In July of 1997, doctors at the Mayo Clinic in Rochester, Minnesota, and at another clinic in Fargo, North Dakota, reported an unusual heart ailment amongst 24 women. All of them were taking fenuramine and phentermine, or fen-phen, a powerful diet drug. The doctors diagnosed the women with a rare heart and lung illness called primary pulmonary hypertension.
Primary Pumonary Hypertension Overview
Primary pulmonary hypertension is a rare lung disorder that causes the blood pressure in your pulmonary artery to rise above normal levels. Your pulmonary artery transports oxygen-poor blood from the right ventricle to your lungs, explains the American heart Association. Once your blood reaches your lungs, it picks up oxygen. The oxygenated blood then flows to the heart's left side, where the left ventricle pumps it to the rest of your body. Primary pulmonary hypertension affects the small blood vessels in your lungs. As pressure in these vessels increases, they increase the blood flow resistance, thereby straining the right ventricle and forcing the heart to work harder than normal.
Fen-Phen
Good intentions pave the road to weight loss and fitness, but taking an uncharted shortcut might lead to danger. The fen-phen phenomenon illustrates this point. This fast-acting diet drug, which was marketed in the 1990s under the name Redfux, took the diet pill industry by storm. In 1996, doctors wrote 18 million fen-phen prescriptions, reports Gina Kolata of the "New York Times." While scientists remain unclear about the exact causes of primary pulmonary hypertension, researchers at Columbia-Presbyterian Medical Center speculate that diet drugs such as fen-phen injure the small blood vessels in your lungs, thereby damaging interactions with the smooth smooth muscle cells in the walls of the blood vessels. A viscous cycle begins.
Chain of Events
Impairing the interaction between small blood vessels and smooth muscle cells causes the smooth muscle to contract. The chronic state of contraction narrows the blood vessels and increases blood pressure. New muscle cells form in response to the raised blood pressure. As the new cells accumulate, they form thick scar tissue, which further narrows and thickens the small blood vessels in your lungs. The narrow blood vessels case an even greater blood pressure increase, which in turn tasks the heart to work harder to pump and distribute blood.
Discussion
In 1996, frequent reports of diet drug-related pulmonary hypertension prompted the "New England Journal of Medicine" to perform a study about the issue. While the journal usually has strict rules about pre-publication of research, the "New York Times" reports that they felt their findings had crucial significance to the public's health; they agreed to an early release to the general media. The report released some shocking details, says Robert Pool, author of "Fat: Fighting the Obesity Network." At least 50 out of every 1 million patients who took fen-phen or Redux longer than three months would likely develop pulmonary hypertension, and half who developed the disease would die within five to 10 years.
References
- American Heart Association: Primary or Unexplained Pulmonary Hypertension
- Columbia Presbyterian Medical Center: Help for Primary Pulmonary Hypertension
- 'New York Times"; Two Popular Diet Pills Linked to Problems With Heart Valves; Gina Kolata; July 1997
- "Fat: Fighting the Obesity Epidemic"; Robert Pool; February 2001
