Celiac Disease (cont.)

The signs and symptoms of celiac disease vary depending on the degree of malabsorption, and ranges from no symptoms, few or mild signs and symptoms, to severe signs and symptoms. There are two categories of signs and symptoms: 1) signs and symptoms due to malabsorption, and 2) signs and symptoms due to malnutrition including vitamin and mineral deficiencies.

1. Signs and symptoms of malabsorption

The three major categories of dietary nutrients are carbohydrates, proteins, and fat. Absorption of all of these nutrients can be reduced in celiac disease; however, fat is the most commonly and severely affected nutrient. Most of the gastrointestinal symptoms and signs of celiac disease are due to the inadequate absorption of fat (fat malabsorption). Gastrointestinal symptoms of fat malabsorption include diarrhea, malodorous flatulence (foul smelling gas), abdominal bloating, and increased amounts of fat in the stool (steatorrhea). The unabsorbed fat is broken down by intestinal bacteria into fatty acids, and these fatty acids promote secretion of water into the intestine, resulting in diarrhea. Fatty stools typically are large in volume, malodorous (foul smelling), greasy, light tan or light grey in color, and tend to float in the toilet bowl. Oil droplets (undigested fat) also may be seen floating on top of the water.

Loss of intestinal villi also causes malabsorption of carbohydrates, particularly the sugar lactose. Lactose is the primary sugar in milk. Lactose is made up of two smaller sugars, glucose and galactose. In order for lactose to be absorbed from the intestine and into the body, it must first be split into glucose and galactose. The glucose and galactose can then be absorbed by the cells lining the small intestine. The enzyme that splits lactose into glucose and galactose is called lactase, and it is located on the surface of the small intestinal villi. In celiac disease the intestinal villi along with the lactase enzymes on their surface are destroyed, leading to the malabsorption of lactose.

The signs and symptoms of malabsorption of lactose are particularly prominent in individuals with celiac disease who have an underlying lactose intolerance, a genetically determined reduction in the activity of lactase. The symptoms of lactose malabsorption (diarrhea, excessive flatulence [passing gas], abdominal pain and abdominal bloating or distension) occur because unabsorbed lactose passes through the small intestine and into the colon. In the colon, the normal colony of bacteria contain lactase and are able to split the lactose, and utilize the resulting glucose and galactose for their own purposes. Unfortunately, when they split the lactose into glucose and galactose, the bacteria also release gas (hydrogen and /or methane). A proportion of the gas is expelled and is responsible for the increased flatus (passing gas) that may occur in celiac disease. Increased gas mixed in the stool is responsible for the stools to float in the toilet bowl.

Not all of the lactose that reaches the colon is split and used by the colonic bacteria. The unsplit lactose that reaches the colon causes water to be drawn into the colon (by osmosis). This promotes diarrhea.

2. Signs and symptoms of malnutrition and vitamin or mineral deficiencies

Symptoms of malnutrition and vitamin or mineral deficiencies include: weight loss, fluid retention, anemia, osteoporosis, bruising easily, peripheral neuropathy (nerve damage), infertility, and muscle weakness.

• Weight loss and fluid retention: Weight loss is the direct result of inadequate absorption of carbohydrates, proteins and fat. However, weight loss may not always occur because individuals with celiac disease often have an enormous appetite that compensates for the reduced absorption of nutrients. Moreover, weight loss can be masked by fluid retention. Fluid retention occurs in advanced malnutrition because the reduced absorption of proteins results in low protein levels in the blood. Normal protein levels in the blood are necessary to keep fluid from leaking out of blood vessels and into the body's tissues. When blood protein levels fall as in celiac disease, fluid leaks into many tissues (edema) but particularly the ankles and feet, which swell due to the edema.
  
  
• Anemia: Lack of absorption of vitamin B12 and iron can lead to anemia.
  
  
• Osteoporosis: Lack of absorption of vitamin D and calcium can lead to osteoporosis and bone fractures.
  
  
• Easy bruising: Lack of absorption of vitamin K can lead to diminished ability of blood to clot and hence to easy bruising or excessive bleeding.
  
  
• Peripheral neuropathy (nerve damage): Deficiencies of vitamins B12 and thiamine may contribute to nerve damage with symptoms of poor balance, muscle weakness, and numbness and tingling in the arms and legs.
  
  
• Infertility: Untreated celiac disease can lead to infertility in women, lack of menses (menstruation), spontaneous abortions and low birth weight infants.
  
  
• Muscle weakness: Lack of absorption and low levels of potassium and magnesium can lead to severe muscle weakness, muscle cramps, and numbness or tingling sensations in the arms and legs.
  
  
• Abnormal liver tests: For unclear reasons, patients with celiac disease may have abnormal blood tests that suggest liver injury, specifically, elevated levels of aspartate amino transferase (AST) and/or leucine amino transferase (ALT). Occasionally, abnormalities of these tests may lead to a suspicion and subsequently a diagnosis of celiac disease.

Source: MedicineNet.com
http://www.medicinenet.com/celiac_disease/article.htm