Design, methods and demographics from phase I of Alberta's Tomorrow Project cohort: a prospective cohort profile.

Background: Prospective cohorts have the potential to support multifactorial, health-related research, particularly if they are drawn from the general population, incorporate active and passive follow-up and permission is obtained to allow access by researchers to data repositories. This paper describes Phase I of the Alberta's Tomorrow Project cohort, a broad-based research platform designed to support investigations into factors that influence cancer and chronic disease risk.

Methods: Adults aged 35-69 years living in Alberta, Canada, with no previous cancer diagnosis other than nonmelanoma skin cancer were recruited to the project by telephone-based random digit dialling.

Free estradiol and sex hormone-binding globulin.

SHBG is a plasma protein that participates in the regulation of free estradiol and free testosterone in plasma. We discuss the concept of the nature of a free estradiol and how best to ascertain its value. It can be measured or calculated; the ways in which this can be done are explored along with the advantages and disadvantages of each.

Androgen therapy in women: a reappraisal: an Endocrine Society clinical practice guideline.

Objective: To update practice guidelines for the therapeutic use of androgens in women.

Participants: A Task Force appointed by the Endocrine Society, American Congress of Obestricians and Gynecologists (ACOG), American Society for Reproductive Medicine (ASRM), European Society of Endocrinology (ESE), and International Menopause Society (IMS) consisting of six experts, a methodologist, and a medical writer.

Evidence: The Task Force commissioned two systematic reviews of published data and considered several other existing meta-analyses and trials.

Challenges to the measurement of estradiol: an endocrine society position statement.

Objective: The objective of the study was to evaluate the current state of clinical assays for estradiol in the context of their applications.

Participants: The participants were appointed by the Council of The Endocrine Society and charged with attaining the objective using published data and expert opinion.

Evidence: Data were gathered from published sources via online databases (principally PubMed, Ovid MEDLINE, Google Scholar), and the clinical and laboratory experience of the participants.

Toward excellence in testosterone testing: a consensus statement.

Background: Testosterone assays are widely used. However, deficiencies in these assays limit their broad and effective implementation and threaten the health of those patients whose medical care relies upon its accurate measurement. Furthermore, the translation of research findings into information useful for patient care, such as new evidence-based clinical guidelines, is not possible unless both research and clinical assays are held to higher standards than are currently required.

Endocrine aspects of women's sexual function.

Introduction: Endocrine changes during aging as well as endocrine disorders may either directly or indirectly modulate female sexual function by altering sex hormones, or by impacting on vascular, neurogenic, or psychologic factors.

Aim: To review information on the impact of the hormonal changes associated with aging or those caused by endocrine disorders on female sexual function and current information on the risks and benefits of hormonal treatments.

Methods: Committee members outlined topics and reviewed the published literature on endocrine aspects of female sexual function over a 2-year period.

Interactions of sex hormone-binding globulin with target cells.

Sex hormone-binding globulin (SHBG) was initially described as a plasma protein synthesized in, and secreted by, the liver. It was discovered by its ability to bind certain androgens and estrogens and, for many years, was believed to serve as a transporter/reservoir for the steroids which it bound. Subsequently, it became clear that the cell membranes of selected tissues contained a receptor for SHBG (R(SHBG)).

Human sex hormone-binding globulin gene expression- multiple promoters and complex alternative splicing.

Background: Human sex hormone-binding globulin (SHBG) regulates free sex steroid concentrations in plasma and modulates rapid, membrane based steroid signaling. SHBG is encoded by an eight exon-long transcript whose expression is regulated by a downstream promoter (P(L)). The SHBG gene was previously shown to express a second major transcript of unknown function, derived from an upstream promoter (P(T)), and two minor transcripts.

Sex hormone-binding globulin influences gene expression of LNCaP and MCF-7 cells in response to androgen and estrogen treatment.

Sex hormone-binding globulin (SHBG), a plasma protein that binds androgens and estrogens, also participates in the initial steps of a membrane-based steroid signaling pathway in human prostate and breast. We have recently shown that SHBG is expressed at the mRNA and protein levels in the prostate and breast. In this study, we addressed whether locally expressed SHBG: (1) Functions to regulate activation of membrane-based steroid signaling and (2) influences activation of the androgen (AR) and estrogen (ER) receptors.

Position statement: Utility, limitations, and pitfalls in measuring testosterone: an Endocrine Society position statement.

Objective: The objective of the study was to evaluate the current state of clinical assays for total and free testosterone.

Participants: The five participants were appointed by the Council of The Endocrine Society and charged with attaining the objective using published data and expert opinion.

Evidence: Data were gleaned from published sources via online databases (principally PubMed, Ovid MEDLINE, Google Scholar), the College of American Pathologists, and the clinical and laboratory experiences of the participants.

Androgen therapy in women: an Endocrine Society Clinical Practice guideline.

Objective: The objective was to provide guidelines for the therapeutic use of androgens in women.

Participants: The Task Force was composed of a chair, selected by the Clinical Guidelines Subcommittee (CGS) of The Endocrine Society, six additional experts, a methodologist, and a medical writer. The Task Force received no corporate funding or remuneration.

Measurement of free testosterone in normal women and women with androgen deficiency: comparison of methods.

Androgen deficiency in women is increasingly recognized as a new clinical syndrome and has raised our awareness of the importance of accurate and well-validated measurements of serum free testosterone (T) concentrations in women. Therefore, we compared serum free T levels measured by equilibrium dialysis to those measured by a direct RIA (analog method) and to those calculated from the law of mass action (requires the measurement of total T and SHBG). We also calculated the free androgen index, 100 x T/SHBG, as a simple index known to correlate with free T.

Sex difference in the effect of obesity on 24-hour mean serum gonadotropin levels.

To determine the effect of obesity on serum gonadotropin levels and any possible sex difference in the effect, we measured the 24-hour mean serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) concentrations in 62 healthy men with Body Mass Index (BMI) ranging from 20 - 94 and 61 healthy, regularly cycling women with BMIs ranging from 19 - 76. We also measured free testosterone (T) and estradiol (E2) in these subjects. There was a significant negative correlation between serum FSH and BMI in men: FSH(IU/L) = 49.