Chapter 11: Diabetes Mellitus

Question 1

Pregestational Diabetes

Answer 1

a chronic metabolic disorder characterized by hyperglycemia that results from limited or absent insulin production, deficient insulin action, or a combination of the two
>Diabetes type 1 and type 2

Question 2

Type 1 Diabetes

Answer 2

absolute insulin deficiency; “insulin-dependent”

• usually diagnosed >30 years old
• acute symptoms precede the diagnosis; polyuria, polydipsia, and significant weight loss
• abrupt onset that requires emergency medical attention

Question 3

Type 2 Diabetes

Answer 3

combination of insulin resistance and inadequate insulin production

• diagnosed in adults older than 30, but with current obesity epidemic, now in children
• symptom free for many years, with a slow onset and a gradual progression of symptoms
• not ketosis prone
• does not always require insulin and can often be treated with diet, exercise, and/or oral hypoglycemic agents

Question 4

Gestational Diabetes Mellitus

Answer 4

impairment in carbohydrate metabolism that first manifests during pregnancy

• develops in the latter half of pregnancy as a result of the altered hormonal milieu
• symptoms usually mild and not life threatening
• may be treated by diet and exercise or requires the addition of oral medication and/or insulin depending on the blood glucose levels
• are at increased risk for developing diabetes later in life

Question 5

Risk Factors for Gestational Diabetes

Answer 5

• women older than age 25 years
• obesity
• insulin resistance
• polycystic ovary syndrome
• hx of pregnancy-related diabetes mellitus
• hx of a large for gestational age infant, hydramnios
• stillbirth, miscarriage, or an infant with congenital anomalies during a previous pregnancy
• family hx of type 2 diabetes (first-degree relative)
• ethnicity

Question 6

Pathophysiology of Gestational Diabetes

Answer 6

the body requires a constant source of energy, provided mainly by glucose
-once glucose enters the cell, it may undergo oxidative (glycolysis) or nonoxidative (glycogen synthesis) metabolism
>in response to glucose ingestion, the pancreatic beta cells of the islets of Langerhans secrete insulin, a hormone that promotes the uptake of glucose into the cells
>changes in carbohydrate, protein, and fat metabolism in normal pregnancy are profound, in part of the developing fetus and the production of placental hormones
-first half of pregnancy = “anabolic phase”, increased storage of fat and protein, along with an increased secretion of estrogen and progesterone; lead to maternal hyperplasia and hyperinsulinemia (body has too much insulin); the increased insulin production prompts an increased tissue response to insulin and the increased uptake and storage of glycogen and fat in the liver and tissues
-second half of pregnancy= “catabolic phase”, breakdown of protein and fat; also increased insulin resistance caused by heightened production of placental hormones, cortisol, and growth hormones; these hormones are diabetogenic and act as insulin antagonists; in woman who cannot meet the increasing needs for insulin production, this change leads to an altered carbohydrate metabolism and progressive hyperglycemia
>during this time, the developing fetus continuously removes glucose and amino acids from the maternal circulation; because insulin does not cross the placenta, the fetus must increase its own insulin production; fetal hyperinsulinemia develops and acts as a growth hormone that contributes to an increase fetal size (macrosomia), and a decrease in pulmonary surfactant production
-when pregnant woman’s blood glucose level remains elevated, there is a constant transport of maternal glucose across the placenta, this glucose load prompts the fetus to produce insulin at a greater rate to use the glucose

Question 7

Teaching about hypoglycemia

Answer 7

• levels decrease to less than 60 mg/dL
• more common during pregnancy
• light-headedness, shaking, headache, sweating, confusion, hot flashes, nervous and anxiety attacks, intense hunger, sudden irritability, and changes in vision
• drinking a glass of milk is better than a glass of juice that contains high levels of glucose
• keep glucagon on hand for severe hypoglycemia or loss of consciousness

Question 8

Screening and Diagnosis

Answer 8

-all women be screened for gestational diabetes after 24 weeks of pregnancy
-Glucose Challenge Test: a 50g oral glucose solution is administered and a blood sample is taken 1 hour after it is consumed; patients with a 1 hour plasma glucose value that exceeds 130 to 140 mg/dL should be further evaluated with the 3-hour oral glucose tolerance test (OGTT)
-The 3-hour OGTT: requires the fasting patient to ingest 100g of glucose with blood drawn at 1 hour intervals. Before the test, the woman should avoid caffeine and refrain from smoking at least 12 hours before and during the test; diagnosis is made when two values or more of the threshold are above the norm
>Normal Plasma Values:
-Fasting: <95 mg/dL
-1 hour: <180 mg/dL
-2 hour: <155 mg/dL
-3 hour: <140 mg/dL
(diagnosed when two or more of these values are above the norm)

Question 9

Management

Answer 9

• maintain blood glucose levels as close to normal (Euglycemia) as possible (65-105 mg/dL)
• Two hour post-prandial blood glucose levels should be less than 120 mg/dL
• home blood glucose monitoring
• ongoing fetal surveillance
• diet and exercise
• physical activity; walking, cycling on stationary bikes, and swimming
• have fasting venous plasma glucose less than or equal to 95 mg/dL

Question 10

Euglycemia

Answer 10

normal blood glucose range of 65 to 105 mg/dL