DM Pt. 1

What is DM characterized by?

What is DM characterized by?

• Hyperglycemia

• Disordered metabolism of CHO, protein & fat

• Inulin deficiency and/or resistance

Insulin is a catabolic/anabolic hormone?

Anabolic

How does insulin regulate BG levels?

• Transport glucose into cells

• Glycogenesis

• Lipogenesis

• Inhibits lipolysis

• Increases protein synthesis

• Brings glycolysis

What is needed for glucose to enter cells (other than insulin)

Specialized insulin receptors

In which tissues are insulin receptors located?

Adipose & muscle

Which cells are responsible for secreting insulin and in which organ are they located?

• Beta cells of Islets of Langerhans

• Pancreas

Glucagon is a catabolic/anabolic hormone?

Catabolic

Which cells are responsible for secreting glucagon and in which organ are they located?

• Alpha cells of Islets of Langerhans

• Pancreas

What are the 2 functions of glucagon?

• Glycogenolysis

• Gluconeogenesis

T/F: Somatostatin is another word for growth hormone inhibiting hormone (GHIH)

True

Which cells are responsible for secreting GHIH and in which organ are they located?

• Delta cells of Islets of Langerhans

• Pancreas

What is the function of somatostatin?

Coordinate insulin/glucagon secretion to maintain BG levels

In simple terms, how are the functions of insulin & glucagon antagonistic?

Insulin decreases BG, whereas glucagon increases BG

T/F: Insulin is ONLY secreted after consumption of food

False, there is also some secretion in between meals

Why is insulin secreted in small amounts between meals?

To restrain glucose-raising actions of glucagon

Which tissues uptake BG after meal consumption?

Adipose & muscle

T/F: Increased secretion of glucagon is a result of low insulin

True, the body cells are not getting glucose so the body thinks it needs more

What complications can result from sustained hyperglycemia?

• Nephropathy

• Neuropathy

• Retinopathy

Due to high pressure in blood vessels => causes damage

What are the potential symptoms that result from high blood sugar?

• Glucosuria

• Polyuria

• Dehydration => polydipsia

• Severe: coma

What happens when the body begins to breakdown fats for energy?

Ketone bodies are produced and may lead to acidosis

What are the 3 ketone bodies?

• Acetone

• Acetoacetate

• B-hydroxybutyrate

Why would a diabetic patient have higher nitrogen losses in the urine?

Due to protein breakdown for energy (nitrogen is released from metabolism)

What are the 4 most common types of DM?

• T1DM

• T2DM

• Gestational DM

• Prediabetes

What % of cases is T1DM? T2DM?

• T1DM: 5-10%

• T2DM: 90-95%

During which life stage is T1DM most common?

Adolescents

• Girls: 10-12 y

• Boys: 12-14 y

What is wrong with the insulin in T1DM?

It is not produced by the body at all (autoimmune disorder that destroys b-cells), patients are insulin-dependent

Is T1DM characterized by weight loss or weight gain? Why?

Weight loss; result of dehydration & lack of insulin => lack of storage of excess glucose

T/F: Infection cannot cause onset of T1DM

False

T/F: T1DM cannot be idiopathic (for no known reason)

False

What are the risk factors of T1DM?

• Genetics (HLA-DQ genes determine susceptibility)

• Active autoimmunity

• Environment (trigger or suppress)

T/F: >90% secretion capacity of B-cells are destroyed, this will result in appearance of hyperglycemia & other symptoms

True

What is this honeymoon phase? When does it end?

• After intervention, insulin resistance & requirements decrease up to 1 year

• After 5-10 years of onset => B-cells are completely destroyed => increase insulin dose & frequency

What is Amylin? What are its functions?

• Glucoregulatory hormone secreted by B-cells of Iselts of Langerhans, co-secreted with insulin

• Functions are to regulate PPG & decrease glucagon secretion

T/F: Amylin is deficient in T1DM

True

What is latent autoimmune diabetes in adults (LADA)?

T1DM in adults that progresses over time; affected by autoantibodies and high susceptibility from genetic predisposition.

What are the ways to manage T1DM?

• Daily blood glucose monitoring

• HbA1c testing

• Medication (insulin injection/pump)

  • Short, rapid, long, intermediate acting

• Nutrition management

  • Timing of meal with medication

  • Dosage according to CHO intake

What is wrong with insulin in T2DM?

Insufficient production or resistance

What is the end result of hyperinsulinemia?

Worsening of hyperglycemia; due to inability of pancreas to compensate (decrease in insulin secretion)

Define post-prandial glucose

BG after eating a meal

Explain the fluctuations in BG after a meal is consumed

PP glucose (hyperglycemia) followed by fasting BG due to hypersecretion of glycogen as compensation for low glucose in cells

T/F: The liver releases more glucose in the evening in diabetic patients

False, in the morning; action of glucagon

Name some risk factors for T2DM

• BMI >25 kg/m²

• Waist circumference >40” M, >35” F

• Physical inactivity

• Family history of diabetes

• High-risk ethnic groups

• Prior GDM, >4 kg baby

• Blood pressure >140/90 mmHg

• HDL <35 mg/dL and/or TG’s >250 mg/dL

• PCOS

• History of IGT or IFG

What are some medications used to treat T2DM?

• Sulphonylureas

• Non-sulphonylurea secratogogues

• Biguanides

• a-glucosidase inhibitors

• Thiazolidinediones

• Incretins

All of these are hypoglycemic (decrease BG)

What % of weight loss is ideal to improve insulin sensitivity in T2DM?

5-10%

T/F: Chronotype affects BG levels throughout the day

True

What do IFG & IGT stand for?

• Impaired fasting glucose

• Impaired glucose tolerance

What are the biochemical characteristics of prediabetes?

• FBG: >100-125 mg/dL

• Random blood sugar (RBS) or PP: 140-199 mg/DL

• HbA1c: 5.7 - 6.4%

What % of women develop GDM with onset of pregnancy?

7%

During which trimester should women at high risk of diabetes be tested and why?

First trimester; it is when the baby’s vital organs are developing & has highest risk of deformities

When and what is the screening process for GDM?

• Weeks 24-28

• Oral glucose tolerance test (OGTT) using 75 g CHO

What results of OGTT are needed to determine GDM?

• FG: >92 mg/dL

• 1-h glucose >180 mg/dL OR 2-h glucose of 153 mg/dL

T/F: GDM can cause congenital anomalies if DM is present before pregnancy

True

What are the 2 risks of GDM?

• Macrosomia (large baby)

• Neonatal hypoglycemia

Explain neonatal hypoglycemia

Fetus produces extra insulin to manage high BG from mother => when baby is born, no more blood is transferred from mother anymore => high insulin will cause sharp decrease in baby’s BG (hypoglycemia)