No acute effect of physiological insulin increase on dehydroepiandrosterone sulfate in women with obesity and/or polycystic ovarian disease**Supported in part by the Clinical Research Center, University of California at Los Angeles United States Public Health Service Grant No. RR00865 and the University of Alabama at Birmingham, Clinical Nutrition Research Unit, National Institute of Health (Bethesda, Maryland) grant no. CA-28103.††Presented at the 38th Annual Meeting of the Society for Gynecologic Investigation, San Antonio, Texas, March 20 to 23, 1991

DHEA, DHEAS and PCOS

Approximately 20-30% of PCOS women demonstrate excess adrenal precursor androgen (APA) production, primarily using DHEAS as a marker of APA in general and more specifically DHEA, synthesis. The role of APA excess in determining or causing PCOS is unclear, although observations in patients with inherited APA excess (e.g., patients with 21-hydroxylase deficient congenital classic or non-classic adrenal hyperplasia) demonstrate that APA excess can result in a PCOS-like phenotype. Inherited defects of the enzymes responsible for steroid biosynthesis, or defects in cortisol metabolism, account for only a very small fraction of women suffering from hyperandrogenism or APA excess. Rather, women with PCOS and APA excess appear to have a generalized exaggeration in adrenal steroidogenesis in response to ACTH stimulation, although they do not have an overt hypothalamic-pituitary-adrenal axis dysfunction. In general, extra-adrenal factors, including obesity, insulin and glucose levels, and ovarian secretions, play a limited role in the increased APA production observed in PCOS. Substantial heritabilities of APAs, particularly DHEAS, have been found in the general population and in women with PCOS; however, the handful of SNPs discovered to date account only for a small portion of the inheritance of these traits. Paradoxically, and as in men, elevated levels of DHEAS appear to be protective against cardiovascular risk in women, although the role of DHEAS in modulating this risk in women with PCOS remains unknown. In summary, the exact cause of APA excess in PCOS remains unclear, although it may reflect a generalized and inherited exaggeration in androgen biosynthesis of an inherited nature.

Adrenal androgen production capacity remains high up to menopause in women with polycystic ovary syndrome

INTRODUCTION

Hyperandrogenism is one of the main features of polycystic ovary syndrome (PCOS). Of circulating androgens, 50% of androstenedione and testosterone are of ovarian and adrenal origin, whereas dehydroepiandrosterone (DHEA) and DHEA sulfate are almost uniquely of adrenal origin. Our previous studies have indicated that ovarian androgen production capacity is enhanced in women with PCOS, and it remains high until late reproductive age. To study whether this also applies to adrenal androgen production, ACTH tests were performed in healthy women and in women with PCOS.

MATERIALS

Sixty-nine healthy women (aged 19-62 yr; body mass index 19.2-35.0 kg/m2) and 58 women with previously diagnosed PCOS (aged 18-59 yr; body mass index 19.0-42.9 kg/m2) participated in the study.

METHODS

The subjects underwent ACTH stimulation tests, and serum cortisol, 17-hydroxyprogesterone, androstenedione, testosterone, DHEA, and DHEA sulfate levels were analyzed at 0, 30, and 60 min.

RESULTS

Basal and ACTH-stimulated levels of most adrenal androgens decreased in healthy women with age, whereas in women with PCOS, only the concentrations of basal serum 17-hydroxyprogesterone decreased, and all areas under the curve (AUCs) remained unchanged and significantly higher (except for DHEA) than those in control women. Likewise, at the menopausal transition, pre- and postmenopausal women with PCOS exhibited mainly unchanged and higher basal androgen and AUC levels.

CONCLUSIONS

Similarly to ovarian endocrine function, serum adrenal steroid levels and adrenal steroid production capacity remain enhanced at least up to menopause in women with PCOS.

Dehydroepiandrosterone sulfate and insulin resistance in patients with polycystic ovary syndrome

OBJECTIVE

To test the hypothesis that increasing DHEAS levels is associated with improved insulin resistance in patients with polycystic ovary syndrome (PCOS).

DESIGN

Cross-sectional cohort analysis.

SETTING

Academic medical center.

PATIENT(S)

Three hundred fifty-two women with PCOS.

INTERVENTION(S)

Patients presenting for evaluation of symptoms related to androgen excess were evaluated physically and biochemically through laboratory analysis.

MAIN OUTCOME MEASURE(S)

Circulating DHEAS, total T, free T, sex hormone-binding globulin (SHBG), and 17-hydroxyprogesterone (17-OHP) levels, and calculated homeostasis model assessment of insulin resistance (HOMA-IR).

RESULT(S)

Bivariate analysis indicated that all parameters were associated with HOMA-IR, except 17-OHP and age, and confirmed a negative correlation between DHEAS and HOMA-IR. Multivariate analysis indicated that increases in DHEAS, SHBG, 17-OHP, and age were associated with decreasing HOMA-IR, whereas increases in free T, body mass index (BMI), and waist-to-hip ratio (WHR) were associated with increasing HOMA-IR. In decreasing order of importance, the following variables predicted insulin resistance: BMI > WHR > age > DHEAS > free T > SHBG > 17-OHP.

CONCLUSION(S)

DHEAS is negatively correlated to insulin resistance in patients with PCOS, and in our model ranked just behind other well-established predictors including BMI, WHR, and age. Whether this is due to a direct beneficial effect on insulin action by adrenal androgens such as DHEA, or whether DHEAS simply reflects the circulating levels of hyperinsulinemia, remains to be determined.

Hyperglycaemia acutely decreases circulating dehydroepiandrosterone levels in healthy men

OBJECTIVE

This study was conducted in order to evaluate the effect of glucose-insulin homeostasis on adrenal steroids and was designed to separate the effects of hyperglycaemia from those of insulin.

DESIGN

Eight healthy men aged 22.6 +/- 3.4 (SD) underwent an 80 mU/m2/min hyperinsulinaemic euglycaemic 100-min clamp, a 200-min graded glucose infusion at 2-16 mg/kg/min and a measurement of fat mass.

MEASUREMENTS

Circulating glucose, insulin and adrenal steroid levels including dehydroepiandrosterone (DHEA) were determined before and during both infusion tests. Steroid variations in relation to insulinaemia and glycaemia were analysed using univariate, multivariate tests and nonlinear mixed models.

RESULTS

Hyperinsulinaemia induced no significant modification of adrenal steroid levels. By contrast, hyperglycaemia decreased all adrenal steroids except DHEA-sulphate by 47-66%. The drop occurred early, averaging 51% for 17OH pregnenolone and 57% for DHEA at the 80th minute of glucose infusion, whereas blood glucose was 7.1 +/- 1.2 mmol/1. This effect was independent of insulinaemia, fat mass and waist circumference. Thus, we estimated models that could best predict steroid variations according to blood glucose. At thresholds defining impaired fasting glycaemia and diabetes, the estimated decrease in DHEA was 40% and 45%, respectively, culminating at 60% at 9.3 mmol/1 glycaemia, with no detectable further decrease.

CONCLUSIONS

Our data suggest that hyperglycaemia dramatically decreases adrenal androgen levels in men, possibly by acting at early steps of synthesis, independently of insulinaemia and fat mass.

The effect of physiologic hyperinsulinemia during an oral glucose tolerance test on the levels of dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) in healthy young adults born with low and with normal birth weight

Several data support that adrenal hyperandrogenism affects women with low birth weight (LBW). We also found an association between serum dehydroepiandrosterone (DHEA) and fasting insulin levels. The aim of our study was to detect the acute effects of reactive hyperinsulinemia during oral glucose tolerance test (OGTT) on DHEA(S) levels in LBW men and women. Fifty three men and 47 women (of those, 37 men and 33 women were LBW) were enrolled. DHEA, DHEAS, and insulin levels were measured before and during OGTT. Cortisol was also measured. DHEA/cortisol ratio during OGTT was calculated to analyze the acute effect of hyperinsulinemia on DHEA levels. During OGTT, DHEA and cortisol levels decreased in each individual, independently of gender and birth weight. Serum DHEAS decreased to a minor (but significant) extent only in LBW women (p<0.05). The rate of DHEA/cortisol increased in both gender, independently of birth weight. The increase of the rate of DHEA/cortisol during OGTT was associated with maximal insulin response (r = 0.45, p<0.05) and with the insulin(AUC) (r = 0.48, p<0.05) in women. Our results suggest that reactive hyperinsulinemia during OGTT might activate the androgen pathway of adrenal cortex including DHEA production. Therefore acute hyperinsulinemia might counterbalance to some extent the diurnal decrease of DHEA during OGTT.

Influence of insulin and testosterone on adrenocortical steroidogenesis in vitro: preliminary studies

OBJECTIVE

The mechanisms underlying the adrenal androgen (AA) excess of polycystic ovary syndrome (PCOS) remain unclear, although it is possible that the adrenocortical dysfunction may be a response to other, extraadrenal factors. Consistent with the pathophysiology of PCOS and with in vivo data in normal and PCOS women, we have hypothesized that insulin inhibits and that T stimulates AA secretion in vitro.

DESIGN

In vitro experimental study.

SETTING

University medical center.

PATIENT(S)

Normal human adrenals (n = 4 women, ages 25-57 years) were obtained with consent at the time of organ donation.

INTERVENTION(S)

Fresh adrenal tissue minces were incubated in serum-free medium with 10-microM pregnenolone substrate and 1-microM ACTH-(1-24). Challenge doses of 0.2, 1, 5, 20, and 100 nM of insulin and 1, 10, 100, 1,000, and 10,000 nM of T were added, and the media were sampled after 8 hours of incubation at 37 degrees C, 4% CO2. Dehydroepiandrosterone (DHEA), DHEA-sulfate (DHEAS), and cortisol (F) were measured by radioimmunoassay (significant effects compared with the case of zero-dose control).

MAIN OUTCOME MEASURE(S)

The production of DHEA, DHEAS, and F in the media of the adrenal minces was compared between different subjects and at different concentrations of T and insulin.

RESULT(S)

Analysis of the combined data from all donors indicated that insulin stimulated DHEAS and suppressed DHEA production but had no consistent effect on F. Similar analyses of the combined data indicated that T had no significant predictable effect on the production of DHEAS, DHEA, or F. When examining donor data individually, insulin and T did elicit significant increases and/or decreases in steroid production within subjects, although no consistent trends were observed.

CONCLUSION(S)

On the basis of these data, it is clear that extra-adrenal factors such as insulin and T have some adrenal regulatory capacity. In general, insulin stimulated DHEAS and decreased DHEA production, suggesting that it increases adrenocortical sulfotransferase activity. However, although in the individual subjects studied, both insulin and T frequently altered the production of DHEAS, DHEA or F, these effects did not appear to be uniform or consistent from subject to subject. Expanded studies are required to confirm these results.

The role of the adrenal cortex in polycystic ovary syndrome

Adrenal androgen excess affects approximately 25% of PCOS patients. The exact etiology of this excess in PCOS patients is unclear. Some evidence that adrenal androgen excess may be a genetic trait. The adrenal androgen response to ACTH is highly individualized, and the relative response seems to be constant over time. In addition, there is a strong familial component to adrenal androgen levels in normal individuals and PCOS patients. It is possible that the tendency to overproduce adrenal androgens is an inherited risk factor for the development of PCOS. Overall, few hyperandrogenic patients actually have isolated deficiencies of 3 beta-hydroxysteroid dehydrogenase, 21-hydroxylase, and 11-hydroxylase. The ovarian hormonal secretion in PCOS can affect adrenal androgen secretion and metabolism, although this factor accounts for only part of this abnormality. More likely, the adrenal androgen excess results from a generalized hyperresponsiveness of the adrenal cortex to ACTH, but without an increase in CRH or ACTH sensitivity. Although glucocorticoid administration may improve the ovulatory function of these patients, the results are modest and cannot be predicted by the circulating androgen levels.

Prevalence of 21-hydroxylase-deficient nonclassic adrenal hyperplasia and insulin resistance among hirsute women from Puerto Rico

OBJECTIVE

To determine the prevalence of 21-hydroxylase (21-OH)-deficient nonclassic adrenal hyperplasia (NCAH) and insulin resistance in hirsute women from Puerto Rico.

DESIGN

Cross-sectional prospective study.

SETTING

Clinical research center.

PATIENT(S)

100 consecutive untreated hirsute women.

MAIN OUTCOME MEASURE(S)

Fasting total T, free T, DHEAS, insulin, and glucose were measured, and a 60-minute acute ACTH-(1-24) stimulation for 17-hydroxyprogesterone (17-HP) was performed. A diagnosis of 21-OH-deficient NCAH was considered when the stimulated 17-HP level was >30.3 nmol/L. The glucose/insulin ratio was calculated as a measure of insulin resistance (normal value, > or =4.5).

RESULT(S)

Patients had a mean (+/-SD) age of 26.8+/-6.6 years; 82 were oligomenorrheic. Overall, 12%, 8%, and 60% of patients had elevated levels of DHEAS, total T, or free T, respectively. One patient was identified as having 21-OH-deficient NCAH. Eight women, none of whom had NCAH, were found to be hyperglycemic; four of these women had type 2 diabetes mellitus. Excluding hyperglycemic patients, a glucose/insulin ratio of <4.5, consistent with IR, was found in 51.7%.

CONCLUSION(S)

The prevalence of 21-OH-deficient NCAH among patients from Puerto Rico does not differ significantly from that reported for other non-Jewish, non-Hispanic white populations.

Chronic hyperinsulinemia and the adrenal androgen response to acute corticotropin-(1-24) stimulation in hyperandrogenic women

OBJECTIVE

Many women with androgen excess demonstrate elevated circulating insulin levels independent of obesity. In addition, in these women some investigators have demonstrated a negative correlation between the circulating levels of the adrenal androgens, dehydroepiandrosterone or dehydroepiandrosterone sulfate and insulin. The mechanism by which insulin decreases adrenal androgens is unclear. The objective of this study was to determine whether chronic hyperinsulinemia in hyperandrogenic women results in an alteration in the adrenocortical response to corticotropin, resulting in decreased androgen secretion.

STUDY DESIGN

We studied seven hyperandrogenic women with severe chronic hyperinsulinemia and eight hyperandrogenic normoinsulinemic patients. Nine healthy women served as controls for the basal hormonal levels and the response to a 3-hour, 100 gm oral glucose tolerance test. In all subjects insulin and glucose were measured hourly during the oral glucose tolerance test and the baseline sample was assayed for total testosterone, dehydroepiandrosterone sulfate, dehydroepiandrosterone, androstenedione, sex hormone-binding globulin, and free testosterone. In hyperandrogenic women cortisol, dehydroepiandrosterone, and androstenedione were also measured, before and 60 minutes, after acute intravenous administration of 0.25 mg corticotropin (1-24).

RESULTS

There was no difference in the response of cortisol, dehydroepiandrosterone, or androstenedione to corticotropin-(1-24) stimulation between normoinsulinemic and hyperinsulinemic hyperandrogenic patients. As defined, the hyperinsulinemic patients had higher basal and peak insulin levels and areas under the insulin response curve compared with the normoinsulinemic patients or controls. Total testosterone and dehydroepiandrosterone did not differ among study groups. As expected, hyperandrogenic patients demonstrated lower sex hormone-binding globulin activity and higher free testosterone, androstenedione, and dehydroepiandrosterone sulfate basal levels compared with controls.

CONCLUSIONS

The results of this study do not support the hypothesis that chronic hyperinsulinemia in hyperandrogenic patients significantly inhibits the andrenocortical secretion of dehydroepiandrosterone or androstenedione in response to corticotropin stimulation or the basal circulating adrenal androgen levels. Additional studies, including a greater number of patients, may be needed to fully establish these conclusions.

Low serum levels of dehydroepiandrosterone may cause deficient IL-2 production by lymphocytes in patients with systemic lupus erythematosus (SLE)

The principal cause of IL-2 deficiency, a common feature of both murine lupus and human SLE, remains obscure. Recent studies of our own as well as others have shown that dehydroepiandrosterone (DHEA), an intermediate compound in testosterone synthesis, significantly up-regulates IL-2 production of T cells, and that administration of exogenous DHEA or IL-2 via a vaccinia construct to murine lupus dramatically reverses their clinical autoimmune diseases. Thus, we have examined serum levels of DHEA in patients with SLE to test whether abnormal DHEA activity is associated with IL-2 deficiency of the patients. We found that nearly all of the patients examined have very low levels of serum DHEA. The decreased DHEA levels were not simply a reflection of a long term corticosteroid treatment which may cause adrenal atrophy, since serum samples drawn at the onset of disease, which are devoid of corticosteroid treatment, also contained low levels of DHEA. In addition, exogenous DHEA restored impaired IL-2 production of T cells from patients with SLE in vitro. These results indicate that defects of IL-2 synthesis of patients with SLE are at least in part due to the low DHEA activity in the serum.