Serum sex hormone concentrations in insulin dependent diabetic women with and without amenorrhoea

Gonadal dysfunction in women with diabetes mellitus

It is well known that both type 1 and type 2 diabetes mellitus (DM) are related to increased risk for cardiovascular (CV) and chronic kidney disease (CKD). However, besides these prominently presented complications, DM has also been associated with reproductive dysfunctions. It seems that these disorders are met in up to 40% of women with DM and consist of delayed menarche, all types of menstrual disorders, such as amenorrhea, oligomenorrhea, menstrual irregularity, as well as menorrhagia, infertility, characteristics of polycystic ovary syndrome (PCOS) and early (or rarely late) menopause. In type 1 DM (T1DM), insulin treatment, although it has reduced the rates of insulinopenic-induced hypogonadotropic hypogonadism, an entity commonly presented in many women with the disease in the past decades, when it is used in excess it can also promote hyperandrogenism. Regarding type 2 DM (T2DM), insulin resistance (IR) and hyperinsulinemia have mainly been implicated in the pathogenesis of reproductive dysfunctions, as insulin can act as gonadotropin on the theca cells of the ovary and can lead to hyperandrogenism and inhibition of proper ovulation. This review aims to detail the reproductive dysfunctions associated with DM and provide scientific data to enlighten the underlying pathogenetic mechanisms.

Alterations in the Menstrual Cycle as a Peculiar Sign of Type 1 Diabetes Mellitus: A Meta-analytic Approach

BACKGROUND

Menstrual irregularities are present in >30% of women with type 1 diabetes mellitus (T1DM). These abnormalities will likely lead to reduced fertility and earlier menopause. T1DM management has changed over time, with even more emphasis on stringent levels of glycemic management. Thus, we investigated whether therapeutic T1DM changes have an influence on the proportion of menstrual disorders in women with T1DM.

METHODS

A meta-analysis was performed that included clinical trials in which menstrual abnormalities in women with T1DM were studied. The literature was checked for studies in which women with T1DM were compared with healthy, age-matched controls. Case-control, cohort, and cross-sectional studies were included. The primary endpoint was rate of menstrual dysfunction.

RESULTS

Menstrual dysfunction was higher in women with T1DM compared with controls (odds ratio 2.08, 95% confidence interval [CI] 1.43 to 3.03, p<0.001), even when sensitivity analysis was performed, considering only studies published after 2000. The age at menarche was higher for women with T1DM compared with controls (mean difference 0.53, 95% CI 0.32 to 0.74 years, p<0.001). The proportion of menstrual abnormalities in T1DM was inversely related to diabetes duration, but was unrelated to both body mass index and glycated hemoglobin.

CONCLUSIONS

The meta-analytic approach used confirmed the correlation between T1DM and menstrual irregularities. T1DM menstrual dysfunction seemed unrelated to change in therapeutic management across years, as well as to glycemic management and body weight. The underlying pathogenetic mechanisms are not fully understood.

Diabetes: a metabolic and reproductive disorder in women

Reproductive dysfunction is a common but little studied complication of diabetes. The spectrum of reproductive health problems in diabetes is broad, and encompasses delayed puberty and menarche, menstrual cycle abnormalities, subfertility, adverse pregnancy outcomes, and potentially early menopause. Depending on the age at diagnosis of diabetes, reproductive problems can manifest early on in puberty, emerge later when fertility is desired, or occur during the climacteric period. Historically, women with type 1 diabetes have frequently had amenorrhoea and infertility, due to central hypogonadism. With the intensification of insulin therapy and improved metabolic control, these problems have declined, but do persist. Additional reproductive implications of contemporary diabetes management are now emerging, including polycystic ovary syndrome and hyperandrogenism, which are underpinned by insulin action on the ovary. The sharp rise in type 2 diabetes incidence in youth suggests that more women of reproductive age will encounter diabetes-related reproductive problems in their lifetimes. With an ever increasing number of young women living with diabetes, clinicians need to be aware of and equipped for the challenges of navigating reproductive health concerns across the lifespan.

Sex-specific differences in insulin resistance in type 1 diabetes: The CACTI cohort

OBJECTIVE

To test the hypothesis that multitissue deficits in insulin sensitivity are greater among women than men with type 1 diabetes compared to respective controls.

RESEARCH DESIGN AND METHODS

Three-stage hyperinsulinemic-euglycemic clamps (4, 8, 40 mU/m2/min) were performed on 41 people with type 1 diabetes and 47 adults without diabetes (mean ± SD age 46 ± 8). Infusions of [1-13C]palmitate, [1,1,2,3,3-2H2]glycerol, and [6,6-2H2]glucose isotope tracers were used to determine free fatty acid (FFA), glycerol, and glucose kinetics in 52 of these participants (25 M and 27 W).

RESULTS

There was no difference in age or BMI by type 1 diabetes status in either sex. Free fatty acid rate of appearance (FFA Ra) was higher in both sexes with type 1 diabetes compared to those without diabetes during stages 1 and 2. The same was seen with glycerol for stages 1 and 2. During stage 3 glucose rate of disappearance (Rd) was lower in those with type 1 diabetes among both sexes. All had sex by type 1 diabetes interactions with greater deficits in insulin sensitivity in women. While there was no sex by diabetes interaction in regards to glucose rate of appearance (Ra), those with type 1 diabetes had a higher glucose Ra than those without diabetes.

CONCLUSIONS

We found that type 1 diabetes affected adipose and skeletal muscle insulin sensitivity to a greater extent in women than in men, perhaps contributing to the greater relative increase in cardiovascular risk in women with type 1 diabetes.

Oestradiol levels may differ between premenopausal women, ages 18-50, with type 1 diabetes and matched controls

BACKGROUND

This study aimed to investigate whether oestradiol differs between premenopausal women with and without type 1 diabetes and whether levels are associated with such factors as age, reproductive history or diabetes management.

METHODS

Oestradiol in premenopausal women with type 1 diabetes (n = 89; age = 18-50 years; duration = 13-18 years) and age-matched/race-matched controls without diabetes (n = 76) was collected during a cross-sectional ancillary study of the Wisconsin Diabetes Registry Study, a population-based incident cohort. Total and bioavailable oestradiol and sex hormone-binding globulin were compared using multivariable regression (e.g. adjusting for reproductive history).

RESULTS

Adjusted mean total and bioavailable oestradiol did not differ overall by diabetes status (p ≥ 0.74), while adjusted mean sex hormone-binding globulin was higher in type 1 diabetes women (p = 0.02). However, only in women with type 1 diabetes and not controls (interaction p = 0.0005) was total oestradiol positively associated with the duration of reproductive years with unsuppressed ovarian function (UnsuppOvFx = years since menarche minus years on hormonal contraceptives/pregnant/breastfeeding). When stratified into less than/equal to or greater than the median 9 years' duration of UnsuppOvFx, compared with controls, women with type 1 diabetes had significantly lower total oestradiol in the ≤9 years group [β = -43.2 pg mL^-1 (-158.6 pmol L^-1 ), p = 0.04] and significantly higher total oestradiol in the >9 years group [β = 53.9 pg mL^-1 (197.9 pmol L^-1 ), p = 0.04]. Results remained consistent during additional statistical adjustments and sensitivity analyses.

CONCLUSIONS

Compared with controls, women with type 1 diabetes may have lower oestradiol when they have a shorter duration of UnsuppOvFx and higher oestradiol when they have a longer duration of UnsuppOvFx. Given the potential effects of insulin on ovarian function, oestradiol production may vary across the lifespan for women with type 1 diabetes. Copyright © 2016 John Wiley & Sons, Ltd.

Metformin for the treatment of hyperandrogenism in adolescents with type 1 diabetes mellitus

BACKGROUND

A high prevalence of hyperandrogenism has been reported in women with type 1 diabetes (T1D). Metformin has been used as a therapeutic agent in patients with polycystic ovarian syndrome and in T1D patients without hyperandrogenism. This study sought to determine the effect of metformin on hyperandrogenism and ovarian function in adolescents with T1D.

METHODS

We recruited 24 girls with T1D. The participants had hyperandrogenism and displayed suboptimal metabolic control. The patients were enrolled in a randomized, double-blind, placebo-controlled trial. One group received metformin (850 mg bid) and the other group received a placebo. Treatment was administered for 9 months. Ovulation, steroids and gonadotropin levels were evaluated.

RESULTS

Metformin treatment was associated with decreases in testosterone, free androgen index, androstenedione, 17-OH progesterone and estradiol levels. The girls who were treated with placebo showed stable steroid, gonadotropin and sex hormone-binding globulin levels during the analysis. No differences were observed in the Ferriman-Gallwey scores, ovulation rates, HbA1c levels or daily insulin doses of the girls treated with metformin compared with the placebo group.

CONCLUSION

Treating hyperandrogenic T1D adolescents with metformin significantly decreased the serum androgens compared to the placebo, but metformin therapy did not significantly affect clinical parameters, such as hirsutism, ovulation and metabolic control.

[Falsely elevated testosterone in a type 1 diabetes patients with acne and chronic renal failure on dialysis]

The purpose of this report is to present the case of a patient with type 1 diabetes with acne and chronic renal failure on dialysis admitted to the hospital with high total total and free testosterone (612 ng/dL, normal < 90 ng/dL; 255 pMol/L, normal: 20-45 pMol/L). On clinical evaluation, she presented facial acne, and no other signs of hyperandrogenism. As this result was confirmed, she underwent adrenal and ovary morphological assessment (adrenal CT and pelvic ultrasound), which yielded normal results. Due to divergence between clinical and laboratory findings, we considered other possibilities that could explain the elevation of testosterone, including the presence of comorbidities (diabetes and chronic renal failure) and failure of the testosterone assay. Testosterone levels were determined again by high performance liquid chromatography, as a preparative method, and tandem mass spectrometry, yielding normal results (21 ng/dL), which were compatible with a falsely elevated total testosterone level caused by the presence of factors that intereferred with the assay.

Female reproduction and type 1 diabetes: from mechanisms to clinical findings

BACKGROUND

The functional reproductive alterations seen in women with type 1 diabetes (T1D) have changed as therapy has improved. Historically, patients with T1D and insufficient metabolic control exhibited a high prevalence of amenorrhea, hypogonadism and infertility. This paper reviews the impact of diabetes on the reproductive axis of female T1D patients treated with modern insulin therapy, with special attention to the mechanisms by which diabetes disrupts hypothalamic-pituitary-ovarian function, as documented mainly by animal model studies.

METHODS

A comprehensive MEDLINE search of articles published from 1966 to 2012 was performed. Animal model studies on experimental diabetes and human studies on T1D were examined and cross-referenced with terms that referred to different aspects of the gonadotropic axis, gonadotrophins and gonadal steroids.

RESULTS

Recent studies have shown that women with T1D still display delayed puberty and menarche, menstrual irregularities (especially oligomenorrhoea), mild hyperandrogenism, polycystic ovarian syndrome, fewer live born children and possibly earlier menopause. Animal models have helped us to decipher the underlying basis of these conditions and have highlighted the variable contributions of defective leptin, insulin and kisspeptin signalling to the mechanisms of perturbed reproduction in T1D.

CONCLUSIONS

Despite improvements in insulin therapy, T1D patients still suffer many reproductive problems that warrant specific diagnoses and therapeutic management. Similar to other states of metabolic stress, T1D represents a challenge to the correct functioning of the reproductive axis.

Contraception, and pregnancy in adolescents with type 1 diabetes: a review

Adolescence is a critical period for girls with type 1 diabetes mellitus (T1D). Reproductive issues, such as menstrual abnormalities, risk of an unplanned pregnancy, and contraception, should be addressed during this phase of life. This paper reviews several reproductive issues that are important in the care of adolescents, including pubertal development, menstrual abnormalities, ovulatory function, reproductive problems, the effects of hyperglycemia, contraception, and treatment of an unplanned pregnancy. A review of the literature was conducted. A MEDLINE search January 1966 to March 2011 was performed using the following MESH terms: puberty, menarche, ovary, polycystic ovary syndrome, menstruation, contraception, contraception-barrier, contraceptives-oral-hormonal, sex education, family planning services, and pregnancy in adolescence. This literature search was cross-referenced with an additional search on diabetes mellitus-type 1, diabetes complications, and pregnancy in diabetes. All published studies were searched regardless of the language of origin. Bibliographies were reviewed to extract additional relevant sources.

Reproductive history and hormonal birth control use are associated with coronary calcium progression in women with type 1 diabetes mellitus

CONTEXT

Coronary artery disease is increased in women with type 1 diabetes (T1D), compared with nondiabetic (Non-DM) women. Women with T1D have more menstrual dysfunction and are less likely to use hormonal birth control (BC) than Non-DM women.

OBJECTIVE

The purpose of this study was to determine whether coronary artery calcium (CAC) is associated with menstrual dysfunction and BC use in women with T1D.

MATERIALS AND METHODS

This was a prospective cohort study, and participants were followed up for an average of 2.4 yr.

PATIENTS

Patients included 612 women (293 T1D, 319 Non-DM) between the ages of 19 and 55 yr who had CAC measured twice by electron beam tomography.

RESULTS

Irregular menses and amenorrhea were more common in T1D than Non-DM women (22.1 vs. 14.9%, P < 0.05 and 16.6 vs. 7.0%, P < 0.001). T1D women reported less BC use than Non-DM women (79.8 vs. 89.9%, P < 0.001) and reached menarche at an older age (13.1 +/- 1.8 vs. 12.8 +/- 1.5 yr, P < 0.05). Use of BC was associated with less CAC progression in all women, but this association was stronger in T1D women (P value for interaction = 0.02). Irregular menses were associated with greater CAC progression only among T1D women.

CONCLUSIONS

A prior history of BC use is associated with reduced CAC progression among all women, with a stronger association in T1D than in Non-DM women. Women with T1D who report irregular menses have increased CAC progression, compared with those with regular menses.

Clinical review: Hyperandrogenism and polycystic ovary syndrome in women with type 1 diabetes mellitus

CONTEXT

At present, women with type 1 diabetes (DM1) are being treated with supraphysiological doses of exogenous insulin with the aim of providing a strict metabolic control, thereby avoiding the long-term complications of this disease. We hypothesized that PCOS would be especially prevalent in DM1, as might happen in any condition in which the ovary and the adrenals are exposed to excessive insulin concentrations. As will be seen in the present review, androgen excess and PCOS are very frequent complaints in women with DM1, yet nowadays hyperandrogenism is seldom diagnosed in these patients.

EVIDENCE ACQUISITION

We conducted a systematic review of all the published studies addressing hyperandrogenic symptoms in women with DM1, identified through the Entrez-PubMed search engine, followed by a comprehensive review of the pathophysiology and clinical and laboratory features of PCOS in women with DM1.

EVIDENCE SYNTHESIS

The prevalence of PCOS in adult women with DM1 is 12-18, 40, and 31% using National Institute for Child Health and Human Development, Rotterdam, and Androgen Excess Society criteria, respectively. Mild hirsutism and biochemical hyperandrogenism are present in 30 and 20% of the patients, respectively. In addition, menstrual abnormalities are observed in 20% of adult women with DM1, and a prevalence of 50% of polycystic ovarian morphology is reported.

CONCLUSIONS

Physicians treating women with DM1 should be aware of the risk of hyperandrogenism in them and should include evaluation of hirsutism, menstrual abnormalities, and biochemical hyperandrogenism in their routine examinations. Future studies are needed to determine the best preventive and therapeutic options for the hyperandrogenism of these patients.

The association of increased total glycosylated hemoglobin levels with delayed age at menarche in young women with type 1 diabetes

CONTEXT

Delayed menarche is associated with subsequent reproductive and skeletal complications. Previous research has found delayed growth and pubertal maturation with type 1 diabetes and poor glycemic control. The effect of diabetes management on menarche is important to clarify, because tighter control might prevent these complications.

OBJECTIVE

The objective of this study was to investigate age at menarche in young women with type 1 diabetes and examine the effect of diabetes management [e.g. total glycosylated hemoglobin (GHb) level, number of blood glucose checks, insulin therapy intensity, and insulin dose] on age at menarche in those diagnosed before menarche.

DESIGN

The Wisconsin Diabetes Registry Project is a follow-up study of a type 1 diabetes population-based incident cohort initially enrolled between 1987 and 1992.

SETTING

This study was performed in 28 counties in south-central Wisconsin.

PATIENTS OR OTHER PARTICIPANTS

The study participants were recruited through referrals, self-report, and hospital/clinic ascertainment. Individuals with newly diagnosed type 1 diabetes, less than 30 yr old, were invited to participate. Of 288 young women enrolled, 188 reported menarche by 2002; 105 were diagnosed before menarche.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURE

The main outcome measure was age at menarche.

RESULTS

Mean age at menarche was 12.78 yr, compared with 12.54 yr in the United States (P = 0.01). Ages at menarche and diagnosis were not associated. For those diagnosed before menarche, age at menarche was delayed 1.3 months with each 1% increase in mean total GHb level in the 3 yr before menarche.

CONCLUSIONS

Age at menarche was moderately delayed in young women with type 1 diabetes. Delayed menarche could potentially be minimized with improved GHb levels.

The hypothalamus–pituitary–ovary axis and type 1 diabetes mellitus: a mini review

A high prevalence of menstrual cycle and fertility disturbances has long been associated with diabetes mellitus. However, rationalization of the intrinsic mechanisms of these alterations is controversial and even contradictory. This review considers (i) the relationship between diabetes mellitus, especially type 1 diabetes mellitus (T1DM), and the hypothalamus-pituitary-ovary (HPO) axis, (ii) the state of our knowledge concerning neuroendocrine control and its relationship with dopaminergic and opioid tonus, and (iii) the influence of the hypothalamus-pituitary-adrenal axis on ovarian function. Functional disturbances that occur as a consequence of diabetes are also discussed, but some T1DM-related diseases of autoimmune origin, such as oophoritis, are not further analysed. Although there are clear indications of a relationship between menstrual and fertility alterations and glycaemic control, in many instances the improvement of the latter is not sufficient to reverse such alterations. It appears that the oligoamenorrhoea and amenorrhoea associated with T1DM is mainly of hypothalamic origin (i.e. failure of the GnRH pulse generator) and may be reversible. The importance of the evaluation of the HPO axis in T1DM women with menstrual irregularities, even in the presence of adequate metabolic control, is emphasized.

Cancer incidence and mortality in patients with insulin-treated diabetes: a UK cohort study

Raised risks of several cancers have been found in patients with type II diabetes, but there are few data on cancer risk in type I diabetes. We conducted a cohort study of 28 900 UK patients with insulin-treated diabetes followed for 520 517 person-years, and compared their cancer incidence and mortality with national expectations. To analyse by diabetes type, we examined risks separately in 23 834 patients diagnosed with diabetes under the age of 30 years, who will almost all have had type I diabetes, and 5066 patients diagnosed at ages 30–49 years, who probably mainly had type II. Relative risks of cancer overall were close to unity, but ovarian cancer risk was highly significantly raised in patients with diabetes diagnosed under age 30 years (standardised incidence ratio (SIR)=2.14; 95% confidence interval (CI) 1.22–3.48; standardised mortality ratio (SMR)=2.90; 95% CI 1.45–5.19), with greatest risks for those with diabetes diagnosed at ages 10–19 years. Risks of cancer at other major sites were not substantially raised for type I patients. The excesses of obesity- and alcohol-related cancers in type II diabetes may be due to confounding rather than diabetes per se.

Upper abdominal obesity, insulin resistance and breast cancer risk

PURPOSE

A majority of prospective studies show breast cancer risk to be higher in obese postmenopausal women with upper abdominal adiposity than in those with overall adiposity. The evidence is more limited and inconsistent in the case of premenopausal women. The review examines evidence that aberrant insulin signalling may be involved in the promotion of mammary carcinogenesis. The aetiology and concomitants of abdominal visceral obesity are examined.

MECHANISMS

Clinical and experimental evidence suggests that the higher breast cancer risk associated with greater abdominal visceral obesity may be related to aberrant insulin signalling through the insulin receptor substrate 1 pathway, leading to insulin resistance, hyperinsulinaemia and increased concentrations of endogenous oestrogen and androgen. The putative role of aberrant insulin signalling in the promotion of mammary carcinogenesis may help to explain clinical relationships between breast cancer risk and age at menarche, pregnancies and onset of obesity.

CONCLUSION

Overall adiposity in women adversely affects breast cancer risk mainly by greater exposure of mammary epithelial tissue to endogenous oestrogen. Upper abdominal adiposity appears to involve an additional effect related to the presence of insulin resistance. Aetiological factors in the development of hyperinsulinaemic insulin resistance are still uncertain but may involve aberrant susceptibility genes in adipocyte insulin receptors or in the insulin receptor substrate 1 pathway. Epigenetic factors are also likely to contribute, including high free fatty acid levels and obesity. Dietary fatty acids, particularly polyunsaturated fatty acids, are known to regulate adipocyte differentiation through the nuclear peroxisome proliferator-activated receptor gamma, and may also have a role in insulin resistance. These aetiological factors are likely to be relevant to the high risk of postmenopausal breast cancer in industrialised Western populations.

Serum androgen levels in adolescents with type 1 diabetes: relationship to pubertal stage and metabolic control

Delayed sexual maturation is still frequently seen in adolescents with type 1 diabetes. A close relationship between insulin and androgen metabolism has been found in a number of studies. Our study was designed to investigate whether or not abnormalities in androgen secretion could play a role in the onset of sexual maturation in adolescents with type 1 diabetes. We have asked whether or not there was a correlation between daily insulin dosage, duration of diabetes, metabolic control, age, pubertal stage, and body mass index (BMI) versus serum androgen concentrations. Basal total and free testosterone, dehydroepiandrosterone-sulfate (DHEA-S), dihydrotestosterone (DHT), sex hormone binding globulin (SHBG) and 3alpha-androstanediol glucuronide (3alpha diol-G) plasma concentrations were measured in 36 pubertal boys and 31 pubertal girls with type 1 diabetes and in 59 sex- and pubertal stage-matched control subjects without diabetes. Significantly higher serum total testosterone (p<0.01) and free testosterone (p<0.05) levels were found in females and males with type 1 diabetes than in controls at pubertal stage 5. DHEA-S, SHBG, DHT and 3alpha diol G concentrations in patients with diabetes were not significantly different from those in controls. There was no correlation between daily insulin requirements and serum androgen levels. These data suggest that adolescents with diabetes have similar serum levels of DHEA-S, SHBG, DHT and 3alpha diol G as healthy subjects at all stages of puberty. However, there are significant differences in serum testosterone and free testosterone levels in adolescents with diabetes when compared to healthy, sex- and pubertal stage-matched controls in late puberty. We hypothesize that the increased testosterone levels in patients with diabetes could relate to reduced fertility in females, disorders of sexual maturation and an increased risk for cardiovascular complications later in life.

Influence of residual insulin secretion and duration of diabetes mellitus on the control of luteinizing hormone secretion in women

BACKGROUND

The aim of the present study was to establish whether the persistence of residual beta-cell activity after long-term diabetes mellitus (DM) exerts a protective role on luteinizing hormone (LH) secretion.

METHODS

The LH responses to stimulation with gonadotropin-releasing hormone (Gn-RH) (100 microg in an i.v. bolus) or naloxone (4 mg injected in an i.v. bolus, followed by the constant infusion of 8 mg in 2 h) were measured in C-peptide-positive (CpP) and C-peptide-negative (CpN) normally menstruating women with short-term (group 1 < 3 years, CpP n = 11, CpN n = 11) or long-term (group 2 > 10 years, CpP n = 11, CpN n = 11) DM and in age-matched normal control subjects (n = 11).

RESULTS

Gn-RH induced significant increments in LH secretion in all groups. Significant LH responses to naloxone were observed in all groups, except in group 2 CpN patients. However, the LH response to either Gn-RH or naloxone was significantly lower in group 1 CpN, group 2 CpP and group 2 CpN patients than in the normal control subjects. Furthermore, the LH response was significantly lower in group 2 CpP than in group 1 CpP patients and in group 2 CpN than in group 1 CpN subjects.

CONCLUSIONS

These results indicate a role for both deficiency in residual endogenous insulin secretion and duration of diabetes in the derangement of LH secretory control. The data suggest that the protective role exerted by residual beta-cell activity on LH secretion during the early years of DM diminishes with time elapsed after the onset of diabetes mellitus.

Nutrition, hormones, and breast cancer: is insulin the missing link?

Breast cancer incidence rates are high in societies with a Western lifestyle characterized by low levels of physical activity, and by an energy-dense diet rich in total and saturated fat and refined carbohydrates. Epidemiologic studies, so far mostly on postmenopausal women, have shown that breast cancer risk is increased in hyperandrogenic women, with decreased levels of plasma sex-hormone binding globulin, and with increased levels of testosterone and of free estrogens. This paper describes the role of hyperinsulinemia as a physiologic link between nutritional lifestyle factors, obesity, and the development of a hyperandrogenic endocrine profile, and reviews evidence that may or may not support the theory that chronic hyperinsulinemia is an underlying cause of breast cancer. An hypothesis is presented, stipulating that breast cancer risk is increased not only in hyperandrogenic postmenopausal women, but also in premenopausal women with mild hyperandrogenism and normal (ovulatory) menstrual cycles. The author suggests further investigation as to whether there is a positive association between risk of breast cancer before menopause and subclinical forms of the polycystic ovary syndrome (PCOS), and to what extent diet and physical activity during childhood, by modulating the degree of insulin resistance during adolescence, may or may not be determinants of a PCO-like hyperandrogenic endocrine profile persisting into adulthood.

Insulin-dependent diabetes mellitus and menstrual dysfunction

Disordered reproductive function has long been recognized as a prevalent problem among women of reproductive age who suffer from insulin-dependent diabetes mellitus (IDDM). Delay in menarchial age is frequently seen if IDDM develops in the peripubertal years and some form of menstrual dysfunction is found in nearly one-third of all women of reproductive age with IDDM. This review summarizes some of the prevailing views regarding the mechanisms through which uncontrolled IDDM is thought to disrupt normal hypothalamic-pituitary-gonadal function. Although animal studies have suggested that poorly controlled IDDM may adversely affect the uterovaginal outflow tract and/or ovarian function, no clinical studies have suggested that abnormal uterine or ovarian function underlies the menstrual dysfunction observed in young diabetic women. Similarly, pituitary function as assessed by basal gonadotrophins and gonadotrophin-releasing hormone (GnRH)-stimulated gonadotrophin release appears to be normal in young women with IDDM. Moreover, although there has been some suggestion that pituitary function may decline with increasing duration of diabetes, this issue has not been thoroughly investigated. It appears that the oligo/amenorrhea noted in IDDM is principally hypothalamic in origin and may represent intermittent (and perhaps reversible) failure of the GnRH pulse generator, similar to the situation observed in women who engage in endurance training or who suffer from anorexia nervosa. Although the exact pathophysiological mechanisms that subserve dysfunction of the GnRH neuronal system are not well understood, attention has focused on increased central opioidergic activity, increased central dopaminergic activity, and central glucose deprivation. In this era of emphasis on tight glycaemic control and its impact in preventing diabetes complications, the consequences of IDDM on reproductive potential appear to be important and must be included in future investigative efforts.

Menstrual irregularities are more common in adolescents with type 1 diabetes: association with poor glycaemic control and weight gain

Ovarian function in post-menarchal girls with Type 1 diabetes was evaluated. Menstrual histories from 24 adolescents with Type 1 diabetes were compared with those from 24 age and sex matched controls. A fasting blood sample was obtained from subjects with Type 1 diabetes for the measurement of ovarian and adrenal sex hormones, LH and FSH, glucose and insulin, insulin-like growth factor-I (IGF-I), and insulin-like growth factor binding protein-1 (IGFBP-1); and an ovarian ultrasound scan was performed. Menstrual irregularity was more prevalent in patients with Type 1 diabetes than controls (54% vs 21%, p < 0.01) and their mean body mass index (BMI) was greater (22.3 +/- 0.5 (+/- SEM) vs 20.7 +/- 0.6 kg m-2, p < 0.05). Subjects with Type 1 diabetes with irregular menses (when compared with diabetic subjects with a regular cycle) had a significantly higher HbA1 (12.8 +/- 0.4 vs 10.5 +/- 0.5%, p < 0.01) and BMI (23.2 +/- 0.6 vs 21.4 +/- 0.6 kg m-2, p < 0.05) associated with a lower sex hormone binding globulin (SHBG) (37.2 +/- 4.0 vs 52.6 +/- 4.0 nmol l-1, p < 0.025) and IGF-I (1.4 +/- 0.2 vs 2.2 +/- 0.2 mUI-1, p < 0.025) and a higher LH:FSH ratio (2.6 +/- 0.5 vs 1.4 +/- 0.2, p < 0.05). Polycystic ovarian changes were identified in 10/13 (77%) of these patients with an irregular cycle. Menstrual irregularity is common in post-menarchal girls with Type 1 diabetes and is associated with poor glycaemic control and weight gain. The apparent high incidence of polycystic ovarian change requires further investigation.

Is there an altered steroid profile in patients with endometrial carcinoma?

BACKGROUND

Besides the well-known association between endometrial carcinoma (EC) and unopposed estrogen, androgens also may play a role in this respect; however, previous studies on endogenous estrogens and androgens in patients with EC and control subjects have yielded mostly divergent results, probably because of the use of poorly defined control groups.

METHODS

Circulating steroid and pituitary hormones and sex hormone-binding globulin were measured in patients with EC and matched control groups of either patients with nonmalignant postmenopausal bleeding (hospital control subjects) and healthy, symptom-free women (nonhospital control subjects).

RESULTS

Patients with EC had higher serum levels of adrenal C21 and C19 steroids, estrogens, and biologically active testosterone than nonhospital control subjects, whereas the hospital control subjects constituted an intermediate group in this respect.

CONCLUSIONS

The results clearly indicate an altered steroid homeostasis, probably reflecting an increased "adrenal drive" in patients with EC. The results also stress the necessity of using strictly defined, healthy, symptom-free control subjects instead of the frequently used hospital control subjects when studying more subtile endocrine aberrations.

Menopausal age and sex hormones in postmenopausal women with alcoholic and non-alcoholic liver disease

In order to evaluate age at menopause and serum sex hormone profiles in postmenopausal women with stable chronic liver disease, six non-cirrhotic alcoholics, 13 with alcoholic cirrhosis, eight with non-alcoholic cirrhosis, and 46 healthy controls were studied. In all three groups, patients were significantly (p less than 0.05) younger at the time of natural menopause than controls. Compared to controls, non-cirrhotic alcoholic women had significantly (p less than 0.05) reduced levels of DHAS, significantly (p less than 0.05) more alcoholic cirrhotic women had detectable oestradiol concentrations, elevated concentrations of oestrone and sex hormone binding globulin (SHBG) and reduced levels of 5 alpha-dihydrotestosterone (DHT), while women with non-alcoholic cirrhosis had significantly elevated concentrations of SHBG and reduced levels of oestrone sulphate, DHT, androstenedione and dehydroepiandrosterone sulphate (DHAS) (p less than 0.05). The observed changes may be a consequence of liver disease since similar changes were observed in patients with alcoholic and non-alcoholic liver disease, but an additional effect of alcohol cannot be excluded.

Subnormal follicular-phase serum progesterone levels and elevated follicular-phase serum estradiol levels in young women with insulin-dependent diabetes

In a search for possible hormonal reasons for the loss of protection from myocardial infarction seen in diabetic women, serum levels of estradiol, progesterone, and luteinizing hormone were compared throughout a menstrual cycle (17 points) in eight healthy nonsmoking women and five otherwise healthy nonsmoking insulin-dependent diabetic women. The total length of the menstrual cycle and the lengths of the follicular and luteal phases did not differ between the groups. During the periovulatory and luteal phases, there was no significant intergroup difference with respect to any of the three hormones. During the follicular phase, in both groups, there was a plateau in serum progesterone concentration, with the level approximately 42% lower in the diabetic group (12.0 +/- 6.6 ng/dl versus 20.7 +/- 5.7; P less than 0.0001). Follicular-phase serum estradiol showed a rising curve in both groups; day-by-day comparison (days -10 to -3 before the luteinizing hormone peak) showed consistently higher levels in the diabetic group (mean, 108 pg/ml versus 95 pg/ml; P less than 0.001). The follicular-phase serum estradiol to progesterone ratio was nearly twice as high in the diabetic group as in the normal group (8.9 versus 4.6), a difference that was highly significant. The finding of elevated serum estradiol and subnormal serum progesterone concentrations during the follicular phase is so far unique to women with insulin-dependent diabetes mellitus. The possibility that this pronounced abnormality in diabetic women may be related to coronary disease merits testing in suitable in vivo and in vitro models of atherogenesis.

The effect of smoking on serum progesterone, estradiol, and luteinizing hormone levels over a menstrual cycle in normal women

Since smoking has been shown to affect serum progesterone and estradiol levels in postmenopausal women, we evaluated the levels of these hormones and luteinizing hormone (LH) over an entire menstrual cycle (17 points) in eight healthy nonsmokers and eight healthy smokers. The total length of the cycle and the lengths of the follicular and luteal phases did not differ between the groups. There was no difference in estradiol, progesterone, or LH levels during the periovulatory and luteal phases. Follicular-phase serum progesterone, which had a level 37% higher in smokers, showed a plateau in both groups (28.3 +/- 5.7 ng/dl versus 20.7 +/- 5.7; P less than 0.0001). Follicular-phase serum estradiol showed a rising curve in both groups. The mean value in smokers was slightly higher than that in nonsmokers (107 pg/ml versus 95; P approximately 0.05); during the early part of the follicular phase, prior to the rapid preovulatory increase, the difference was greater (23%) and of higher statistical significance (80 pg/ml versus 65; P less than 0.001). The follicular-phase LH levels of smokers were skewed downward from the levels in nonsmokers, presumably by negative feedback from the elevated estradiol and progesterone levels; the difference was significant (P less than 0.001). The elevations of serum progesterone and estradiol in smokers probably represent activation of adrenocortical secretion by smoking. The greater and more clear-cut rise of progesterone than of estradiol is probably due to the fact that essentially all of the follicular-phase serum progesterone is secreted by the adrenal, while only part of the follicular-phase serum estradiol comes from the adrenal (via androstenedione and estrone).

The effect of residual beta cell activity on menstruation and the reproductive hormone profile of insulin-dependent diabetics

To investigate the cause of secondary amenorrhoea in insulin-dependent diabetes gonadotrophins, sex steroid hormone levels and residual beta cell activity (C-peptide index) were estimated in a group of 43 women with IDDM. Among 26 women with residual insulin secretion, the C-peptide positive (CpP) group, 5 had secondary amenorrhoea (CpP-Am); among 17 women without endogenous beta cell activity, the C-peptide negative (CpN) group 6 had secondary amenorrhoea (CpN-Am). In this study two different types of secondary amenorrhoea in insulin-dependent diabetics were observed. All CpP-Am women have the classical hormone profile of the polycystic ovary syndrome (increased (LH/FSH ratio, increased serum testosterone, decreased SHBG) together with a history of oligomenorrhoea and excess weight before the onset of diabetes. On the other hand, all CpN-Am women had decreased LH levels as well as low LH/FSH ratio and testosterone levels. These results strongly suggest that a lack of residual pancreatic beta cell activity influences hypothalamus-pituitary function in insulin-dependent diabetes. It might be concluded that PCOS is independent of diabetes while low LH amenorrhoea seems to be the consequence of diabetes and is strongly associated with a lack of residual insulin secretion.

Effect of fenoldopam, a dopamine D-1 receptor agonist, on pituitary, gonadal and thyroid hormone secretion

The influence of fenoldopam, a dopamine (DA) D-1 receptor agonist, on basal and GnRH/TRH stimulated PRL, GH, LH, TSH, testosterone and thyroid hormone secretion was studied in nine normal men. All men received 4-h infusions of either 0.9% saline or fenoldopam at an infusion rate of 0.5 microgram/kg min, 12-16 ml/h, adjusted according to weight. After 3 h of infusion, 50 micrograms GnRH and 100 micrograms TRH was given i.v. Blood samples were collected every 15 min from 1 h before to 1 h after the infusion for a total of 6 h for measurements of PRL, LH, FSH, GH, TSH, testosterone, T4 and T3. The median PRL concentration increased significantly (P less than 0.01) to 128%, range 87-287, of preinfusion levels, compared to the decline during control infusion (85%, 78-114). Basal TSH levels declined significantly to 71% (60-91) during fenoldopam compared with 82% (65-115) during control infusion (P less than 0.05). Basal LH, FSH, GH and thyroid hormones were similar during fenoldopam and control infusions (P greater than 0.05). The LH response to GnRH/TRH was significantly (P less than 0.02) increased by fenoldopam infusion. Basal and stimulated testosterone concentration was lower during fenoldopam (P less than 0.01) infusion compared with control. Other hormones were similar after GnRH/TRH stimulation during fenoldopam and saline infusions. These results suggest that DA D-1 receptors are involved in the modulation of pituitary hormone secretion. We suggest that the effect of fenoldopam on PRL and TSH is mainly at the hypothalamic level. Regarding the effect on LH concentrations, an additional direct effect of fenoldopam on testosterone regulation can not be excluded.

Effect of alcohol and glucose infusion on pituitary-gonadal hormones in normal females

During 1 h, median 976 mmol ethanol in 5.5% glucose was administered i.v. to six healthy female volunteers (aged 26-37 years) in the luteal phase of the menstrual cycle. The median maximal blood ethanol concentration was median 33.5 mmol/l and serum ethanol concentrations of 2 mmol/l were reached after 8 h. Four of the women participated in a control experiment with infusion of an equal volume of glucose 5.5%. Venous blood samples were drawn 5 times during the 24-h follow up period. Serum concentrations of sex steroids and pituitary hormones decreased in both ethanol and control experiments and the results did not differ significantly. The lowest hormone concentrations were observed 1-5 h after the start of infusion. Oestradiol, oestrone and oestrone-sulphate concentrations decreased 24-46% compared to basal values. 5 alpha-dihydro-testosterone levels decreased 23-31%, androstenedione and dehydroepiandrosterone-sulphate levels decreased 6-48%, while testosterone levels did not change significantly. Prolactin concentrations were reduced by 41-51% of basal values and luteinizing hormone concentrations by 37-68% Follicle stimulating hormone levels did not change significantly. Stress factors or haemodilution are not likely explanations of the observed changes in hormone concentrations. A circadian rhythm could not explain changes in hormones of non-adrenal origin.

Plasma sex hormones and ischemic heart disease

The reason why men have a higher incidence of ischemic heart disease than women, and women rarely develop ischemic heart disease before the menopause, is not known. However, elevated plasma estradiol and estrone concentrations have been found in men surviving myocardial infarction. Hence, hyperestrogenemia has been suggested as a coronary risk factor. To assess this theory we review the literature on sex steroid production, the relationship between established coronary risk factors and plasma sex hormones, as well as results from clinical trials in which estrogens have been administered to men and women. Other possible explanations why plasma estradiol levels are elevated in male survivors of myocardial infarction are discussed. Based on earlier and recent evidence, it is hypothesized that the elevated plasma estradiol concentration found in men surviving myocardial infarction is due to either the myocardial infarction itself or established risk factors such as smoking or hypertension.