Carbohydrate Metabolism Disorders Lecture Notes PDF

Almaaqal University Carbohydrate Metabolism Disorders Dr/ Wael Sobhy Darwish Biochemistry PhD Lec-9  Diabetes mellitus Diabetes mellitus refers to the group of d...

Almaaqal University Carbohydrate Metabolism Disorders Dr/ Wael Sobhy Darwish Biochemistry PhD Lec-9  Diabetes mellitus Diabetes mellitus refers to the group of diseases that lead to high blood glucose levels (hyperglycemia) due to defects in either insulin secretion or insulin action in the body. Diabetes develops due to 1 - Diminished production of insulin (type 1diabetes ) 2- Resistance to insulin action (type 2), including gestational diabetes.  Signs of diabetes Excessive urine production (polyuria) Thirst and increased fluid intake (polydipsia) Blurred vision Weight loss (in type 1) Lethargy Changes in energy metabolism.  Types of diabetes mellitus. 1. Type 1 diabetes mellitus )Insulin dependent diabetes mellitus ( 2. Type 2 diabetes mellitus (non-insulin-dependent diabetes mellitus (NIDDM) 3. Gestational diabetes.  Types 1 diabetes mellitus. Type 1 diabetes(T1D)/ childhood/Juvenile diabetes/ Insulin dependent diabetes. T1D affects both adults and children at any age and occurs when the person’s pancreas stop producing insulin due to destruction of the pancreatic beta cells or by inactivity of these insulin-producing cells. Type 1 diabetes is treated with insulin replacement therapy, usually by insulin injection or insulin pump, along with attention to dietary management and careful monitoring of blood glucose levels.  Cause of type 1 diabetes An autoimmune attack (to the β- cells of the pancreas) may be triggered by reaction to an infection, for example Coxsackie virus or German measles. Individuals may display genetically Environmental factors can also strongly influence expression of type 1 diabetes. Lifestyle factors are not believed to play a role.  Laboratory distinguishing between type 1 from type 2 diabetes The most definitive laboratory test to distinguish type 1 from type 2 diabetes is the C-peptide assay, which is a measure of endogenous insulin production. The presence of anti-islet antibodies Absence of insulin resistance  Types 2 diabetes mellitus. Type 2 diabetes (non-insulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes) is a metabolic disorder characterized of two processes: 1- A slowly developing resistance to insulin signaling 2- A compensatory increase in β-cell release of the hormone. With time β-cells no longer produce enough insulin. There is see correlation between obesity, increased plasma lipids and insulin resistance. Insulin resistance is generally ‘post receptor’, meaning it is a problem with the cells that respond to insulin rather than a problem with production of insulin.  Central obesity is known to predispose individuals to insulin resistance.  Obesity is found in approximately 55% of patients diagnosed with type 2 diabetes.  There is also a strong inheritable genetic connection in type 2 diabetes. Having relatives (especially first degree) with this disorder substantially increases the risk of developing type 2 diabetes.  Environmental exposures may contribute to recent increases in the rate of type 2 diabetes.  Complication of type 2 diabetes Renal failure due to diabetic nephropathy Vascular disease (including coronary artery disease) Vision damage due to diabetic retinopathy Loss of sensation or pain due to diabetic neuropathy Liver damage from non-alcoholic steatohepatitis Heart failure from diabetic cardiomyopathy. Type 2 diabetes may be first treated by increasing physical activity, decreasing carbohydrate intake and weight loss. Insulin sensitivity can be restored with only moderate weight loss.  Gestational diabetes mellitus Resembles type 2 diabetes, but is transient, occurring in about 2–5% of pregnancies. While it is fully treatable, about 20–50% of affected women develop type 2 diabetes later in life. Diabetes mellitus is diagnosed by demonstrating any one of the following: Fasting plasma glucose level at or above 126 mg/dl (7.0 mmol/l). Plasma glucose at or above 200 mg/dl (11.1 mmol/l), 2 hours after a 75 g oral glucose load in a glucose tolerance test.  Galactosemia Is a genetic metabolic disease in which there is a defect in the body's ability to convert galactose to glucose in normal manner Galactose makes up half of the sugar called lactose that is found in milk. Galactosemia affects 1 in every 55,000 newborns. Normally, the body breaks down lactose into galactose and glucose People with galactosemia are missing an enzyme called GALT , (galactose-1- phosphate uridyl transferase which normally converts galactose into glucose. Without this enzymes, harmful amounts of galactose build up in the blood.  Galactosemia a genetic disease Galactosemia is inherited in an autosomal recessive manner, meaning a child must inherit one defective gene from each parent to show the disease. Heterozygotes are carriers, because they inherit one normal gene and one defective gene. Carriers show no symptoms of galactosemia  Complication of galactosaemia Cataracts. Developmental delays. Jaundice Speech difficulties. Hepatomegaly Neurological impairments. Kidney disease.  Lactose intolerance People with lactose intolerance are unable to fully digest the sugar (lactose) in milk due to decrease production of lactase enzyme. As a result, they have diarrhea, gas and bloating after eating or drinking dairy products. The condition, which is also called lactose malabsorption, is usually harmless, but its symptoms can be uncomfortable. The signs and symptoms of lactose intolerance usually begin from 30 minutes to two hours after eating or drinking foods that contain lactose. Common signs and symptoms include: Diarrhea, Nausea, and sometimes, vomiting, Stomach cramps, Bloating, and Gas.