabolic components than testosterone. Testosterone was not related to lipids, IIEF-5 or AMS scores. WC, not BMI, was a key determinant of TT, cBT and cFT in younger subjects, while FSH seemed a more sensitive indicator of primary hypogonadism than LH in older males.

CONCLUSION

The preferred measures of serum testosterone in older men are cBT and cFT. Visceral adiposity and SHBG, rather than testosterone, appeared to be the link between androgen deficiency and poorer metabolic status. QOL scores correlate poorly with androgen concentrations.

Testosterone and metabolic syndrome: a meta-analysis study

INTRODUCTION

Metabolic syndrome (MetS) is often associated with male hypogonadism. Despite the well-known link, the role of testosterone replacement therapy (TRT) in MetS has not been completely clarified.

AIM

To systematically analyse the relationship between androgen levels and MetS we performed a review and meta-analyses of available prospective and cross-sectional studies. In addition, a specific meta-analysis on the metabolic effects of TRT in available randomized clinical trials (RCTs) was also performed.

METHODS

An extensive Medline search was performed including the following words "testosterone,""metabolic syndrome," and "males".

MAIN OUTCOME MEASURES

Out of 323 retrieved articles, 302 articles were excluded for different reasons. Among the 20 published studies included, 13, 3, and 4 were cross-sectional, longitudinal, and RCTs, respectively. Another unpublished RCT was retrieved on http://www.clinicaltrials.gov.

RESULTS

MetS patients showed significantly lower T plasma levels, as compared with healthy individuals. Similar results were obtained when MetS subjects with and without erectile dysfunction were analyzed separately or when NCEP-ATPIII MetS criteria were compared with other definitions. Meta-regression analysis demonstrated that type 2 diabetes (T2DM) increased the MetS-associated T fall. In a multiple regression model, after adjusting for age and BMI, both T2DM and MetS independently predicted low testosterone (adj. r = -0.752; P < 0.001 and -0.271; P < 0.05, respectively). Analysis of longitudinal studies demonstrated that baseline testosterone was significantly lower among patients with incident MetS in comparison with controls (2.17 [-2.41;-1.94] nmol/L; P < 0.0001). Combining the results of RCTs, TRT was associated with a significant reduction of fasting plasma glucose, homeostatic model assessment index, triglycerides, and waist circumference. In addition, an increase of high-density lipoprotein cholesterol was also observed.

CONCLUSIONS

The meta-analysis of the available cross-sectional data suggests that MetS can be considered an independent association of male hypogonadism. Although only few RCTs have been reported, TRT seems to improve metabolic control, as well as central obesity.

Association of testosterone and sex hormone-binding globulin with metabolic syndrome and insulin resistance in men

OBJECTIVE

We sought to assess the associations of testosterones and sex hormone-binding globulin (SHBG) with metabolic syndrome and insulin resistance in men.

RESEARCH DESIGN AND METHODS

We defined metabolic syndrome according to the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Among men aged >or=20 years who participated in the Third National Health and Nutrition Examination Survey (n = 1,226), the Cox proportional hazards model was used to estimate the prevalence ratio and 95% CI of metabolic syndrome according to circulating concentrations of testosterones and SHBG.

RESULTS

After adjustment for age, race/ethnicity, smoking status, alcohol intake, physical activity level, LDL cholesterol, C-reactive protein, and insulin resistance, men in the first quartile (lowest) (prevalence ratio 2.16 [95% CI 1.53-3.06]) and second quartile of total testosterone (2.51 [1.86-3.37]) were more likely to have metabolic syndrome than men in the fourth quartile (highest, referent group) (P < 0.001 for linear trend). Similarly, men in the first quartile of SHBG (2.17 [1.32-3.56]) were more likely to have metabolic syndrome than men in the fourth quartile (P = 0.02 for linear trend). No significant associations of calculated free testosterone (P = 0.31 for linear trend) and bioavailable testosterone (P = 0.11 for linear trend) with metabolic syndrome were detected after adjustment for all possible confounders.

CONCLUSIONS

Low concentrations of total testosterone and SHBG were strongly associated with increased likelihood of having metabolic syndrome, independent of traditional cardiovascular risk factors and insulin resistance.