Dehydroepiandrosterone: the "missing link" between hyperinsulinemia and atherosclerosis?

Adrenal Androgen Predictive Effects on Clinical and Metabolic Abnormalities of Polycystic Ovary Syndrome

OBJECTIVE

 To examine the possible effects of adrenal prohormones in the prediction of clinical and metabolic abnormalities in women with polycystic ovary syndrome (PCOS).

METHODS

 The present study enrolled 299 normal cycling non-PCOS, 156 normoandrogenemic, and 474 hyperandrogenemic women with PCOS. Baseline characteristics were compared using a chi-squared test or analysis of variance (ANOVA) as appropriate. The roles of adrenal prohormones and their ratios with total testosterone in predicting co-occurring morbidities in women PCOS were evaluated using univariate and multivariate logistic regression analyses.

RESULTS

 Adrenal hyperandrogenism per dehydroepiandrosterone sulfate (DHEAS) levels were found in 32% of women with PCOS. In non-PCOS women, dehydroepiandrosterone (DHEA) and its sulfate had no predictive role concerning clinical, anthropometric, and metabolic parameters. In PCOS women, mainly in the hyperandrogenemic group, DHEA showed to be a significant predictor against most anthropometric-metabolic index abnormalities (odds ratio [OR] = 0.36-0.97; p < 0.05), and an increase in triglycerides (TG) levels (OR = 0.76; p = 0.006). Dehydroepiandrosterone sulfate presented a few predictive effects regarding PCOS-associated disorders. In controls, DHEAS predicted against the increase in estimated average glucose (OR= 0.38; p = 0.036). In the normoandrogenic group, it predicted against elevation in the waist/hip ratio (WHR) (OR= 0.59; p = 0.042), and in hyperandrogenemic PCOS women, it predicted against abnormality in the conicity index (CI) (OR = 0.31; p = 0.028).

CONCLUSION

 Dehydroepiandrosterone was shown to be a better predictor of abnormal anthropometric and biochemical parameters in women with PCOS than DHEAS. Thus, regarding adrenal prohormones, DHEA measurement, instead of DHEAS, should be preferred in PCOS management. The effects of androgen prohormones on the prediction of PCOS abnormalities are weak.

A 6-Week Worksite Positivity Program Leads to Greater Life Satisfaction, Decreased Inflammation, and a Greater Number of Employees With A1C Levels in Range

OBJECTIVE

To determine whether a 6-week Positivity Program could impact employee cardiovascular inflammation, blood sugars, cortisol, dehydroepiandrosterone (DHEA), and/or life satisfaction.

METHODS

Pre- and post-study blood draw and life satisfaction questionnaire tracked changes in 10 cardiovascular and inflammatory biomarkers for 63 employees who participated in a 6-week Positivity Program comprised of three interventions: gratitude, HeartMath's Heart Lock-In, and yoga stretches with guided imagery.

RESULTS

Improvements were recorded in life satisfaction as well as in seven of 10 cardiovascular and inflammatory biomarkers, including high sensitivity C-reactive protein (HsCRP) (-27%), hemoglobin A1c (HbA1c) (-1%), glucose (-2%), myeloperoxidase (MPO) (-5%), lipoprotein-associated phospholipase-A2 (Lp-PLA2) (-9%), apolipoprotein B (ApoB) (-6%), and DHEA (1%). No improvements were recorded in cortisol (11%), small-dense LDL (sdLDL) (0%), or oxidized LDL (OxLDL) (7%).

CONCLUSIONS

Data suggest that engaging in 6 weeks of a workplace Positivity Program may improve employee life satisfaction, blood sugar levels, and some markers of cardiovascular inflammation.

Altered metabolic homeostasis is associated with appetite regulation during and following 48-h of severe energy deprivation in adults

BACKGROUND

Military personnel frequently endure intermittent periods of severe energy deficit which can compromise health and performance. Physiologic factors contributing to underconsumption, and the subsequent drive to overeat, are not fully characterized. This study aimed to identify associations between appetite, metabolic homeostasis and endocrine responses during and following severe, short-term energy deprivation.

METHODS

Twenty-three young adults (17M/6F, 21±3years, BMI 25±3kg/m(2)) participated in a randomized, controlled, crossover trial. During separate 48-h periods, participants increased habitual energy expenditure by 1647±345kcal/d (mean±SD) through prescribed exercise at 40-65% VO2peak, and consumed provided isovolumetric diets designed to maintain energy balance at the elevated energy expenditure (EB; 36±93kcal/d energy deficit) or to produce a severe energy deficit (ED; 3681±716kcal/d energy deficit). Appetite, markers of metabolic homeostasis and endocrine mediators of appetite and substrate availability were periodically measured. Ad libitum energy intake was measured over 36h following both experimental periods.

RESULTS

Appetite increased during ED and was greater than during EB despite maintenance of diet volume (P=0.004). Ad libitum energy intake was 907kcal/36h [95% CI: 321, 1493kcal/36h, P=0.004] higher following ED compared to following EB. Serum beta-hydroxybutyrate, free fatty acids, branched-chain amino acids, dehydroepiandrosterone-sulfate (DHEA-S) and cortisol concentrations were higher (P<0.001 for all), whereas whole-body protein balance was more negative (P<0.001), and serum glucose, insulin, and leptin concentrations were lower (P<0.001 for all) during ED relative to during EB. Cortisol concentrations, but not any other hormone or metabolic substrate, were inversely associated with satiety during EB (R(2)=0.23, P=0.04). In contrast, serum glucose and DHEA-S concentrations were inversely associated with satiety during ED (R(2)=0.68, P<0.001). No associations between physiologic variables measured during EB and ad libitum energy intake following EB were observed. However, serum leptin and net protein balance measured during ED were inversely associated with ad libitum energy intake following ED (R(2)=0.48, P=0.01).

CONCLUSION

These findings suggest that changes in metabolic homeostasis during energy deprivation modulate appetite independent of reductions in diet volume. Following energy deprivation, physiologic signals of adipose and lean tissue loss may drive restoration of energy balance.

CLINICAL TRIALS REGISTRATION

www.clinicaltrials.gov #NCT01603550.

Regulation of local steroidogenesis in the brain and in prostate cancer: lessons learned from interdisciplinary collaboration

Sex steroids play critical roles in the regulation of the brain and many other organs. Traditionally, researchers have focused on sex steroid signaling that involves travel from the gonads via the circulation to intracellular receptors in target tissues. This classic concept has been challenged, however, by the growing number of cases in which steroids are synthesized locally and act locally within diverse tissues. For example, the brain and prostate carcinoma were previously considered targets of gonadal sex steroids, but under certain circumstances, these tissues can upregulate their steroidogenic potential, particularly when circulating sex steroid concentrations are low. We review some of the similarities and differences between local sex steroid synthesis in the brain and prostate cancer. We also share five lessons that we have learned during the course of our interdisciplinary collaboration, which brought together neuroendocrinologists and cancer biologists. These lessons have important implications for future research in both fields.

Fasting serum lipid and dehydroepiandrosterone sulfate as important metabolites for detecting isolated postchallenge diabetes: serum metabolomics via ultra-high-performance LC-MS

BACKGROUND

Isolated postchallenge diabetes (IPD), a subtype of type 2 diabetes mellitus (T2DM) defined as 2-h postprandial plasma glucose ≥ 200 mg/dL (≥ 11.1 mmol/L) and fasting plasma glucose (FPG) <108 mg/dL (<6.0 mmol/L), is often overlooked during screening for diabetes on the basis of FPG concentrations. A key challenge is early identification of IPD by the use of fasting serum, which is critical for large-scale diabetes screening.

METHODS

We applied a nontargeted metabolomic approach using ultra-high-performance liquid chromatography-quadrupole TOF-mass spectrometry (UPLC-QTOF-MS) to analyze serum samples from 51 patients with IPD, 52 with newly diagnosed T2DM, and 49 healthy individuals. We processed metabolite profiles by multivariate analysis to identify potential metabolites, which were further confirmed by tandem MS (MS/MS). We also used GC-MS and ELISA methods to detect potentially important metabolites. A number of independent samples were selected to validate the identified candidates.

RESULTS

We selected 15 metabolites with a view to distinguishing patients with IPD, whereas 11 were identified with an authentic standard. The selected metabolites included linoleic acid, oleic acid, phospholipids, and dehydroepiandrosterone sulfate (DHEA-S). In IPD samples, significantly higher linoleic and oleic acid (P < 0.001) and lower DHEA-S (P < 0.001) concentrations were observed, compared with controls. The area under the curve from a combination of linoleic acid, oleic acid, and DHEA-S in the validation study was 0.849 for the IPD group.

CONCLUSIONS

The current study provides useful information to bridge the gaps in our understanding of the metabolic alterations associated with IPD and might facilitate the characterization of patients with IPD by the use of fasting serum.

Serum dehydroepiandrosterone and lipid peroxides in human volunteers of different age groups

The objective of the present study was to evaluate the changes in serum dehydroepiandrosterone (DHEA) and lipid peroxide levels during ageing in human subjects. Random blood samples were collected from a total of 128 apparently normal human volunteers of both sexes, whose age ranged between 21-70 years. The subjects were divided into groups of a decade years of age difference. Serum levels of dehydroepiandrosterone (DHEA), lipid peroxides as malondialdehyde (MDA), and insulin were analysed in all the subjects recruited in the study. In the present study there was decrease in serum DHEA levels with age (11.30 to 7.99 ng/ml). However the differences were significant only after 50 years up to 70 years. Serum MDA levels of these subjects were higher (3.91 to 4.74 ng/ml) as compared to the values reported earlier (2.64 to 3.94 ng/ml). The serum MDA levels also showed an increasing trend with age but the increase was significant only in the 40-50 years age group and values plateaud off at later ages. The MDA and DHEA levels in women in general were lower than in men and this could be due to female hormones, which are known to protect lipid against peroxidation. There was a significant negative correlation between age and DHEA (r=-0.311 P<0.05) and positive correction between MDA and age (r=+0.405 P<0.01). No significant differences were seen in serum insulin, albumin and total protein levels. These preliminary findings support the possible utility of DHEA and MDA as markers for chronological ageing.

Appetite and endocrine regulators of energy balance after 2 days of energy restriction: insulin, leptin, ghrelin, and DHEA-S

Using a double-blind, placebo-controlled crossover design, the effects of 48 h near complete energy restriction on endocrine regulators of appetite and satiety were assessed. Twelve men and one woman participated in this controlled, 2-day diet intervention study. One experimental trial was completed in a calorie deprived state (CAL-DEP; <10% of estimated energy requirements) and others in a fed condition (carbohydrate only and carbohydrate and fat; data were pooled and compared to CAL-DEP). Test meals containing prescribed energy intake and indistinguishable in sensory characteristics were provided during each trial. Glucose, insulin, leptin, ghrelin, cortisol, dehydroepiandrosterone-sulfate (DHEA-S), and satiety were repeatedly assessed. Mean glucose, insulin, and leptin concentrations were lower (P < 0.0001) for CAL-DEP compared to the fully fed (FED) state. Ghrelin and DHEA-S were higher (P < 0.0001) for CAL-DEP relative to FED. Cortisol levels declined each day regardless of diet (P < 0.0001) but were 32% higher (P < 0.01) at the conclusion of the session for CAL-DEP compared to FED. Satiety was 25% lower (P < 0.0001) for CAL-DEP relative to FED and decreased (P < 0.0001) over time regardless of diet. In the FED state, insulin (r = 0.55), glucose (r = 0.76), cortisol (r = -0.59), and DHEA-S (r = -0.62) were associated (P < 0.05) with satiety, but not during CAL-DEP. These findings show that 2 days of severe energy restriction alter several endocrine regulators of appetite independent of perception of increased hunger suggesting a physiological mechanism to explain overeating following acute periods of severe energy restriction.

Skin responses to topical dehydroepiandrosterone: implications in antiageing treatment?

BACKGROUND

Although low dehydroepiandrosterone (DHEA) is suspected to have a role in skin ageing, little information is available on the mechanisms potentially involved.

OBJECTIVES

To obtain information on androgen receptor (AR) and procollagen expression in ageing skin during DHEA treatment.

METHODS

A placebo-controlled, randomized, prospective study was performed with 75 postmenopausal women aged 60-65 years. The women were treated twice daily for 13 weeks with 3·0 mL of placebo or 0·1%, 0·3%, 1% or 2% DHEA cream applied on the face, arms, back of hands, upper chest and right thigh where 2-mm biopsies were collected before and after treatment.

RESULTS

Although the overall structure of the epidermis was not significantly affected at the light microscopy level, AR expression examined by immunocytochemistry was markedly increased by DHEA treatment. In the dermis, the expression levels of procollagen 1 and 3 mRNA estimated by in situ hybridization were increased by DHEA treatment. In addition, the expression of heat shock protein (HSP) 47, a molecule believed to have chaperone-like functions potentially affecting procollagen biosynthesis, was also found by immunocytochemistry evaluation to be increased, especially at the two highest DHEA doses.

CONCLUSION

These data suggest the possibility that topical DHEA could be used as an efficient and physiological antiageing skin agent.

Quantitative analysis of secretome from adipocytes regulated by insulin

Adipocyte is not only a central player involved in storage and release of energy, but also in regulation of energy metabolism in other organs via secretion of peptides and proteins. During the pathogenesis of insulin resistance and type 2 diabetes, adipocytes are subjected to the increased levels of insulin, which may have a major impact on the secretion of adipokines. We have undertaken cleavable isotope-coded affinity tag (cICAT) and label-free quantitation approaches to identify and quantify secretory factors that are differentially secreted by 3T3-L1 adipocytes with or without insulin treatment. Combination of cICAT and label-free results, there are 317 proteins predicted or annotated as secretory proteins. Among these secretory proteins, 179 proteins and 53 proteins were significantly upregulated and down-regulated, respectively. A total of 77 reported adipokines were quantified in our study, such as adiponectin, cathepsin D, cystatin C, resistin, and transferrin. Western blot analysis of these adipokines confirmed the quantitative results from mass spectrometry, and revealed individualized secreting patterns of these proteins by increasing insulin dose. In addition, 240 proteins were newly identified and quantified as secreted proteins from 3T3-L1 adipocytes in our study, most of which were up-regulated upon insulin treatment. Further comprehensive bioinformatics analysis revealed that the secretory proteins in extracellular matrix-receptor interaction pathway and glycan structure degradation pathway were significantly upregulated by insulin stimulation.

Effect of dehydroepiandrosterone replacement on lipoprotein profile in hypoadrenal women

CONTEXT

Levels of dehydroepiandrosterone (DHEA) and its sulfate form (DHEAS) are inversely associated with cardiovascular mortality in men but not women. Very little evidence is available on the impact of DHEA administration on lipoprotein profile in women. DHEAS levels are very low/undetectable in hypoadrenal women.

OBJECTIVE

The objective of the study was to determine the impact of DHEA replacement on lipoprotein profile in hypoadrenal women.

DESIGN AND SETTING

A double-blind, randomized, placebo-controlled, cross-over design study was conducted at the Mayo Clinic.

PARTICIPANTS

Thirty-three hypoadrenal Caucasian women (mean +/- sd; age 50.3 +/- 15.2 yr, body mass index 26.6 +/- 4.4 kg/m(2)) took part in the study.

INTERVENTION

Study participants were assigned to receive either a placebo or 50 mg/d of DHEA for 3 months each. Lipid levels and lipoprotein profile were analyzed using the Lipo Science Lipoprotein nuclear magnetic resonance system.

MAIN OUTCOME MEASURES

Changes in various lipoprotein sizes and levels were measured.

RESULTS

The DHEA period had higher plasma DHEAS levels than during placebo (<0.3 +/- 0.0 vs. 3.5 +/- 1.3 nmol/liter, P < 0.001). DHEA replacement significantly reduced total cholesterol (20.0 vs. -22, P = 0.02) and high-density lipoprotein (HDL) levels (2.0 vs. -6.0, P = 0.006) and tends to reduce triglyceride and total low-density lipoprotein levels. Although, DHEA replacement had no effect on low-density lipoprotein particle size, it significantly reduced larger HDL particles and to modest extent small HDL particles.

CONCLUSIONS

Our study findings showed that oral DHEA administration in hypoadrenal women results in an unfavorable lipoprotein profile. The results warrant long-term studies to determine the impact of DHEA replacement on cardiovascular risk.

Adiponectin is involved in the protective effect of DHEA against metabolic risk in aged rats

The aim of the present work was to analyze the effect of dehydroepiandrosterone (DHEA) on several metabolic risk factors, including cardiovascular health and insulin resistance, in aged rats submitted to a high-fat diet. For that, weaned rats were fed on a high-fat diet until 20 months of age. In the last 13 weeks of life, a group (n=11) received the diet supplemented with DHEA (0.5%, w/w), serving the rest (n=10) as controls. Body weight, body fat, serum lipids (triglycerides, total cholesterol and non-esterified fatty acids (NEFA)), HOMA index, n-6/n-3 polyunsaturated fatty acid (PUFA) ratios, serum adiponectin, leptin, resistin and TNF-alpha, as well as adiponectin expression in adipose tissue, were measured. A stepwise discriminant test was used to analyze these variables, and an index of overall metabolic risk was generated from them. DHEA treatment resulted in a significantly lower overall metabolic risk index, as generated by the discriminant test (P<0.01). The DHEA group had lower body fat and n-6/n-3 polyunsaturated fatty acid (PUFA) ratios than the control group (P<0.01), and the same trends were observed for serum cholesterol, triglycerides and HOMA index; in contrast, adiponectin expression in adipose tissue increased in DHEA-treated rats (P<0.05). The discriminant analysis revealed that adiponectin, both from serum and adipose tissue, was the most influencing factor, followed by n-6/n-3 ratios in adipose tissue, and by body fat. Our results then suggest that adiponectin is involved in the protective effect of DHEA against metabolic risk demonstrated in the present work.

Serum DHEA-S level is associated with the presence of atherosclerosis in postmenopausal women with type 2 diabetes mellitus

We investigated the relationship between serum dehydroepiandrosterone-sulfate (DHEA-S) and insulin-like growth factor-I (IGF-I) to various parameters for atherosclerosis in type 2 diabetes. The levels of DHEA-S and IGF-I are known to decrease with aging and thereby might be associated with an increased risk of cardiovascular disease. One hundred forty-eight men and 106 postmenopausal women with type 2 diabetes were assessed in a cross-sectional study. Serum DHEA-S and IGF-I concentrations were measured and brachial-ankle pulse wave velocity (baPWV) and ultrasonographically-evaluated intima-media thickness (IMT) were assessed. Although simple regression analysis showed that log(DHEA-S) and IGF-I in men and log(DHEA-S) in women were significantly and inversely correlated with baPWV and IMT, only log(DHEA-S) in women was still significantly and inversely correlated with these atherosclerotic parameters after multiple regression analysis was adjusted for age, duration of diabetes, BMI, HbA(1C), systolic blood pressure, LDL-Cholesterol (C), serum creatinine, and smoking (Brinkman index). Serum DHEA-S level seemed to be associated with atherosclerosis in diabetic postmenopausal women independent of age, body stature, diabetic status, and other atherosclerotic risk factors, and might be a useful addition to other parameters for assessing the risk of atherosclerosis in this population.

Dehydroepiandrosterone substitution in female adrenal failure: no impact on endothelial function and cardiovascular parameters despite normalization of androgen status

BACKGROUND

Female adrenal insufficiency implicates reduced production of the adrenal androgen precursor dehydroepiandrosterone (DHEA) and low androgen levels. Oral DHEA restores androgen deficit but the clinical implications and safety of substitution therapy is uncertain. A putative DHEA receptor in vascular endothelium has been described and in vitro studies have shown involvement of DHEA in NO dependent pathways.

AIM

To evaluate effects of DHEA substitution on cardiovascular parameters.

DESIGN

Six months randomized, double-blind, placebo-controlled crossover study. Treatment consisted of DHEA 50-mg or placebo. Each treatment period was followed by a 2-month washout period.

MATERIAL AND METHODS

Ten females with documented adrenal failure were included. Androgen levels were measured. Cardiovascular evaluation was performed before and after every treatment period. Two patients left the study because of skin side effects and anxiety, respectively. All patients had low circulating androgens baseline and normal range androgens during DHEA treatment. We examined patients with noninvasive endothelial cell function, magnetic resonance imaging (MRI)-based cardiac output, echocardiography, ambulatory 24-h blood pressure and maximal oxygen consumption.

RESULTS

DHEA treatment normalized androgen status to levels seen in healthy women. DHEA and placebo treatment had no effect on echocardiographic parameters of myocardial dimensions or systolic and diastolic function, noninvasive endothelial cell function at the level of the brachial artery, 24-h blood pressure and heart rate, cardiac output and maximal oxygen consumption during exercise cycle testing. Remarkably, all participants had evidence of concentric left ventricular remodelling by echocardiography.

CONCLUSION

Restoration of physiological androgen levels using 6 months of DHEA replacement in this pilot study did not affect cardiovascular parameters and endothelial function in female adrenal insufficiency.

Serum dehydroepiandrosterone sulfate concentration and carotid atherosclerosis in men with type 2 diabetes

Decreased serum dehydroepiandrosterone (DHEA) concentrations may be associated with an increased risk of cardiovascular disease (CVD) in men. We evaluated relationships between serum DHEA sulfate (DHEA-S) concentration and carotid atherosclerosis, as well as major cardiovascular risk factors, in men with type 2 diabetes. Serum DHEA-S concentrations were measured in 206 consecutive men with type 2 diabetes. Relationships were analyzed between serum DHEA-S concentration and carotid atherosclerosis, determined by ultrasonographically evaluated intima-media thickness (IMT) and plaque score (PS), as well as major cardiovascular risk factors, including age, blood pressure, and lipid concentrations. Negative correlations were found between DHEA-S concentration and IMT (r = -0.298, P < 0.0001) and between DHEA-S concentration and PS (r = -0.308, P < 0.0001). IMT and PS were significantly greater in patients with lower concentrations of DHEA-S (<1000 ng/ml) than in patients with higher concentrations of DHEA-S (1.07+/-0.30 mm versus 0.91+/-0.19 mm, P < 0.0001, and 5.5+/-4.2 versus 3.1+/-3.4, P < 0.0001, respectively). A negative correlation was found between serum DHEA-S concentration and age (r = -0.488, P < 0.0001). Multiple regression analysis demonstrated that serum DHEA-S concentration was an independent determinant of IMT (beta = -0.289, P < 0.0001) and of PS (beta = -0.301, P < 0.0001). In conclusion, serum DHEA-S concentration is negatively associated with carotid atherosclerosis determined by ultrasonographically evaluated IMT and PS in men with type 2 diabetes.

The Metabolic Syndrome and Disturbances in Hormone Levels in Long-Term Survivors of Disseminated Testicular Cancer

Purpose

The metabolic syndrome may be an important risk factor for cardiovascular disease in long-term survivors of testicular cancer (TC). We investigated the associations between hormone levels and the metabolic syndrome in these men.

Patients and Methods

We included TC patients cured by orchidectomy and cisplatin-based chemotherapy, stage I TC patients after orchidectomy only, and healthy men of comparable age. Presence of the metabolic syndrome was determined using guidelines from the National Cholesterol Education Program Adult Treatment Panel III. Thyroid-stimulating hormone, follicle-stimulating hormone (FSH), inhibin B, luteinizing hormone (LH), total testosterone, sex-hormone–binding globulin, free testosterone, estradiol, dehydroepiandrosterone sulfate, and insulin-like growth factor 1 were determined in blood. Cortisol metabolite excretion was measured in urine.

Results

Eighty-six chemotherapy patients (median follow-up, 7 years) were compared with 44 stage I patients and 47 controls. LH and FSH were higher, and inhibin B and total and free testosterone were lower in chemotherapy patients than controls. Adrenal and thyroid hormone production were unaffected. Chemotherapy patients with the metabolic syndrome (n = 22; 26%) had a higher body mass index (BMI) pretreatment, a larger BMI increase during follow-up, lower total testosterone, and higher urinary cortisol metabolite excretion than those patients without the metabolic syndrome. BMI and insulin were associated with the metabolic syndrome, while total testosterone and urinary cortisol metabolite excretion were associated with BMI.

Conclusion

We found gonadal dysfunction, but normal adrenal and thyroid function. Through its association with BMI, testosterone may play a role in the development of the metabolic syndrome in long-term TC survivors.

Role of dehydroepiandrosterone sulfate levels on body composition after laparoscopic adjustable gastric banding in pre-menopausal morbidly obese women

In humans, dehydroepiandrosterone (DHEAS) has been postulated to have anabolic and lipolytic properties that could potentially counteract the catabolic effect of cortisol. DHEAS secretion is reduced in morbid obesity, likely due to hyperinsulinemia, and laparoscopic adjustable gastric banding (LASGB), by inducing considerable and rapid weight loss, reduces insulin levels. To investigate the role of decreased insulin levels after LASGB-induced weight loss on DHEAS levels and on body composition changes, we studied 30 pre-menopausal morbidly obese women (BMI ranging 37-62 kg/m2) before, 6, 12 and 24 months after LASGB. Total body water (TBW), fat-free mass (FFM) and fat mass (FM) were measured by bioelectrical impedance analysis; tissue hydration was also assessed by impedance vector analysis. At study ending, the subjects had a total weight loss of 28% of baseline body weight (15% after 6 months). After LASGB, weight loss was mainly due to decreased FM, and TBW, FFM, and body hydration were not significantly reduced. Weight loss was associated with an 82% rise in serum DHEAS already after 6 months while cortisol, cortisol/DHEAS molar ratio, and insulin levels fell by 5.5, 62 and 50%, respectively, after 6, 12 and 24 months (p<0.05).

CONCLUSIONS

LASGB associated with a well balanced low-calorie diet permits a satisfactory 2-yr weight loss, sparing FFM and without body fluid alterations. As the result of a stable weight reduction program weight loss is associated to decrease in cortisol, cortisol/DHEAS molar ratio, and insulin plasma levels with marked rise in DHEAS. Higher cortisol/DHEAS molar ratio values at baseline are also associated to lower weight loss after LASGB, with lower decrease in FM and higher reduction in FFM and body cell mass, in spite of no differences in dietary regimes. Cortisol/DHEAS molar ratio is likely to represent a reliable marker of favourable modifications in body composition.

Modulation of collagen metabolism by the topical application of dehydroepiandrosterone to human skin

Dehydroepiandrosterone (DHEA) and its sulfate conjugate (DHEA-S) are the most abundantly produced human adrenal steroids to be reduced with age. DHEA may be related to the process of skin aging through the regulation and degradation of extracelluar matrix protein. In this study, we demonstrate that DHEA can increase procollagen synthesis and inhibit collagen degradation by decreasing matrix metalloproteinases (MMP)-1 synthesis and increasing tisuue inhibitor of matrix metalloprotease (TIMP-1) production in cultured dermal fibroblasts. DHEA was found to inhibit ultraviolet (UV)-induced MMP-1 production and the UV-induced decrease of procollagen synthesis, probably due to the inhibition of UV-induced AP-1 activity. DHEA (5%) in ethanol:olive oil (1:2) was topically applied to buttock skin of volunteers 12 times over 4 weeks, and was found to significantly increase the expression of procollagen alpha1(I) mRNA and protein in both aged and young skin. On the other hand, topical DHEA significantly decreased the basal expression of MMP-1 mRNA and protein, but increased the expression of TIMP-1 protein in aged skin. We also found that DHEA induced the expressions of transforming growth factor-beta1 and connective tissue growth factor mRNA in cultured fibroblasts and aged skin, which may play a role in the DHEA-induced changes of procollagen and MMP-1 expression. Our results suggest the possibility of using DHEA as an anti-skin aging agent.

Is premature adrenarche a risk factor for atherogenesis?

BACKGROUND

The aim of this study was to evaluate serum lipids and atherosclerosis risk in children with premature adrenarche (PA) in comparison with age-matched controls.

METHODS

Lipid profile, glucose, insulin, and insulin-like growth factor binding protein-1 (IGFBP-1) levels were studied in 24 girls with premature adrenarche and 13 healthy age-matched controls after overnight fasting.

RESULTS

The bone age, weight and body mass index were higher in the premature adrenarche group than the control group. Systolic, diastolic and mean arterial blood pressure of patients were higher than controls. The mean total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), very low-density lipoprotein-cholesterol (VLDL-C), TC/high-density lipoprotein-cholesterol (HDL-C) and LDL-C/HDL-C ratio, and atherogenic index were significantly higher in the premature adrenarche group compared to the control group. There was no significant difference in the levels of apolipoprotein A1, apolipoprotein B and lipoprotein (a) in both groups. In the premature adrenarche group there were inverse correlations between the levels of IGFBP-1 and TC/HDL-C (rho, -0.54; P, 0.011), and LDL-C/HDL-C (rho, -0.50; P < 0.05) and atherogenic index (AI; rho, -0.54; P < 0.05). Dehydroepiandrosterone sulfate levels of the patients was negatively correlated with AI and TC/HDL-C (rho, -0.0503, P < 0.05).

CONCLUSIONS

Girls with premature adrenarche should be investigated for serum lipids, and atherogenic risk criteria should be assessed periodically in the follow up of patients with PA, as PA seems to be a risk factor for future atherosclerosis.

Vanadyl sulfate ameliorates insulin resistance and restores plasma dehydroepiandrosterone-sulfate levels in fructose-fed, insulin-resistant rats

OBJECTIVES

To elucidate whether vanadyl sulfate ameliorates the decreased dehydroepiandrosterone sulfate (DHEAS) in hyperinsulinemic rats, we evaluated plasma DHEAS, insulin and triglyceride (TG) levels in fructose-induced, insulin-resistant rats.

DESIGN AND METHODS

Animals were divided into three groups: control (C), fructose fed (F-F), and vanadyl-treated fructose fed (F-T). Control animals were fed with standard chow; F-F and F-T groups fed with 66% fructose diet. F-F and C groups received tap water; F-T group received water supplemented with 0.2 mg/ml vanadyl sulfate.

RESULTS

Fasting plasma glucose levels of three groups were comparable. Vanadyl treatment prevented the increase in plasma insulin and TG in the F-T group (P < 0.001) compared with the F-F group. Fructose feeding led to a decrease in plasma DHEAS in the F-F group (P < 0.001) compared with the C group. Vanadyl treatment prevented the decrease in plasma DHEAS in the F-T group (P < 0.001) compared with the F-F group.

CONCLUSIONS

Our results indicated that the hyperinsulinemia in fructose-fed, insulin-resistant rats is associated with low levels of DHEAS. Vanadyl sulfate probably restores plasma DHEAS, due to the improved insulin action.

Effects of the long-acting calcium channel blockers, amlodipine, manidipine and cilnidipine on steroid hormones and insulin resistance in hypertensive obese patients

OBJECTIVE

To demonstrate that calcium channel blockers can improve insulin resistance clinically, we investigated the effects of the calcium channel blockers, amlodipine, manidipine and cilnidipine on serum levels of steroid hormones and insulin.

SUBJECTS AND METHODS

Thirty hypertensive obese patients [15 men and 15 women; mean age 55.9 years, mean body mass index (BMI) 27.6] were divided into three groups and treated with either 5 mg of amlodipine, 20 mg of manidipine or 10 mg of cilnidipine. Blood pressure (BP), fasting plasma glucose (FPG), HbA1c, fasting serum immunoreactive insulin (F-IRI), insulin resistance index [as assessed by the homeostasis model assessment (HOMA-R)], serum DHEA, serum DHEA-S, plasma ACTH, serum cortisol, plasma renin activity (PRA), and serum aldosterone, were measured before and after 1, 2, 3 and 6 months of treatment.

RESULTS

In all three groups, BP decreased significantly after 1 month and F-IRI and HOMA-R decreased significantly after 2-3 months. A concurrent rise in serum DHEA and DHEA-S levels was also observed, however, the differences were not significant. No changes in FPG, HbA1c, ACTH, cortisol, PRA or aldosterone levels were observed during treatment.

CONCLUSIONS

We conclude that amlodipine, manidipine and cilnidipine all improve insulin resistance and consequently increase serum levels of DHEA and DHEA-S.

The effect of dehydroepiandrosterone on regional blood flow in prepubertal anaesthetized pigs

Dehydroepiandrosterone has been implicated in vascular disease and its associated insulin resistance and hypertension, though little is known about its vascular effects. We have recently shown in prepubertal anaesthetized pigs that intravenous infusion of dehydroepiandrosterone caused coronary vasoconstriction through the inhibition of a vasodilatory beta-adrenergic receptor-mediated effect related to the release of nitric oxide. The present study was designed to investigate the effect of dehydroepiandrosterone on mesenteric, renal and iliac vascular beds. In prepubertal pigs of both sexes anaesthetized with sodium pentobarbitone, changes in superior mesenteric, left renal and left external iliac blood flow caused by intravenous infusion of dehydroepiandrosterone were assessed using electromagnetic flowmeters. Changes in heart rate and arterial blood pressure were prevented by atrial pacing and by connecting the arterial system to a pressurized reservoir containing Ringer solution. In 22 pigs, infusion of 1 mg h(-1) of dehydroepiandrosterone decreased mesenteric, renal and iliac blood flow. In a further 10 pigs, dose-response curves were obtained by graded increases in the infused dose of hormone between 0.03 and 4 mg h(-1). The mechanisms of the above response were studied in the 22 pigs by repeating the experiment after haemodynamic variables had returned to the control values observed before infusion. Blockade of alpha-adrenoceptors with intravenous phentolamine (five pigs) did not affect the dehydroepiandrosterone-induced mesenteric, renal and iliac vasoconstriction. This response was abolished by blockade of beta(2)-adrenoceptors with intravenous butoxamine (five pigs) and by blockade of mesenteric, renal and iliac nitric oxide synthase with intra-arterial administration of N(omega)-nitro-L-arginine methyl ester (seven pigs), even after reversing the increase in local vascular resistance caused by the two blocking agents with intravenous infusion of papaverine. In five pigs, the increase in measured blood flow caused by intravenous infusion of isoproterenol (isoprenaline) was significantly reduced by infusion of dehydroepiandrosterone. The present study showed that intravenous infusion of dehydroepiandrosterone primarily caused mesenteric, renal and iliac vasoconstriction. The mechanisms of this response were shown to be due to the inhibition of a vasodilatory beta(2)-adrenergic receptor-mediated effect, which possibly involved the release of nitric oxide.

Left ventricular mass index and ventricular septum thickness are associated with serum dehydroepiandrosterone-sulphate levels in hypertensive women

OBJECTIVE

Several data indicate that endogenous sex steroids might influence left ventricular mass. Our aim was to examine the association between dehyroepiandrosterone-sulphate (DHEAS) levels and left ventricular mass index (LVMI) and ventricular septal thickness (VST) in pre- and in postmenopausal women with treated essential hypertension.

PATIENTS AND METHODS

LVMI and VST were related to serum DHEAS in 26 pre- and in 34 postmenopausal women. The associations between DHEAS and LVMI, VST were adjusted for body mass index, duration of hypertension, systolic blood pressure, serum cholesterol and testosterone levels using a multiple regression model.

RESULTS

In premenopausal women there was a significant linear correlation between DHEAS and LVMI (P < 0.02) after adjustment for confounding variables. In contrast, DHEAS was inversely correlated with LVMI and VST in postmenopausal women (r = -0.49, P < 0.02, r =-0.42, P < 0.02, respectively). These associations also remained significant (P = 0.04, P = 0.03, respectively) after adjustment for confounding variables.

CONCLUSION

DHEAS might be an independent determinant of LVMI and VST. Its effect on the heart may depend on hormonal milieu. In premenopausal women, DHEAS might have androgenic effects and might enhance fibroblast proliferation; while during the postmenopausal period it is dominantly oestrogenic in action, with antiproliferative effect on cardiac cells.

The effect of dehydroepiandrosterone on coronary blood flow in prepubertal anaesthetized pigs

Extensive research suspecting an association between plasma levels of dehydroepiandrosterone and the risk of coronary heart disease has not been conclusive. The present study was designed to investigate the effect of dehydroepiandrosterone on the coronary circulation and to determine the mechanisms involved. In prepubertal pigs of both sexes anaesthetized with sodium pentobarbitone, changes in left circumflex or anterior descending coronary flow caused by intravenous infusion of dehydroepiandrosterone were assessed using an electromagnetic flowmeter. Changes in heart rate and arterial pressure were prevented by atrial pacing and by connecting the arterial system to a pressurized reservoir containing Ringer solution. In 20 pigs, infusion of 1 mg h-1 of dehydroepiandrosterone caused a decrease in coronary flow without affecting left ventricular dP/dtmax (rate of change of left ventricular systolic pressure) and filling pressures of the heart. In a further eight pigs, a dose-response curve was obtained by graded increases in the infused dose of hormone between 0.03 and 4 mg h-1. The mechanisms of the above response were studied in the 20 pigs by repeating the experiment after haemodynamic variables had returned to the control values observed before infusion. Blockade of muscarinic cholinoceptors with intravenous atropine (five pigs) and of alpha-adrenoceptors with intravenous phentolamine (five pigs) did not affect the dehydroepiandrosterone-induced coronary vasoconstriction. This response was abolished by blockade of beta-adrenoceptors with intravenous propranolol (five pigs) and of coronary nitric oxide synthase with intracoronary injection of Nomega-nitro-L-arginine methyl ester (five pigs) even after reversing the increase in arterial pressure and coronary vascular resistance caused by the two blocking agents with intravenous infusion of papaverine. The present study showed that intravenous infusion of dehydroepiandrosterone primarily caused coronary vasoconstriction. The mechanisms of this response were shown to involve the inhibition of a vasodilatory beta-adrenergic receptor-mediated effect related to the release of nitric oxide.

Chronic effects of dehydroepiandrosterone on rat adipose tissue metabolism

The goal of the present study was to examine cellular mechanisms that regulate adipose cell metabolism in ovariectomized (OVX) and intact rats that were subjected to long-term (27 weeks) treatment with dehydroepiandrosterone (DHEA). Forty-eight 16-month-old female rats were divided into 4 groups of 9 to 11 animals (intact, intact-DHEA, OVX, OVX-DHEA). Adipose tissue lipoprotein lipase (LPL), hormone-sensitive lipase (HSL), and cyclic adenosine monophosphate (cAMP)-dependent phosphodiesterase (cAMP-PDE) activities were determined, and alpha2-, beta1/beta2-, and beta3-adrenoceptors (ARs) were quantified. DHEA did not affect body weight, fat, or muscle mass in intact rats. The similar retroperitoneal fat pad weight of intact-DHEA rats compared to intact animals was in agreement with the lack of difference in the enzyme activities and AR densities. The increased body weight of OVX rat was paralleled by a greater retroperitoneal adipose tissue mass (P <.01), which was in turn associated with a marked rise in LPL activity (P <.005) and a slight decrease in HSL activity (P <.05) compared to intact animals. OVX-DHEA rats, compared to untreated OVX animals, had a smaller retroperitoneal fat depot, which correlated with a decrease in LPL activity (P <.005) and moderate increase in both HSL activity and beta3-AR density (P <.05). DHEA-treatment lowered fasting insulin and triglyceride levels in both intact and OVX rats (P <.05). Plasma testosterone, androsterone, androstenedione, and androstenediol levels were also significantly increased in both intact-DHEA and OVX-DHEA rats compared to untreated animals (P <.0001). These findings suggest that the antiobesity action of DHEA may be related in part to changes in lipase activities and in beta3-AR density, and that it is dependent on the ovarian status of the animal.

DHEA and sport

Dehydroepiandrosterone (DHEA), a 19-carbon steroid, is situated along the steroid metabolic pathway. It is the most abundant circulating hormone in the body and can be converted to either androgens or estrogens. It is readily conjugated to its sulphate ester DHEAS, and they are designated as DHEA(S) here when used together. Its secretion reaches a peak in early adulthood and thereafter decreases, until approximately age 70 years when it reaches a concentration of approximately 20%. Many hormonal changes may take place with aging but none is as marked as this. This "relative DHEA deficiency" resulted in DHEA being enthusiastically labelled by some as a fountain of youth or an antidote to aging that would prove to be the panacea they are seeking. Its use was also taken up enthusiastically by the athletic community and used as a prohormone in the belief or hope that it would be converted mainly to testosterone in the body.

The effect of 1,3-diaryl-[1H]-pyrazole-4-acetamides on glucose utilization in ob/ob mice

This article provides evidence of a new class of compounds, 1,3-diaryl-[1H]-pyrazole-4-acetamides, initially identified from their ability to increase glucose transport in an adipocyte and muscle cell line and ultimately demonstrating dramatic glucose lowering in ob/ob mice, a diabetic animal model. The lead compound, 1, possessed some behavioral-like effects which were removed by structural variation during the course of this investigation. Specifically, 11g (R1 = meta-CF(3), Ar2 = 4'biphenyl, R3 = diethylamide) illustrated the potency of this series with ED(50) values for glucose lowering in ob/ob mice of 3.0 mg/kg/day. Concomitant with its effect on glucose lowering, 11g also caused a 50% reduction in insulin levels consistent with an agent that increases whole body insulin sensitivity. 11g showed favorable pharmacokinetic data with acceptable absorption, negligible metabolism, and good duration of action. 11g demonstrated no appreciable adipogenic effect through PPAR gamma agonism, a characteristic of the thiazolidinediones (TZD), and so represents a potentially new class of agents for the treatment of diabetes.

Reduction in glucose levels in STZ diabetic rats by 4-(2,2-dimethyl-1-oxopropyl)benzoic acid: a prodrug approach for targeting the liver

The overproduction of glucose by the liver in NIDDM patients markedly contributes to their fasting hyperglycemia and is a direct consequence of the increased oxidation of excess free fatty acids (FFA) being released from the adipocyte. 2-(1,1-Dimethylethyl)-2-(4-methylphenyl)[1,3]dioxolane (SAH51-641, 1) has previously been demonstrated to reduce glucose levels in animal models of diabetes by reducing fatty acid oxidation and hence depriving the system of the energy and cofactors necessary for gluconeogenesis. However, attempts at lowering glucose levels in vivo with 1 have been associated with toxicity in other organs such as the testes. An approach was developed utilizing the natural processing of triglyceride-like intermediates as a basis for selectively targeting the absorption, processing, and delivery of a prodrug to the liver. Compounds were identified by this method which lowered glucose levels in vivo without releasing toxic amounts of the active metabolites of 1 into circulation.

Low dehydroepiandrosterone and ischemic heart disease in middle-aged men: prospective results from the Massachusetts Male Aging Study

The adrenal steroid dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) have been characterized as "protective" against ischemic heart disease (IHD), especially in men, on the basis of sparse epidemiologic evidence. The authors used data from the Massachusetts Male Aging Study, a random sample prospective study of 1,709 men aged 40-70 years at baseline, to test whether serum levels of DHEA or DHEAS could predict incident IHD over a 9-year interval. At baseline (1987-1989) and follow-up (1995-1997), an interviewer-phlebotomist visited each subject in his home to obtain comprehensive health information, body measurements, and blood samples for hormone and lipid analysis. Incident IHD between baseline and follow-up was ascertained from hospital records and death registries, supplemented by self-report and evidence of medication. In the analysis sample of 1,167 men, those with serum DHEAS in the lowest quartile at baseline (<1.6 microg/ml) were significantly more likely to incur IHD by follow-up (adjusted odds ratio = 1.60, 95 percent confidence interval: 1.07, 2.39; p = 0.02), independently of a comprehensive set of known risk factors including age, obesity, diabetes, hypertension, smoking, serum lipids, alcohol intake, and physical activity. Low serum DHEA was similarly predictive. These results confirm prior evidence that low DHEA and DHEAS can predict IHD in men.

Characterization of serum dehydroepiandrosterone secretion in golden hamsters

Dehydroepiandrosterone (DHEA) is an adrenal androgen whose function is poorly understood. Although DHEA and DHEA sulfate (DHEAS) are secreted in relatively high quantities by the human adrenal, the laboratory rat secretes very little, thus hindering experimental studies of the hormone. In this paper, we measured the changes in serum DHEA and DHEAS under various physiological conditions in golden hamsters. Evening serum DHEAS fell from 6.30 +/- 0.78 microg/dl (mean +/- SE) before surgery to 3.03 +/- 0.23 microg/dl 12 days after bilateral adrenalectomy. Hamsters had higher levels of DHEA and DHEAS in the evening than in the morning, but removal of the gonads did not consistently decrease serum DHEA or DHEAS in males or females. Evening levels of DHEA and DHEAS reached a peak around 7 weeks of age and then gradually decreased to about one-third of these levels by one year of age. These results suggest that DHEA and DHEAS are secreted at least in part from the hamster adrenal, that they do not originate from the gonads, and that there is a daily rhythm with peak levels at a time of day just preceding the active phase. In addition, the levels of these hormones decrease with aging.

The plasma levels of dehydroepiandrosterone sulfate are decreased in patients with chronic heart failure in proportion to the severity

Dehydroepiandrosterone sulfate (DHEAS) is the major secretory steroid of the human adrenal glands. The secretion of DHEAS decreases with aging. The incidence of heart failure also rises in the elderly population. We measured the plasma levels of DHEAS and cortisol in 49 patients with chronic heart failure (CHF) and 32 age-matched controls and assessed its relation to plasma levels of A-type natriuretic peptide and B-type natriuretic peptide, biochemical markers of heart failure. Plasma levels of DHEAS were significantly lower in patients with CHF than in controls, whereas there was no significant difference in plasma levels of cortisol between the two groups. In stepwise regression analysis, the plasma level of DHEAS was significantly and independently correlated with age (beta = -0.451; P < 0.0001) and the plasma level of B-type natriuretic peptide (beta = -0.338; P < 0.001), and the plasma cortisol/DHEAS ratio was significantly and independently correlated with the plasma levels of A-type natriuretic peptide (beta = 0.598; P < 0.0001) and thiobarbituric acid-reactive substances (a marker of oxidative stress; beta = 0.252; P < 0.01) and age (beta = 0.171; P < 0.05). These results indicate that the plasma levels of DHEAS are decreased in patients with CHF in proportion to its severity and that oxidative stress is associated with decreased levels of DHEAS in patients with CHF.

No association between dehydroepiandrosterone sulfate and development of atherosclerosis in a prospective population study (Bruneck Study)

Antiatherogenic properties of dehydroepiandrosterone (DHEA) have been postulated for >40 years. Large-scale epidemiological studies on this important issue, however, are still sparse, and those available have yielded contradictory results. The Bruneck Study involved a large random sample of men and women aged 40 to 79 years that were enrolled in 1990 and reevaluated 5 years later. Baseline DHEA sulfate (DHEAS) levels were measured in 867 subjects after an overnight fast. Development and progression of carotid atherosclerosis was monitored by high-resolution duplex ultrasound. DHEAS levels declined with advancing age (29% and 44% per decade in men and women) and showed a complex sex-specific association with various vascular risk attributes and factors conferring protection against atherosclerosis. Age- and sex-adjusted DHEAS baseline levels did not differ between subjects with or without incident/progressive atherosclerosis (geometric mean 1161 versus 1253 microg/L). After adjustment for vascular risk factors and potential confounders, the odds ratio of incident/progressive atherosclerosis comparing a 50% increase in DHEAS levels was 0.99 (95% CI 0.89 to 1.11). Lack of an association between DHEAS and atherogenesis was confirmed in sex-specific and a variety of supplementary analyses. Statistical power would be high enough to detect differences in DHEAS between outcome categories as low as 15% (alpha=0.05). This prospective community-based study does not support a role for endogenous DHEA(S) in the development of human atherosclerosis.

Lifelong treatment with oral DHEA sulfate does not preserve immune function, prevent disease, or improve survival in genetically heterogeneous mice

OBJECTIVES

To determine whether lifelong exposure to dehydroepiandrosterone sulfate extends the lifespan or retards immune senescence in mice.

DESIGN

Double-blind, placebo-controlled intervention trial.

SETTING

A specific pathogen-free rodent vivarium.

PARTICIPANTS

120 mice bred as a cross between CB6F1 females and C3D2F1 males.

INTERVENTION

DHEAS at 100 microg/mL in drinking water from weaning until death.

MEASUREMENT

Age at death, cause of death, antibody production after erythrocyte immunization, and T cell subset profiles in peripheral blood at ages 8 and 18 months.

RESULTS

DHEAS ingestion did not lead to a significant increase in mean or maximal longevity: the 95% confidence interval for DHEAS effect on mean lifespan ranged from +35 days to -80 days. There were no significant effects of DHEAS on incidence of lethal illnesses, except for a trend toward higher levels of mammary adenocarcinoma in DHEAS-treated females and mouse urinary syndrome in DHEAS-treated males. DHEAS treatment did not improve the ability of middle-aged mice to produce antibody to a foreign particulate antigen, and it did not alter the proportions of age-sensitive T cell subsets in middle-aged animals.

CONCLUSION

Although differences among species in pharmacokinetics complicate interpretation of studies in which DHEA or DHEAS is administered to rodents, our data provide no support for the idea that chronic exposure to this steroid retards immune senescence or prevents late life illness.

Dehydroepiandrosterone and related steroids alter 3T3-L1 preadipocyte proliferation and differentiation

The purpose of the present study was to determine if the anti-adipogenic effects of dehydroepiandrosterone (DHEA) are mediated solely by DHEA or by one or more of its downstream metabolites. In Experiment 1, preconfluent proliferating cultures of 3T3-L1 preadipocytes were incubated for either 24 or 72 h with 0, 1, 5 or 25 microM DHEA, DHEA sulfate (DHEAS), testosterone, estrone and 17beta-estradiol. Pregnenolone, a precursor of DHEA(S), was also tested at these concentrations. After 24 h of incubation, DHEAS, 17beta-estradiol and estrone at the 1 microM level stimulated preadipocyte proliferation. In contrast, DHEA and 17beta-estradiol at the 25 microM level attenuated proliferation to a greater extent than all other steroids. After 72 h of incubation, DHEA and 17beta-estradiol at the 25 microM level attenuated proliferation to a greater extent than all other steroids. In Experiment 2, post-confluent cultures of differentiating 3T3-L1 preadipocytes were incubated for 6 days with 0, 5, 30, or 60 microM levels of these steroids. Preadipocyte differentiation, as assessed by lipid content and glycerol-3-phosphate dehydrogenase activity, decreased markedly when treated with 30 and 60 microM DHEA, 17beta-estradiol, estrone and pregnenolone. In contrast, DHEAS had no impact on preadipocyte proliferation or differentiation. These results suggest that the anti-adipogenic actions of DHEA in adipose tissue may be mediated, in part, by one or more of its distal metabolites, including 17beta-estradiol.

The role of dehydroepiandrosterone in diabetes mellitus

Much has been written in the lay literature regarding potential benefits of dehydroepiandrosterone (DHEA). Although it was removed from the over-the-counter market in 1985, the Dietary Supplement Health Education Act of 1994 allowed the drug to be marketed as a food supplement. Because DHEA no longer falls under the scrutiny of the Food and Drug Administration, many unverified claims have been put forth in the press espousing its therapeutic value. This barrage of "infomercials" has left the average American consumer (and health care professional) curious about DHEA and its possible therapeutic utility. One focus of recent research is to define the role of DHEA in diabetes mellitus. Although it has been claimed that decreased levels of endogenous DHEA are associated with diabetes, impaired glucose tolerance, hyperglycemia, and insulin resistance, much of the information is based on cross-sectional studies. Other claims correlate decreased endogenous DHEA levels with adverse cardiovascular effects. Some information is contradictory and indicates high doses of exogenous DHEA may produce adverse cardiovascular effects, an undesirable outcome in patients with diabetes mellitus. At this time, its administration in patients with diabetes is not warranted. Long-term trials evaluating the role of exogenous DHEA and its effect on patients with diabetes should be conducted.

Insulin resistance, impaired glucose tolerance and non-insulin-dependent diabetes, pathologic mechanisms and treatment: current status and therapeutic possibilities

Impaired glucose tolerance and non-insulin-dependent diabetes (NIDDM) are the pathologic consequence of two co-incident and interacting conditions, namely insulin resistance and relative insulin deficiency. Recognised by the World Health Authority as a global health problem there are at 1995 estimates at least 110 million diagnosed diabetics world wide with at least the same number undiagnosed. Diabetes is the 4th leading cause of death in developed countries and its management exerts a vast economic and social burden. Insulin resistance is established as the characteristic pathologic feature of patients with glucose intolerance and NIDDM describing a state in which insulin stimulated glucose uptake and utilisation in liver, skeletal muscle and adipose tissue is impaired and coupled to impaired suppression of hepatic glucose output. Although the biochemical mechanisms underpinning both defects are becoming better understood, the genetic and molecular causes remain elusive; and whether insulin resistance or relative insulin deficiency represents the primary defect in patients with NIDDM is the matter of some debate. In this article we review the biochemical and molecular nature of the defects in insulin sensitivity and glucose uptake, and discuss some of the potential causative mechanisms. The genetic and environmental basis of insulin resistance is reviewed and presented, and potential therapeutic targets including thiazolidinediones are discussed.

Association of dehydroepiandrosterone sulfate with serum HDL-cholesterol concentrations in post-menopausal Japanese women

OBJECTIVES

Positive association between serum dehydroepiandrosterone sulfate (DHEAS) and high-density lipoprotein (HDL) cholesterol has been observed in men but not women. We aimed to examine the cross-sectional relationships of DHEAS, estradiol (E2), and sex hormone-binding globulin (SHBG) to serum lipid concentrations in post-menopausal Japanese women.

METHODS

A total of 56 post-menopausal Japanese women were derived from female residents in Takayama City in Japan. The information on body size, disease history, reproductive history, diet, and physical activity were obtained by a self-administered questionnaire.

RESULTS

DHEAS was significantly and positively correlated with HDL-cholesterol after controlling for age and body mass index (BMI) (r = 0.28). There was no correlation between DHEAS and total-cholesterol (r = -0.02). E2 was not significantly correlated with total- and HDL-cholesterol and triglyceride. However, SHBG-unbound E2 was significantly positively correlated with HDL-cholesterol (r = 0.34) and negatively correlated with triglyceride (r = -0.27) after controlling for age and BMI. SHBG was negatively correlated with triglyceride, although the correlation was not statistically significant (r = -0.22).

CONCLUSION

These data suggest favorable effect of DHEAS as well as E2 and SHBG on lipid profile in Japanese post-menopausal women.

Activation of 11 beta-hydroxysteroid dehydrogenase by dehydroepiandrosterone sulphate as an anti-hypertensive agent in spontaneously hypertensive rats

The anti-hypertensive properties of dehydroepiandrosterone sulphate (DHEAS) have been investigated by studying its effects on blood pressure, on serum concentrations of corticosterone and dehydrocorticosterone, and on 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) activity in spontaneously hypertensive rats (SHR). SHR were given intraperitoneal injections of DHEAS (10 mg day-1 for 70 days) from six to 16 weeks of age. The blood pressure-time curve was significantly (P < 0.05) suppressed immediately after administration of DHEAS. There was no difference between the heart rates of control and DHEAS groups. Serum concentrations of corticosterone and dehydrocorticosterone in the DHEAS group were significantly (P < 0.05) lower than those of the control group. The dehydrocorticosterone/corticosterone concentration ratio was, however, significantly (P < 0.05) higher in the DHEAS group, suggesting that treatment with DHEAS enhanced the overall interconversion of corticosterone to dehydrocorticosterone. The activity of 11 beta-HSD in specific organs of the DHEAS group was affected, characteristic changes being increases in the kidney (14-58%), decreases in the liver (11-27%) and no change in the testis. Direct addition of DHEAS to 11 beta-HSD preparations from the kidneys of control SHR had the same effect as that observed in the in-vivo experiments. The fall in serum corticosterone in the DHEAS group is considered to be related, at least partly, to increased activity of kidney 11 beta-HSD. The inverse correlation of kidney 11 beta-HSD activity with serum corticosterone and blood pressure (-r = 0.628, P < 0.01, and -r = 0.478, P < 0.05, respectively) suggest that DHEAS delayed the development of hypertension in SHR by selective promotion of kidney 11 beta-HSD activity which in turn resulted in lower serum concentrations of corticosterone and its minimal aldosterone-like activity.

Dehydroepiandrosterone attenuates preadipocyte growth in primary cultures of stromal-vascular cells

The purpose of this study was to determine whether the antiobesity actions of dehydroepiandrosterone (DHEA) are due to an influence on preadipocyte proliferation and/or differentiation in primary cultures of pig and rat stromal-vascular (SV) cells. Pig SV cells were isolated from dorsal subcutaneous adipose tissue of 7-day-old pigs. For the proliferation assays, pig SV cells were grown for 4 days in plating medium containing DHEA at 0, 15, 50, or 150 microM. For the differentiation assays, pig SV cells were grown in plating medium for 3 days and then switched to a serum-free medium containing DHEA at 0, 15, 50, or 150 microM for the next 6 days. Rat SV cells were isolated from inguinal fat pads of 5-wk-old male rats. Rat SV cells were exposed to DHEA at 0, 5, 25, or 75 microM during proliferation. For the differentiation assays, rat SV cells were grown for 8 days in a serum-free medium containing DHEA at 0, 5, 25, or 75 microM. Preadipocyte differentiation [lipid staining, glycerol-3-phosphate dehydrogenase (GPDH) activity] and proliferation (preadipocyte-specific antigen staining) decreased with increasing levels of DHEA in cultures of pig SV cells. In cultures of rat SV cells, preadipocyte differentiation (lipid staining, GPDH activity) and proliferation ([3H]thymidine incorporation) were decreased in the 25 and 75 microM DHEA groups compared with the control and 5 microM DHEA groups. The level of expression of CCAAT enhancer binding protein-alpha, a master regulator of adipogenesis, in cultures of pig SV cells treated with 150 microM DHEA was 38% of control cultures. These data support the hypothesis that DHEA directly attenuates adipogenesis via attenuation of preadipocyte proliferation and differentiation.

Dehydroepiandrosterone reduces proliferation and differentiation of 3T3-L1 preadipocytes

The purpose of these studies was to determine whether the antiobesity actions of dehydroepiandrosterone (DHEA) and DHEA-sulfate (DHEAS) observed in vivo are due to an influence on proliferation and/or differentiation in monolayer cultures of 3T3-L1 preadipocytes. For the proliferation study (Exp. 1), cells were grown in plating medium containing DHEA at 0, 5, 25, 50, or 100 microM for 1-4 d. DHEAS was added at the 100 microM level only. For the differentiation study (Exp. 2), cultures were grown in plating medium containing DHEA at 0, 5, 30, 60, 120, or 240 microM for 2-6 d. DHEAS was added at the 240 microM level only. In Exp. 3, the effect of DHEA on mature adipocytes was determined by exposing adipocytes grown in plating medium to DHEA at 0, 75, 125, and 250 microM for 1-4 d. In Exp. 1, preadipocyte proliferation decreased as the level of DHEA increased in cultures of 3T3-L1 cells. DHEAS had no effect on preadipocyte proliferation. The antiproliferative effect of DHEA was partially reversed by the addition of 1 microM mevalonic acid to proliferating cultures containing 25 microM DHEA. In Exp. 2, preadipocyte differentiation decreased as the level of DHEA in the cultures increased. In contrast, neither DHEAS nor mevalonic acid treatment influenced preadipocyte differentiation decreased as the level and duration of DHEA treatment increased in cultures of mature adipocytes. These data support the hypothesis that DHEA, but not DHEAS, is the active form of the steroid that attenuates obesity via altering preadipocyte proliferation and differentiation. The addition of 1 microM mevalonic acid to cultures of 3T3-L1 preadipocytes partially reversed DHEA's antiproliferative effects.

Low dehydroepiandrosterone sulfate and heart disease in middle-aged men: cross-sectional results from the Massachusetts Male Aging Study

PURPOSE

Serum concentrations of the adrenal androgen dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS), both of which decline with age more markedly than other sex hormone levels, have been alternately credited and discredited as "protective" correlates of heart disease. Baseline data from the Massachusetts Male Aging Study (MMAS), collected in 1987-89, provided a large population-based random sample (n = 1709) in which to examine cross-sectionally the relation of DHEA and DHEAS levels to heart disease, while controlling for a comprehensive set of potential confounders including serum lipid and hormone levels as well as smoking, alcohol intake, obesity, hypertension, diabetes, diet, medication, physical activity, and psychological measures.

METHODS

The subjects were men aged 40-70 years, randomly sampled from the Massachusetts state census listing, measured and interviewed at home. Nonfasting blood samples were assayed for hormones and lipids.

RESULTS

In all strata of age, smoking, and alcohol intake, the age-adjusted odds ratio for self-reported heart disease was between 0.55 and 0.85 per standard deviation (SD) of log DHEA and DHEAS concentration. Multiple logistic regression analysis indicated a strong independent role for DHEAS as a predictor of self-reported heart disease, controlling for age and the potential confounders listed above. The multiply-adjusted odds ratio for heart disease was 0.64 per SD log DHEAS concentration, with 95% confidence interval (CI) 0.50-0.83 (P = 0.0002). The DHEAS effect was not diminished by controlling for use of cardiac, vasodilator, antihypertensive, or lipid-lowering medication.

CONCLUSIONS

These findings suggest that serum DHEAS levels bear an inverse relationship to heart disease, independently of a large set of established cardiovascular risk factors. The cross-sectional nature of this study requires that the findings be interpreted with caution.

The impact of a new emotional self-management program on stress, emotions, heart rate variability, DHEA and cortisol

This study examined the effects on healthy adults of a new emotional self-management program, consisting of two key techniques, "Cut-Thru" and the "Heart Lock-In." These techniques are designed to eliminate negative thought loops and promote sustained positive emotional states. The hypotheses were that training and practice in these techniques would yield lowered levels of stress and negative emotion and cortisol, while resulting in increased positive emotion and DHEA levels over a one-month period. In addition, we hypothesized that increased coherence in heart rate variability patterns would be observed during the practice of the techniques. Forty-five healthy adults participated in the study, fifteen of whom acted as a comparison group for the psychological measures. Salivary DHEA/DHEAS and cortisol levels were measured, autonomic nervous system function was assessed by heart rate variability analysis, and emotions were measured using a psychological questionnaire. Individuals in the experimental group were assessed before and four weeks after receiving training in the self-management techniques. The experimental group experienced significant increases in the positive affect scales of Caring and Vigor and significant decreases in the negative affect scales of Guilt, Hostility, Burnout, Anxiety and Stress Effects, while no significant changes were seen in the comparison group. There was a mean 23 percent reduction in cortisol and a 100 percent increase in DHEA/DHEAS in the experimental group. DHEA was significantly and positively related to the affective state Warmheartedness, whereas cortisol was significantly and positively related to Stress Effects. Increased coherence in heart rate variability patterns was measured in 80 percent of the experimental group during the use of the techniques. The results suggest that techniques designed to eliminate negative thought loops can have important positive effects on stress, emotions and key physiological systems. The implications are that relatively inexpensive interventions may dramatically and positively impact individuals' health and well-being. Thus, individuals may have greater control over their minds, bodies and health than previously suspected.

Inhibition of migration and proliferation of vascular smooth muscle cells by dehydroepiandrosterone sulfate

Dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S) are the most abundant steroids in humans, and their serum concentrations progressively decrease with age. Although relationships between DHEA(-S) and many age-related illnesses have been postulated, the mechanisms for their effects remain unknown, and specific receptors for these molecules have not been identified. In this paper, to investigate the role of DHEA(-S) in atherogenesis, we studied the proliferation and migration of a rabbit vascular smooth muscle cell line, SM-3, in the presence of DHEA(-S). Cellular proliferation was inhibited by DHEA-S, and to a lesser extent by DHEA. Modified Boyden's chamber assays revealed that DHEA-S inhibited the migration of SM-3 cells toward PDGF-BB. In cell attachment assays, DHEA-S inhibited the attachment of SM3 cells to fibronectin. It was suggested that the inhibitory effect of DHEA-S for SM-3 proliferation and migration was due to the decreased interaction with fibronectin. Scatchard analysis revealed the presence of two populations of DHEA-S binding sites in the nuclear fraction, and a smaller number in the cytosolic fraction. Since the dissociation constant of the higher affinity site was similar to the serum DHEA-S concentration in humans (Kd = 5.8 microM), this binding site could be functional under physiologic conditions. These findings suggest that there may be receptor-mediated anti-atherogenic actions of DHEA-S.

Stress reduction and preventing hypertension: preliminary support for a psychoneuroendocrine mechanism

Our objective was to identify endocrine-related mechanisms capable of mediating preventive effects of stress reduction in hypertensive heart disease. Since beneficial effects of stress reduction accrue over time, this cross-sectional, descriptive study sought differences between healthy students not practicing a systematic technique for reducing stress (the average stress, or AS, group, n = 33) and a similar group who for 8.5 years had practiced the Transcendental Meditation (TM) technique, used widely to reduce stress (the low stress, or LS, group, n = 22). The two groups of students, matched for age and area of study, performed timed collections of urine that included (separately) the entire waking and sleeping portions of 1 day. They also completed the Profile of Mood States and the State-Trait Anxiety Inventory, self-report instruments sensitive to subjective level of stress. Urine samples were analyzed for adrenocortical steroids by radioimmunoassay, for Na+, K+, Mg2+, Ca2+, and Zn2+ by atomic absorption spectrometry, and for neurotransmitter metabolites by reverse-phase, high-performance, liquid chromatography, and spectrophotometry. The two groups differed significantly on most measures. Specifically, the LS group was lower in cortisol and aldosterone and higher in dehydroepiandrosterone sulfate (DS) and the serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA). Excretion of sodium, calcium, zinc, and the norepinephrine metabolite, vanillylmandelic acid (VMA), was also lower in this group, as were Na+/K+ ratio, mood disturbance, and anxiety. In women practicing TM, cortisol correlated inversely and DS directly with number of months of TM practice. The results identify improvements in mood state, adrenocortical activity, and kidney function as probable factors in the preventive and treatment effects of stress reduction. Because suboptimal levels of these parameters result from chronic, subjective stress, the findings add mechanistic support to the contention that hypertensive heart disease is avoidable, even in modern industrialized societies.

Effects of glucose/insulin perturbations on aging and chronic disorders of aging: the evidence

Among changes associated with aging is a decline in glucose tolerance. The reported causes are increased insulin resistance from receptor and/or post receptor disturbances and diminished pancreatic islet B-cell sensitivity to glucose. Many recent reports indicate that insulin resistance with hyperinsulinemia and/or hyperglycemia contribute to or even causes many chronic disorders associated with aging, i.e., chronic metabolic perturbations including noninsulin-dependent diabetes mellitus, obesity, hypertension, lipid abnormalities, and atherosclerosis. How could such disturbances in glucose/insulin metabolism lead to many chronic disorders associated with aging? In aging, similar to diabetes, the elevation in circulating glucose and other reducing sugars secondary to age-induced insulin resistance can react nonenzymatically with proteins and nucleic acids to form products that affect function and diminish tissue elasticity. Also, perturbations in glucose/insulin metabolism are associated with enhanced lipid peroxidation secondary to greater free radical formation. Free radicals of oxygen are important known causes of tissue damage and have been associated with many aspects of aging including inflammatory diseases, cataracts, diabetes, and cardiovascular diseases. Augmented free radical formation and lipid peroxidation are not uncommon in diabetes mellitus, commonly associated with "premature aging". Ingestion of sugars, fats, and sodium have been linked to decreased insulin sensitivity, while caloric restriction, exercise, ingestion of chromium, vanadium, soluble fibers, magnesium, and certain antioxidants are associated with greater insulin sensitivity. Thus, manipulation of diet by influencing the glucose/insulin system may favorably affect lifespan and reduce the incidence of chronic disorders associated with aging.

Relations between fasting serum insulin, glucose, and dihydroepiandrosterone-sulfate concentrations in obese patients with hypertension: short-term effects of antihypertensive drugs

A randomized, single-blind, placebo-controlled study was conducted in 82 obese patients with mild to moderate essential hypertension, to determine the incidence of hyperinsulinemia, the relations between fasting insulin and dihydroepiandrosterone-sulfate (DHEA-S) levels, and the short-term effects of antihypertensives on DHEA-S and insulin serum concentrations. Increased insulin/glucose ratios (IGR) suggestive of insulin resistance were found in half of our patients. Hyperinsulinemic and normoinsulinemic obese patients with hypertension had comparable fasting glucose and DHEA-S concentrations and comparable blood pressure (BP) levels. Thus no relations were found between fasting insulin and DHEA-S levels. Fasting hyperinsulinemia was found in only half of the obese subjects with hypertension, suggesting that not all obese patients with hypertension are at the same high cardiovascular risk. Short-term treatment with captopril, prazosin, verapamil, atenolol, or hydrochlorothiazide (HCTZ) reduced BP; greater BP reduction was observed with drugs with vasodilatory effects. Captopril, prazosin, and verapamil reduced fasting insulin levels, whereas atenolol and hydrochlorothiazide did not. The former drugs reduced fasting insulin levels that were either within normal limits or in the hyperinsulinemic range. None of the drug treatments produced significant increases in serum DHEA-S concentrations, although some of them considerably reduced fasting insulin levels. No relations between insulin and DHEA-S levels were observed either at baseline or at the end of the antihypertensive treatment. The BP reduction resulting from the peripheral vasodilation may explain the insulin-reducing action of captopril, verapamil, and prazosin. These results further emphasize the large heterogeneity present in the pathophysiologic mechanisms operating in obesity and hypertension.