Primary amenorrhea associated with hirsutism, acanthosis nigricans, dermoid cysts of the ovaries and a new type of insulin resistance

Imaging features of intra-abdominal and intra-pelvic causes of hirsutism

Hirsutism is a relatively common disorder which affects approximately 5% to 15% of women. It is defined by excessive growth of terminal hair in women, which primarily affects areas dependent on androgens, such as the face, abdomen, buttocks, and thighs. Hirsutism can be caused by a variety of etiologies, which are most often not lifethreatening. However, in some cases, hirsutism can be an indicator of more serious underlying pathology, such as a neoplasm, which may require further elucidation with imaging. Within the abdomen and pelvis, adrenal and ovarian pathologies are the primary consideration. The goal of this manuscript is to review the etiologies and imaging features of various intra-abdominal and intra-pelvic causes of hirsutism.

An adolescent female with a testosterone-secreting ovarian teratoma: a case report

Ovarian neoplasms constitute 1% of childhood tumors. The majority of them are teratomas and usually are asymptomatic or present with paraneoplastic syndromes. Our case is a 16-year-old female who presented with chronic abdominal pain, virilization and oligomenorrhea and found to have a complex cystic mass of the left ovary, more likely cystic teratoma on abdomen and pelvis CT. Further work-up revealed significantly elevated serum total and free testosterone. The patient subsequently underwent left salpingo-oophorectomy confirming the radiological findings. Within two week after surgery, serum testosterone normalized and the patient started having regular menstrual cycles. In summary, ovarian teratomas should be include in the differential diagnosis of abdominal pain and menstrual abnormalities in female adolescents. Further studies are needed to determine the role of ovarian-sparing surgery in this patient population.

Virilization in a Postmenopausal Female Due to Androgen Secreting Ovarian Dermoid Cyst

Virilizing ovarian dermoid cysts are very rare. The source of androgen in these cysts may be tumors such as Sertoli–Leydig cell tumor or Leydig cell hyperplasia. A 52-year-old postmenopausal female with virilization was found to have an ovarian dermoid cyst on ultrasound. Her serum testosterone levels were elevated. Leydig cell hyperplasia within the dermoid cyst was found to be the source of androgen in this patient.

Microscopic Acanthosis Nigricans in Type 2 Diabetes

Background:

Acanthosis nigricans (AN) has been associated with insulin resistance. Individuals with type 2 diabetes are insulin-resistant and, therefore, could be expected to manifest AN. However, the prevalence and predictors of AN are unknown in this population.

Objective:

An outpatient population with Type 2 diabetes (DM) was compared with matched controls (C) for microscopic and clinical AN along with measurement of body habitus, insulin, glucose, and androgen levels.

Methods:

Twenty-four individuals with DM (12M, 12F) from a tertiary care center were compared with 24 C (12M, 12F). Fasting glucose, insulin, sex hormone binding globulin, androstenedione, dihydroepiandrosterone sulfate, and testosterone were measured. Height, weight, waist/hip measures, and a clinical survey for acanthosis were recorded. A 2-mm skin biopsy from midaxilla of the nondominant arm was taken for pathological review.

Results:

C and DM were matched for age and body mass index (BMI). Prevalence of microscopic AN in C was 12% (3/24) and in DM was 21% (5/24; NS). In C, AN was predicted by waist, waist/hip ratio, and fasting insulin measures, while none of the variables examined was predicative of AN in DM.

Conclusions:

Microscopic acanthosis nigricans was found in similar numbers of people with DM when compared with C. Fasting insulin levels most strongly predicted the presence of AN in C, while no significant predictors of AN were found in the population with DM.

Polycystic ovary syndrome and insulin: our understanding in the past, present and future

Insulin resistance is prevalent in women with polycystic ovary syndrome (PCOS), and plays a critical pathophysiologic role in both the metabolic and reproductive complications of PCOS. This review focuses on the contribution of insulin resistance to anovulation in PCOS and to the high risk for Type 2 diabetes, metabolic syndrome and early cardiovasular disease. Key points for clinicians emphasized by this review are the following: PCOS is a clinical diagnosis and alternative diagnoses must be excluded; PCOS carries an inherent risk of insulin resistance and, hence, metabolic consequences for which women with PCOS should be screened regardless of BMI or degree of obesity; and PCOS is associated with infertility and this should be discussed early on in care of women diagnosed with PCOS, recognizing that there are several possible strategies to address infertility in women with PCOS, each with its own risks and benefits.

A study of pathogenesis of acanthosis nigricans and its clinical implications

Background:

Acanthosis nigricans (AN) is a dermatosis characterized by thickened, hyperpigmented plaques, typically on the intertriginous surfaces and neck. Common in some populations, its prevalence depends on race. Clinicians should recognize AN; it heralds disorders ranging from endocrinologic disturbances to malignancy. In this review, we discuss the pathogenesis of AN and its clinical implications and management.

Materials and Methods:

We selected 30 patients for the study. Diagnosis of associated disorders was established by history, physical examination, body mass index (BMI), hormone measurements by radioimmunoassays of thyroidnfunction tests, free testosterone, 17 (OH) progesterone, dehydroepiandrosterone sulfate (DHEAS), cortisol, gonadotropins, prolactin, immunoreactive insulin, and C-peptide levels.

Results and Discussion:

In our study, the flexural involvement (flexures of groins, knees and elbows) was seen in 40% patients, lip involvement was seen in 6.6% patients, and dorsal involvement was seen in 3.3% patients each. Increased serum testosterone levels were seen in 13.3% patients and increased DHEAS levels were seen in 20% patients. Regarding the types of AN, obesity induced AN or pseudo-AN was seen 70% patients, syndromic AN was seen in 23.35% patients and malignant AN was seen in 6.6% patients. The commonest histopathological feature of patients with AN was hyperkeratosis, seen in 100% patients, papillomatosis was seen in 90% patients, dermal infiltrate of lymphocytes and plasma cells was seen in 60% patients, horn pseudocysts were seen in 30% patients, and irregular acanthosis was seen in 26.6% patients.

Virilizing ovarian dermoid cyst with leydig cells

BACKGROUND

The clinical observation of virilization is a rare finding that has a number of possible explanations. Overall, ovarian tumors causing virilization are exceedingly rare and mostly occur in post-menopausal women. In fact, there are no reported cases of virilization from a testosterone-producing ovarian dermoid in the adolescent female age group. The most frequent germ cell tumor derived from the ovaries is the benign cystic teratoma (dermoid) which accounts for 25% of all ovarian neoplasms. Teratomas consist of tissues that recapitulate the ectoderm, endoderm, and mesoderm. Usually the tumors are asymptomatic, but they occasionally can cause severe pain if there is torsion or if sebaceous material perforates the cyst wall, leading to reactive peritonitis.

CASE

A 12-year-old female was found to have a large 3 5 x 19 x 12 cm ovarian mature cystic teratoma arising from her right ovary. The patient also displayed evidence of masculinization demonstrated by a deepening voice and clitoromegaly. The dermoid was producing large amounts of testosterone from a nest of Leydig cells found pathologically in the mass.

CONCLUSION

Benign cystic teratomas can produce active hormones, albeit rarely. This is a finding important to consider when ovarian cystectomy is performed for removal of a benign cystic teratoma.

Microscopic acanthosis nigricans in type 2 diabetes

BACKGROUND

Acanthosis nigricans (AN) has been associated with insulin resistance. Individuals with type 2 diabetes are insulin-resistant and, therefore, could be expected to manifest AN. However, the prevalence and predictors of AN are unknown in this population.

OBJECTIVE

An outpatient population with Type 2 diabetes (DM) was compared with matched controls (C) for microscopic and clinical AN along with measurement of body habitus, insulin, glucose, and androgen levels.

METHODS

Twenty-four individuals with DM (12M, 12F) from a tertiary care center were compared with 24 C (12M, 12F). Fasting glucose, insulin, sex hormone binding globulin, androstenedione, dihydroepiandrosterone sulfate, and testosterone were measured. Height, weight, waist/hip measures, and a clinical survey for acanthosis were recorded. A 2-mm skin biopsy from midaxilla of the nondominant arm was taken for pathological review.

RESULTS

C and DM were matched for age and body mass index (BMI). Prevalence of microscopic AN in C was 12% (3/24) and in DM was 21% (5/24; NS). In C, AN was predicted by waist, waist/hip ratio, and fasting insulin measures, while none of the variables examined was predicative of AN in DM.

CONCLUSIONS

Microscopic acanthosis nigricans was found in similar numbers of people with DM when compared with C. Fasting insulin levels most strongly predicted the presence of AN in C, while no significant predictors of AN were found in the population with DM.

Excess insulin binding to insulin-like growth factor receptors: proposed mechanism for acanthosis nigricans

Clinical and epidemiologic evidence has shown acanthosis nigricans to be closely related to defective tissue utilization of insulin in a number of previously recognized (e.g., obesity, lipodystrophy, and leprechaunism) as well as recently characterized (e.g., type A and type B syndromes) disorders. This article reviews the relationship of acanthosis nigricans to these insulin-resistant states. It also focuses attention on the possibility that interaction between excessive amounts of circulating insulin with insulin-like growth factor receptors on keratinocytes and dermal fibroblasts leads to the development of acanthosis nigricans.

Acanthosis nigricans: a cutaneous marker of tissue resistance to insulin

Tissue resistance to insulin is a major feature underlying the development of acanthosis nigricans in many patients. We report two unusual cases of acanthosis nigricans with contrasting forms of insulin resistance and propose an algorithm for the evaluation of patients with acanthosis nigricans. Further, we present a schematic framework that emphasizes the role of insulin and insulin growth factors in the pathogenesis of acanthosis nigricans.

Hirsutism in the adolescent female

Prompt evaluation should be carried out for any adolescent complaining of excessive hair growth. The workup should be directed toward the exclusion of androgen secreting neoplasms and correctable adrenal pathology. A minimal workup must include total serum testosterone, DHEA-S, and prolactin. The clinician must then determine if further testing will alter management substantially. Treatment includes removal or neutralization of any discrete source of serum androgens, normalization of altered steroid physiology, and cosmetic correction (electrolysis) of existing hair growth. Successful management will allow normal socialization of the young woman afflicted with this distressing condition.

Insulin administration alters gonadal steroid metabolism independent of changes in gonadotropin secretion in insulin-resistant women with the polycystic ovary syndrome

We have investigated the hypothesis that hyperinsulinemia may cause the polycystic ovary syndrome (PCO) by directly stimulating gonadal steroidogenesis and/or gonadotropin secretion. 10 insulin-resistant women with PCO and 5 age- and weight-matched ovulatory normal women had pulsatile gonadotropin release, gonadotrope sensitivity to gonadotropin-releasing hormone, and sex hormone levels studied on two consecutive study days, basally and during the infusion of insulin (mean +/- SEM steady state insulin levels, 1,254 +/- 63 microU/ml PCO vs. 907 +/- 92 microU/ml normal, P less than or equal to 0.01). Insulin acutely increased mean delta (6 h minus prestudy) levels of androstenedione (A) (P less than or equal to 0.001) and estradiol (E2) (P less than or equal to 0.05) and decreased mean plasma pool (0-6 h) levels of testosterone (T) (P less than 0.05), nonsex hormone binding globulin-bound T (P less than 0.05), and dihydrotestosterone (P less than or equal to 0.01) in the PCO women. Insulin also decreased mean plasma 6 h A to estrone (E1) ratios and increased 6 h E1 levels (both P less than or equal to 0.05) in the PCO women. There were significant sequence effects (insulin + day) in the PCO women on T/E2 ratios, indicating a carryover action of insulin. Insulin had no effects on gonadotropin release in the PCO women. In the normal women, the only significant change was an insulin or study day effect that increased mean 6 h E2 levels (P less than or equal to 0.01). There were significant spontaneous decreases in mean luteinizing hormone (p less than 0.05) and follicle-stimulating hormone levels (p less than or equal to 0.01) in the PCO but not the normal women on the second day of study. This study indicates that insulin can directly alter peripheral sex hormone levels independent of changes in gonadotropin release in insulin-resistent PCO women. Insulin decreased the levels of potent androgens in PCO women and did not increase androgen levels in normal women, arguing against a simple, direct causal relationship between hyperinsulinemia and hyperandrogenism in PCO.

Alterations in carbohydrate metabolism as they apply to reproductive endocrinology

This review has characterized the current state of knowledge of four clinical situations in which an interrelationship of gynecology, endocrinology and carbohydrate metabolism is recognized. The literature contains conflicting descriptions of changes in glucose homeostasis during the menstrual cycle and while using birth control pills. Physiologic changes in receptor number have been demonstrated in each of these situations, so failure to observe differences using glucose tolerance testing may reflect an in vivo homeostatic response to changes in these hormone levels. Thus, in vivo identification of alterations in carbohydrate metabolism induced by endogenous or exogenous steroids may require utilization of models that prevent these homeostatic mechanisms. The association between hyperandrogenism and hyperinsulinism has been better characterized, but the relationship is complicated by the frequent coexistence of obesity. The association may be due to insulin-stimulated ovarian androgen production, and insulin insensitivity may reflect a postreceptor defect. Insulin and its metabolic effects have also been implicated in ovulatory dysfunction in women with diabetes mellitus and identified as a factor affecting all levels of the hypothalamic-pituitary-ovarian axis. A clearer understanding of these relationships and their application to clinical management await further study.

The role of hyperinsulinemia in the pathogenesis of ovarian hyperandrogenism

The evidence that supports the hypothesis that insulin and LH both regulate ovarian androgen production was presented. The most dramatic clinical example of the association between hyperinsulinemia and hyperandrogenism is the HAIR-AN syndrome. Our hypothesis is that, in the HAIR-AN syndrome, the severe insulin resistance causes a compensatory hyperinsulinemia, which stimulates ovarian androgen production if adequate LH is present. The acanthosis nigricans is an epiphenomenon of the syndrome. Acanthosis nigricans is a dermatologic manifestation of severe insulin resistance. In vitro evidence suggests that insulin and IGF-I stimulate androgen production in incubations of human stroma and theca. The stromatropic effects of insulin may sensitize the stroma to the stimulatory effects of LH. In some hyperandrogenic-insulin-resistant women, a glucose load appears to produce an acute rise in circulating androgens. The magnitude of the rise in circulating androgens is proportional to the magnitude of the insulin response to the glucose load. These data suggest that hyperinsulinemia may play a central role in the development of ovarian hyperandrogenism.

Acanthosis nigricans, insulin resistance and cutaneous virilism

Thirteen patients with the syndrome of acanthosis nigricans and insulin resistance are described. They all had a combination of dermatoses related to hyperandrogenism (cutaneous virilism): hirsuties (II), acne vulgaris (6), hidradenitis suppurativa (5) and androgenic alopecia (4). In addition, 9 out of 13 had keratosis pilaris. The patients had raised fasting plasma insulin levels compared with matched normal controls (P less than 0.01) and increased insulin resistance (P less than 0.02). Insulin resistance correlated with total serum testosterone (rs = 0.65; P less than 0.02).

Prolonged suppression of hirsutism with combination therapy in an adolescent with insulin resistance and acanthosis nigricans

Spironolactone and oral contraceptives have been used separately with some success in the treatment of hirsutism. Hirsutism associated with the Kahn type-A syndrome of insulin resistance, acanthosis nigricans, and polycystic ovaries may be severe and refractory to conventional treatment. In view of their different sites and mechanisms of action, spironolactone and an oral contraceptive were used in combination to treat severe hirsutism in a 13-year-old girl with features of this syndrome. The two therapeutic agents, apparently acting together, resulted in a marked reduction in facial hair and serum androgen concentrations, which persisted during 18 months of treatment. Testosterone and androstenedione levels fell from 100 ng/dl and 628 ng/dl, respectively, to 47 ng/dl and 230 ng/dl by six months and to 35 ng/dl and 156 ng/dl by 18 months. This result suggests that combination therapy may be an effective treatment for severe hirsutism.

Acanthosis nigricans, hypothyroidism, and insulin resistance

Acanthosis nigricans has been associated with multiple endocrinopathies. The common denominator appears to be insulin resistance. Three patients are described (one woman and two men) who presented with hypothyroidism and acanthosis nigricans. All the patients had elevated insulin levels in the fasting state and in response to an oral glucose load. The mechanism for the resistance to insulin was a post-receptor binding defect or a structural abnormality in circulating insulin, since glucose tolerance and plasma cortisol, somatomedin, growth hormone, and insulin receptor concentrations in peripheral monocytes were all normal. Antibodies to insulin or the insulin receptor were absent. Neither insulin resistance nor acanthosis nigricans diminished following correction of the hypothyroidism. It is concluded that hypothyroidism may be associated with acanthosis nigricans, that hyperinsulinemia is a regular correlate of the skin disorder, and that treatment of the hypothyroidism does not resolve the hyperinsulinemia or the acanthosis nigricans.

Insulin resistance with acanthosis nigricans: the roles of obesity and androgen excess

The roles of hyperandrogenemia and obesity in the syndrome of severe insulin resistance with acanthosis nigricans were evaluated in studies of 11 females with this condition. Our results in these subjects were compared to evaluations of control subjects matched for degree of androgen excess or obesity. Fasting insulin levels were 3-, 5-, and 15-fold higher in the obese (OB), hyperandrogenemic (HO), and acanthosis nigricans (AN) groups, respectively, when compared to normal females. Responsiveness to a standard bolus of exogenous insulin was 78% of normal in the OB group, 40% of normal in the HO group, and 30% of normal in the AN group. Insulin binding to monocytes from both the OB group, and the HO group was modestly diminished primarily due to decreased receptor number. As a group, AN subjects when compared to either normal or weight-matched controls, demonstrated a significant decrease in monocyte insulin binding predominantly due to a decrease in receptor number. However, two patients in the AN group had normal insulin binding suggesting a postreceptor mechanism for the insulin resistance in at least some of these subjects. In vivo glucose utilization insulin dose response curves were determined in 3 acanthotic subjects using the euglycemic clamp technique. All 3 of these subjects had a right shift of the curve and diminished maximal utilization, consistent with combined receptor and postreceptor defects in insulin action. In evaluating the relationship between hyperandrogenemia, insulin resistance, and acanthosis nigricans, significant correlations among basal levels of plasma insulin, and both testosterone and androstenedione were demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

Obesity, acanthosis nigricans, insulin resistance, and hyperandrogenemia: pediatric perspective and natural history

We studied the syndrome of acanthosis nigricans, obesity, insulin resistance, and hyperandrogenemia in 22 patients. Although isolated case reports in adolescents have appeared, this syndrome has not received full recognition as a pediatric entity. Our patients (17 girls, five boys) had a mean weight 5.7 SD above the mean for age, although mean height was only 0.5 SD above the mean for age. All patients had acanthosis nigricans. Their insulin resistance was significantly greater than that in a control group with comparable obesity. Fasting insulin concentration was 5.25 microU/ml in lean controls, 19.6 microU/ml in obese controls, and 49.8 microU/ml in study patients (P less than 0.002). Mean glucose disappearance rate during an insulin tolerance test was 6.7%/min in lean controls, 5.19%/min in obese controls, and 2.35%/min in study patients (P less than 0.02). After menarche, mean plasma testosterone concentration was 106 ng/dl, compared with less than 50 ng/dl in all lean and obese control patients. Data derived from our series of patients lead us to conclude that (1) this is a genetic syndrome, although the exact mode of inheritance is unclear; (2) the natural history of the syndrome invariably begins with the onset of obesity, followed by acanthosis nigricans that worsens with progressive weight gain; (3) acanthosis nigricans is thus a marker for hyperinsulinemia, which occurs before hyperandrogenemia; (4) hyperandrogenemia occurs only after menarche. Identification of this syndrome should permit monitoring for the development of hyperandrogenemia during puberty and determination of other affected family members.

Acanthosis nigricans and insulin resistance

Acanthosis nigricans has been reported in association with many conditions and most recently with insulin resistance. A case is presented to illustrate the clinical characteristics of acanthosis nigricans and insulin resistance. The various subtypes of this syndrome complex and its pathogenic mechanisms are reviewed.

Insulin resistance in polycystic ovary syndrome

Patients with polycystic ovary syndrome (PCO) who are obese and exhibit acanthosis nigricans have been reported to have insulin resistance. We studied 21 euglycemic, euprolactinemic patients with PCO without acanthosis nigricans. Eleven of these patients were hirsute and the remaining 10 were not. Eight women with chronic anovulation, who were weight matched with the PCO patients, were studied along with the 11 ovulatory control subjects. Compared to control subjects, women with chronic anovulation had similar levels of immunoreactive luteinizing hormone (LH), bioactive LH, 17 beta-estradiol, testosterone (T), and dehydroepiandrosterone sulfate but significantly higher fasting immunoreactive insulin levels (p less than 0.05). The nonhirsute patients with PCO had higher immunoreactive insulin levels compared to patients with chronic anovulation and control subjects (p less than 0.05) while hirsute patients with PCO had higher immunoreactive insulin levels than nonhirsute ones (p less than 0.05). There was a significant positive correlation between fasting immunoreactive insulin levels and serum T. Fasting immunoreactive insulin also showed a significant correlation with serum LH and bioactive LH. After receiving 100 gm of oral glucose, hirsute patients with PCO had significantly higher insulin responses compared to those of control subjects despite similar glucose responses. Red blood cell insulin-binding sites and receptor affinities were similar in hirsute patients and control subjects. These data suggest that the hyperinsulinemia of patients with PCO may be related, in part, to the elevated LH and androgen levels and may be a postreceptor defect.

Hyperandrogenism, insulin resistance, and acanthosis nigricans syndrome: a common endocrinopathy with distinct pathophysiologic features

The HAIR-AN syndrome that consists of hyperandrogenism (HA), insulin resistance (IR), and acanthosis nigricans (AN) is an underdiagnosed endocrinopathy, because hyperandrogenic women are not commonly screened for insulin resistance or acanthosis nigricans. The distinct pathophysiologic features of the HAIR-AN syndrome are discussed in detail. In this syndrome, the primary pathophysiologic derangements are the insulin resistance and the hyperandrogenism. The acanthosis nigricans is an epiphenomenon of these primary processes. In patients with the HAIR-AN syndrome, the degree of severity of the insulin resistance is positively correlated with the degree of severity of the hyperandrogenism. In patients with adequate pancreatic beta-islet cell reserve, insulin resistance results in a long-term increase in circulating insulin levels. The hyperinsulinemia probably directly stimulates ovarian androgen production. In turn, hyperandrogenism itself produces insulin resistance. This positive feedback loop between insulin resistance and hyperandrogenism propagates the disease, and increases its severity over time. The relationship between insulin resistance and hyperandrogenism may explain the hyperandrogenemia seen in the following disease processes: obesity, acromegaly, lipoatrophic diabetes, leprechaunism, and Kahn types A and B insulin resistance.

Insulin receptors in normal and disease states

The binding of insulin to its receptor has been studied under various physiological and pathological conditions. Quantitative studies have involved human circulating cells such as monocytes and erythrocytes, adipocytes, placental cells, and cultured cells such as fibroblasts and transformed lymphocytes. In animals, other target tissues such as liver and muscle have been studied and correlated with the human studies. Various physiological conditions such as diurnal rhythm, diet, age, exercise and the menstrual cycle affect insulin binding; in addition, many drugs perturb the receptor interaction. Disease affecting the insulin receptor can be divided into five general categories: (1) Receptor regulation--this involves diseases characterized by hyper- or hypoinsulinaemia. Hyperinsulinaemia in the basal state usually leads to receptor 'down' regulation as seen in obesity, type II diabetes, acromegaly and islet cell tumours. Hypoinsulinaemia such as seen in anorexia nervosa or type I diabetes may lead to elevated binding. (2) Antireceptor antibodies--these immunoglobulins bind to the receptor and competitively inhibit insulin binding. They may act as agonists, antagonists or partial agonists. (3) Genetic diseases which produce fixed alterations in both freshly isolated and cultured cells. (4) Diseases of receptor specificity where insulin may bind with different affinity to its own receptor or related receptors such as receptors for insulin-like growth factors. (5) Disease of affinity modulation where physical factors such as pH, temperature, ions, etc. may modify binding. In this review, we have considered primarily abnormality in insulin receptor binding. There are numerous other functions of the receptor such as coupling and transmission of the biological signal. These mechanisms are frequently referred to as postreceptor events, but more properly should be referred to as postbinding events since the receptor subserves other functions in addition to recognition and binding of insulin.

Impaired insulin degradation in a patient with insulin resistance and acanthosis nigricans

The kinetics of plasma insulin were studied in a 14 year old girl with the syndrome of insulin resistance and acanthosis nigricans. The clearance of plasma insulin was found to be strikingly reduced (135 ml/min . m2 versus 456 +/- 22 in 17 normal control subjects), whereas the basal systemic insulin delivery rate was increased about 10-fold (25.5 mU/min . m2 versus 2.6 +/- 0.3 in normal subjects). Thus, reduced insulin clearance and excessive posthepatic delivery of the hormone both contributed to the severe fasting hyperinsulinemia (218 microunits/ml) associated with the other clinical features of the syndrome (glucose intolerance, primary amenorrhea, polycystic ovaries, hirsutism). Following ovarian wedge resection, insulin clearance rose to 264 ml/min . m2, and insulin delivery fell to 9.8 microunits/ml min . m2. The resulting abatement of the patient's hyperinsulinism (fasting plasma insulin = 37 microunits/ml) was accompanied by the appearance of menses, normalization of glucose tolerance, and amelioration of the acanthosis. The improvement in menstrual function and acanthosis, however, was not sustained. This case provides evidence for interdependence of insulin action and insulin degradation in humans.

Qualitative abnormalities in insulin binding in a patient with extreme insulin resistance: decreased sensitivity to alterations in temperature and pH

Cultured lymphocytes transformed by Epstein--Barr virus were employed to study insulin receptors from a patient with extreme insulin resistance associated with the syndrome of leprechaunism. With cultured lymphocytes from normal subjects, insulin binding to its receptor is exquisitely sensitive to changes in temperature and pH. In cells from normal subjects, insulin binding was increased by approximately 250% as the temperature was decreased from 37 degrees C to 12 degrees C. In contrast, with cells from the leprechaun, insulin binding was only approximately 30% higher at 12 degrees C than at 37 degrees C. Similarly, insulin binding to cells from the leprechaun was markedly less sensitive to changes in pH, as compared to cells from normal subjects. Binding studies suggested that the number of insulin receptors per cell was within the normal range in this patient. Despite the unusual characteristics of insulin binding in cells from this insulin-resistant patient, the receptors were typical in at least two respects: (i) binding was inhibited normally by antibodies to the receptor; and (ii) the specificity for insulin analogs was normal (chicken insulin greater than porcine insulin much greater than guinea pig insulin greater than porcine proinsulin). This patient has an inborn error affecting insulin receptor function. The receptor's binding function was abnormal in having decreased sensitivity to alterations in temperature and pH. However, the level of insulin binding to cells from the leprechaun was within normal limits. Consequently, the hormonal resistance probably results from a decreased ability of the receptor to couple insulin binding to insulin action.

Hirsutism: implications, etiology, and management

Hirsutism usually results from a subtle excess of androgens. As such, it is a clue to possible endocrine disturbance in addition to presenting cosmetic problems. We use the term hirsutism to mean male-pattern hirsutism--excessive growth of hair in areas where female subjects normally have considerably less than male subjects. An elevation of the plasma free (unbound) testosterone level is the single most consistent endocrinologic finding in hirsutism. The plasma free testosterone level is sometimes elevated when the total level of plasma testosterone is normal because testosterone-estradiol--binding globulin (TEBG) levels are often depressed in hirsute women. Frequent blood sampling is sometimes necessary to demonstrate subtle hyperandrogenic states since androgen levels in the blood are pulsatile and seemingly reflect episodic ovarian and adrenal secretion. The source of hyperandrogenemia can usually be determined from dexamethasone suppression testing. Those patients whose plasma free androgen levels do not suppress normally usually have functional ovarian hyperandrogenism (polycystic ovary syndrome variants). Very high plasma androgen levels or evidence of hypercortisolism, which is not normally suppressible by dexamethasone, should lead to the search for a tumor or Cushing's syndrome. Those patients in whom hyperandrogenemia is suppressed normally by dexamethasone have a form of the adrenogenital syndrome, a prolactinoma, obesity, or idiopathic hyperandrogenemia. In such patients, glucocorticoid therapy may reduce hirsutism and acne and normalize menses. The treatment of hirsutism resulting from functional ovarian hyperandrogenism is not as satisfactory; estrogen-progestin treatment is the most useful adjunct to cosmetic approaches to hirsutism in this country. However, other manifestations of polycystic ovary syndrome, such as infertility, may take precedence over hirsutism when an optimal therapeutic program is designed for many patients.

Malignant acanthosis nigricans: a review

Malignant acanthosis nigricans is a dermatosis that appears grossly as a hyperpigmented, velvety, or verrucous hyperplasia of the epidermis, most marked in flexural areas. It is always associated with a malignancy. In 277 cases reviewed, the condition was associated with gastric carcinomas in 55.5%, with other intra-abdominal carcinomas in 17.7%, and with malignancies in other sites in 26.8%. Current theories for the association and pathogenesis of the cutaneous process are discussed.

Characterization of hyperandrogenism with insulin-resistant diabetes type A

The characterization of the hyperandrogenism of two sisters with type A insulin-resistant diabetes and hirsutism is presented. Testosterone (T) and androstenedione levels were elevated in peripheral serum. These were not markedly affected by infusion of adrenocorticotropic hormone. In patient 1 glucocorticoid suppression decreased T levels by 50% and androstenedione levels by 30% but had no effect on them in patient 2. Estrogen-progestin suppression markedly reduced testosterone levels in both patients. The blood production of T in patient 1 was 0.8 mg/day and in patient 2 was 4.5 mg/day, both of which are elevated. Selective venous catheterization in patient 2 revealed markedly elevated testosterone levels in the ovarian veins, and polycystic ovaries were found at subsequent laparotomy. These endocrine studies have shown that the source of excessive testosterone in these patients is excessive production by the ovaries, and it can be suppressed by oral contraceptives.

Characterization of insulin receptors in patients with the syndromes of insulin resistance and acanthosis nigricans

This report analyzes the in vitro characteristics of 125I-insulin binding to the monocytes of nine patients with the syndromes of acanthosis nigricans and insulin resistance. The 3 Type A patients (without demonstrable autoantibodies to the insulin receptor) had decreased binding of insulin due to a decreased concentration of receptors. In these patients the residual receptors demonstrated normal dissociation kinetics, negative cooperativity, and were blocked by anti-receptor antibodies in a manner similar to normal cells. In contrast, monocytes from the 6 Type B patients (with circulating anti-receptor autoantibodies) had decreased binding of insulin due to a decrease in receptor affinity. Insulin binding to monocytes of Type B patients demonstrated accelerated rates of dissociation with no evidence of cooperative interactions among insulin receptors. When coupled with previous data, the present studies further suggest that different mechanisms account for the defects in insulin binding and insulin resistance observed in these patients.