CARBOHYDRATEMETABOLISM

Disorders

molecular formula C12H22O11

Major index which describes metabolism ofcarbohydrates, is a sugar level in blood.

In healthy people it is4,4-6,6 mmol/l (70-110 mg/dl)

Sucrose is the organic compound commonlyknown as table sugar and sometimescalled saccharose.

The molecule is a disaccharide composed ofthe monosaccharides glucose and fructose

GlucoseC6H12O6, also knownas D-glucose, dextrose, or grapesugar) is asimple monosaccharide

Open-chain form Cyclic forms

This value is summary result of complicatedinteraction of many exogenous andendogenous influences.

1. The first it reflects a balance between

amount of glucosewhich entrance in blood

amount of glucosewhich is utilized by cells

2. The second, glucose level inblood reflects an effect ofsimultaneous regulatory influence oncarbohydrates metabolism of thenervous system and endocrineglands:

pituitary gland(somatotropicthyreotropic

adrenocorticotropichormones)

adrenal cortex(adrenalin,

noradrenalin)layer

pancreas(insulin,

glucagone,somatostatin)

thyroid(thyroxin,

triiodthyronine)

Among enumerated hormones onlyinsulin lowers glucose concentration inblood (hypoglycemic hormone)the rest ofhormones increase it (hyperglycemichormones) .

The glucose concentration in blooddescribes carbohydrates metabolismboth of healthy man and sick.

Illnesses base of which is disorder ofcarbohydrates metabolism can flow withrise of glucose concentration in bloodand with lowering of it.

Rise of glucose concentration is namedhyperglicemia; lowering hypoglicemia.

For example, hyperglicemia is very typicalfor diabetes mellitus, hypoglycemia – forglycogenosis.

hyperglicemia hypoglicemia

diabetes mellitus glycogenosis

Diabetes mellitus Diabetes mellitus, often simply referred to

as diabetes—is a group of metabolicdiseases in which a person has highblood sugar,

either because the body does not produceenough insulin,

or because cells do not respond to theinsulin that is produced.

This high blood sugar produces theclassical symptoms:

polyuria (frequent urination),polyuria (frequent urination),

polydipsia (increased thirst)polydipsia (increased thirst)

polyphagia (increased hunger).polyphagia (increased hunger).

There are three main types ofdiabetes:

Type 1 diabetes: results from the body'sfailure to produce insulin, and presentlyrequires the person to inject insulin.

(Also referred to as insulin-dependentdiabetes mellitus,

IDDM for short, and juvenile diabetes.)

Type 2 diabetes: results frominsulin resistance, a condition inwhich cells fail to use insulinproperly, sometimes combinedwith an absolute insulindeficiency. (Formerly referred toas non-insulin-dependentdiabetes mellitus, NIDDM for short,and adult-onset diabetes.)

Gestational diabetes: is whenpregnant women, who have neverhad diabetes before, have a highblood glucose level duringpregnancy. It may precededevelopmentof type 2 DM.

Other forms of diabetes mellitusincludecongenital diabetes, which is

due to genetic defects of insulinsecretion,cystic fibrosis-related diabetes,

steroid diabetes induced by highdoses of glucocorticoids,several forms of monogenic

diabetes.

Feature Type 1 diabetes Type 2 diabetesOnset Sudden GradualAge at onset Any age

(mostly young)Mostly in adults

Body habitus Thin or normal Often obeseKetoacidosis Common RareAutoantibodies Usually present AbsentEndogenousinsulin

Low or absent Normal,decreasedor increased

Concordancein identicaltwins

50% 90%

Prevalence Less prevalent More prevalent-90 to 95% ofU.S.

Type 1diabetesmellitus ischaracterizedby loss of theinsulin-producingbeta cells ofthe islets ofLangerhans inthe pancreasleading toinsulindeficiency.

In 1869, whilelooking down themicroscope, theBerlin physicianPaul Langerhansdiscovered small“islets” of cellsscatteredthroughout thepancreas. Thesecells areresponsible forthe production ofinsulin.

Digestive enzymesinclude trypsin,chymotrypsin,pancreatic lipase,and pancreaticamylase, areproduced andsecreted by acinarcells of theexocrine pancreas.

insulin

glukagonSomato-statin

Type 2 Type 2 diabetes mellitus is characterized

by insulin resistance which may becombined with relatively reduced insulinsecretion. The defective responsivenessof body tissues to insulin is believed toinvolve the insulin receptor. However,the specific defects are not known.Diabetes mellitus due to a known defectare classified separately. Type 2diabetes is the most common type.

In the early stage of type 2 diabetes, thepredominant abnormality is reducedinsulin sensitivity. At this stagehyperglycemia can be reversed by avariety of measures and medicationsthat improve insulin sensitivity or reduceglucose production by the liver.

Gestational diabetes Gestational diabetes mellitus (GDM)

resembles type 2 diabetes in severalrespects, involving a combination ofrelatively inadequate insulinsecretion and responsiveness. Itoccurs in about 2%–5% of allpregnancies and may improve ordisappear after delivery. Gestationaldiabetes is fully treatable butrequires careful medical supervisionthroughout the pregnancy. About20%–50% of affected womendevelop type 2 diabetes later in life.

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) mayalso present with diabetic ketoacidosis, astate of metabolic dysregulationcharacterized by the smell of acetone; arapid, deep breathing known as Kussmaulbreathing; nausea; vomiting andabdominal pain; and an altered states ofconsciousness.

A rarer but equally severe possibility ishyperosmolar nonketotic state, which is morecommon in type 2 diabetes and is mainly theresult of dehydration. Often, the patient hasbeen drinking extreme amounts of sugar-containing drinks, leading to a vicious circle inregard to the water loss.

A number of skin rashes can occur in diabetesthat are collectively known as diabeticdermadromes.

ChronicComplications of diabetesmellitus Angiopathy Chronic

elevation of bloodglucose level leadsto damage of bloodvessels

The endothelialcells lining theblood vessels takein more glucosethan normal, sincethey do not dependon insulin.

Fundus photo showing scatter lasersurgery for diabetic retinopathy