75060340
`
`HEALTH LETTER
`
`A HEALTHIER LIFE
`
`Unraveling origins of illness:
`progress and possibilities
`
`A, T, C and G—onlyfour letters. But
`to genetic scientists, these four letters
`tell one of the greatest stories ever
`told.
`
`A, T, C and G represent four
`molecules — adenine, thymine, cy-
`tosine and guanine — contained in
`deoxyribonucleic acid (DNA). In a
`typical human gene, thousands of
`these four molecules are strung to-
`gether in precise order. DNA se-
`quence makes up the genetic code
`and determines which parts make
`the gene work -— or not work.
`Defects withinacell’s DNAcode
`
`are at the root of as many as 4,000
`
`inherited disorders. Scientists also
`
`have identified genetic factors in
`common illnesses such as cancer,
`
`heart disease, diabetes and psychiat-
`ric illnesses.
`
`Discovering a genetic defect al-
`lows scientists to study the gene's
`structure and characterize the muta-
`tions that can lead to disease. Dis-
`
`covery doesn’t always translate into
`an effectivetherapy, letalone a cure.
`But greater understanding is already
`improving how some diseases are
`managed and the knowledge prom-
`ises better therapies to come.
`
`Your master blueprint
`An estimated 100,000 genes are
`contained in chromosomes located
`
`within the nucleus of each of your
`cells. In addition to determiningyour
`unique physical characteristics,
`
`1.
`
`aaifi
`
`‘l‘l'*“~*"
`
`About 60 trillion cells make up your body. Within each cell's nucleus are 23 pairs of
`chromosomes. Each chromosome contains thousands of genes that determine your heredity.
`Genes use the chemical DNA to instruct cells to make proteins. Instructions are spelled out by
`a specific code of four molecules — adenine (A), thymine (T), cytosine (C) and guanine (G).
`A single mistake in a code can disrupt a protein's function and lead to disease.
`
`I‘?
`
`RELIABLE
`
`VOLUME 14
`
`NUMEER1
`
`Inside this issue
`
`HEALTH TIPS . . . .
`
`.
`
`. .
`
`.
`
`.
`
`.
`
`.
`
`. . 3
`
`How to reduce belching.
`
`MEDICATION . .
`
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`
`. . . . 4
`
`More and more prescription drugs
`are available over the counter.
`Here's what's behind the switch
`
`and how you can benefit.
`
`UPDATE '96 .
`
`.
`
`.
`
`.
`
`.
`
`. . . .
`
`. . .
`
`.
`
`.
`
`. 4
`
`Antibiotics: There's danger in tak-
`ing shortcuts or leftovers. Laser
`surgery for nearsightedness isn't
`picture perfect.
`
`WELLNESS . .
`
`.
`
`. . .
`
`. . . . .
`
`. . .
`
`.
`
`. 6
`
`Part of staying healthy this year
`means living by certain numbers.
`
`FAINTINC .
`
`. . .
`
`.
`
`.
`
`.
`
`. . . . .
`
`.
`
`.
`
`.
`
`. 7
`
`Scary? Usually. Serious? Not al-
`ways.
`
`. 8
`.
`. . . . . .
`SECOND OPINION .
`Too little salt and heart attack.
`
`Fighting bacteria in the kitchen.
`Care for cat bites.
`
`
`
`Coming in February
`
`HEMORRHOIDS
`
`Managing pain and inflammation
`— from fiber and exercise to rub-
`ber bands and lasers.
`
`ASTHMA
`
`In the next Medical Essay, learn
`how new understanding of this
`complex lung condition can help
`you gain more control over your
`symptoms and lifestyle.
`
`m%o
`
`

`

`MAYO CLINIC HEALTH LETTER
`
`JANUARY 1996
`
`genes use DNA to instruct cells to
`make proteins.
`Some proteins regulate chemi-
`cal reactions in cells. Some provide
`structural support. Others, such as
`hormones, regulate a range of ac-
`tivities including growth, metabo-
`lism,
`reproduction and your re-
`sponse to environmental factors.
`Because a protein's makeup is
`determined by its DNA code, any
`variation in the sequence of A, T, C
`and G means a cell may make the
`wrong amount of protein or an ab»
`normal version. These mistakes can
`lead to disease (see illustration).
`
`Searching for genetic links
`Inherited conditions such as
`
`cystic fibrosis and sickle cell ane-
`mia are caused by a single gene
`defect
`that’s present from birth.
`Many other conditions such as can-
`cer, heart disease and AIDS may
`develop from damage to one or
`more genes.
`Since the early 1980s, scientists
`have identified genetic defects for
`about 50 hereditary disorders. More
`recently, scientists have discovered
`single or multiple genetic links to
`these conditions:
`
`I Amyotrophic lateral sclerosis
`(ALS) — Popularly called Lou
`Gehrig's disease, ALS is character-
`ized by degeneration of nerve cells
`in regions of your brain and spinal
`cord that control your muscles.
`In about 10 percent of people
`with ALS, thefatal disease may stem
`from a flaw in a gene called SOD1.
`This gene normally acts as a house-
`keeper, blocking damage to cells by
`free radicals. How the defect may
`lead to nerve cell degeneration is
`unknown.
`I Asthma — Researchers have
`
`discovered a gene that may cause
`chronic lung inflammation. How~
`ever, asthma likely results from many
`factors or genetic defects.
`
`I Huntington’s disease —
`People who inherit this fatal brain
`disorder, characterized by progres-
`sive loss of muscle control and
`
`dementia, have a defective gene
`called lT15.
`
`Huntington's disease is an un-
`common disorder that affects
`25,000 Americans. Yet a child
`whose parent has Huntington's dis-
`ease has a 50 percent chance of
`inheriting the gene and developing
`the condition.
`
`I Melanoma — Some people
`at risk for this deadly skin cancer
`lack a gene called P16 or possess a
`mutated version. Defects in other
`
`genes are also involved.
`About 32,000 Americans de-
`velop melanoma each year; 10 per-
`cent of cases may be inherited.
`I Obesity — The obese gene,
`nicknamed ”ob” (oh-be), may be
`essential
`for maintaining healthy
`body weight.
`If the gene is defec-
`tive, scientists suspect
`it fails to
`make a hormone-like protein that
`helps regulate appetite.
`I Alzheimer’s disease — Sci-
`entists have identified four defec-
`
`tive genes in the inherited form of
`this neurologic disease. Hereditary
`Alzheimer's makes up 10 percent
`of cases and generally strikes be-
`fore age 65.
`Another gene APOE 4 is a risk
`factor in late—onsetA|zheimer’s, the
`more common form of the disease
`
`(see ourJuly 1995 issue).
`I Breast cancer— Two genes,
`BRCA1 and BRCA2, may cause
`some inherited forms of breast and
`ovarian cancers.
`
`Hereditary breast cancer ac-
`counts for 5 percent of breast can-
`cer cases. And only about 1
`in 200
`to 400 women inherits a defective
`
`BRCAJ gene.
`in families with early—onset
`breast cancer,
`less than half the
`women who develop cancer carry
`
`the defective gene. In families with
`early—onset cases of both breast and
`ovarian cancers, BRCA1 may be
`responsible 80 percent of the time.
`BRCA1 may also be involved in
`some nonhereditary breastand ova-
`rian cancers.
`I Colon cancer —— Scientists
`
`have discovered several genes for a
`common form of hereditary colon
`and rectal cancer. The cancer gen-
`erally affects younger adults and
`causes about 5 to 10 percent of all
`colon cancers.
`
`Discoveries lead to new paths
`Once scientists link a gene to a
`particular disease, they must deter-
`
`MAYO CLINIC HEALTH LETTER
`
`Managing Editor
`N. Nicole Spelhaug
`Associate Editors
`Donna H. Cortese
`Karen R. Wallevand
`get}, A, vvaikins
`
`Medical Editor
`Charles C. Kennedy, MD.
`Associate Medical Editor
`Philip T. Hagen, M.D.
`Customer Service
`Manager
`Christie L. Herman
`
`EDITORIAL BOARD
`
`Mayo Clinic Rochester
`Susan L. Ahlquist, R.N., Patient and Health Education;
`Richard M. Devine, M.D., Colon and Rectal5urgery;
`Joseph Duffy, M.D., Rheumatology; Mary M.
`Gallenberg, M.D., Medical Gynecology; Philip T.
`Hagen, M.D., Preventive Medicine; Mary L. Jurisson,
`M.D., Physical Medicine and Rehabilitation; Charles
`C. Kennedy, M.D., Internal Medicine; Robert L.
`MacCarty, M.D., Diagnostic Radiology; J. Thomas
`Mangan, M.D., Family Medicine; Randolph 5. Marks,
`M.D., Medical Oncology;Michael D. McGo0n, M.D.,
`Cardiology; Gregory A. Poland, M.D., Internal
`Medicirie,'Thomas C. Shives, M.D., Orthopedic
`Surgery; Marc D. Silverstein, M.D., Internal
`Medicine; N. Nicole Spelhaug, Nutrition/
`Communications. Ex-officio: Donna l I. Cortese,
`Vicki L. Moore, Karen R. Wallevand, Beth A. Watkins.
`
`Mayo Clinic Jacksonville
`C. Richard Fleming, M.D., Gastroentero/og,v. Bruce
`W. Pearson, M.D., Otorhinolaryngo/ogy
`Mayo Clinic Scottsdale
`Quinton C. Callies, M.D., Allergic Diseases; Bruce K.
`Kimbel, Jr., M.D., Community Internal Medicine
`
`MayoC|inicHealth Letter (ISSN 0741-6245) ispublished
`monthly by Mayo Foundation for Medical Education
`and Research, a subsidiary of Mayo Foundation, 200
`First Street SW, Rochester, MN 55905. Subscription
`price is $24 a year, which includes three eight-page
`Medical Essays and a Five—Year Cumulative Index
`published in December. Second«class postage paid at
`Rochester, MN, and at additional mailing offices.
`POSTMASTER: Send address changes to Mayo Clinic
`Health Letter, Subscription Services, PO. Box 53889,
`Boulder, CO 80322—3889.
`
`

`

`MAYO CLINIC HEALTH LETTER
`
`JANUARY 1996
`
`mine if other genes or defects may
`also be involved. For example, of
`the two genes involved in heredi-
`tary breast and ovarian cancers, sci-
`entists estimate at
`least 38 muta-
`
`tions in the BRCA1 gene.
`The next step is to develop a test
`to detect the genetic flaw, often by
`analyzing a blood sample. Blood
`tests are available to detect many
`hereditary disorders such as cystic
`fibrosis, Huntington’s disease and
`hemophilia.
`ThegenetictestforHuntington's
`disease took only a few months to
`develop. Others involving multiple
`genetic links can take much longer.
`Genetic testing for hereditary breast
`and colon cancers may be available
`within two years.
`Usually, the benefits of genetic
`testingarelimitedto identifying risk,
`not diagnosing the disease. Coun-
`seling regardingfamilyplanningand
`lifestyle decisions can be helpful in
`these situations. Yet the value of
`
`re-
`testing remains limited until
`searchers can develop treatments
`for high—risk people.
`In addition, ethical questions
`complicate scientific issues. For
`example, how do you feel about
`being tested for a disease that can't
`be treated? Do you want to know
`you carry a gene for a disease that
`may develop years later? How will
`a medical
`institution protect your
`privacy? Should you know if your
`unborn child will develop an incur-
`able disease?
`
`Repairing the defect
`One promising treatment for
`genetic diseases is gene therapy. in
`this experimental approach, healthy
`genes are injected into your blood
`or tissues.
`
`The genes are contained within
`molecules targeted to seek out de-
`fective cells. Commonly, the carri-
`ers are virus particles that have been
`
`altered to prevent them from caus-
`ing illness.
`When a carrier reaches its tar-
`
`get, itunloads the genes. Ultimately,
`the goal
`is for the new genes to
`activate or ”express” themselves to
`correct the mutation or to make the
`
`defective cell susceptible to drug
`treatment.
`
`Although only five years old,
`gene therapy is being tested in more
`than 100 clinical trials.
`
`researchers re-
`Last October,
`ported what may be the first suc-
`cessful genetherapy. Healthy genes
`were injected into two young chil-
`dren with severe combined immu-
`
`nodeficiency disease (SCID), a rare
`hereditary disorder that shuts down
`immune function. Early reports show
`the targeted cel ls have incorporated
`the new genes.
`But other experiments aren't as
`promising. For cystic fibrosis and
`muscular dystrophy, scientists
`haven’t been able to correct genetic
`mutations using gene therapy. For
`these and other genetic diseases,
`standard medical and surgical treat-
`ment remains most useful.
`
`Long road ahead
`By 2005, scientists worldwide
`hope to identify all 100,000 ormore
`human genes through the Human
`Genome Project. Pinpointing spe-
`cific genes will allow scientists to
`decode the estimated 3 billion bits
`
`of genetic instruction they contain.
`Thisisthefirststep in understanding
`the molecular origins of a genetic
`disease — and eventually curing it.
`But the road from discovery to
`therapy is long, difficult and costly.
`During the past decade, scientists
`have collected data on about 6,300
`
`human genes.
`As gene analysis continues, treat-
`ing genetic diseases by correcting
`the error or replacing the abnormal
`gene may become a reality. CI
`
`Health tips
`How to reduce belching
`
`Every time you eat or drink,
`you swallow small amounts of
`air. It's normal, then, to get rid
`of most of the air you swallow
`with an occasiona|—and ever
`
`so discreet —— burp.
`Swallowing too much air,
`however, can add to stomach
`gas, causing bloating and fre-
`quent belching.
`Sometimes, chronic belch-
`ing results from a nervous habit
`of swallowing excessive air,
`especially when talking.
`To reduce the amount of
`
`air you swallow:
`I Eat meals slowly.
`I Don't gulp your food or
`beverages.
`I Chew your food thor-
`oughly.
`I Avoid chewing gum or
`sucking on hard candy.
`I Limit sipping through
`straws or drinking from nar-
`row-mouthed bottles.
`
`I Don't smoke cigarettes,
`pipes or cigars.
`I Cut down on carbonated
`soft drinks and beer.
`I Correct loose dentures.
`
`I Recognize andtrytocon-
`trol stress that may add to ner-
`vous swallowing of air.
`To avoid gas buildup
`caused by increased produc-
`tion and retention:
`I Limit rich foods such as
`
`fatty meats, fried foods, cream
`sauces, gravies and pastries.
`I Avoid lying down imme-
`diately after eating.
`I Don’t force yourself to
`belch. CI
`
`

`

`MAYO CLINIC HEALTH LETTER
`
`IAN UARY 1996
`
`Update '96
`
`News and our views
`
`Antibiotics: the dangers of shortcuts and leftovers
`Is there a half—finished antibiotic prescription lurking in your medi-
`cine cabinet? If so, you’re not alone.
`A survey released last October by the American Lung Association
`polled more than 1,000 adults about antibiotic use. It found:
`I About halfthe people who had received an antibiotic prescrip-
`tion didn’t finish it.
`
`I Most who stopped taking their antibiotics before finishing the
`prescription did so because they felt better.
`I More than a third saved leftover medications.
`
`Improper use of antibiotics adds to the growing problem of drug-
`resistant infections. We suggest you:
`I Finish yourprescription— Even ifyou feel better, stopping your
`medication prematurely allows the hard iest bacteria to survive and
`reproduce. Next time, you may need a more powerful antibiotic.
`Eventually, you can develop an infection resistant to some antibiot-
`ics, limiting your treatment options.
`I Don't take leftovers— A leftover antibiotic may not be the right
`drug to fight your current infection. Using it allows bacteria to
`multiply and delays your getting appropriate care.
`I Recognize uses and limitations — Antibiotics work against
`bacteria. Almost 60 percent of those polled believed incorrectly that
`an antibiotic would treat a viral infection such as a cold or flu. El
`
`Laser surgery for nearsightedness is worth a closer look
`The Food and Drug Administration (FDA) has approved photorefractive
`keratectomy, an irreversible laser surgery for mild to moderate
`nearsightedness.
`During the one- to two—minute surgery, a surgeon flattens your
`cornea by vaporizing microscopic slivers from the cornea’s surface.
`Flattening the cornea improves distance vision by allowing light rays
`to focus on your retina.
`In studies supplied to FDA by the laser manufacturer, surgery
`eliminated the need for corrective lenses in most people. Others
`continued to need glasses or contact lenses.
`Side effects included poor night vision, morning eye pain and
`tenderness and premature farsightedness. For about 5 percent of
`people, vision worsened after the surgery.
`Photorefractive keratectomy isn't effective if you're severely
`nearsighted, farsighted or have astigmatism. If you're mild to moder-
`ately nearsighted and considering laser surgery, Mayo ophthalmolo-
`gists advise you to wait. An improved laser with less risk of side effects
`may be available soon. Costs also should drop as the surgery becomes
`more widely used. Photorefractive keratectomy costs from $1 ,500 to
`$2,000 for each eye and isn't covered by most insurance plans. CI
`O.
`
`Medication
`
`The story behind drugs
`that switch from Rx to OTC
`
`You can't watch the evening news
`withoutseeingthe war. During com-
`mercial breaks, drug companies are
`battling for your business as they
`bring formerly prescription—only
`medications overthe counter(OTC).
`Within the past year, the war-
`ring factions have been manufac-
`turers of medications for heartburn.
`
`Their weapons — more than $100
`million in advertising.
`Why isthe competition sofierce?
`And how can you see past the dust
`clouds of battle and be a savvy
`consumer?
`
`Behind the ads
`
`All prescription drugs have pat-
`ents. As patents expire, brand-name
`drugs no longer have a corner on
`the prescription market. Generic
`drug companies can market
`the
`same medications at lower cost.
`
`Because the Food and Drug Ad-
`ministration (FDA) has already ap-
`proved the drug, generic drug mak-
`ers bypass the expense involved in
`testing for safety and effectiveness.
`A |ower—priced generic drug can
`cut a company's profits on a pre-
`scription medication by 50 percent.
`To hold on to the brand-name
`
`market, companies look for new
`uses and users for their medica-
`
`tions. Many view OTC sales as a
`way to expand their markets and
`reap financial rewards.
`Because many consumers opt
`for the more recognized brands,
`former prescription—only medica-
`tions often outsell traditional OTC
`medications. More than half the
`
`drugs that have gone over the
`counter in the last 20 years are top
`or second sellers in their markets.
`
`

`

`MAYO CLINIC HEALTH LETTER
`
`JANUARY 1996
`
`Leaping over the counter
`To make the jump to OTC sta-
`tus, a prescription medication must
`clear FDA hurdles. Generally, FDA
`approves a medication if you can
`safely and effectively use the drug
`after reading the instructions and
`packaging (see "Side panel savvy”).
`FDA considers whether the medi-
`
`cation is safe at high doses, how it
`interacts with other medications and
`
`if there’s potential for abuse.
`Most often, OTC drugs are not
`twins to prescription medications.
`They're sold at lower doses with
`instructions for less frequent use.
`For
`example,
`cimetidine
`(Tagamet HB)
`is sold over the
`counter in 100 milligram (mg) tab-
`lets and indicated for a maximum
`
`daily dose of40O mg. In its prescrip-
`tion form, cimetidine is available in
`tablets ranging from 200 to 800 mg
`and is prescribed for a maximum
`daily dose of 1,600 mg.
`In addition, OTC medications
`often aren't indicated for the same
`
`uses as their stronger prescription
`counterparts. Famotidine (Pepcid
`AC) and cimetidine are available
`over the counter for heartburn and
`
`indigestion. In prescription strength,
`they're used to treat ulcers and
`chronic acid reflux (see our Sep-
`tember l995 issue).
`
`Taking control of choices
`Bringing prescription medica-
`tions over the counter means you
`have more control over your medi-
`cations — and more responsibility:
`I Know your medications —
`Along with instructions for use,
`many new OTC drugs include in-
`serts about how to recognize symp-
`toms. If you don’t get enough infor-
`mation from the label and insert,
`
`talk to your pharmacist.
`I Involve your doctor — Most
`OTC medications are intended for
`
`short—term use to relieve acute symp-
`
`toms. Don't take OTC medications
`
`in higher dosages or for longerthan
`indicated without seeing your doc-
`tor. You may feel better, but the
`medication could be masking symp-
`toms of a serious illness.
`
`I Watch your wallet — For
`short—term use, an OTC medication
`will probably save you money.
`If
`you're going to use a medication
`long—term, you may be better off
`with a prescription generic than an
`OTC name brand.
`
`insurance coverage for
`Also,
`OTC medications may not be the
`same as it is for prescription drugs.
`
`Toeing the line
`More than 600 OTC products
`are available with ingredients lim-
`ited to prescription medications 20
`years ago.
`
`In addition to Pepcid AC and
`Tagamct HB, Children's Motrin and
`the nonsteroidal anti-inflammatory
`drug ketoprofen (Orudis KT) were
`approved for OTC status in 1995.
`Likely Rx—to—OTC switches in
`the future:
`
`I Additional
`ucts for children
`
`ibuprofen prod-
`
`I Cholestero|—lowering drugs
`I Heartburn medications
`ranitidine HCI
`(Zantac 75) and
`nizatidine (Axid)
`I Nicotine chewing gum
`I Rogaine hair—growth product
`The list of OTC wannabes is
`
`unending, from muscle relaxants to
`acne treatments.
`
`In the end, it can be a win-win
`situation for both drug manufactur-
`ers and you — as long as you use
`OTC drugs wisely. Cl
`
`Side panel savvy
`Drugs that switch from prescription to over-the—counter (OTC) status
`are subject to the Food and Drug Administration's new labeling
`guidelines. The new labels aim to simplify the presentation of
`important drug information, replacing long paragraphs with short,
`easy-to-read statements.
`
`Look for this type of information on the new label:
`
`Active ingredients — This section lists the medications that act on
`C)
`your symptoms.
`
`Use — Does the description fit your symptoms? If not, you may be
`wasting your time and money without getting relief from
`your symptoms. Also, make sure you're not taking two drugs
`designed to treat the same symptoms.
`
`Directions — Consider, ”How many can I take and for how long?”
`If you still have questions, talk to your pharmacist.
`
`Warnings — Note possible interactions. An OTC medication may
`V interact with your prescription medications, a health condi-
`tion, alcohol or certain foods.
`
`Look for recommendations about seeing a doctor. Some medica-
`tions, such as topical treatments for vaginal yeast infections, assume
`you'll see a physician before using the product. Others describe
`certain symptoms for which your doctor's input is suggested.
`
`

`

`MAYO CLINIC HEALTH LETTER
`
`IANUARY 1996
`
`Wellness
`
`Know your numbers for 1996
`
`You can’t be a picture of health by
`numbers only. The unique blend of
`your genes,
`lifestyle and environ-
`ment makes health more than a
`
`scientific type of paint-by—number.
`But some numbers are major
`mile markers to staying well. Know-
`ingthem can pointto areas you may
`need to work on as you journey
`through the new year.
`
`Blood pressure: 130 and 85
`High blood pressure increases
`your risk of cardiovascular disease,
`stroke and kidney disease.
`A high systolic pressure (top
`number) means maximum pressure
`within your arteries during each
`heartbeat is great enough to eventu-
`ally weaken vessel walls. High dias-
`tolic pressure (bottom number)
`means your heartand blood vessels
`don't relax well between beats.
`Be alert to sustained elevations
`
`in either systolic or diastolic pres-
`sure. Know these classifications for
`
`healthy adults:
`I Normal — Less than 130/
`
`85 mm Hg
`I High-normal—130t0139/
`85 to 89 mm Hg
`I Hypertension — Consis-
`tently greater than 140/90 mm Hg.
`If your blood pressure is 210/120
`mm Hg or higher, see your doctor
`immediately.
`
`Calories: 13
`
`Fat seems to get all the atten-
`tion, but weight control requires a
`close eye on the balance between
`the calories you eat and those you
`burn through activity.
`You can estimate your daily
`calories simply:
`I To maintain weight — Cur-
`
`rent weight (in pounds) x 13 = daily
`calories.
`
`I To lose weight — Current
`weight (in pounds) x 10 = daily
`calories.
`
`Fat: 30
`
`Ahigh—fatdiet raises yourrisk of
`cardiovascular disease and high
`blood pressure.
`To avoid too much fat, control
`fat grams to 30 percent of daily
`calories. To figure: Divide daily calo-
`ries by 30. For example, if you need
`1,800 calories, limit fat to 60 grams
`(1,800 + 30 = 60).
`
`Waist-to-hip: 1 or .85
`Carrying extra weight around
`your stomach (app|e—shaped)
`in-
`
`Routine screening:
`how much, how often
`Regular checkups play a
`useful role in helping you stay
`well. if you're healthy, have a
`medical examination:
`
`I Four times in your 405
`I Five times in your 505
`I Annually after age 60
`if you're at least 50 years
`old and healthy, routine
`screening generally includes:
`I Blood pressure check —
`every 2 years.
`I Colon examination —
`
`every 3 to 5 years.
`I Eye examination —
`every 2 to 4 years until age
`65, then every 1 to 2 years.
`I Cholesterol and triglycer-
`ide tests — every 5 years, if
`your values are in desirable
`ranges.
`I Mammogram — annu-
`ally.
`I Pap smear— every 1 to
`3 years.
`
`creases your risk for cardiovascular
`disease, high blood pressure, stroke
`and diabetes.
`
`If you carry extra fat on your
`hips and thighs (pear—shaped), you
`may not have greater health risks
`than someone who isn't overweight.
`The wayyourbodyfatisdistrib—
`uted is expressed asthe waist«to—hip
`ratio. To figure:
`1. Measure your waist at your
`navel
`
`2. Measure your hips at the
`widest point (over your buttocks).
`3. Divide your waist measure-
`ment by the hip measurement.
`|fyou’reaman,anumbergreater
`than 1 indicates higher health risk.
`if you're a woman, health risks are
`associated with a number greater
`than .85.
`
`Exercise: 30 and 7
`
`An inactive lifestyle increases
`your risk of cardiovascular disease,
`osteoporosis and weight gain. But
`the concept of ’’no pain, no gain” is
`no longer the way to be healthy (see
`our May 1995 issue).
`Instead, be moderately active
`for at least 30 minutes on 5, if not 7,
`days. You can accumulate minutes
`throughout the day with a variety of
`activities such as riding your bike or
`mowing the lawn. Exert yourself to
`the level of walking briskly.
`
`Cholesterol ratio: 4.5
`
`Total cholesterol is made up of
`low—density lipoproteins (LDLs),
`high-density lipoproteins (HDLs)
`and other blood particles.
`Even if yourtotal cholesterol is
`withinadesirab|erange(below200
`mg/dl), high LDL and low HDL lev-
`els still put you at riskfor cardiovas-
`cular disease and atherosclerosis.
`
`To figure your cholesterol ratio:
`Divide your total cholesterol level
`byyourHDLlevel.Adesirablenum-
`ber is less than 4.5. CI
`
`

`

`MAYO CLlNlC HEALTH LETTER
`IAN UARY 1996
`
`Fainting
`
`Passing out is usually scary
`but not always serious
`You felt fine. Then with little warn-
`
`ing, you found yourself lying on the
`floor with a circle of concerned
`
`faces peering down at you.
`One in three people faints at
`least once in a lifetime, most often
`after age 65. Although frightening
`and maybe a bitembarrassing, faint-
`inggenerallyisn’tareasonto panic.
`
`When the lights go out
`Fainting, also called syncope
`(SING-kuh-pe), occurs when not
`enough oxygen-rich blood reaches
`your brain. Without adequate oxy-
`gen, brain metabolism slows, caus-
`ingyoutoloseconsciousness briefly.
`You may have no warning. But
`usually you feel nauseated or
`lightheaded, become sweaty and
`pale, then experience a graying out
`of your vision.
`Within about a minute of lying
`flat, sufficient blood flow to your
`brain is restored and you regain
`consciousness.
`
`A symptom with many causes
`About 25 percent of adults faint
`because of a heart condition (see
`
`”When fainting signals something
`serious”). In as many as 35 percent
`of people, the reason is unknown.
`In other cases, fainting may be
`due to a drop in blood pressure
`related to these factors:
`
`I Standing too quick/y—When
`you stand, your sympathetic ner-
`vous system triggers release of the
`hormone adrenaline. This leads to
`
`an increase in your heart rate and
`blood pressure, preserving adequate
`blood flow to your brain.
`With age,
`this cardiovascular
`response can slow. Standing too
`
`quickly may cause blood to pool in
`your legs, leading to a sudden drop
`in blood pressure.
`I Medications — High blood
`pressure drugs and antiarrhythmics
`that slow heart rate are typically
`associated with fainting.
`These drugs can make you more
`susceptible to blood pressure
`changes. They also can keep your
`heart from beating fast enough to
`meet higher demands caused by a
`change in position or activity.
`I Anx/'ety— Emotional stress or
`sudden severe pain can trigger in-
`terplay between your neurologic
`and cardiovascular systems that re-
`sults in stimulation of your vagus
`nerve. This signals your heart to
`slow and your arteries to dilate.
`When the changes occur too
`quickly, blood pressure drops sud-
`denly.
`I Activity —— Adequate sodium
`helps maintain blood pressure. 50-
`dium lost through excessive sweat
`duringstrenuous activity, especially
`in heat and humidity, can lead to a
`drop in blood pressure.
`
`Ways to prevent fainting
`A few simple steps may keep
`you from fainting:
`I Loweryourhead— lfyou feel
`as though you're going to faint, lie
`down. Raise your legs above the
`level ofyour head to increase blood
`flow to your brain.
`lfyou can't lie down, sitorbend
`forward with your head between
`your knees. Wait until
`the
`lightheadedness or nausea has sub-
`sided before trying to stand.
`I Stana'slowly—This gives your
`blood pressure and heart rate more
`timeto adjustto an uprightposition.
`I Checl<medications—lf a new
`
`drug or change in prescription
`causes occasional lightheadedness,
`talk with your doctor. You may need
`an adjustment in your dosage.
`
`When fainting signals
`something serious
`Serious causes of fainting
`typically involve problems
`with your heart-or theblood
`vessels leading to your
`brain. An irregular rhythm,
`the most common heart
`
`condition, reduces blood
`pumped from your heart.
`Severe narrowing of your
`aortic valve (aortic stenosis)
`or accumulation of plaque
`in your carotid arteries may
`cause fainting by limiting
`blood flow to your brain.
`See your doctor right
`away if fainting occurs
`without warning, when you
`turn your head or extend
`your neck, or when accom-
`panied by:
`I irregular heartbeat
`I Chest pain
`I Shortness of breath
`I Blurred vision
`I Confusion
`
`I Trouble talking
`
`'
`
`If you take several medications,
`don't take them all at the same time
`
`unless your doctor advises other-
`wise.The combined effectmay over-
`whelm your body’s ability to main-
`tain homeostasis.
`
`I Pace yourself— When work-
`ing or exercising in heatand humid-
`ity, take frequent breaks and drink
`plenty of liquids.
`
`Don't minimize fainting
`if you have a chronic health
`condition such as cardiovascular
`
`disease, high blood pressure or dia-
`betes coupled with recurrent faint-
`ing, have your doctor evaluate the
`problem. Contactyourdoctor about
`even a single fainting episode if
`you're more than 40 years old. CI
`
`

`

`MAYO CLINIC HEALTH LETTER
`
`JANUARY 1996
`
`Second opinion
`
`Questions and our answers
`
`Q. I read your October article on
`”Sodium,” outlining the benefits
`of avoiding excess sodium. But
`what about a recent report sug-
`gesting too little salt increases your.
`risk of a heart attack?
`
`A. You may be referring to the
`coverage given a June 1995 report
`in Hypertension. The study found
`heart attack risk was greatest among
`hypertensive men with the lowest
`levels of sodium in their urine.
`
`The report points out a low-
`sodium diet causes your kidneys to
`secrete higher levels of an enzyme
`called renin. The study suggests
`increased renin raises heart attack
`
`risk. Yet it didn’t prove this rela-
`tionship.
`In addition, the men who expe-
`rienced heart attacks had much
`lower sodium levels in their urine
`
`than most people on low-saltdiets,
`suggesting other factors may have
`been involved.
`
`In large population studies,
`blood pressures dropped when
`people cut back on sodium. The
`lower your blood pressure, the less
`risk of a heart attack or stroke.
`
`We agree with the National
`High Blood Pressure Education
`Program recommendations for
`healthy adults: Limit sodium to
`2,400 milligrams daily. If you have
`high blood pressure, talk to your
`physician about sodium control,
`
`maintain a healthy weight, exercise
`regularly and limit alcohol. D
`
`Q. Do antibacterial kitchen sprays
`help prevent food-borne illness?
`
`A. Yes. But so will wiping kitchen
`surfaces with any cleaner and rou-
`tinely washing your hands.
`A recent comparison of com-
`mercial kitchen cleaners found new
`
`antibacterial products killed four
`common bacteria better than regu-
`lar disinfectant sprays. Antibacterial
`cleaners contain some of the same
`
`chemicals and detergents in anti-
`bacterial soaps and surgical scrubs.
`But you can adequately reduce
`your exposure to bacteria in the
`kitchen by wiping surfaces with
`dishwashingliquids,cleansersordis-
`infectant sprays. Using a disposable
`paper towel instead ofa dishcloth or
`sponge further reduces spread. Even
`after rinsing, some bacteria remain
`in a cloth or sponge and multiply.
`Ifyou prefera dishcloth, change
`it daily. Run a sponge or scouring
`pad through the dishwasher with
`each load of dishes. D
`
`Q. My cat is getting older and
`more easily frightened. What
`should I do if she bites?
`
`A. Wash the wound gently with
`soap and water.
`If
`it's bleeding,
`
`apply pressure and hold the injury
`above heart
`level. Then place a
`sterile bandage over the wound.
`Cats bites are often deep punc-
`ture wounds. Up to 40 percent of
`bites — usually those on your hand
`— become infected.
`
`For a puncture wound, your
`doctor may prescribe an antibiotic
`to prevent infection. You may also
`need a tetanus shot. Be sure to tell
`
`your doctor of your cat's rabies vac-
`cination status.
`
`If you’re bitten by a stray ani-
`mal, look for identification and try
`to Contact its owner to determine
`whether the cat has been vacci-
`nated for rabies.
`
`If you can't identify an owner,
`Contact the local animal shelter to
`
`catch and quarantine the cat. Your
`doctor may suggest you receive ra-
`bies vaccines as a protective mea-
`sure ifthe animal can't be found or
`
`seemed to bite without being pro-
`voked. D
`
`Have a question? Send it to Second Opinion.
`Second Opinion focuses on common health
`problems of broad interest. We appreciate
`every