fenfluramine, the component of Fen-Phen thought to be the primary cause for these problems, be removed from the U.S. market. Phentermine remains approved for use. Injuries attributed to Fen-Phen have been part of thousands of product liability lawsuits.
* * * *
The WHIs and Wherefores of Estrogen Therapy
Certain diseases are caused by a person's body producing inadequate amounts of a hormone or other chemical needed for good health. “Hypothyroidism” occurs when the thyroid gland doesn't produce enough of two hormones—thyroxine and triiodothyronine— to meet a person's metabolic needs. Diabetes mellitus is associated with either an absolute deficiency of insulin (Type 1), or an at least relative deficiency of insulin and resistance to its effects (Type 2). Having too little of other hormones—growth hormone, parathyroid hormone, aldosterone, etc.—also causes well-described symptoms and diseases. Replacement of a hormone when its blood level is too low may improve or cure the disease caused by its lack.
However, levels of some hormones fall not because of a clearly pathological process, but as a “normal” part of aging. These include dehydroepiandrosterone (DHEA), a hormone produced by the adrenal glands, and growth hormone. Although further studies might change this assessment, so far research has not definitively shown that replacement of these hormones to “youthful” levels produces a clinically significant improvement in health.
In women, levels of the female sex hormone estrogen fall dramatically at menopause. The higher level of estrogen present in premenopausal women compared to men is associated with a significantly lower risk of these women developing coronary artery disease (CAD). Roughly speaking, the risk of a woman developing CAD prior to menopause is about the same as a man ten years younger with similar risk factors (e.g. high blood pressure, an abnormal blood cholesterol level, diabetes, or tobacco use). The drop in estrogen level that occurs with menopause is associated with a significant increase in the risk of a woman developing CAD.
The “logical” conclusion was that, if a woman's estrogen level were restored to what it was before menopause, her risk of developing CAD would fall. The possibility that giving estrogen replacement might have effects that reduce the risk of developing CAD seemed to support this idea. These potentially beneficial effects include lowering low-density lipoprotein (LDL) cholesterol, increasing high-density lipoprotein (HDL) cholesterol, and reducing blood sugar. Some known effects of giving estrogen, such as raising the blood level of triglycerides (another component of cholesterol) and increasing the risk of developing blood clots, were recognized as being potentially harmful. However, these bad effects were not thought to be as significant as estrogen's good effects.
Some small studies done in the early and mid-1990s did in fact suggest that estrogen replacement was, overall, beneficial for preventing CAD in postmenopausal women. These studies contributed to the expanded use of estrogen for this indication and an unsuccessful attempt to have the FDA give official approval for it. In general, post-menopausal women were prescribed “hormone replacement therapy” (HRT) as a combination of estrogen and either another female sex hormone, progesterone, or a chemical with progesteronelike effects called a “progestin,” such as medroxyprogesterone. Giving estrogen by itself increases a woman's risk of developing cancer involving the lining of her uterus (endometrial cancer). Using estrogen with a progestin reduces this risk significantly. If a woman had a hysterectomy (removal of the uterus), she could receive estrogen alone.
However, large studies conducted in the late 1990s and in this century reached different conclusions about the effects of HRT on cardiovascular disease. They showed that using estrogen and a progestin together didn't reduce the risk of
* * * *
The WHIs and Wherefores of Estrogen Therapy
Certain diseases are caused by a person's body producing inadequate amounts of a hormone or other chemical needed for good health. “Hypothyroidism” occurs when the thyroid gland doesn't produce enough of two hormones—thyroxine and triiodothyronine— to meet a person's metabolic needs. Diabetes mellitus is associated with either an absolute deficiency of insulin (Type 1), or an at least relative deficiency of insulin and resistance to its effects (Type 2). Having too little of other hormones—growth hormone, parathyroid hormone, aldosterone, etc.—also causes well-described symptoms and diseases. Replacement of a hormone when its blood level is too low may improve or cure the disease caused by its lack.
However, levels of some hormones fall not because of a clearly pathological process, but as a “normal” part of aging. These include dehydroepiandrosterone (DHEA), a hormone produced by the adrenal glands, and growth hormone. Although further studies might change this assessment, so far research has not definitively shown that replacement of these hormones to “youthful” levels produces a clinically significant improvement in health.
In women, levels of the female sex hormone estrogen fall dramatically at menopause. The higher level of estrogen present in premenopausal women compared to men is associated with a significantly lower risk of these women developing coronary artery disease (CAD). Roughly speaking, the risk of a woman developing CAD prior to menopause is about the same as a man ten years younger with similar risk factors (e.g. high blood pressure, an abnormal blood cholesterol level, diabetes, or tobacco use). The drop in estrogen level that occurs with menopause is associated with a significant increase in the risk of a woman developing CAD.
The “logical” conclusion was that, if a woman's estrogen level were restored to what it was before menopause, her risk of developing CAD would fall. The possibility that giving estrogen replacement might have effects that reduce the risk of developing CAD seemed to support this idea. These potentially beneficial effects include lowering low-density lipoprotein (LDL) cholesterol, increasing high-density lipoprotein (HDL) cholesterol, and reducing blood sugar. Some known effects of giving estrogen, such as raising the blood level of triglycerides (another component of cholesterol) and increasing the risk of developing blood clots, were recognized as being potentially harmful. However, these bad effects were not thought to be as significant as estrogen's good effects.
Some small studies done in the early and mid-1990s did in fact suggest that estrogen replacement was, overall, beneficial for preventing CAD in postmenopausal women. These studies contributed to the expanded use of estrogen for this indication and an unsuccessful attempt to have the FDA give official approval for it. In general, post-menopausal women were prescribed “hormone replacement therapy” (HRT) as a combination of estrogen and either another female sex hormone, progesterone, or a chemical with progesteronelike effects called a “progestin,” such as medroxyprogesterone. Giving estrogen by itself increases a woman's risk of developing cancer involving the lining of her uterus (endometrial cancer). Using estrogen with a progestin reduces this risk significantly. If a woman had a hysterectomy (removal of the uterus), she could receive estrogen alone.
However, large studies conducted in the late 1990s and in this century reached different conclusions about the effects of HRT on cardiovascular disease. They showed that using estrogen and a progestin together didn't reduce the risk of
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