Intolerance metabolic disorders

A much more common metabolic disorder, lactose intolerance, occurs commonly in most parts of the world (notable exceptions being some parts of Africa and northern Europe). Lactose intolerance is an inability to digest lactose because of the absence of the enzyme lactase in the intestines of adults. The symptoms of this disorder, which include diarrhea and general discomfort, can be relieved by eliminating milk from the diet. 

Intolerance. Non-immunologically mediated adverse reactions. In food intolerances, these may be due to pharmacological properties of food constituents, metabolic disorders, or responses of unknown etiology. 

Carbohydrate metabolism disorders like hereditary fructose intolerance and galactosemia result in acute, leading to chronic, liver damage through depletion of available ATP (by depleting the total phosphate pool) as well as aberrant glycosylation [1, 2]. Gluconeogenic defects like pyruvate carboxylase or 1,6-fructose-bis-phosphatase deficiency... 

Health Problems from Milk. Several metabolic disorders are found in certain individuals when milk is introduced into the diet among them, milk allergy, lactose intolerance, milk intolerance, galactose disease, milk anemia, or following gastric surgery. 

Chronic diseases and disorders of digestion, metabolism and immune function, such as chronic gastric ulcer, duodenal ulcer, food allergy and intolerance, hypotension, hypoglycemia, hypothyroidism, diabetes, chronic fatigue syndrome and prolapse of organs. 

Disorders of glycerol metabolism include glycerol kinase (GK) deficiency (GKD) and glycerol intolerance syndrome (GIS). Of these, only GKD is well characterized and has a defined biochemical defect [1]. 

Abdominal obesity is associated with a threatening combination of metabolic abnormalities that includes glucose intolerance, insulin resistance, hyperinsulinemia, dyslipidemia (low HDL and elevated VLDL), and hypertension. This clustering of metabolic abnormalities has been referred to as syndrome X, the insulin resistance syndrome, or the metabolic syndrome. Individuals with this syndrome liave a significantly increased risk for developing diabetes mellitus and cardiovascular disorders. For example, men with the syndrome are three to four times more likely to die of cardiovascular disease. 

DHAP is a glycolysis intermediate, whereas glyceraldehyde must be reduced by a mitochondrial enzyme, glyceraldehyde dehydrogenase, to glycerol, which is then subject to action by glycerol kinase in the liver. The aldolase seems to be the principal pathway of metabolizing fructose and depends on the initial phosphorylation step catalyzed by fructokinase, which produces fructose-l-phosphate. Fructokinase is defective in an inherited disorder, essential fructosuria. Fructose-l-phosphate aldolase is deficient in the hereditary disorder fructose intolerance. 

Hereditary fructose intolerance is caused by an autosomal recessive hereditary defect of the enzyme fructose-l-phosphate aldolase. Whenever fructose is supplied, severe hypoglycaemia and functional disorders occur in the liver, kidneys and CNS. The prevalence is estimated at 1 20,000 births. As with galactose intolerance, the gene which codes aldolase B is also localized on chromosome 9. This enzyme defect causes fructose-l-phosphate to accumulate in the liver and tissue. The cleavage of fructose-1,6-biphosphate is only slightly compromised since the enzymes aldolase A and C are available for this process. The consumption of phosphate and ATP in the tissue results in various functional disorders (i.) inhibition of gluconeogenesis in the liver and kidneys, (2.) increase in lactate in the serum with metabolic acidosis, (3.) decrease in protein synthesis in the liver, and (4.) functional disorders of the proximal tubular cells with development of Fanconi s syndrome, (s. pp 593, 594) (193, 194, 196, 198)... 

Storage diseases Some of the genetic metabolic diseases require special dietary measures, e.g. (1.) disorders of the urea cycle are treated by means of a diet similar to that applied in encephalopathy (s. p. 594), (2.) Gierke s disease necessitates a high-carbohydrate diet (s. p. 595), (i.) Cori s disease is treated with formula diets and a starch diet (s. p. 596), (4.) galactosaemia requires a galactose-and lactose-free diet (s. p. 597), and (5.) in fructose intolerance, a fructose- and saccharose-free diet must be given, (s. p. 597)... 

Intoxication disorders include urea cycle disorders, organic acidurias, aminoacidopathies, fatty acid oxidation disorders, and carbohydrate disorders such as galactosemia or hereditary fructose intolerance. In these disorders, a partial or complete lack of enzymatic activity causes the accumulation of substances proximal to the metabolic block in tissues and body fluids, where they act as toxins (Fig. 5.1). Treatment is based on limiting the substances that are the source of the toxic metabolites and introducing alternatives (e.g., drugs, procedures) that speed the elimination of those toxic metabolites. 

Previous observations in hereditary fructose intolerance also suggest that fructose-induced hyperuricemia cannot be attributed to increased levels of PP-ribose-P. The infusion of fructose produces hyperuricemia in this disorder despite a block in the further metabolism of fructose-l-P in these patients. 

Lactose intolerance. Disorder characterized by the incapacity of the organism in digesting and metabolizing lactose, a sugar present in milk. It is caused by a lack of lactase, required to break down lactose in the digestive tract. 

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