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1 Introduction
Pages 11-31

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From page 11...
... and other largescale clinical trials, for example, have provided new insights into the benefits and risks of postmenopausal hormone therapy in women that are quite different from what had been assumed during decades of widespread use of estrogen-progestin therapy. Now, as large-scale clinical trials of testosterone therapy are being considered by the National Institutes of Health (NIH)
From page 12...
... The committee members included experts from many fields including bioethics, endocrinology, internal medicine, urology, oncology, epidemiology, biostatistics, clinical trials research, geriatrics, and behavioral science. The committee held four meetings over the course of the 12-month study and convened a public scientific workshop in Phoenix, Arizona, on March 31, 2003.
From page 13...
... Recent information, particularly the analysis of the results of the estrogen plus progestin component of the WHI randomized trial, has provided insights into the risks and benefits of hormone treatment. Although women taking orally administered estrogen plus progestin in this study experienced fewer hip and other fractures and were less likely to develop colorectal cancer, they were more likely to develop heart disease events, stroke, blood clots, and breast cancer (Rossouw et al., 2002~.
From page 14...
... levels, low testosterone levels, poor nutrition, use of certain medications, smoking, excessive alcohol intake, inactivity and lack of exercise, inadequate calcium intake, certain illnesses, and genetic predisposition. The multifactorial etiology of reduced bone mass puts into perspective the complexities involved in diagnosing, treating, and preventing age-related adverse clinical outcomes.
From page 15...
... and estradiol. Both testosterone and DHT bind to the androgen receptor, but DHT has a higher affinity for the receptor and is therefore a more potent androgen (Bagatell and Bremner, 1996; Bruchovsky and Wilson, 1999~.
From page 16...
... The fraction available to the tissues (also termed bioavailable testosterone) is believed to be the free plus the albumin-bound testosterone, consisting of approximately half of the total plasma testosterone (Griffin and Wilson,
From page 17...
... Late in gestation the levels drop, and, at birth, serum testosterone levels are only slightly higher in males than in females. After birth, plasma testosterone levels in male infants rise and are elevated for approximately the first three months, after which the testosterone levels decrease and remain only slightly higher in boys than in girls until the beginning of puberty (Griffin and Wilson, 2001~.
From page 18...
... Alternatively, bioavailable testosterone can be calculated using measures of total testosterone and immunoassayed SHBG concentrations. Measures of free testosterone are more controversial.
From page 19...
... (Handelsman, 1996~. The oral forms of alkylated androgen compounds available in the United States are generally not recommended for use as testosterone therapy because they may produce deleterious effects, including hepatotoxicity (hemorrhagic liver cysts, cholestasis, and hepatocellular adenoma)
From page 20...
... Selective androgen receptor modulators (SARMs) are a class of compounds that have been reported to have androgenic effects similar to testosterone on muscle mass, sexual function, and bone density in animal
From page 21...
... (Medline Plus, 2002~. In secondary hypogonadism testosterone levels are low, while the levels of FSH and LH remain in the low to low-normal range.
From page 22...
... total testosterone levels greater than 400 ng/dL: considered not to have testosterone deficiency. Many studies have used the 300 to 350 ng/dL range of total testosterone as a cutoff for identifying hypogonadal patients, although there is not a clearly defined standard, and other factors such as SHBG, LH, and FSH levels and the clinical presentation and physical findings are key in making a diagnosis of hypogonadism.
From page 23...
... These issues include the vagueness of the definition of hypogonadism/androgen deficiency in older men, the overlap with normal aging symptoms and health status, the wide range of normal levels in a given population, and the uncertainty as to which measure of testosterone should be used to diagnose hypogonadism in older men. However, the association of lower testosterone levels with lower muscle mass and other age-related conditions suggests that testosterone therapy might be beneficial in some older men.
From page 24...
... GROWING USE OF TESTOSTERONE THERAPY In recent years there has been growing concern about an increase in the use of testosterone by middle-aged and older men who have borderline testosterone levels or even normal testosterone levels in the absence of adequate scientific information about its risks and benefits. More than 1.75 million prescriptions for testosterone products were written in 2002,2 an estimated increase of 30 percent over the approximately 1.35 million prescriptions in 2001, and an increase of 170 percent from the 648,000 prescriptions in 1999 (Rose, 2003)
From page 25...
... Growth in the use of testosterone can also be seen in the data on the number of people purchasing testosterone products. According to data collected by IMS Consulting, there were more than 800,000 testosteronetreated patients (men and women)
From page 26...
... SOURCE: Rose, 2003. Reprinted with permission of IMS Consulting, a division of IMS Health, from a report to Solvay Pharmaceuticals.
From page 27...
... CLINICAL TRIALS As mentioned previously, the federal government and the private sector have sponsored and conducted long-term, large-scale trials of the relative risks and benefits of postmenopausal hormone therapy in women. In 1991, the National Heart, Lung, and Blood Institute and other units of the NIH launched the WHI, one of the largest studies of its kind ever undertaken in the United States.
From page 28...
... ORGANIZATION OF THE REPORT This report examines the state of current scientific knowledge regarding testosterone therapy in older men and assesses the types of clinical research needed to determine the benefits and risks of testosterone therapy in the aging male population. Chapter 2 provides an overview of the research that has been conducted on changes in endogenous testosterone levels with aging and on the associations of testosterone therapy with a range of health outcomes including bone mineral density, body composition, physical function, sexual function, cardiovascular outcomes, prostate outcomes, cognitive function, mood, depression, and quality of life.
From page 29...
... 2001. Longitudinal effects of aging on serum total and free testosterone levels in healthy men.
From page 30...
... 2002. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women's Health Initiative randomized controlled trial.
From page 31...
... 2003. Pharmacodynamics of selective androgen receptor modulators.


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