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Digestion
and
Metabolism
Protecting
Liver Health
Liver
Disease


สนใจรายละเอียดเพิ่มเติม
กรุณาแจ้งให้ทึมงานเพื่อ
จัดเตรียมหาสาระให้

Contact :
info@thailabonline.com
ชมรมเรารักสุขภาพ
ไทยแล็ปออนไลน์
|
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| ตับ
หน้าที่และการดูแลสุขภาพตับ
Liver function and Disease |
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It's
Role in Digestion
and
Metabolism
The liver performs
many functions that are fundamental to life. It is essential in the
digestion
of fats and performs key functions in metabolism, the processing,
storing,
and producing of substances that maintain life. Eighty-five to
ninety percent of the
blood that leaves the stomach and intestines passes
through the liver first. Here,
carbohydrates, proteins,
fats,
vitamins,
and minerals are processed and
converted into substances the body can
use.
Carbohydrates
Dietary carbohydrates are the body's primary source of energy. Foods such
as
grains, cereals, fruit, and sugar are the main source of energy for the
brain, cells,
and muscles. The liver maintains this source of energy.
During mealtimes,
carbohydrates are broken down in the intestines to
sugars. These sugars are
absorbed and sent to the liver.
Absorbed sugars are
used to replenish blood sugar (glucose), or excess sugar
amounts can be
stored in the liver in a form called glycogen. The liver can store a
two
day energy supply as glycogen. If this supply is depleted, the liver is
able to
help generate new glucose from other substances in the body. For
example,
during strenuous exercise, starvation, or even during sleep,
various organs
(especially the brain) require energy. The liver receives a
hormonal message in
the blood and creates glucose from its stores. This
glucose is sent by the blood to
the requesting organs.
Fats
The liver functions both in the digestion and metabolism of dietary fats.
During
digestion, bile produced by the liver and stored in the gallbladder
is released into
the intestine. Bile acts to emulsify fats, breaking them
into smaller droplets so that
they can be digested and absorbed.
The liver is also
the hub for receiving dietary fat and cholesterol from the intestines.
Here fats can be used for energy if needed. Fats and cholesterol are
processed
and sent to different parts of the body. Fat is an energy source
for the liver and is
also the most efficient long-term storage form of
energy. The liver plays a major
role in the production and metabolism of
fat. Glucose that exceeds the needs of
the body can be converted by the
liver into fat and stored.
The liver also has
the capability of producing cholesterol. Cholesterol is a
necessary
component of every cell, used for production of bile and body
hormones,
and necessary for vitamin D production. Of course, too much
cholesterol
can be associated with serious cardiovascular disorders.
Proteins
The liver is also the site of protein metabolism. Here proteins that are
broken
down into amino acids and absorbed in the intestine may be rebuilt
into proteins
for use throughout the body. The liver may also break down
body protein for use
as energy when sugars are not available. Proteins
produced by the liver perform
a variety of vital functions including
coagulating blood, maintaining fluid balance,
iron storage, and delivery
of iron, vitamin A, zinc, and copper within the body.
Vitamins
and Minerals
The liver is involved in the storage, activation, transport, and excretion
of many
vitamins and minerals. Vitamins A, D, E, K, and B12, iron, zinc,
copper, and
magnesium are all stored in the liver. The liver is the major
storage site for iron,
storing 10 percent of the body's total iron stores.
Carotene (a precursor to
vitamin A), folate, and vitamin D all require the
liver to be come active, usable
forms for the body.
References:
Jones AL (1996). Anatomy
of the Normal Liver. IN: Zakim D, and Boyer TD (eds.)
Hepatology: A
Textbook of Liver Disease. Pennsylvania, WB Saunders Company, pp 3-31.
Sherlock S and
Dooley J (1993). Anatomy and Function. Diseases of the Liver and
Biliary System.
Oxford, Blackwell Scientific Publications, pp 1-17.
Stolz, A (1998). Liver
Physiology and Metabolic Function. IN: Feldman M, Scharschmidt BF,
and
Sleisenger MH (eds), Gastrointestinal and Liver Disease:
Pathophysiology, Diagnosis, and
Management. Pennsylvania, W.B.
Saunders Company, pp. 1061-1080.
Wanless, IR. (1998).
Anatomy and Developmental Anomalies of the Liver. IN: Feldman M,
Scharschmidt BF, and Sleisenger MH (eds), Gastrointestinal and Liver
Disease: Pathophysiology,
Diagnosis, and Management. Pennsylvania, W.B.
Saunders Company, pp. 1055-1058.
Zankim D (1996).
Metabolism of Glucose and Fatty Acids by the Liver. IN: Zakim D, and
Boyer TD
(eds.) Hepatology: A Textbook of Liver Disease.
Pennsylvania, WB Saunders Company, pp 58-91.
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Protecting
Liver Health
There are many risk
factors associated with liver disease. Being knowledgeable of these
factors and taking preventative measures to avoid these risks can reduce a
person's chance of developing liver disease. Moreover, if you live with
someone who has known liver disease, practicing healthy living
together skills can help decrease chance of sharing liver disease.
| Protecting
Liver Health |
| Alcohol |
Excessive
alcohol intake (beer, wine, hard liquor) can damage the liver and lead to
cirrhosis. If you choose to drink alcohol
at all, do so in moderation. If you already have liver disease, dont
use alcohol at all. |
| Sex |
Hepatitis
A and B can be transmitted through sexual contact. This is especially a
risk when a person is suffering from other sexually transmitted diseases
that produce sores or breaks in the skin. Practicing safe sex can avoid
this risk.
Hepatitis C is
rarely transmitted through sexual contact, however, use of a latex condom
is recommended as hepatitis C can be transmitted through blood-to-blood
contact.
|
| Drugs |
Intravenous drug use
involving dirty needles is the most common mode of transport for viral
hepatitis. Just sharing a needle once at any point in a person's life is a
major risk factor for hepatitis. There is unacceptable danger here.
Also, mixing several
drugs, or drugs and alcohol, can tax the liver and potentially cause
damage. Avoid mixing drugs and alcohol and always consult your physician
before adding a medication, prescription or over-the-counter drug, to your
routine.
|
| Tattoo |
Viral
hepatitis can be transferred with dirty needles during tattooing. |
| Health
Workers |
For
those whose work increases risk of blood and body fluid exposure
(dentists, doctors, nurses, lab technicians, etc.), follow precautionary
measures of wearing protective apparel, using proper needle handling
techniques, and get prophylactic vaccinations for hepatitis B when
recommended. |
| Herbs
and Supplements |
It is unknown how
the majority of herbal
extracts are prepared and how they interact with the liver and other
medications. Certain herbs have been known to induce liver injury alone or
in combination with other drugs. The fact that herbs are natural
does not mean that they are free of toxic effects.
Avoid high doses of vitamins
or minerals unless prescribed by your healthcare practitioner.
|
| Over-the-Counter
Medications |
Be cautious about
using prescription or over-the-counter medications.
Follow instructions carefully. ((
NSAIDs (such as
aspirin), ibuprofen, and acetominophen (Tylenol) are safe when taken as
directed. However, high concentrations such as might occur with overdose
can lead to liver damage. If you have liver disease, these medications may
have to be avoided altogether. Usually, discontinuing medications that
appear to be starting to causing liver injury will avert permanent damage.
|
| Environmental
Toxins |
Use appropriate
precautions when working around industrial chemicals.
Consult with your
local health department about infectious disease risks when traveling
to foreign countries. Get vaccinations as appropriate for protection
from hepatitis A. Take appropriate food handling precautions when in areas
where food and water safety is in question. For example, boil water prior
to use. Thoroughly cook foods. Peel all fruits and vegetables.
|
| Hygiene |
Practice good
personal hygiene and handwashing. Hepatitis A is most readily transmitted
as a result of inadequate handwashing and hygiene.
Practice good food
hygiene. Do not eat uncooked shellfish. Avoid shellfish from water
whose cleanliness is questionable. Shellfish, that smells and tastes fine,
may be infected by bacteria and viruses carried in sewage runoff. Vibrio
vulnificus is a bacterial organism that is found in contaminated oysters
and other seafood. In healthy people, it rarely causes serious infection,
but in individuals with cirrhosis it can quickly cause death. Hepatitis A
virus can be contracted from uncooked clams and oysters.
|
| Other
Blood-to-Blood Contact |
Protect all cuts,
open sores, your eyes and mouth from contact with blood. Use latex gloves
when handling blood of anyone who has known hepatitis infection or whose
hepatitis status is unknown to you.
Don't share
toothbrushes or razors. If you are pregnant,
get tested for hepatitis B and C and ask for guidance from your physician.
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|
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1.
ABC's of Hepatitis
Viral hepatitis
encompasses a variety of viruses that infect and attack liver tissue.
Eight to 10 viruses have been identified, of which hepatitis A, B, C, D,
E, and G are
the most well known. They can be transmitted through various
routes although
intravenous drug use is the most common. Viral infection
can be either acute
(rapid onset and of short duration) or chronic (long
duration and slow progression).
Once a diagnosis
is made and doctors are aware that a person has viral hepatitis,
they can
determine through more specialized blood tests whether a person has
acute
or chronic viral hepatitis and the exact type of infection present.
Sometimes the virus
may be cleared, making the person immune to it. This means,
unless the
next exposure to the virus is different (like a different cold virus), the
person will not be infected again. If a person has chronic disease, the
doctor may
recommend a liver biopsy to determine the progression of
disease. A liver biopsy
is helpful to direct the doctor in treatment and
to provide a prognosis.
Hepatitis
A Virus (HAV)
People are exposed to HAV from a fecal oral route or person-to-person
contact.
People who are at the greatest risk are daycare workers (changing
diapers),
injection drug use, recent travel, or from a food or waterborne
outbreak. Forty-two
percent of cases of HAV have no known source of
infection. HAV infection is
always of short duration; it is not a
long-term disease. Sixty percent of people with
HAV recover in two months
and 100 percent recover in six months.
|
Incidence: |
Occurs
in 9.1 persons per 100,000 in the U.S. |
| Symptoms: |
Fatigue,
weakness, anorexia, nausea, vomiting, and abdominal pain. Jaundice occurs
in 90 percent of people with HAV and lasts less than two weeks. Once
jaundice occurs, symptoms tend to decrease. |
| Medications: |
None |
| Vaccine: |
A
vaccine is available for HAV. |
Hepatitis
B Virus (HBV)
Transmission of HBV occurs through needle exposure, transfusions, sexual
contact and exposure while giving birth. HBV infection can be either
short-term (acute) or long-term (chronic). Chronic infection develops in
90 percent of infants infected at birth and 25 to 50 percent of children
infected between 1 and 5 years of age. Ninety-five percent of people with
acute HBV will spontaneously clear the virus, however, in 2 to 5 percent
of adults, the virus will become chronic. Persons who develop chronic HBV
may develop liver failure, cirrhosis,
and 22 percent of people with chronic disease will |
develop
liver
cancer. There are no medications for acute HBV and the virus will
ordinarily spontaneously clear. Interferon and lamivudine are approved medications
in the U.S. for chronic infection. The way interferon works is not clearly
understood but it appears to interfere with the body's ability to
replicate the virus. About 30 to 40 percent of people on interferon
respond to treatment and clear the virus. Lamivudine, an antiviral that
also inhibits viral replication, may be given with interferon to help
clear hepatitis B virus. Transplantation may not be a very good option for
people who have HBV due to the high rate of re-infection with HBV after
transplant.
|
Incidence: |
There
are 350 million carriers of HBV worldwide. About 1 to 1.25 million persons
in the U.S. are infected. |
| Symptoms: |
People
with HBV commonly have no symptoms. |
| Medications: |
None
for acute infection; Interferon and lamivudine available for chronic
infection in the U.S.. |
| Vaccine: |
A
vaccine is available and highly effective. It is recommended that
healthcare workers, adolescents and all newborns receive the vaccine. |
Hepatitis
C Virus (HCV)
Exposure to HCV occurs predominantly through intravenous drug use.
Transfusion and any other blood-to-blood contact are other modes of
transmission. Of the people who are exposed to HCV, 15 percent will clear
the virus. Meanwhile, 85 percent will have chronic (long-term) infection;
20 to 50 percent will eventually be diagnosed with cirrhosis,
20 percent will have liver failure, and 20 percent will |
| have
liver
cancer. HCV is most commonly diagnosed during routine testing at the
doctor's office or during a blood test prior to donating blood. This is
because disease progression is silent, taking 20 to 30 years to develop
into cirrhosis, although it is much quicker in the elderly and in persons
with alcoholic liver disease. Combination therapy with interferon and
ribavirin is often suggested for treatment of HCV. Interferon is injected
three times a week for 12 months and ribavirin is taken daily by mouth for
12 months. The goal of treatment is to reduce replication of the virus and
eventually clear the virus from the body. Close to 40 percent of people
who undergo treatment clear HCV. The response rate is lower in those
co-infected with HIV. Research on alternative HCV treatment is quite
active. |
Incidence: |
Among
intravenous drug users, 48 to 90 percent have HCV. In the U.S., 4 million
people are infected. |
| Symptoms: |
People
with HCV report the following symptoms, fatigue, depression, nausea,
abdominal discomfort, and difficulty concentrating. Jaundice occurs more
in people who have acute disease, and is rare in
chronic disease. |
| Medications: |
Interferon
and ribavirin are approved for use in the U.S. for chronic HCV. |
| Vaccine: |
None
are available. |
Hepatitis
D Virus (HDV, Delta agent/virus)
HDV is a viral infection that only occurs in persons with
preexisting HBV infection. The most common mode of transmission is of HDV
is through intravenous drug use. It can either be acute or chronic.
Co-infection of acute HBV and HDV has a short course. However, there is a
risk that co-infected people |
can
have a severe and progressive course known as 'superinfection.' Fifteen
percent of superinfected people have spontaneous recovery while 70 percent
have a slow, progressive course leading to cirrhosis.
People who use intravenous drugs usually have a more aggressive course of
disease. For people who have chronic disease, interferon may be
recommended.
|
Incidence: |
A
total of 15 million people are infected worldwide. |
| Symptoms: |
Commonly
there are no symptoms. |
| Medications: |
None
for acute infection; interferon may be recommended for chronic infection. |
| Vaccine: |
There
is no vaccine for HDV. |
Hepatitis
E Virus (HEV)
HEV is an acute disease with no chronic state that is most commonly
transmitted
via water contaminated with feces. Pregnant women and
travelers are most at
risk for this disease. HEV causes inflammation of
the liver with most people
having a complete recovery. Pregnant women,
however, have a high risk of liver
disease and death to the mother and
fetus.
|
Incidence: |
HEV
is rare in the U.S. |
Symptoms:
|
Fever,
jaundice, dark urine, clay colored stools, lack of appetite, nausea,
vomiting and abdominal pain. |
| Medications: |
None
available. |
| Vaccine: |
There
is no vaccine for HEV. |
Hepatitis
G Virus (HGV)
Transmission of HGV is common in blood and organ recipients, as well as
intravenous drug users. HGV has just recently been identified and the
symptoms, treatment, and recovery rate are yet unknown. It can be acute
and chronic.
|
Incidence: |
Unknown. |
| Symptoms: |
Unknown. |
| Medications: |
None
available. |
| Vaccine: |
None
available. |
References:
Poynard T, Marcellin
P, Lee SS, et al (1998). Randomized trial of inteferon a2b plus
ribavirin for 48
weeks or for 24 weeks versus interferon a2b plus placebo
for 48 weeks for treatment of chronic
infection with hepatitis C virus.
Lancet;352:1426-1432.
Reichard O, Narkrans
G, Fryden A, et al (1998). Randomized, double-blind, placebo-controlled
trial of
interferon a -2b with and without ribavirin for chronic hepatitis
C. Lancet;351:83-87.
Terrault NA, Wright
TL (1998). Viral Hepatitis A Through G. IN: Feldman M, Scharschmidt
BF,
and Sleisenger MH (eds), Gastrointestinal and Liver Disease:
Pathophysiology, Diagnosis, and
Management. Pennsylvania, W.B.
Saunders Company, pp. 1123-1164.
|
2.
Alcoholic Liver Disease
|
Alcoholic liver
disease impacts two million people in the United States. The liver is the
'Poison Control Center' of the body, detoxifying toxic chemicals
introduced into the blood. The development of alcoholic liver disease can
often be compounded by the simultaneous intake of medications and other
poisons, as the liver is then charged with detoxifying all substances at
once. Although the exact cause of liver disease in those that drink
alcohol is unclear, alcohol appears to cause liver damage by blocking the
normal metabolism of proteins, carbohydrates, and fats. Substances called
cytokines, chemicals involved in the immune system and inflammation, also
seem to be involved.
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| |
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|
Also, women appear
to be more likely to suffer liver damage from alcohol than men. Women, as
well as older adults, have less enzyme activity required to detoxify the
alcohol. There is some data to suggest that part of the problem for women
is the relative lack of an enzyme in the lining of the stomach that is
need to metabolize alcohol. Moreover, a woman have relatively more body
fat and less body water than a man, and this can result in a higher
concentration of alcohol, even if she is the same weight and drinks the
same amount as a man. For women, alcohol is truly more potent.
Researchers are
currently studied other factors that make individuals who drink more
susceptible to alcoholic liver disease. These may include ethnicity,
nutritional status, drug use, or simultaneous hepatitis
B or C infection.
Alcoholic liver
disease, if left unchecked, can eventually result in cirrhosis
of the liver. Cirrhosis refers to a process of liver scarring that is
usually thought to be permanent. Of the 26,000 people who die from
cirrhosis each year, 40 to 90 percent have a history of alcohol abuse.
However, if detected and treated early, cirrhosis can be prevented.
|
|
How
Much Alcohol is Too Much?
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|
Liver disease most
commonly develops only after a 'threshold' of alcohol has been consumed,
although the amount of alcohol that can cause injury varies widely.
Generally, if a
person drinks the equivalents of eight 12 ounce cans of beer, 1 1/3
bottles of wine, or 1/2 pint of distilled spirits daily for about 20
years, it is likely that liver disease will occur. Such liver damage may
be anywhere on a spectrum ranging from relatively mild to extremely
serious.
On the other hand,
there are certainly some individuals who can consume these amounts of
alcohol and never develop any identifiable liver abnormality.
|
|
Many alcohol users
do not experience symptoms of liver disease until damage becomes extensive
and complications such as cirrhosis, jaundice (buildup of bilirubin in the
blood such that skin and eyes become yellow), ascites (abdominal fluid
retention), and altered mental status arise. However, flu-like symptoms of
fatigue and fever, as well as an enlarged liver may occur earlier in the
disease process. If alcoholic liver disease is suspected, a liver biopsy
is commonly performed. This test will determine the severity of disease
and predict a prognosis.
Treatment
The primary treatments for alcoholic liver disease is cessation of alcohol
use and improvement of nutritional state if necessary. The physician may
assist in the process of alcohol withdrawal by providing counseling,
referrals to supportive programs, and prescribing medication to minimize
withdrawal symptoms.
Nutritionally, the
person with alcoholic liver disease is encouraged to consume a diet high
in calories, protein, and fruit and vegetables. Vitamin
and mineral supplementation may also be recommended. People who have
alcoholic liver disease are frequently malnourished. Alcohol, which has
seven calories per gram, typically replaces more nutritious foods in the
diet. The alcohol calories are 'empty' calories, totally devoid of
nutrition. Malnutrition may weaken a person's ability to fight disease and
repair tissue. If liver disease patients are experiencing an altered
mental state , protein restriction may be necessary. In ascites, sodium
and fluid intake may need to be restricted. A health care team can best
evaluate liver function and complications and give recommendations for
optimal nutrition care.
Further medications
and procedures
may be necessary to help reduce liver disease complications and maximize
liver function. Some authorities believe that steroids can help in the
management of some forms of alcoholic liver disease (although this is
controversial). It is thought that these medications may help reduce
inflammation, thus minimizing liver damage. Steroid use is associated with
a great many serious complications, and the addition of steroids to any
treatment program should only be considered after a careful review of
possible benefits as compared to the wide range of steroid complications.
References:
Maher, JJ (1998). Alcoholic
Liver Disease. IN: Feldman M, Scharschmidt BF, and Sleisenger MH (eds),
Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, and
Management. Pennsylvania, W.B. Saunders Company, pp. 1199-1210.
Sherlock S and
Dooley J (1993). Alcohol and the Liver. Diseases of the Liver and
Biliary System. Oxford, Blackwell Scientific Publications, pp 370-389.
|
|
3.
Cirrhosis
Cirrhosis is the
irreversible damage of the liver that can be caused by a variety
of
diseases including viral
hepatitis, alcoholic
liver disease, cancer,
and others.
Cirrhosis occurs when there is damage of liver tissue resulting an
accumulation
of scar tissue, decreased functioning liver tissue, and a
distortion of normal liver
structure that will ultimately further
interfere with normal liver function. There are
many debilitating
complications associated with cirrhosis including
encephalopathy,
ascites,
portal
hypertension, gastrointestinal bleeding,
hepatorenal
syndrome, osteoporosis,
and malnutrition.
Liver transplantation is the
only cure for people with cirrhosis.
|
Encephalopathy
Encephalopathy occurs when the liver is no longer able to clear waste
products (especially protein byproducts) and toxins from the blood usually
processed by the liver. Symptoms of encephalopathy include loss of
consciousness, drowsiness, confusion, and coma. A person with
encephalopathy has difficulty explaining simple statements or even stating
the day, month, and year.
The initial
treatment for encephalopathy is the medication
lactulose that may be administered in combination with a low protein diet.
About 75 to 80 percent of people who take lactulose respond to therapy
with an improved mental state.
Increased protein in
the diet has been shown to be the culprit in only 7 to 9 percent of the
cases of encephalopathy. Adequate protein intake in liver disease is
essential to maintaining health and improving healing and immune response.
Protein requirements should be discussed with the health care team and
determined individually by considering nutritional status, disease state,
and
|
| Common
Symptoms of Cirrhosis |
- Anorexia
- Indigestion
- Nausea and vomiting
- Constipation or
diarrhea
- Dull aching
abdominal pain
- Gastrointestinal
bleeding
- 'Mousy' breath
- Itching
- Extreme skin
dryness
- Changes in skin
elasticity
- Appearance of blood
vessels under the skin
- Jaundice
|
|
| prior
protein intake. Of
course, preventing or stopping any bleeding in the gastrointestinal tract
is also of extreme importance as digestion and absorption of digested
blood will increase protein byproducts in the blood. |
Ascites
Ascites is an accumulation of abdominal fluid caused by changes in portal
blood
pressure and the reduction of liver proteins responsible for
maintaining fluid
balance. Ascites may appear suddenly or without much
notice. Symptoms
associated with ascites include dehydration, muscle
wasting (thin limbs and a
large belly), and lack of sweating. When the
conditions associated with ascites
are present, normal blood flow
throughout the body is reduced. The kidneys
recognize this reduction and
typically react by conserving sodium and water, often
worsening the
ascites and sometimes leading to kidney failure as well.
The treatment for
ascites is a low
sodium diet and medications
called diuretics. A
low sodium diet (less than 2000 milligrams/day) when
followed on a daily basis
can be extremely effective. Eating low sodium
one day and a regular sodium diet
the next day does not help reduce the
accumulation of fluid. Follow-up visits are
necessary to monitor weight,
blood pressure, and adjust the dosage of the
diuretic as necessary.
Portal
Hypertension/Gastrointestinal Bleeding
As scar tissue accumulates and disrupts normal liver structure, blood flow
through
the liver can become difficult. The usual pathways for blood flow
are often blocked
or become inefficient. This difficulty of flow increase
blood pressure in portal vein
leading to the liver.
The most common
consequence of portal hypertension is esophageal varices,
or enlarged
veins. As portal blood pressure rises, blood flow is diverted to other
close blood vessels such as those feeding the digestive tract. These
dilated
blood vessels unused to the high flow and pressure of blood often
break and
bleed. Fifty to sixty percent of people with cirrhosis will
develop varices.
Symptoms include vomiting of blood and dark stools. Upon
examination, the
doctor will feel the liver and spleen. An enlarged spleen
is one of the most useful
diagnostic signs of portal hypertension, and a
firm liver suggests that the scarring
of cirrhosis may be present.
To diagnose varices, the doctor can
visualize the esophagus using using an
endoscope (a small flexible tube
that is swallowed). Varices can often be seen
bulging in the lining of the
esophagus. Endoscopy allows the doctor to grade the
severity of the
varices and to treat varices that are bleeding. The greater the size
of
the varices, the greater the chance they will bleed.
If bleeding occurs,
the chance of having a second bleed is high, 60 to 70 percent
chance over
a two-year period. Factors that can increase
the risk of bleeding
include alcohol intake, aspirin, and
non-steroidal anti-inflammatory drugs (NSAID)
use such as Advil, Motrin,
ibuprofen, Naprosyn. There are endoscopy-related
procedures
a doctor can use to treat and prevent bleeding such as sclerotherapy
or
variceal banding.
Hepatorenal
Syndrome
This syndrome usually but not always affects patients with end stage
alcoholic
cirrhosis. The cause of this hepatorenal syndrome is unclear but
likely results from
changes in blood flow to the kidney associated with
portal hypertension and
some medications such as diuretics. Symptoms
include poor appetite, weakness,
and fatigue initially and then nausea,
vomiting, and thirst. Management of
hepatorenal syndrome typically
involves admission to the hospital for careful
monitoring and treatment to
restore normal kidney function.
Osteoporosis
Nutrient deficiencies are common in people with cirrhosis due to their
symptoms
of poor appetite, nausea, vomiting, and diarrhea that make
getting adequate
nutrients difficult. Osteoporosis (reduced bone mass)
caused by limited calcium
intake can be common. Also, alcohol, one cause
of liver disease, can interfere
with bone formation as well as adequate
nutrient intake. If osteoporosis is present,
a calcium supplement may be
used to help prevent any further bone loss.
Malnutrition
Malnutrition, literally meaning bad nutrition, is a term used to describe
a person
is not getting the essential nutrients necessary for proper body
function. Many
people with cirrhosis are malnourished due to their
symptoms and the body's
additional energy requirements due to disease.
Worsening this situation, the
decreased production of bile by the damaged
liver may impair the body's ability
to absorb nutrients. Diet restrictions
such as low sodium and low protein can also
impact food choices and food
taste and decreasing intake of food. Malnutrition
can result in decreased
immune function and decreased ability to heal. People
who find themselves
eating less, losing more than 10 pounds in one month, or
having difficulty
finding enough food to eat because of a restrictive diet should
consult
their physician and a dietitian to discuss meal planning to optimize
nutrition without compromising liver health.
References:
Bass NM and Somberg
KA (1998). Portal Hypertension and Gastrointestinal Bleeding. IN:
Feldman M,
Scharschmidt BF, and Sleisenger MH (eds), Gastrointestinal
and Liver Disease: Pathophysiology,
Diagnosis, and Management.
Pennsylvania, W.B. Saunders Company, pp. 1284-1295.
Hasse J, Weseman B,
Fuerman MP, Loeffler M et al (1997). Nutrition Therapy for End-Stage
Liver
Disease: A Practical Approach. Support Line; 19(4), 8-15.
Runyon BA (1997). Treatment
of Patients with Cirrhosis and Ascites. Seminars in Liver
Disease;17(3),
249-260.
Sherlock S and
Dooley J (1993). Hepatic Encephalopathy. Diseases of the Liver and
Biliary System.
Oxford, Blackwell Scientific Publications, 1993, pp
86-101.
Sherlock S and
Dooley J (1993). Ascites. Diseases of the Liver and Biliary System. Oxford,
Blackwell
Scientific Publications, pp 114-131.
Sherlock S and
Dooley J (1993). The Portal Venous System and Portal Hypertension.
Diseases of the
Liver and Biliary System. Oxford, Blackwell Scientific
Publications, pp 132-178.
Sherlock S and
Dooley J (1993). Hepatic Cirrhosis. Diseases of the Liver and Biliary
System. Oxford,
Blackwell Scientific Publications, pp 357-369.
4.
Liver Cancer
Liver cancer is the
7th most common cause of cancer in men and the 9th in women
worldwide.
About 310,000 to one million cases occur each year with risk for liver
cancer increasing as a person ages. Tumors in the liver can either
originate in the
liver or spread to the liver from remote or adjacent
organs. Major risk factors for
liver cancer are chronic, active hepatitis
B (HBV) and C (HCV) and cirrhosis.
In simple terms,
cancer is the uncontrolled overgrowth of cells. Under normal
circumstances, cell growth is organized. It takes place at a natural pace
for each
organ or tissue type and is controlled by each cell's genetic
material.
Occasionally this genetic material is corrupted, and more often
than not, this
'mutation' is corrected. But, at times, it is not and the
pace and control of cell
growth goes array. In the case of chronic, active
liver diseases, experts speculate
that an increased incidence of cancer
occurs because of the accelerated
regeneration of liver tissue in response
to constant injury.
| The
liver is a difficult organ to examine and often the growth of cancer can
progress with minimal symptoms. When a liver tumor is big enough to be
felt by hand, the tumor has already reached an appreciable size. Because
of the ability of the liver to accommodate itself to changes, the tumor
must reach a large size before the liver has difficulty functioning.
Unfortunately, the tumor is typically advanced at the time of the first
doctor visit. |
Common
Symptoms of Liver Cancer
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Ascites may be present
at the initial visit, however most people with ascites
already have
cirrhosis which can cause abdominal fluid rentention also. Weight
loss and
decreased lean muscle mass may be present initially or it can occur as
the
disease progresses. Jaundice does not usually happen initially, but can
occur
as the disease progresses.
Small liver cancers
are a common complication of cirrhosis. The presence of the
cancer can be
masked by other symptoms. However, if symptoms of cirrhosis
worsen, it may
be a signal that disease process has changed or worsened.
Common blood tests
of liver function do not distinguish liver cancer from other
masses or
from cirrhosis. The blood test of choice to detect liver cancer is
alpha-fetoprotein (a protein that is produced by cancer cells), and an
elevated
test can indicate potential tumors. Elevations in cholesterol can
occur in 10 to 40
percent of people with liver cancer, however, this is
not diagnostic of cancer.
Computed
tomography (CT) detects the majority of liver cancer and can define
the extent of the tumor within the liver and in other parts of the body.
Magnetic
resonance imaging (MRI) is useful in detecting small tumors.
Treatment for liver
cancer depends on the size of the cancer, the number of
cancers, and if
they have spread into other organs. Surgery can provide the best
chance of
a cure only when the tumor is in a confined space and the remaining
non-cancer tissue is not already damaged (cirrhotic). There is a high
recurrence
rate after surgery, usually making the person with liver cancer
in eligible for
transplant.
Chemotherapy,
attempting to erradicate the cancer with toxic
medications, has a success
rate of 20 percent. Discussions with an oncologist
will
determine if a person is eligible for this type of therapy. For more
information on
cancer visit Mediconsult's About
Cancer program listed in the resources
section.
References:
Kew MC (1998). Hepatic
Tumors and Cysts. IN: Feldman M, Scharschmidt BF, and Sleisenger MH
(eds),
Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, and
Management.
Pennsylvania, W.B. Saunders Company, pp. 1404-1415
5.Other
Liver Diseases
There are a variety
of diseases other than viral hepatitis, alcohol, and cancer that
can cause
liver disease. The most common are discussed here.
Primary
Biliary Cirrhosis (PBC)
PBC is an uncommon, chronic, progressive disease. There are only 40 to 150
cases per one million people in the U.S. and the majority of cases (90
percent)
are women. PBC is usually diagnosed around 50 years of age.
Symptoms of this
disease commonly include itching and fatigue. Other signs
include jaundice,
cholesterol deposits in the skin, and ascites (swollen
abdomen). About 25 percent
of people who are diagnosed with PBC have no
symptoms and normal liver
function tests. This liver disease destroys the
bile ducts of the liver and causes
portal hypertension. Fibrosis is
initially seen with the disease progressing to
cirrhosis.
The only completely effective treatment available for liver disease is
transplantation.
Complications that
can occur with PBC include osteoporosis, itching, deficiency of
fat-soluble vitamins (ADEK), elevated cholesterol and lipids, and fatty
diarrhea.
Most of these complications are due to the inability of the
liver to process bile
acids correctly that leads to poor fat absorption in
the intestinal tract.
Primary
Sclerosing Cholangitis (PSC)
PSC is a liver disease of unknown cause. In PSC, the bile ducts become
narrowed due to inflammation and scarring. This progressive narrowing can
cause blocked bile flow that can result in liver damage. About 75 percent
of the
cases diagnosed with the disease are men who are about 40 years of
age. There
is an association between PBC and irritable bowel disease (IBD).
In fact 70
percent of people who have PBC have IBD; of those people, 87
percent have
ulcerative colitis and 13 percent have Crohn's disease.
Most people do not
have symptoms at the time of diagnosis and the disease
usually progress
slowly over 10 to 15 years. As the disease becomes more
advanced, a person
may complain of fatigue, itching, and fatty diarrhea. Upon
further
evaluation, vitamin A, D, and E deficiencies can be found along with
elevated cholesterol and osteoporosis. Liver biopsy is helpful in staging
the
severity of disease. Currently there is no dependable treatment
although studies
continue with several medications. Liver transplantation
is the treatment of choice
and PSC is the fourth leading cause of
transplantation.
Wilson's
Disease
Wilson's Disease is a hereditary disorder of the liver that causes the
liver to store
excess copper. It effects 1 in 30,000 people and is
detected between ages 3 and
40. If diagnosed promptly and treated
consistently, the prognosis is good.
Copper
is an essential mineral required by the body and most people consume
1.5
to 4 milligrams (mg) a day. Copper is absorbed in the upper intestine and
excess copper is excreted in the bile (about 1 to 4 mg). In people with
Wilson's
disease, the excess copper is not used properly by the liver to
make essential
proteins and is not excreted efficiently in the bile,
resulting in copper overload.
The symptoms of
Wilson's disease include malaise, anorexia, and nausea.
Some people may
develop severe chronic liver disease and develop symptoms
of enlarged
liver and spleen, ascites, low albumin, and an abnormal ability to
coagulate blood. Wilson's disease rarely progresses into liver cancer.
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Unique symptoms
experienced by those with liver disease include:
- Neurological
Involvement
A person may have poor coordination, loss of fine motor control, changes
in gait, drooling, and swallowing difficulties. Intellectual ability is
not impaired.
- Psychiatric
Changes
This impacts only 20 percent of people with Wilson's Disease. People may
have neurotic and/or compulsive behaviors and fears.
- Eyes
Changes
While vision changes are not noticed, a classic symptom of Wilson's
Disease is Kayser-Fleischer rings, a characteristic brown pigment that can
be seen on slit-lamp exam by an ophthalmologist. These develop when excess
copper is distributed throughout the cornea.
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The treatment for
people with Wilson's disease includes reducing the amount of
copper rich
foods they eat and medication. Copper rich foods include organ
meats,
shellfish, nuts, chocolate, and mushrooms. Medications
used for the
treatment of Wilson's disease work by increasing the
excretion of excess copper
in the urine or the feces.
Hereditary
Hemochromatosis (HHC)
HHC is a disorder causing iron overload due to an increase in intestinal
absorption of iron. In a normal diet, 1 to 2 mg of iron
is absorbed each day. In
people with HHC, about 3 to 6 grams (gm) is
absorbed daily resulting in iron
overload and liver damage. If it is
diagnosed and treated early, a person can
have a normal lifespan.
Detection is most likely to occur during a routine blood
screening.
Detection typically
occurs between 4 and 50 years of age with more men than
women found to
have HHC. Some people are identified because of other
relatives and will
present with no symptoms. Others may complain of weakness,
fatigue,
abdominal pain, loss of libido, and joint pain. Diabetes and bronzed skin
may be present. People may also present with symptoms of liver damage
including an enlarged liver and spleen, ascites, swelling, and jaundice.
If a HHC is
diagnosed and effective treatment undertaken before cirrhosis
develops,
the person will not develop any long-term liver complications. If
detected
after cirrhosis develops, the risk of liver cancer rises. Treatment of HHC
involves weekly removal of 1 to 2 pint of blood until the blood levels of
iron drop to
within the normal range. Once iron levels are normal, blood
draws of one pint may
only be required every 2 to 3 months.
Drug-Induced
Liver Disease
Liver injury caused by drugs or other chemicals accounts for less than 5
percent of
jaundice or acute hepatitis and very few cases of chronic liver
disease. The
mechanism of injury is often poorly understood. Factors that
put a person at risk
for drug-induced liver disease include age, sex, dose
of drug taken, history of
other drug use, alcohol, nutrition status
(obesity or fasting), preexisting liver
disease, and the presence of other
diseases such as diabetes, HIV/AIDS, kidney
failure, and prior organ
transplant. The diagnosis of drug induced liver disease is
confirmed by a
liver biopsy.
Symptoms and
treatment of drug-induced liver disease vary widely and depend
on the
extent of liver damage. They also include removal of the offending agent.
Acetominophen
Induced Injury
Acetominophen (Tylenol) is safe when taken at its recommended dosage (1 to
4
gm a day). However, when taken in excess, it is the leading cause of
liver injury
and has been recognized as such since the 1960's. Moderate
doses of 15 to 20
gm over a three day time period in people who are
fasting or taking drugs that can
interact with Acetominophen can cause
liver injury. The combination of
acetominophen and alcohol leads to
further risk of liver injury.
Most commonly,
people present with symptoms such as nausea, vomiting,
malaise and liver
pain. In severe cases, jaundice, low blood sugars, and features
of liver
failure may be present. Liver
function tests (the transaminase enzymes)
can be extremely high, often
a clue to the diagnosis. If a person presents within
four hours of
ingestion of acetominophen, the stomach should be emptied by
placing a
tube in the stomach and suctioning out the contents. Blood levels of
acetominophen should be determined to determine the extent of the
exposure,
options for treatment, and outcome. As with other drug-induced
liver injuries,
symptoms and treatment will be determined by extent of
damage.
References:
Bacon, BR (1997). Diagnosis
and Management of Hemochromatosis. Gastroenterology; 113:995-999.
Bacon BR, Britton,
RS (1998). Hereditary Hemochromatosis. IN: Feldman M, Scharschmidt
BF, and
Sleisenger MH (eds), Gastrointestinal and Liver Disease:
Pathophysiology, Diagnosis, and
Management. Pennsylvania, W.B.
Saunders Company, pp. 1097-1102.
Cox DW, Roberts EA
(1998). Wilson's Disease. IN: Feldman M, Scharschmidt BF, and
Sleisenger MH
(eds), Gastrointestinal and Liver Disease:
Pathophysiology, Diagnosis, and Management.
Pennsylvania, W.B.
Saunders Company, pp. 1104-1111.
Farrell GC (1998). Liver
Disease Caused by Drugs, Anesthetics and Toxins. IN: Feldman M,
Scharschmidt BF, and Sleisenger MH (eds), Gastrointestinal and Liver
Disease: Pathophysiology,
Diagnosis, and Management. Pennsylvania, W.B.
Saunders Company, pp. 1221-1247.
Harnois DM, Lindor
KD (1997). Primary Sclerosing Cholangitis: Evolving Concepts in
Diagnosis and
Treatment. Digestive Diseases;15:23-41.
Lindor KD (1998). Primary
Biliary Cirrhosis. IN: Feldman M, Scharschmidt BF, and Sleisenger MH (eds),
Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, and
Management. Pennsylvania,
|W.B. Saunders Company, pp. 1275-1281.
Neuberger J (1997). Primary
Biliary Cirrhosis. Lancet;350:875-79.
Schilsky, ML (1996).
Wilson Disease: Genetic Basis of Copper Toxicity and Natural History. Seminars
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n Liver Disease; 16(1), 83-93.
Sherlock S and
Dooley J (1993). Primary Biliary Cirrhosis. Diseases of the Liver
and Biliary System.
Oxford, Blackwell Scientific Publications, pp 236-248.
Sherlock S and
Dooley J (1993). Sclerosing Cholangitis. Diseases of the Liver and
Biliary System.
Oxford, Blackwell Scientific Publications, pp 249-259.
Sherlock S and
Dooley J (1993). Wilson's Disease. Diseases of the Liver and
Biliary System. Oxford,
Blackwell Scientific Publications, pp 400-407.

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