Association between metabolic syndrome or its components and asymptomatic cardiovascular disease in the RIVANA-study

Vascular calcification in Takayasu arteritis: relationship with metabolic syndrome, left ventricular mass index, and intima-media thickness

OBJECTIVE

The present study aims to determine the frequency of vascular calcification in Takayasu arteritis (TA) and the risk factors for it and to evaluate its relation with atherosclerotic predictors such as metabolic syndrome (MS), left ventricular mass index (LVMI) and carotid intima-media thickness (CIMT).

METHODS

A cross-sectional study was conducted in patients with TA; MS was defined according to the US National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATP III) criteria. The study included 49 TA patients (22 with MS, 27 without MS) and 31 healthy controls (HCs). Non-contrast computed tomography measured calcification in coronary arteries, aorta, and branches.

RESULTS

Forty-seven patients (95.9%) were female and mean age was 33.45 ± 8.53 years. Total calcification score (mean ± SD; 5223.9 ± 18041.1 AU vs. 35.87 ± 72.70 AU (p = 0.05)), CIMT, and LVMI were found to be significantly higher in TA patients than HCs (p < 0.05). While there was no significant difference between the total calcification score of MS (+) TA patients and MS (-) TA patients, in both patient groups, the total calcification score was found to be significantly higher than HCs. MS (+) and MS (-) groups were found to have significantly higher CIMT and LVMI values than the control group, in addition, MS (+) patients were found to have significantly higher LVMI and CIMT values than MS (-) group (p < 0.05).

CONCLUSION

Vascular calcification, CIMT, and LVMI are elevated in all TA patients, with greater impact in the presence of MS.

Various Obesity Indices and Arterial Function Evaluated with CAVI - Is Waist Circumference Adequate to Define Metabolic Syndrome?

Obesity has been known to relate to various diseases and metabolic disorders. Since the implication of body shape has been mentioned, obesity can be divided into visceral obesity and subcutaneous obesity. The former is considered the upstream pathophysiology of metabolic syndrome (MetS), and has been emphasized worldwide for the prevention of cardiovascular diseases in the last quarter century. However, some prospective studies have shown that cardiovascular mortality and morbidity are not necessarily higher in patients with MetS compared to those without. Recently, cardio-ankle vascular index (CAVI) has been established as an indicator of arteriosclerosis. This parameter is independent of blood pressure at the measuring time, and reflects systemic arterial stiffness from the aortic origin to the ankle. However, since CAVI is not necessarily high in MetS patients, attempts have been made to clarify this unexpected phenomenon. In several studies, CAVI was found to correlate negatively with body mass index (BMI), and also with waist circumference (WC) which is a widely used representative visceral obesity index. On the other hand, a body shape index (ABSI) is also a visceral obesity index designed to be minimally associated with BMI, and is calculated by dividing WC by an allometric regression of weight and height. Replacing high WC with high ABSI in MetS diagnosis promoted the identification of MetS patients with increased CAVI in cross-sectional studies on Japanese and Korean populations. Additionally, the incidence of MetS diagnosed using high ABSI was associated with significant increase in CAVI after 1 year of observation. Enhanced predictive ability for renal function decline by replacing WC with ABSI in MetS diagnosis was also observed in a longitudinal study in Japanese urban residents. These findings suggest that MetS diagnosis using high ABSI instead of high WC as a visceral obesity index needs to be reconsidered. However, further research is desirable on Caucasian, whose body shape differs slightly from that of Asians.

Enhanced prediction of renal function decline by replacing waist circumference with "A Body Shape Index (ABSI)" in diagnosing metabolic syndrome: a retrospective cohort study in Japan

Background

Abdominal obesity as a risk factor for diagnosing metabolic syndrome (MetS) is conventionally evaluated using waist circumference (WC), although WC does not necessarily reflect visceral adiposity.

Objective

To examine whether replacing WC with “A Body Shape Index (ABSI)”, an abdominal obesity index calculated by dividing WC by an allometric regression of weight and height, in MetS diagnosis is useful for predicting renal function decline.

Subjects/Methods

In total, 5438 Japanese urban residents (median age 48 years) who participated in a public health screening program for 4 consecutive years were enrolled. Systemic arterial stiffness was assessed by cardio-ankle vascular index (CAVI). The predictability of the new-onset renal function decline (eGFR < 60 mL/min/1.73 m²) by replacing high WC with high ABSI (ABSI ≥ 0.080) was examined using three sets of MetS diagnostic criteria: Japanese, IDF and NCEP-ATPIII.

Results

In Japanese and NCEP-ATPIII criteria, MetS diagnosed using ABSI (ABSI-MetS) was associated with significantly higher age-adjusted CAVI compared to non-MetS, whereas MetS diagnosed using WC (WC-MetS) showed no association. Kaplan–Meier analysis of the rate of new-onset renal function decline over 4 years (total 8.7%) showed remarkable higher rate in subjects with ABSI-MetS than in those without (log-rank test p < 0.001), but almost no difference between subjects with and without WC-MetS (p = 0.014–0.617). In gender-specific Cox-proportional hazards analyses including age, proteinuria, and treatments of metabolic disorders as confounders, ABSI-MetS (Japanese criteria for both sexes, IDF criteria for men) contributed independently to the new-onset renal function decline. Of these, the contribution of IDF ABSI-MetS disappeared after adjustment by high CAVI in the subsequent analysis.

Conclusion

In this study, replacing WC with ABSI in MetS diagnostic criteria more efficiently predicted subjects at risk of renal function decline and arterial stiffening.

Risk for cardiovascular disease associated with metabolic syndrome and its components: a 13-year prospective study in the RIVANA cohort

Background

We aimed to investigate the association of metabolic syndrome (MetS) and its single components with cardiovascular risk and estimated their impact on the prematurity of occurrence of cardiovascular events using rate advancement periods (RAPs).

Methods

We performed prospective analyses among 3976 participants (age range: 35–84, 55% female) in the Vascular Risk in Navarre (RIVANA) Study, a Mediterranean population-based cohort. MetS was defined based on the modified criteria of the American Heart Association/National Heart, Lung, and Blood Institute and the International Diabetes Federation. The primary endpoint was major cardiovascular event (a composite of myocardial infarction, stroke, or mortality from cardiovascular causes). Secondary endpoints were incidence of non-fatal myocardial infarction and non-fatal stroke, cardiovascular mortality, and all-cause mortality. Cox proportional hazards models, adjusted for potential confounders, were fitted to evaluate the association between MetS and its single components at baseline with primary and secondary endpoints.

Results

During a median follow-up of 12.8 years (interquartile range, 12.5–13.1), we identified 228 primary endpoint events. MetS was associated with higher risk of incidence of major cardiovascular event, cardiovascular and all-cause mortality, but was neither associated with higher risk of myocardial infarction nor stroke. Compared with participants without MetS, the multivariable hazard ratio (95% confidence interval [CI]) among participants with MetS was 1.32 (1.01–1.74) with RAP (95% CI) of 3.23 years (0.03, 6.42) for major cardiovascular event, 1.64 (1.03–2.60) with RAP of 3.73 years (0.02, 7.45) for cardiovascular mortality, and 1.45 (1.17–1.80) with RAP of 3.24 years (1.21, 5.27) for all-cause mortality. The magnitude of the associations of the single components of MetS was similar than the predicted by MetS. Additionally, for each additional trait of MetS, incidence of major cardiovascular event relatively increased by 22% (1.22, 95% CI 1.09–1.36) with RAP of 2.31 years (0.88, 3.74).

Conclusions

MetS was independently associated with CVD risk, cardiovascular and all-cause mortality. Components of the MetS were associated with similar magnitude of increased CVD, which suggests that MetS was not in excess of the level explained by the presence of its single components. Further research should explore the association of different combinations of the components of MetS with CVD.

Metabolic syndrome is a predictor of decreased renal function among community-dwelling middle-aged and elderly Japanese

PURPOSE

Metabolic syndrome (MetS) is increasing worldwide with the continuous increase in obesity prevalence. Chronic kidney disease (CKD) is also a major public health problem, but there is controversy over whether baseline MetS is a predictor of decreased renal function among Japanese community-dwelling middle-aged and elderly Japanese.

METHODS

We conducted a prospective cohort study designed as part of the Nomura study. We recruited a random sample of 410 men aged 68 ± 8 (mean ± standard deviation; range, 50-95) years and 549 women aged 69 ± 7 (50-84) years during their annual health examination in a single community. We examined the relationship between baseline MetS and renal dysfunction after a 3-year evaluation based on estimated glomerular filtration rate (eGFR_CKDEPI) using the CKD-EPI equations modified by the Japan coefficient. CKD was defined as dipstick-positive proteinuria (> or = 1 +) or a low eGFR_CKDEPI (< 60 mL/min/1.73 m²).

RESULTS

Of the 959 participants, 413 (43.1%) had MetS at baseline. Annual eGFR decline rate was significantly greater in those with MetS than in those without MetS, and the annual eGFR decline rate of < - 1.2 mL/min/1.73 m²/year increased significantly in relation to presence of baseline MetS, especially low HDL cholesterol (HDL-C). Moreover, the incidence rate of CKD after 3 years was 13.5% and increased significantly in relation to presence of baseline MetS, especially its components such as elevated HbA1c. The multivariate-adjusted odd ratio (OR) for CKD in participants with MetS versus those without MetS was 1.55 (0.99-2.43). The multivariate-adjusted ORs for rapid annual eGFR decline rate were significantly high in patients aged ≥ 65 years and presence of medication, regardless of gender and eGFR value.

CONCLUSIONS

Low HDL-C and elevated HbA1c levels correlated significantly with eGFR decline in a short period of 3 years. MetS also showed a significant association with eGFR decline. This study suggests the importance of low HDL-C and elevated HbA1c in the effect of MetS on eGFR decline rather than obesity among Japanese community-dwelling middle-aged and elderly Japanese without CKD.

Metabolic Syndrome and Chronic Renal Disease

Background: The influence of metabolic syndrome (MetS) on kidneys is related to many complications. We aimed to assess the association between MetS and chronic renal disease defined by a poor estimated glomerular filtration rate (eGFR) and/or the presence of microalbuminuria/macroalbuminuria.

METHODS

149 patients (77 males/72 females) were enrolled in the study. Chronic renal disease was defined according to KDIGO 2012 criteria based on eGFR category and classified albuminuria. MetS was studied as a dichotomous variable (0 to 5 components) including hypertension, waist circumference, low HDL-cholesterol, high triglycerides, and high glucose. Results: The association between clustering MetS and both classified eGFR and classified albuminuria (x² = 50.3, p = 0.001 and x² = 26.9, p = 0.003 respectively) was found to be significant. The MetS presence showed an odds 5.3-fold (1.6-17.8) higher for low eGFR and 3.2-fold (1.2-8.8) higher for albuminuria in combination with the presence of diabetes mellitus, which also increased the risk for albuminuria by 3.5-fold (1.1-11.3). Albuminuria was significantly associated with high triglycerides, hypertension, high glucose (x² = 11.8, p = 0.003, x² = 11.4, p = 0.003 and x² = 9.1, p = 0.01 respectively), and it was mildly associated with a low HDL-C (x² = 5.7, p = 0.06). A significant association between classified eGFR and both high triglycerides and hypertension (x² = 9.7, p = 0.04 and x² = 16.1, p = 0.003 respectively) was found. Conclusion: The clustering of MetS was significantly associated with chronic renal disease defined by both classified eGFR and albuminuria. The definition of impaired renal function by classified albuminuria was associated with more MetS components rather than the evaluation of eGFR category. MetS may contribute to the manifestation of albuminuria in patients with diabetes mellitus.

Metabolic Syndrome and Chronic Renal Disease

Background: The influence of metabolic syndrome (MetS) on kidneys is related to many complications. We aimed to assess the association between MetS and chronic renal disease defined by a poor estimated glomerular filtration rate (eGFR) and/or the presence of microalbuminuria/macroalbuminuria.

METHODS

149 patients (77 males/72 females) were enrolled in the study. Chronic renal disease was defined according to KDIGO 2012 criteria based on eGFR category and classified albuminuria. MetS was studied as a dichotomous variable (0 to 5 components) including hypertension, waist circumference, low HDL-cholesterol, high triglycerides, and high glucose. Results: The association between clustering MetS and both classified eGFR and classified albuminuria (x² = 50.3, p = 0.001 and x² = 26.9, p = 0.003 respectively) was found to be significant. The MetS presence showed an odds 5.3-fold (1.6-17.8) higher for low eGFR and 3.2-fold (1.2-8.8) higher for albuminuria in combination with the presence of diabetes mellitus, which also increased the risk for albuminuria by 3.5-fold (1.1-11.3). Albuminuria was significantly associated with high triglycerides, hypertension, high glucose (x² = 11.8, p = 0.003, x² = 11.4, p = 0.003 and x² = 9.1, p = 0.01 respectively), and it was mildly associated with a low HDL-C (x² = 5.7, p = 0.06). A significant association between classified eGFR and both high triglycerides and hypertension (x² = 9.7, p = 0.04 and x² = 16.1, p = 0.003 respectively) was found. Conclusion: The clustering of MetS was significantly associated with chronic renal disease defined by both classified eGFR and albuminuria. The definition of impaired renal function by classified albuminuria was associated with more MetS components rather than the evaluation of eGFR category. MetS may contribute to the manifestation of albuminuria in patients with diabetes mellitus.

Impaired Fasting Glucose Is the Major Determinant of the 20-Year Mortality Risk Associated With Metabolic Syndrome in Nondiabetic Patients With Stable Coronary Artery Disease

Background

We wanted to explore the association of metabolic syndrome (MetS) versus its individual components with 20‐year all‐cause mortality among patients with stable coronary artery disease.

Methods and Results

The cohort comprised 12 403 nondiabetic patients with stable coronary artery disease who were enrolled in the Bezafibrate Infarction Prevention Registry between February 1990 and October 1992 and followed up through December 2014. The study cohort was divided into 4 groups: patients without MetS or impaired fasting glucose (IFG), patients with IFG but without MetS, patients with MetS but without IFG, and patients with both MetS and IFG. Kaplan‐Meier survival analysis showed that at 20 years of follow‐up, the rates of all‐cause mortality were the highest among patients with both MetS and IFG (66%). Patients with IFG without MetS experienced a significantly higher mortality rate compared with those with MetS without IFG (61% versus 56%; log‐rank P<0.001). Multivariable Cox proportional hazard analysis showed that the final Cox model demonstrated that the additive effect of MetS (hazard ratio, 1.13; 95% confidence interval, 1.1–1.16; P=0.02) and IFG (hazard ratio, 1.54; 95% confidence interval, 1.46–1.62; P<0.001) on 20 years mortality was nonsignificant (hazard ratio, 1.01; 95% confidence interval, 0.93–1.11; P=0.69). IFG was associated with the most pronounced increase in mortality risk among the individual components (hazard ratio, 1.22; 95% confidence interval, 1.14–1.3; P<0.001).

Conclusions

Our findings suggest that IFG alone is a major independent predictor of long‐term mortality among patients with stable coronary artery disease versus other components of the MetS.

Epicardial Adipose Tissue in the General Middle-aged Population and Its Association With Metabolic Syndrome

INTRODUCTION AND OBJECTIVES

There is currently increasing interest in epicardial adipose tissue (EAT) as a marker of cardiovascular disease. Our purpose was to describe EAT, measured by transthoracic echocardiography, and to assess its association with metabolic syndrome (MS) in the RIVANA population-based study.

METHODS

Physical examination was performed in 880 participants aged 45 to 74 years (492 of them with MS according to the harmonized definition). Fasting glucose, high-density lipoprotein cholesterol, triglyceride, and C-reactive protein concentrations were determined in a blood sample. In all participants, EAT thickness was measured with transthoracic echocardiography at end-systole.

RESULTS

Among participants without MS, the prevalence of EAT ≥ 5mm significantly increased with age (OR > 65 years vs 45-54 years=8.22; 95%CI, 3.90-17.35; P for trend<.001). Increasing EAT quintiles were significantly associated with MS (OR fifth quintile vs first quintile=3.26; 95%CI, 1.59-6.71; P for trend=.001). Considering the different MS criteria, increasing quintiles of EAT were independently associated with low high-density lipoprotein cholesterol (OR fifth quintile vs first quintile=2.65; 95%CI, 1.16-6.05; P for trend=.028), high triglycerides (OR fifth quintile vs first quintile=2.22; 95%CI, 1.26-3.90; P for trend=.003), and elevated waist circumference (OR fifth quintile vs first quintile=6.85; 95%CI, 2.91-16.11; P for trend<.001).

CONCLUSIONS

In a subsample of the general population, EAT measured by echocardiography increased significantly and independently with age. Increased EAT thickness was independently associated with MS and with low high-density lipoprotein cholesterol, high triglycerides, and elevated waist circumference as individual criteria.

Influence of age on the prevalence and components of the metabolic syndrome and the association with cardiovascular disease

OBJECTIVE

The significance of the metabolic syndrome (MS) is debated. We investigated whether MS component (by ATPIII and IDF definitions) clustering and any association between MS and prevalent cardiovascular disease (CVD) varied with age.

RESEARCH DESIGN AND METHODS

In all, 1429 adults (≥25 years) from randomly selected households in rural Victoria, Australia, were assessed for components of MS and prevalent CVD. The expected prevalence of MS was calculated following a simple probabilistic model using the prevalence of each MS component.

RESULTS

The observed prevalence of MS was greater than expected: 27.0% vs 21.2% (ATPIII) and 36.0% vs 30.1% (IDF; p<0.0001), based on the prevalence of individual components. There was significant clustering of 4 and 5 MS components in participants <65 years (p<0.0001). CVD was more prevalent in MS participants, 13.5% (IDF), 14.5% (ATPIII) versus 5.3% (no MS) p<0.0001. The OR for CVD in MS participants was greatest in those <45 years OR (95% CI): IDF 17.5 (1.8 to 172); ATPIII 24.3(2.4 to 241), p<0.001 for both, and was not significant in those >65 years. The prevalence of MS (ATPIII) with normal waist circumference (WC) was less than expected (4.8% vs 7.9%, p<0.002). Low levels of high-density lipoprotein and high triglyceride were less common in older MS participants.

CONCLUSIONS

ATPIII MS is rare among those with a normal WC. MS components cluster most markedly among those aged <65 years, who also experience substantially greater rates of CVD. Younger patients with MS may warrant more aggressive CVD preventative treatment than suggested by the summation of their individual risk factors.

The effectiveness of IDF and ATP-III in identifying metabolic syndrome and the usefulness of these tools for health-promotion in older Taiwanese

OBJECTIVES

The aim of this study was to compare the effectiveness of IDF (International Diabetes Federation) and ATP-III (National Cholesterol Education Program-Adult Treatment Panel III) for predicting metabolic syndrome, and to evaluate the usefulness of these definitions for health promotion.

DESIGN

A cross-sectional study.

SETTING

A national random sample.

PARTICIPANTS

A population representative sample of 1021 54-91 year-old Taiwanese.

MEASUREMENTS

Subjects were measured for anthropometric and biochemical indicators and rated for the presence of metabolic syndrome using the two definitions. We evaluated the effectiveness of the two definitions in predicting MetS among those who had specific metabolic disorders. Results were analyzed with Student t-test and McNemar's test.

RESULTS

Among the 918 subjects who had one or more MetS-item disorders, ATP-III rated greater proportions of subjects as having MetS than IDF, but both definitions predicted less than 50% (37.7% and 45.4%, respectively) as having MetS.

CONCLUSION

Compared to IDF, ATP-III rated a greater proportion of subjects as having MetS, but both definitions missed more than 50% of subjects who had metabolic disorder(s). Since those who are missed have as much need for lifestyle intervention, the definitions appear not appropriate for health promotion.

The influence of obesity on the assessment of carotid intima-media thickness

BACKGROUND

The assessment of carotid intima-media thickness (CIMT) may improve cardiovascular risk prediction. The optimal protocol for CIMT measurement is unclear. CIMT may be measured in the common carotid artery (CCA), carotid bifurcation (CB), and internal carotid artery (ICA), but measurements from CB and ICA are more difficult to obtain. We studied the influence of body mass index (BMI) and atheroma plaques on the capacity to obtain CIMT measurements at different carotid sites.

METHODS

Using an automatic system, CIMT was measured in 700 subjects aged 45-75, in the near and far walls of CCA, CB, and ICA bilaterally. The presence of atheroma plaques, BMI and vascular risk factors were recorded.

RESULTS

CIMT measurements in CCA were possible in all except one subject. It was not possible to obtain CIMT measurements at CB or ICA in 24.1% of normal weight and 58.8% of obese subjects. The likelihood of obtaining CIMT measurement at all carotid sites decreased as the BMI increased. Atheroma plaques in a carotid segment did not preclude CIMT measurement at this site.

CONCLUSIONS

CIMT measurements in distal carotid segments are more challenging in obese subjects. Measuring CIMT at CCA remains feasible in obese subjects and should be the primary endpoint in these subjects. Nevertheless, CB and ICA measurements, when feasible, would improve risk classification.

Metabolic syndrome and inflammatory biomarkers: a community-based cross-sectional study at the Framingham Heart Study

BACKGROUND

Prior studies reported conflicting findings on the association between metabolic syndrome and inflammatory biomarkers. We tested the cross-sectional associations between metabolic syndrome and nine inflammatory markers.

METHODS

We measured C-reactive protein, CD40 ligand, interleukin-6, intercellular adhesion molecule-1, monocyte chemoattractant protein-1, osteoprotegerin, P-selectin, tumor necrosis factor-alpha, and tumor necrosis factor receptor-2 in 2570 Framingham Offspring Study participants free of diabetes and cardiovascular disease at examination 7. Metabolic syndrome was defined by National Cholesterol Education Program criteria. We performed multivariable linear regressions for each biomarker with metabolic syndrome as the exposure adjusting for age, sex, smoking, aspirin use, and hormone replacement. We subsequently added to the models components of the metabolic syndrome as continuous traits plus lipid lowering and hypertension treatments. We considered P < 0.05 as statistically significant.

RESULTS

Metabolic syndrome was present in 984 (38%) participants and was statistically significantly associated with each biomarker (all P < 0.02) except osteoprotegerin. After adjusting for its component variables, the metabolic syndrome was associated only with P-selectin (1.06 fold higher in metabolic syndrome, 95% CI 1.02, 1.10, p = 0.005).

CONCLUSIONS

Metabolic syndrome was associated with multiple inflammatory biomarkers. However, adjusting for each of its components eliminated the association with most inflammatory markers, except P-selectin. Our results suggest that the relation between metabolic syndrome and inflammation is largely accounted for by its components.

Men's health in primary care: an emerging paradigm of sexual function and cardiometabolic risk

An office evaluation of men's health in primary care requires a thorough understanding of the implications of male sexual dysfunctions, hypogonadism, and cardiometabolic risk stratification and aggressive risk management. The paradigm of the men's health office visit in primary care is the recognition and assessment of male sexual dysfunction, specifically erectile dysfunction, and its value as a signal of overall cardiometabolic health, including the emerging evidence linking low testosterone and the metabolic syndrome. Indeed, erectile dysfunction may now be thought of as a harbinger of cardiovascular clinical events and other systemic vascular diseases in some men.

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.

Testosterone deficiency

Testosterone deficiency (TD) afflicts approximately 30% of men aged 40-79 years, with an increase in prevalence strongly associated with aging and common medical conditions including obesity, diabetes, and hypertension. A strong relationship is noted between TD and metabolic syndrome, although the relationship is not certain to be causal. Repletion of testosterone (T) in T-deficient men with these comorbidities may indeed reverse or delay their progression. While T repletion has been largely thought of in a sexual realm, we discuss its potential role in general men's health concerns: metabolic, body composition, and all-cause mortality through the use of a single clinical vignette. This review examines a host of studies, with practical recommendations for diagnosis of TD and T repletion in middle-aged and older men, including an analysis of treatment modalities and areas of concerns and uncertainty.

Is prediction of cardiovascular disease and all-cause mortality genuinely driven by the metabolic syndrome, and independently from its component variables? The Dubbo study

BACKGROUND

The Metabolic Syndrome (MetS) predicts an increased risk of cardiovascular disease and all-cause mortality. Is this prediction genuinely driven by the syndrome and independently from its component variables?

METHODS

A longitudinal cohort study in Dubbo, Australia of 2805 men and women ≥60 years followed for 16 years from 1988. Cox proportional hazards models were calculated for coronary heart disease (CHD), ischaemic stroke and all-cause mortality with MetS as an independent variable. Separate models included the MetS variable, with or without the presence of one of its five component variables.

RESULTS

MetS was present in 33% of subjects. Obesity was present in 43% of those with MetS, high blood pressure in 99%, elevated triglycerides in 83%, low HDL-C in 75% and glycaemia in 48%. With respect to CHD and all-cause mortality, prediction by MetS was similar in the presence or absence of individual component factors (e.g. hazard ratio (95% CI) for CHD by MetS when low HDL-C present 1.60(1.39-1.84) and 1.67(1.37-2.04) when low HDL-C absent). With stroke, prediction by MetS was lost in the absence of elevated triglycerides or glycaemia factors (e.g. hazard ratio for stroke by MetS when glycaemia present 1.59(1.24-2.05) and 1.08(0.82-1.42) when glycaemia absent).

CONCLUSIONS

The findings suggest that prediction of CHD and all-cause mortality is genuinely driven by the MetS and independently of its component variables. Prediction of ischaemic stroke is more complex, with some components providing prediction independently from the MetS.

Farnesoid X receptor activation improves erectile dysfunction in models of metabolic syndrome and diabetes

The metabolic syndrome (MetS) is an insulin-resistant state characterized by a cluster of cardiovascular risk factors, including abdominal obesity, hyperglycemia, elevated blood pressure and combined dyslipidemia. In this review, we discuss the potential of farnesoid X receptor (FXR) agonists in the treatment of erectile dysfunction (ED), a multifactorial disorder often comorbid with MetS. FXR not only regulates lipid and glucose homeostasis but also influences endothelial function and atherosclerosis, suggesting a regulatory role for this hormone nuclear receptor in the cardiovascular complications associated with the MetS, including ED. MetS induces ED via several mechanisms, and in particular through endothelial dysfunction in penile vessels. In a high-fat diet rabbit model of MetS, a 3-month treatment with the potent and selective FXR agonist INT-747 restores endothelium-dependent relaxation in isolated cavernous tissue, normalizing responsiveness to acetylcholine and to electrical field stimulation. Accordingly, eNOS expression in the penis is greatly up-regulated by INT-747 treatment. Experiments in a rat model of chemically-induced type 1 diabetes further demonstrate that INT-747 treatment preserves erectile function induced by electrical stimulation of the cavernous nerve. These results add a new facet to the pleiotropic activities mediated by FXR, and reveal novel beneficial effects of FXR activation with potential clinical relevance. This article is part of a Special Issue entitled: Translating nuclear receptors from health to disease.

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.