Download
1 / 47
470 likes | 656 Views
DISORDER OF CARBOHYDRATE METABOLISM. Ph.D. , MD , Assistant Professor Ha nna Saturska. molecular formula C12H22O11. Major index which describes metabolism of carbohydrates, is a sugar level in blood. In healthy people it is 4,4-6,6 mmol/l.
E N D
DISORDEROFCARBOHYDRATE METABOLISM Ph.D., MD,Assistant ProfessorHanna Saturska
molecular formulaC12H22O11 • Major index which describes metabolism of carbohydrates, is a sugar level in blood. • In healthy people it is 4,4-6,6 mmol/l. • Sucrose is the organic compound commonly known as table sugar and sometimes called saccharose. • The molecule is a disaccharide composed of the monosaccharidesglucose and fructose
glucose level in blood 3,3-5,5 mmol/l. • GlucoseC6H12O6, also known as D-glucose, dextrose, or grape sugar) is a simple monosaccharide • Open-chain form • Cyclic forms
This value is summary result of complicated interaction of many exogenous and endogenous influences. • 1. The first it reflects a balance between amount of glucose which is utilized by cells amount of glucose which entrance in blood
2. The second, glucose level in blood reflects an effect of simultaneous regulatory influence on carbohydrates metabolism of the nervous system and endocrine glands: adrenal cortex (adrenalin, noradrenalin) layer pituitary gland (somatotropic thyreotropic adrenocorticotropic hormones) pancreas (insulin, glucagone, somatostatin) thyroid (thyroxin, triiodthyronine)
Among enumerated hormones only insulin lowers glucose concentration in blood the rest of hormones increase it . • The glucose concentration in blood describes carbohydrates metabolism both of healthy man and sick. • Illnesses base of which is disorder of carbohydrates metabolism can flow with rise of glucose concentration in blood and with lowering of it.
Rise of glucose concentration is named hyperglicemia lowering hypoglicemia. • For example,hyperglicemia is very typical for diabetes mellitus, hypoglycemia – for glycogenosis. hypoglicemia hyperglicemia diabetes mellitus glycogenosis
Diabetes mellitus • Diabetes mellitus, often simply referred to as diabetes—is a group of metabolic diseases in which a person has high blood sugar, • either because the body does not produce enough insulin, • or because cells do not respond to the insulin that is produced.
This high blood sugar produces the classical symptoms: polyuria (frequent urination), polydipsia (increased thirst) polyphagia (increased hunger).
There are three main types of diabetes: • Type 1 diabetes: results from the body's failure to produce insulin, and presently requires the person to inject insulin. • (Also referred to as insulin-dependent diabetes mellitus, • IDDM for short, and juvenile diabetes.)
Type 2 diabetes: results from insulin resistance, a condition in which cells fail to use insulin properly, sometimes combined with an absolute insulin deficiency. (Formerly referred to as non-insulin-dependent diabetes mellitus, NIDDM for short, and adult-onset diabetes.)
Gestational diabetes: is when pregnant women, who have never had diabetes before, have a high blood glucose level during pregnancy. It may precede development of type 2 DM.
Other forms of diabetes mellitus include • congenital diabetes, which is due to genetic defects of insulin secretion, • cystic fibrosis-related diabetes, steroid diabetes induced by high doses of glucocorticoids, • several forms of monogenic diabetes.
As of 2000 at least 171 million people worldwide suffer from diabetes, or 2.8% of the population. • Type 2 diabetes is by far the most common, affecting 90 to 95% of the diabetes population
Type 1 • Type 1 diabetes mellitus is characterized by loss of the insulin-producing beta cells of the islets of Langerhans in the pancreas leading to insulin deficiency.
In 1869, while looking down the microscope, the Berlin physician Paul Langerhans discovered small “islets” of cells scattered throughout the pancreas. These cells are responsible for the production of insulin.
Somato- statin • Digestive enzymes include trypsin, chymotrypsin, pancreatic lipase, and pancreatic amylase, and are produced and secreted by acinar cells of the exocrine pancreas. glukagon insulin
Type 2 • Type 2 diabetes mellitus is characterized by insulin resistance which may be combined with relatively reduced insulin secretion. The defective responsiveness of body tissues to insulin is believed to involve the insulin receptor. However, the specific defects are not known. Diabetes mellitus due to a known defect are classified separately. Type 2 diabetes is the most common type. • In the early stage of type 2 diabetes, the predominant abnormality is reduced insulin sensitivity. At this stage hyperglycemia can be reversed by a variety of measures and medications that improve insulin sensitivity or reduce glucose production by the liver.
Gestational diabetes • Gestational diabetes mellitus (GDM) resembles type 2 diabetes in several respects, involving a combination of relatively inadequate insulin secretion and responsiveness. It occurs in about 2%–5% of all pregnancies and may improve or disappear after delivery. Gestational diabetes is fully treatable but requires careful medical supervision throughout the pregnancy. About 20%–50% of affected women develop type 2 diabetes later in life.
When a woman has high blood sugar only while she is pregnant, it is a special type called Gestational Diabetes. Usually the blood sugar is kept in the normal range by insulin made by the body. Most of the time, pregnant women make more insulin to lower the blood sugar. • However, some women cannot do this, and these are the women who • develop gestational diabetes. This usually occurs in the second half of pregnancy.
Symptoms: • Increased thirst • Increased urination • Weight loss in spite of increased appetite • Fatigue • Nausea and vomiting • Frequent infections including those of the bladder, vagina, and skin • Blurred vision • Note: Usually there are no symptoms.
People (usually with type 1 diabetes) may also present with diabetic ketoacidosis, a state of metabolic dysregulation characterized by the smell of acetone; a rapid, deep breathing known as Kussmaul breathing; nausea; vomiting and abdominal pain; and an altered states of consciousness.
A rarer but equally severe possibility is hyperosmolar nonketotic state, which is more common in type 2 diabetes and is mainly the result of dehydration. Often, the patient has been drinking extreme amounts of sugar-containing drinks, leading to a vicious circle in regard to the water loss. • A number of skin rashes can occur in diabetes that are collectively known as diabetic dermadromes.
Causes • Type 1 diabetes is also partly inherited and then triggered by certain infections, with some evidence pointing at Coxsackie B4 virus. There is a genetic element in individual susceptibility to some of these triggers which has been traced to particular HLAgenotypes (i.e., the genetic "self" identifiers relied upon by the immune system). However, even in those who have inherited the susceptibility, type 1 diabetes mellitus seems to require an environmental trigger.
Causes • The cause of diabetes depends on the type. Type 2 diabetes is due primarily to lifestyle factors and genetics.
Diagnosis • Diabetes mellitus is characterized by recurrent or persistent hyperglycemia, and is diagnosed by demonstrating any one of the following • Fasting plasma glucose level ≥ 7.0 mmol/L (126 mg/dL). • Plasma glucose ≥ 11.1 mmol/L (200 mg/dL) two hours after a 75 g oral glucose load as in a glucose tolerance test. • Symptoms of hyperglycemia and casual plasma glucose ≥ 11.1 mmol/L (200 mg/dL). • Glycated hemoglobin (Hb A1C) ≥ 6.5% • Glycosylated hemoglobin and Glucose tolerance test
Complications • Diabetes doubles the risk of vascular problems, including cardiovascular disease. • Glycated hemoglobin is better than fasting glucose for determining risks of cardiovascular disease and death from any cause • The complications of diabetes mellitus are far less common and less severe in people who have well-controlled blood sugar levels. • Wider health problems accelerate the deleterious effects of diabetes. These include smoking, elevated cholesterol levels, obesity, high blood pressure, and lack of regular exercise.
AcuteComplications of diabetes mellitus • Diabetic ketoacidosis • Hyperglycemia hyperosmolar state • Hypoglycemia • Diabetic coma • Respiratory infections
ChronicComplications of diabetes mellitus • AngiopathyChronic elevation of blood glucose level leads to damage of blood vessels • The endothelial cells lining the blood vessels take in more glucose than normal, since they do not depend on insulin. Fundus photo showing scatter laser surgery for diabetic retinopathy
Galactosemia • This is hereditary illness. In it’s base lies an blockade of galactose metabolism. In organism intermediate metabolits accumulate. There are two the main forms of galactosemia on base of transferase insufficiency and on base of galactokinase insufficiency. transferase insufficiency galactokinase insufficiency
Glycogenoses • Simple carbohydrates deposit in organism as polysaccharides. In muscles and liver accumulates glycogen. It consist of 4 % of liver weight and 2 % of muscles weight. Muscles glycogen is used as of ready fuel source for immediate guaranteeing by energy. Liver without interruption provides cerebrum and erythrocytes with glucose . • Synthesis and splitting of glycogen are exactly adjusted and coordinated processes. Attached to immediate need in glucose –cells of pancreas secret glucagone. It activates adenylatcyclase of hepatic cells. Adenilatcyclase stimulates derivation of cAMP. Under action of cAMP takes place activation of proteinkinase and this enzyme raises activity glycogenphosphorilase and oppresses activity of glucogensynthase.
Glycogenosis type I – Girke’s disease.Girke’s disease cause deficit of glucose-6-phosphatase. This enzyme provides 90 % of glucose which disengages in liver from glycogen. • It play central role in normal glucose homeostasis. Glucose which disengages attached to disintegration of glycogen or is derivated in process of gluconeogenesis obligatory goes over stage of glucose-6-phosphate. • Enzyme glucose-6-phosphatase tears away a phosphate group from glucose. There free glucose is formed it goes out in blood. • Attached to Girke’s disease stage of tearing phosphate group is blocked. There are no free glucose hypoglycemia occur. • Hypoglycemia arises. Attached to Girke’s disease glycogen is deponed in liver and kidneys. Girke’s disease
Type ІІ glycogenosis – Pompe’s disease. Illness is related to deficit of lysosomal enzyme – sour maltase, or -1,4-glucosidase. This enzyme slits glycogene to glucose in digestive vacuoles. Attached to it’s deficit glycogen accumulates at first in lysosomes and then in cytosole of hepatocytes and myocytes. • Type ІІІ glycogenosis – Cori’s disease, Forbs’ disease.This illness is named limitdecstrinosis. In it’s base lies a deficit of amylo-1,6-glucosidase. Degradation of glycogen pauses in sites of branching. Glycogen accumulates in liver and muscles. Cure is diet with big proteins maintenance. • Type ІV glycogenosis – Anderson’s disease.It is called by deficit of amilo-1,4,1,6-transglucosidase (branching enzyme). As result of this There is derivated anomalous glycogen with very long branches and rare points of branching. It is not exposed to degradation and accumulates in liver, heart, kidneys, spleen, lymphatic nods, skeletal muscles. Glycogen storage disease II (Micro) The myofibers are engorged with glycogen. On cross sections the myofibrils are pushed to the periphery. Despite the thick walls, this is not hypertrophy. These patients present with congestive failure.
Type V glycogenosis – McArdel’s disease.It’s cause is deficit of phosphorilase of myocytes. Typical pain displays in muscles after physical loading. Glycogene does not slit only in muscles. Here it accumulates. In liver mobilization of glycogen comes normal. • Type VІ glycogenosis – Hers’ disease.Illness arises as result of insufficiency of hepatic phosphorilase complex. Glycogen accumulates in liver. Typical sign is hepatomegalia. • Type VІІ glycogenosis.Illness essence is in oppression of muscle phosphofrutkinase. Symptoms are similar to McArdles disease.
