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DHEA metabolism in arthritis: a role for the p450 enzyme Cyp7b at the immune-endocrine crossroad.

For dehydroepiandrosterone (DHEA) both immunosuppressive and immuno-stimulating properties have been described. The immunosuppressive effects may be explained by the conversion of DHEA into androgens and/or estrogens. The described immuno-stimulating effects of DHEA may be due to the conversion of DHEA into 7alpha-hydroxy-DHEA (7alpha-OH-DHEA) by the activity of the p450 enzyme, Cyp7b. 7alpha-OH-DHEA is thought to have anti-glucocoticoid activity preventing the anti-inflammatory action of endogenous glucocorticoids. To investigate a putative role of Cyp7b in the arthritic process, tissues from both the murine collagen-induce arthritis (CIA) model and from patients with rheumatoid arthritis (RA) were studied. We determined the Cyp7b expression levels in synovial tissue and the level of 7alpha-OH-DHEA in both serum and arthritic joints of mice with CIA. Our studies showed that the severity of arthritis correlates with increased Cyp7b activity. Next, we investigated Cyp7b expression and activity in RA patients where the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) are known to control the disease process. Fibroblast-like synoviocytes (FLS), isolated from RA synovial biopsies were found to express Cyp7b mRNA. In addition, Cyp7b enzymatic activity was detected in these cells. We also investigated whether Cyp7b activity is regulated by cytokines. Proinflammatory (e.g., TNF-alpha and IL-1beta) cytokines were found to stimulate Cyp7b activity and the anti-inflammatory cytokine transforming growth factor-beta (TGF-beta) was found to suppress Cyp7b activity in FLS. Next, we studied which signal transduction pathway is involved in the TNF-alpha-mediated induction of Cyp7b activity in human FLS. The results show a role for nuclear factor kappa B (NFkappaB) and activator protein-1 (AP-1) in the regulation of Cyp7b expression. Finally, we established that the effects of DHEA or 7alpha-OH-DHEA on the immune system can not be explained by glucocorticoid receptor (GR) engagement. The role of the p450 enzyme Cyp7b in DHEA metabolism and its relevance in the arthritic process will be discussed.

Animals↗

The relationship of dehydroepiandrosterone sulfate (DHEAS) to endocrine-metabolic parameters and functional status in the oldest-old. Results from an Italian study on healthy free-living over-ninety-year-olds.

Dehydroepiandrosterone sulfate (DHEAS), the major circulating adrenal hormone, has been suggested to have a role in many aging related diseases and perhaps in aging itself. Its precise biologic effects are still unknown, and data on healthy people over 90 yr of age are not available. We measured serum DHEAS levels in 75 healthy subjects aged 90-106 yr of both sexes and searched for correlations between DHEAS and several endocrine-metabolic parameters (serum thyroid hormones, GH-insulin-like-growth factor I (GH-IGF-I) axis, serum lipid profile, anthropometric indices of body composition) of the same subjects. The resulting data, normalized by logarithmic transformation (geometric mean at age 90-99, 551 ng/mL in men, 364 ng/mL in women; at age > 100 yr, 404 ng/mL in men, 521 ng/mL in women) resulted five-fold lower than DHEAS levels measured in a young control group (geometric mean at < 40 yr of age, 3110 ng/mL in men, 2824 ng/mL in women). In women over ninety yr, DHEAS was positively correlated with serum free triodothyronine (FT3) levels (r = 0.34, P = 0.05) and inversely with triglycerides (r = -0.45, P = 0.05). In men over 90 yr, DHEAS had positive correlations with body mass index (r = 0.41, P < 0.03) and waist-to-hip ratio (r = 0.47, P < 0.01) taken as indices of body's energy reserves (fat). To determine whether low serum DHEAS levels predict poor functional status in the very old, the Activity Daily Living (ADL) test was administered in all over-ninety subjects. Men with the highest functioning levels had the highest DHEAS levels (P < 0.03). Our data suggest that DHEAS levels may influence and/or be influenced by several endocrine and metabolic features of oldest-old people, depending on the sexual steroid milieu. DHEAS seems also to have a strong interrelation with functional activities. A favorable role for DHEAS in successful aging is proposed.

Activities of Daily Living↗

[Positive effects of DHEA therapy on insulin resistance and lipids in men with angiographically verified coronary heart disease--preliminary study].

OBJECTIVES: The aim of this study was to analyze the influence of DHEA therapy on insulin resistance (FIRI, FG/FI) and serum lipids in men with angiographically verified coronary heart disease (CHD). MATERIAL AND METHODS: The study included thirty men aged 41-60 years (mean age 52+/-0.90 yr) with serum DHEA-S concentration<2000 microg/l, who were randomized into a double-blind, placebo-controlled, cross-over trial. Subjects completed the 80 days study of 40 days of 150 mg oral DHEA daily or placebo, and next groups were changed after 30 days of wash-out. Fasting early morning blood samples were obtained at baseline and after each treatment to determine serum hormones levels (testosterone, DHEA-S, LH, FSH estradiol and IGF-1) and also metabolic profile (total cholesterol, LDL-cholesterol, triglicerides, HDL-cholesterol, insulin, glucose, fasting insulin resistance index--FIRI and FG/FI ratio). RESULTS: Administration of DHEA was associated with 4.5-fold increase in DHEA-S levels. Relative to baseline DHEA administration resulted in a decrease in insulin levels by 40% (p<0.005) and fasting insulin resistance index (FIRI) by 47% (p<0.004). Also total cholesterol levels and LDL-cholesterol levels decreased significantly (from 222.9+/-6.6 mg/dL to 207.4+/-6.6 mg/dL and from 143.9+/-6.9 mg/dL to 130.5+/-6.0 mg/dL respectively; p<0.05). Glucose levels dropped significant below baseline values after DHEA (p<0.001). Estrogen levels significantly increased after DHEA (p<0.05). While changes of serum concentrations of testosterone, LH, FSH, IGF-I, HDL-cholesterol, triglycerides were not statistical significant. Tolerance of the treatment was good and no adverse effects were observed. CONCLUSIONS: DHEA therapy in dose of 150 mg daily during 40 days in men with DHEA levels<2000 microg/l decreased total cholesterol concentration, insulin and glucose levels and fasting insulin resistance index (FIRI). This therapy may be a beneficial against CHD risk factors.

Adult↗

Pilot clinical trial of dehydroepiandrosterone (DHEA) versus placebo for Sjögren's syndrome.

OBJECTIVE: To screen for potential efficacy and assess feasibility and safety of dehydroepiandrosterone (DHEA) as a treatment for Sjögren's syndrome (SS). METHODS: A 24-week randomized, double-blinded, pilot trial of oral DHEA (200 mg/day) versus placebo was conducted. The primary comparison was to a hypothesized 20% placebo response rate. If 14 consecutive subjects on DHEA did not respond, a Phase III trial would be considered futile. A placebo group of 14 subjects was planned to verify placebo response rate and estimate sample size required for a definitive trial. Response criteria required 20% improvement in at least 2 of 3 domains. Analysis of covariance was used to adjust for baseline differences and for stratified randomization. Outcome measures included visual analog scale questionnaires for dry eye and dry mouth symptoms, lissamine green ocular dye staining and Schirmer I tests, stimulated salivary flow, IgG, and erythrocyte sedimentation rate (ESR). RESULTS: Randomization resulted in 14 DHEA and 14 placebo group subjects. At baseline, mean +/- SD for DHEA versus placebo groups were Schirmer I tests 4.5 +/- 4.5 versus 5.4 +/- 6.1 mm/5 minutes; Van Bijsterveld score 5.3 +/- 2.1 versus 5.5 +/- 2.2; unstimulated saliva 0.03 +/- 0.05 versus 0.04 +/- 0.10 ml/minute; IgG 1,699 +/- 749 versus 1,712 +/- 621 g/dl; and ESR 40 +/- 31 versus 44 +/- 28 mm/hour. Apart from changes over the trial in dry mouth symptoms, no significant differences were noted between the DHEA and placebo groups for dry eye symptoms, objective measures of ocular dryness, stimulated salivary flow; IgG, or ESR. Four DHEA and one placebo group patient dropped out because of adverse effects. Although 7 subjects met response criteria in the DHEA group, 5 met the criteria in the placebo group, and there was no significant difference between groups. CONCLUSION: DHEA showed no evidence of efficacy in SS. Without evidence for efficacy, patients with SS should avoid using unregulated DHEA supplements, since long-term adverse consequences of exposure to this hormone are unknown.

Adjuvants, Immunologic↗

Early carotid atherosclerosis in normotensive severe obese premenopausal women with low DHEA(S).

The aim of this study was to investigate the direct involvement of hyperinsulinaemia, DHEA and DHEA-S [DHEA(S)] in severe obesity in early carotid atherosclerosis, measured as intima-media thickness (IMT). Seventeen normotensive premenopausal women with very high BMI (43.5 +/- 1.6 kg/m2) were recruited for the study. Six women were also evaluated 12 months after laparoscopic adjustable silicone gastric banding (LASGB). Dietary intake, fasting plasma lipid profile, glycemic and insulinemic response to the OGTT, adrenal secretion, at baseline and after ACTH stimulation test, were measured. IMT, common carotid diameter (CD) and left ventricular mass index (LVMi) were measured by B-mode echotomography. All obese subjects showed higher fasting and stimulated insulin levels, but lower DHEA(S) levels than controls, showing a negative correlation between both fasting and stimulated insulin and DHEA(S), either at baseline or after ACTH testing. IMT was higher (p < 0.05) than controls, with a positive correlation with stimulated insulin (p < 0.05) and a strong negative correlation with DHEA(S) (p < 0.001). In a multiple linear regression analysis, insulin response to OGTT maintained an association with DHEA(S) independent of fasting insulin, while DHEA maintained the association with IMT independent of stimulated insulin (p < 0.0001). In the six patients evaluated 12 months after LASGB, fasting insulin levels decreased, while DHEA(S) levels increased (p < 0.05). In conclusion, an early cardiovascular involvement was detected in this group of severe obese with hyperinsulinaemia and low DHEA(S), even in the absence of other well known CVD risk factors.

Adult↗

Effects of dehydroepiandrosterone (DHEA) supplementation on hormonal, metabolic and behavioral status in patients with hypoadrenalism.

Oral DHEA administration to patients with hypoadrenalism, in addition to glucocorticoid and mineralcorticoid replacement, may improve both well-being and hormonal/metabolic parameters. Twenty patients (13 men, 7 women, 26-76 yr, 11 with Addison's disease, 9 with central hypoadrenalism) were recruited in a placebo-controlled, randomized study. Hormone levels, carbohydrate and lipid parameters, bone metabolism, body composition and psychological parameters were evaluated at baseline and after treatment with DHEA 50 mg/day or placebo for 4 months. After 4 months of DHEA administration, serum DHEAS levels raised both in men (from 0.71+/-0.18 to 8.28+/-1.66 micropmol/l, p<0.005) and in women (from 0.25+/-0.07 to 5.65+/-1.93 micromol/l, p<0.05). Only in hypoadrenal women an increase in testosterone (T; from 0.4+/-0.1 to 1.45+/-0.26 nmol/l, p<0.05) and androstenedione (A; from 0.86+/-0.34 to 2.05+/-0.29 nmol/l, p<0.05) levels was observed. In men no significant modifications in T and 17-hydroxyprogesterone (17-OHP) levels were found, whereas serum SHBG significantly decreased. As far as the metabolic parameters are concerned, only in patients with Addison's disease a significant decrease in total cholesterol and in low-density lipoproteins after 4 months of DHEA administration was found. No changes in glucose metabolism and insulin sensitivity were observed. In basal conditions, mean serum osteocalcin (OC) was normal and significantly decreased after DHEA treatment. A significant reduction in body fat mass percentage (BF%) after DHEA administration was observed. As far as well-being is concerned, DHEA replacement did not cause any relevant variation of subjective health scales and sexuality in both sexes. Our study confirms that DHEA may be beneficial for female patients with hypoadrenalism, mainly in restoring androgen levels. Concerning the health status, more sensitive and specific instruments to measure the effects of DHEA treatment could be necessary.

Addison Disease↗

Catabolic effects and the influence on hormonal variables under treatment with Gynodian-Depot or dehydroepiandrosterone (DHEA) oenanthate.

53 patients from a mainly climacteric population were treated monthly with 200 mg dehydroepiandrosterone (DHEA) oenanthate or with 1 ampoule Gynodian-Depot. Pronounced adiposity was present in 15 of these cases. Hormonal variables were determined before the treatment and during the depot effect of the preparations in order to study the principle which supports the oestrogenic influence and any weight-reducing influence under administration of DHEA. The elimination of low-polar oestrogens increased considerably in 4 out of 13 post-menopausal cases treated with DHEA. This effect is probably indirect and presupposes intact ovaries. The incorporation of exogenous DHEA into the excretion of 17-ketosteroids and of 17-ketogenic steroids, such as those of androsterone + aethio-cholanolone, depends on the size of the initial pool inasmuch as it is higher in small initial pools than in saturated pools- the size of the pool being age-dependent. An average weight loss of greater than 1 kg/mth was observed under DHEA treatment in 7 out of 15 adipose cases. In comparison to the other 8 adipose cases, these 7 were younger and therefore also displayed higher values for 17-ketosteroids and their individual fractions. These circumstances appeared to explain why the administration of DHEA resulted in higher levels of free plasma DHEA which, in contrast to the cases without loss of weight, also resulted in an increase of renal DHEA-sulphate clearance. It was concluded from the findings that this is the explanation for the catabolic effect of exogenous DHEA. Post-menopausally increased FSH and LH fractions were markedly suppressed in about half of the determinations after Gynodian-Depot administration, the findings indicating that DHEA is probably involved in suppression of the LH fraction.

17-Hydroxycorticosteroids↗

Trypanosoma cruzi: the effects of dehydroepiandrosterone (DHEA) treatment during experimental infection.

The aim of this study was to evaluate the efficacy of the immunomodulator dehydroepiandrosterone (DHEA) in the treatment of Trypanosoma cruzi infection and the possible biochemistry alterations in male and female Wistar rats. DHEA also known as the steroid of multiple actions has attracted distinct medical areas. Prior studies show that DHEA enhances immune responses against a wide range of viral, bacterial and parasitic pathogens. Furthermore, administration of DHEA seems to protect animals against obesity and diabetes. Male animals subcutaneous treated with 40 mg/kg body weight/day of DHEA displayed a significant reduction in blood parasites during parasitaemia peak, when compared to untreated animals (P<0.001). For female group parasitaemia was also reduced although values are not statistically significant (P>0.05). Sexual dimorphism was also observed, since females displayed lesser parasitaemia levels compared to males group treated (P>0.05) and untreated (P<0.001). Enhanced leucocytes number was observed in control females when compared to control males (P<0.05). DHEA treatment did not triggered any significant alterations in leucocytes levels (P>0.05). DHEA administration induced an enhanced number of macrophages in infected male (P<0.01). DHEA administration causes a decrease in glucose (P<0.001). Cholesterol and tryglicerides levels did not display results statistically significant (P>0.05) during the treatment. These results suggest that DHEA treatment enhances the immune response as evidenced here by reduced levels of parasites. Up-regulation of the immune system by exogenous DHEA may be useful in the treatment of American tripanosomiasis.

Adjuvants, Immunologic↗

Metabolism of DHEA in postmenopausal women following percutaneous administration.

The marked decline in serum dehydroepiandrosterone (DHEA) with age is believed to play a role in health problems associated with aging, these health issues being potentially preventable or reversible by the exogenous administration of DHEA. In the present study, liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) and gas chromatrography/mass spectrometry (GC/MS) were used to measure the serum levels of DHEA and 11 of its metabolites in seventy-five 60-65-year-old Caucasian women who received 3g of 0.1%, 0.3%, 1.0% or 2.0% DHEA cream or placebo applied twice daily on the face, upper chest, arms and legs. The serum levels of DHEA increased 574% over control at the 2.0% DHEA dose while the sum of the androgen metabolites androsterone glucuronide (ADT-G), 3alpha-androstenediol-3G (3alpha-diol-3G) and 3alpha-diol-17G increased by only 231%. On the other hand, serum testosterone and dihydrosterone were increased by 192% and 275%, respectively, above basal levels compared to 139% and 158% for estrone and estradiol. Such data show that the transformation of exogenous DHEA in postmenopausal women is preferentially into androgens rather than into estrogens. On the other hand, the present data indicate that serum DHEA measurements following DHEA supplementation in postmenopausal women are an overestimate of the formation of active androgens and estrogens and suggest a decreased efficiency of transformation of DHEA into androgens and estrogens with aging.

Administration, Cutaneous↗

Treatment with dehydroepiandrosterone (DHEA) stimulates oxidative energy metabolism in the cerebral mitochondria. A comparative study of effects in old and young adult rats.

The content of the neurosteroids, dehydroepiandrosterone (DHEA) in the brain decreases with aging. Also the oxidative energy metabolism is known to decrease with aging. Hence we examined the effects of treatment with DHEA (0.2 or 1.0 mg/kg body weight for 7 days) on oxidative energy metabolism in brain mitochondria from old and young adult rats. State 3 respiration rates in brain mitochondria from old animals were considerably lower than those in young adults. Treatment with DHEA stimulated state 3 and state 4 respiration rates in both the groups of the animals in a dose-dependent manner. In the old rats following DHEA treatment, the state 3 respiration rates became comparable to or increased beyond those of untreated young adults. In contrast to the old rats, stimulatory effect of DHEA treatment was of greater magnitude in the young adults. However, at higher dose (1.0 mg) the effect declined. Cytochrome aa3 content in the brain mitochondria from old rats was significantly low but the content of cytochrome b was unchanged while the content of cytochromes c+c1 had increased. Treatment with DHEA increased the content of cytochrome aa3 and b in old as well as in young adult animals. Higher dose of DHEA (1.0 mg) had adverse effect on the content of cytochrome c+c1. DHEA treatment stimulated ATPase activity in a dose-dependent manner in young adult rats whereas in the old rats the effect on ATPase activity was marginal. Dehydrogenases activities were somewhat lower in the old rats. DHEA treatment stimulated mitochondrial dehydrogenases activities in both the groups. Results of our studies suggest that judicious use of DHEA treatment can improve oxidative energy metabolism parameters in brain mitochondria from young adult as well as old rats.

Adenosine Triphosphatases↗

DHEA-sulfate causes a phase-dependent increase in melatonin secretion: a study of perifused rat pineal glands.

Steroid hormones affect various metabolic activities, including melatonin synthesis, in mammals and nonmammals. We report here the effects of dehydroepiandrosterone (DHEA) and DHEA-sulfate (DHEA-S), two steroids with weak androgen potency, on the levels of isoproterenol-stimulated melatonin released by perifused rat pineal glands removed in the middle of the light and dark spans [7 and 19 Hours After Light Onset (HALO), respectively] in a L/D 12:12 regimen. DHEA-S but not DHEA was found to have a direct action on beta-adrenergic-stimulated melatonin release. DHEA-S increased melatonin secretion (by 50-80%) dose-dependently in pineals obtained during the light span. This effect depended on the circadian stage, because at night (19 HALO), only the highest concentration (10(-3) M) of DHEA-S increased melatonin secretion (by 25%). In contrast, DHEA had no effect on melatonin release in pineals obtained during the light span. This work shows that DHEA-S but not DHEA was able to stimulate melatonin secretion by adrenergic-stimulated pineals removed during the light phase. It also suggests that the effects observed, or their intensity, or both depend on the circadian stage.

Adrenergic beta-Agonists↗

Oxidative stress-mediated DHEA formation in Alzheimer's disease pathology.

An alternative pathway for dehydroepiandrosterone (DHEA) synthesis has been suggested by treating rat and human brain cells with ferrous sulfate and beta-amyloid (Abeta). To determine if this pathway exists in human brain, levels of DHEA in hippocampus, hypothalamus and frontal cortex from Alzheimer's disease (AD) patients and age-matched controls were measured. DHEA is significantly higher in AD brain than control, and was highest in AD hippocampi. Cytochrome p450 17alpha-hydroxylase, responsible for peripheral DHEA synthesis, is not present in hippocampus. DHEA levels in AD cerebrospinal fluid (CSF) were significantly higher than age-matched controls. AD serum DHEA levels are lower than CSF, and not significantly different from controls. Treatment of control hippocampus, hypothalamus and serum with FeSO(4) increases DHEA, suggesting that levels of precursor are higher in control that in AD brain. This suggests that (i). an alternative precursor is present in control brain, (ii). AD brain DHEA is formed by oxidative stress metabolism of precursor, and (iii). CSF DHEA levels and serum DHEA formation in response to FeSO(4) may serve as an indicator of AD pathology.

Aged↗

[DHEA: an unknown star].

PURPOSE: To clarify the physiological function of dehydroepiandrosterone (DHEA), the most abundant steroid in human plasma, which remains poorly understood. To analyse the beneficial effects of a supplementation in order to alleviate its decrease in ageing and improve well-being. CURRENT KNOWLEDGE AND KEY POINTS: DHEA (and its sulfate) acts on peripheral tissues as an androgenic and estrogenic precursor. It is also considered as a neurosteroid. DHEA administration in several pathological animal models is promising, especially in metabolic diseases such as obesity and insulin resistance. It appears like a factor of immunomodulation and facilitates cognitive acquisition. In humans there is little evidence that DHEA may be useful in characterized pathologies apart from adrenal insufficiency. An interesting effect was also noted in severe systemic lupus erythematosus. The effects on cognitive and neuropsychiatric diseases such as midlife dysthymia are not yet convincing. Prospective studies of supplementation versus placebo indicate inconstant improvement in well-being in the post-menopausal state. DHEA is not a panacea against ageing despite there being a well-established aging-related decrease of DHEA. Contrary to some assertions there are no proven relations between cardiovascular or cancer risk. FUTURE PROSPECTS AND PROJECTS: Until now adrenal insufficiency has been the only well-documented indication of an oral DHEA supplementation. However, DHEA may be a good way for androgen supplementation in menopausal men. Further investigations are needed to better know the anti-inflammatory and immunomodulation properties of DHEA. At the least, prospective studies on large populations are necessary to assess the true benefits and dangers of DHEA in prevention of ageing.

Androgens↗

DHEA treatment: myth or reality?

Dehydroepiandrosterone (DHEA) and its sulfate ester are major secretory products of the human adrenal. Serum DHEA concentrations decline with advancing age and DHEA supplementation in elderly people has been advertized as anti-aging medication. However, such claims are based on experiments in rodents with a fundamentally different DHEA physiology. In humans, DHEA is a crucial precursor of sex steroid biosynthesis and exerts indirect endocrine and intracrine actions following conversion to androgens and estrogens. In addition, it acts as a neurosteroid via effects on neurotransmitter receptors in the brain. DHEA has considerable effects on mood, well-being and sexuality in patients with adrenal insufficiency, and also in those with mood disorders. However, subjects with a physiological, age-related decline in DHEA secretion show little benefit from DHEA administration. Future research should focus on DHEA treatment for adrenal insufficiency, and DHEA administration in both patients receiving chronic glucocorticoid treatment and women with androgen deficiency.

Adrenal Insufficiency↗

The relationships between dehydroepiandrosterone sulphate (DHEAS), the intensity of Schistosoma mansoni infection and parasite-specific antibody responses. A cross-sectional study in residents of endemic communities in north-east Ethiopia.

There are speculations that the puberty-related hormone dehydroepiandrosterone sulphate (DHEAS) might influence the intensity of infection and immune responses during Schistosoma infections. We studied the relationships between DHEAS, intensity of Schistosoma mansoni infection and humoral immune responses in 135 residents of Ethiopia. Serum levels of eight antibody isotypes against worm and egg antigens were determined by ELISA. DHEAS was measured with an immunoluminometric assay. There was a significant negative correlation between serum levels of DHEAS and intensity of S. mansoni infection. A significant increase in serum levels of DHEAS in the age group 15-19 years was accompanied by a progressive decline in the intensity of infection. Peak level of DHEAS coincided with the lowest intensity of infection in the age group 20-29 years. Multiple regression analysis showed that DHEAS alone had a significant (p<0.0001) negative effect when the effect of age was removed. Age also had a significant (p<0.0001) negative effect on the intensity of infection, after removing the effect of DHEAS. The two predictive variables accounted for 34.4% of the decline in the intensity of infection. Age accounted for 24.9%, whereas DHEAS accounted for 15.2% when the effect of each of the variables was removed. DHEAS had significant negative effects on AWA-specific IgG (p=0.02) and IgG1 (p=0.018) and SEA-specific IgG1 (p=0.009), after adjusting for the effect of age.

Adolescent↗

Effects of DHEA replacement on bone mineral density and body composition in elderly women and men.

OBJECTIVE: Dehydroepiandrosterone (DHEA) is a precursor for both oestrogens and androgens. Its marked decline with ageing may influence age-related changes in tissues influenced by sex hormones. The aim of this study was to determine the effects of DHEA replacement on bone mineral density (BMD) and body composition in elderly women and men with low serum DHEA sulphate (DHEAS) levels. DESIGN: Prospective 6 month trial of oral DHEA replacement, 50 mg/day. PATIENTS: Experimental subjects were 10 women and eight men, aged 73 +/- 1 years. Control subjects were 10 women and eight men, aged 74 +/- 1 years. MEASUREMENTS: BMD, body composition, serum markers of bone turnover, serum lipids and lipoproteins, oral glucose tolerance, serum IGF-I, total serum oestrogens and testosterone. RESULTS: BMD of the total body and lumbar spine increased (mean +/- SEM; 1.6 +/- 0.6% and 2.5 +/- 0.8%, respectively; both P < or = 0.05), fat mass decreased (- 1.3 +/- 0.4 kg; P < 0.01) and fat-free mass increased (0.9 +/- 0.4 kg; P < or = 0. 05) in response to DHEA replacement. DHEA replacement also resulted in increases in serum IGF-I (from 108 +/- 8 to 143 +/- 7 microg/l; P < 0.01) and total serum testosterone concentrations (from 10.7 +/- 1.2 to 15.6 +/- 1.8 nmol/l in the men and from 2.1 +/- 0.2 to 4.5 +/- 0.4 nmol/l in the women; both P < or = 0.05). CONCLUSIONS: The results provide preliminary evidence that DHEA replacement in those elderly women and men who have very low serum DHEAS levels can partially reverse age-related changes in fat mass, fat-free mass, and BMD, and raise the possibility that increases in IGF-I and/or testosterone play a role in mediating these effects of DHEA.

Adjuvants, Immunologic↗

Obesity in the dog: role of the adrenal steroid dehydroepiandrosterone (DHEA).

It is estimated that 25-50% of pet dogs are overweight. In rodents and humans the adrenal steroid dehydroepiandrosterone (DHEA) has been associated with loss of body weight and reduction in total body fat content. We have shown that administration of DHEA results in weight loss in spontaneously obese dogs. DHEA also lowered serum cholesterol, in particular, the low density lipoprotein component of the plasma cholesterol. We hypothesize that treatment of obese dogs with DHEA in combination with a low energy, high fiber diet will result in greater weight loss when compared with dogs on the same diet, without DHEA. In the current study, spontaneously obese dogs were fed a uniform low energy, high fiber diet and then randomized to receive DHEA or placebo. Preliminary results show that the mean total body weight lost for dogs receiving DHEA was 3.59 kg compared with 2.38 kg for dogs receiving placebo (P greater than 0.05). The percent excess body weight (above ideal body weight) lost for the DHEA group was 65.7 versus 31.4 for the placebo group (P less than 0.02). The percent excess body weight lost per month on the study for the DHEA group was 15 versus 8.2 for the placebo group (P = 0.069). Although these results are preliminary, they indicate that DHEA combined with a low energy, high fiber diet enhances the loss of excess body weight compared with diet modification alone.

Animals↗

Are alterations of lymphocyte subpopulations in polymicrobial sepsis and DHEA treatment mediated by the tumour necrosis factor (TNF)-alpha receptor (TNF-RI)? A study in TNF-RI (TNF-RI(-/-)) knock-out rodents.

Sepsis is associated with depression of T cell-dependent immune reactivity with proinflammatory cytokines, such as tumour necrosis factor (TNF)-alpha, playing an important role. Recent investigations describe an association between these immunological alterations and disturbances of the endocrine system, related most frequently to sex steroid hormones. Dehydroepiandrosterone (DHEA), one of the most abundant adrenal sex steroid precursors, seems to have a protective immunological effect towards septic insults. In this study, both the role of TNF-receptor I (RI) and possible interactions in the protective role of DHEA were investigated in a murine model of polymicrobial sepsis. Polymicrobial sepsis was induced by caecal ligation and puncture (CLP) in a murine model. The effects of DHEA on survival, clinical parameters and cellular immunity (T lymphocytes and natural killer (NK) cells) were investigated. CLP was performed in genetically modified TNF-RI knock-out (TNF-RI(-/-)) and genetically unmodified (wild-type, WT) mice. DHEA application was associated with a decrease in the mortality rate in WT animals. A mortality rate of 91.7% was observed in TNF-RI(-/-) mice after CLP. This mortality rate was reduced to 37.5% by the application of DHEA. In sham-operated TNF-RI(-/-) animals, a significantly higher proportion of NK cells within the lymphocyte population was measured compared with the corresponding WT group. After CLP, a significant increase in the percentage cell count of NK cells was recorded in WT mice. Overall, following DHEA application in WT mice, an alteration in the cellular immune response was characterized by a reduction in the percentage counts of CD4(+), CD8(+) and NK cells. In the group of TNF-RI(-/-) mice treated with DHEA, no increase in the percentage cell count of NK cells was observed after CLP. No data for cell analysis were available from the CLP-TNF-RI(-/-) mice treated with saline, due to the high mortality rate in these animals. DHEA reduces the complications of sepsis in a TNF-RI-independent manner. Our study suggests that NK cells are involved in the protective mechanism of DHEA in WT mice. It would therefore seem that DHEA represents a feasible alternative therapy for the dysregulated immune system in sepsis.

Animals↗