Diabetes Mellitus: Types, Causes & Mechanisms

Diabetes Mellitus

• Diabetes Mellitus covers US data and statistics, pathophysiology, clinical manifestations, contributing factors, screening tests, pathological outcomes, and clinical management.

US Data & Statistics

• About 38 million people in the US have diabetes.
• Diabetes affects about 1 in every 10 people.
• 1 in 5 people with diabetes are not aware they actually have it.
• Diabetes affects 11.2% of the US population (38 million people).
• Pre-diabetes affects 29% of the adult US population (98 million people).
• The yearly cost of diabetes in the US is $413 billion.
• Every 23 seconds someone in the US is diagnosed with diabetes
• 16% of American Indians/Alaska Natives have diabetes.
• 12.5% of Black (non-Hispanic) individuals have diabetes.
• 10.3% of Hispanic individuals have diabetes.
• 9.2% of Asian (non-Hispanic) individuals have diabetes.
• 8.5% of White (non-Hispanic) individuals have diabetes.

Diabetes Risks, Mortality, Costs, & Complications

• The risk of early death is 60% higher for those affected with diabetes
• Medical costs are twice as high for those with diabetes
• Serious health complications linked to undiagnosed diabetes include:
• Heart disease
• Stroke
• Kidney failure
• Blindness
• Amputation

Diabetes and Obesity

• 30.7% of the US adult population is overweight.
• 34.1% are men
• 27.5% are women
• 42.4% of the US adult population has obesity, including severe obesity.
• 16.1% of children and adolescents ages 2 to 19 are overweight.
• 19.3% have obesity
• 6.1% have severe obesity

Impact of Obesity

• Obesity impacts cardiometabolic health and can lead to:
• Insulin resistance
• Glucose intolerance
• High blood pressure
• Inflammation
• Dyslipidemia
• Endothelial dysfunction
• Type 2 diabetes
• This can also lead to cardiovascular events, coronary artery disease, heart failure, arrhythmias, and sudden death.

Fat Classifications

• Visceral fat accounts for 10-20% in Men and 5 -7% in Women
• This is the first fat to go in weight loss.
• Accumulates with stress
• Surrounds organs
• Predictor of metabolic syndrome
• More insulin resistant
• Releases high amounts of pro-inflammatory cytokines
• Subcutaneous fat accounts for 80% of total body fat.
• "Stubborn" fat
• Estrogen increases this type of fat
• May play a protective role
• Less metabolically active
• Normal buffer system for excess energy intake

BMI

• BMI is used to categorize weight.
• Underweight is considered less than 18.5.
• Normal weight falls between 18.5-24.9.
• Overweight is 25.0-29.9.
• Obese (I) is 30.0-34.9.
• Obese (II) 35.0-39.9
• Obese (III) is greater than 40.0.

Endocrine System: Pancreas (dual role)

• The pancreas has both digestive and endocrine functions.
• As a component of the digestive system, it releases enzymes:
• Amylase
• Lipase
• Protease
• As a component of the endocrine system, it releases hormones:
• Insulin
• Glucagon
• Somatostatin
• Pancreatic polypeptide

Functions of Endocrine Hormones

• High blood glucose levels cause the pancreas to release insulin, which allows fat cells to take in glucose from the blood.
• Low blood glucose levels cause the pancreas to release glucagon, which causes the liver to release glucose into the blood.

Pancreas & Serum Glucose

• Increased blood glucose levels are detected by the pancreas.
• The pancreas releases insulin.
• Insulin is a key that unlocks the glucose channel
• Allows muscle cells to take up more glucose
• Allows the liver to store glucose as glycogen
• Allows glucose to store as fat

Glucose 101

• Glucose is a monosaccharide with several functions:
• Energy source
• Brain fuel
• Glycogen storage
• Regulator
• Overall metabolism

Glycemic Effects

• Glucose sources include:
• Dietary intake
• Endogenous production
• When food is ingested, CHO turns to glucose
• is then absorbed from intestines into the blood.
• High blood glucose triggers the pancreas to secrete insulin.

Serum Glucose & Cell Energy

• In a normal state, the blood vessel has glucose traveling in the bloodstream.
• Cells use glucose for energy.
• In prediabetes, there is too much glucose in the bloodstream.
• Because of this, cells are unable to use the glucose.

Insulin

• Insulin is a hormone made by β cells in the Islets of Langerhans of the pancreas.
• The key to open the cell membrane.
• Prandial insulin peaks after a meal.
• Basal insulin is a continuous release.
• Bolus insulin is released in response to increased blood glucose.

Insulin Regulatory Functions

• Promotes cellular uptake of glucose, amino acids (protein), and fats.
• Regulates carbohydrates.
• Metabolizes lipid and protein.
• Promotes cell division and growth.

Insulin Mechanism of Action

• In a normal state, insulin activates the input of glucose in the cell.
• With insulin resistance, the absorption mechanism of glucose remains closed.

Endogenous Insulin Secretion Pattern

• Insulin levels change throughout the day.
• Breakfast and lunch are lower; dinner sees a higher level.

Diabetes Mellitus

• This is a chronic, metabolic disorder that affects how the body turns food into energy related to:
• Insulin deficiency
• Insulin resistance
• Diabeinein is the Greek word, meaning “siphon”.
• Mellitus is the latin word, meaning "sweetened with honey".

Types of Diabetes

• Types of Diabetes Mellitus include:
• T1DM (Type 1 Diabetes Mellitus)
• Autoimmune
• T2DM (Type 2 Diabetes Mellitus)
• Associated with risk factors
• Gestational Diabetes
• Occurs during pregnancy
• Rare DM MODY
• Rare single gene mutation

Iatrogenic Diabetes

• This can be caused by:
• Glucocorticoids
• Antipsychotics
• Antiretroviral
• Immune Inhibitors

Gestational Diabetes

• Defined as glucose intolerance in pregnancy.
• Increased insulin resistance due to placental hormones.
• It can be caused by inadequate insulin secretion for increased insulin needs.
• There is a potential for it to progress to diabetes in >30% of women over 15 years.

Maternal Obesity and GDM

• GDM increased from 6.0% in 2016 to 8.3% in 2021.
• Obesity promotes insulin resistance.
• Potential complications include:
• Mother: preeclampsia
• Baby: macrosomia

Maturity-Onset Diabetes of the Young (MODY)

• This is a less common type of diabetes.
• Is autosomal dominant.
• Caused by mutation in a single gene.
• Typically develops before age 25.

Type 1 Diabetes Mellitus

• This is an autoimmune disorder.
• There is destruction of the β cells of the Islets of Langerhans.
• 80%-90% of β cells functions are lost before symptoms appear.
• It is an insulin-dependent form of DM.
• Potential contributing factors: exposure to virus, certain climates, gestation period and maternal weight

Type 1 DM: Recognize Cues

• Symptoms of Type 1 Diabetes:
• Polyuria: frequent urination
• Polydipsia: increased thirst
• Polyphagia: increased hunger
• Less Common symptoms:
• Tiredness
• Weight loss
• Gastrointestinal symptoms

Type 2 Diabetes Mellitus

• This involves insulin resistance and B cell dysfunction.
• There is reduced glucose uptake by muscles and fat cells.
• Results in an increase in glucose release and production by the liver.

Cellular Function in Healthy Body vs T2DM

• In a normal cell
• Insulin is a key that unlocks the glucose channel
• For Type 2 Diabetes
• Insulin resistance contributes to high glucose levels in the blood

Type 2 DM: Recognize Cues

• Type 2 Diabetes Symptoms:
• Increased urination
• Increased thirst
• Increased hunger
• Fatigue
• Blurred vision
• Frequent infections
• Erectile dysfunction
• Pain and tingling in hands and feet

Contrasting Type I versus Type 2 Diabetes

• In normal physiology, insulin hormone activates receptors and allows normal glucose uptake
• In Type 1 Diabetes, there is no insulin being released
• Increased glucose is not broken down to the intended tissues, like in the muscles
• In Type 2 Diabetes, insulin release begins to decrease over time due to insulin resistance

Contributing Factors

• Modifiable risk factors for type 2 diabetes:
• Obesity
• Hypertension
• Sedentary lifestyle
• Elevated cholesterol
• Non-modifiable risk factors for type 2 diabetes:
• Age
• Family history
• Race/Ethnicity
• Medical Conditions

Metabolic Syndrome

• Metabolic syndrome is a cluster of risk factors that raises risk for heart disease and other health problems.
• Increased blood pressure of 130/85 mm Hg or higher
• High triglycerides of 150 mg/dL or more
• Large waistline (Men: 40" or more Women: 35" or more)
• Low HDL (good) cholesterol (Men: less than 40 mg/dL Women: less than 50 mg/dL)
• Elevated fasting blood sugar of 100 mg/dL or higher

Hemoglobin A1c (HBA1C)

• Hemoglobin A1c is a test to measure glycated hemoglobin or glycohemoglobin.
• It measures the amount of glucose attached to Hgb over the life of the RBC for 120 days.
• Results of the Hemoglobin Alc test:
• Below 5.7% is considered normal
• 5.7 - 6.5% indicates risk
• Over 6.5% indicates diabetes

Understanding Hemoglobin A1c

• This measures the amount of glucose attached to the red blood cells in the body
• The higher the glucose levels in the blood, the mores glucose will attach to the red blood cells

Hemoglobin A1c Conversion Chart

• 5%= 97 MG/DL, Keep Up The Great Work!
• 6%=126MG/DL, Keep Up The Great Work!
• 6.5%=140MG/DL, Room For Improvement
• 7%= 154MG/DL, Room For Improvement
• 7.6%=171MG/DL, Target For Older Adults
• 8%=183MG/DL, Target For Older Adults
• 8.1% = 186 MG/DL, Action Needed
• 8.6% = 200 MG/DL, Action Needed
• 8.7%=203MG/DL, Immediate Medical Intervention Required
• 9%= 212 MG/DL, Immediate Medical Intervention Required
• 10%=240 MG/DL
• 11% = 269 MG/DL
• 12%= 298 MG/DL
• 13%= 326 MG/DL

Screening tests

• The Fasting blood sugar (FBS):
• This requires a blood sugar reading after fasting.
• Normal : 70-100
• Risk of diabetes: 100-125
• Diabetes: 126
• 2-hour postprandial blood sugar
• 140 for those younger than 50 years old.
• 150 for those aged 50-60 years.
• 160 for those older than 60 years.
• Random blood sugar (RBS):
• 80-120 Before meals/after waking up
• 100-140 Before bed

Oral Glucose Tolerance Test (OGTT)

• Instructions:
• NPO x 8-12 hours prior to the test
• BGM prior to the test
• Drink glucose (sugar) solution
• Check BGM after 2 hours

Stages of Glucose Tolerance

• A1C Test:
• Diabetes: 6.5% or above
• Prediabetes: 5.7-6.4%
• Normal: Below 5.7%
• Fasting Blood Sugar Test (mg/dL):
• Diabetes: 126 or above
• Prediabetes: 100-125
• Normal: 99 or below
• Glucose Tolerance Test (mg/dL):
• Diabetes: 200 or above
• Prediabetes: 140-199
• Normal: 140 or below

C-Peptide Test (0.5-2.7 NG/ML)

• Increased Level:
• Type 2 DM
• Insulinoma
• Cushing's Syndrome
• Kidney Disease
• Decreased Level:
• Type 1 DM
• Addison's Disease
• Liver Disease

Hypoglycemia

• Also referred to as "Insulin Shock or "The Lows."
• Usually indicated by a blood sugar level of less than 70 mg/dl.
• May cause patient to become unresponsive.
• Always consider any unconscious person to be hypoglycemic.

Hypoglycemia Etiology

• Reactive hypoglycemia is from too much insulin/oral diabetics.
• Fasting hypoglycemia is from too little food/delayed eating.
• Kidney disease/failure.
• Strenuous physical activity.
• Excessive alcohol consumption.

Hypoglycemia Symptoms

• Symptoms to look out for:
• Sweating
• Pallor
• Irritability
• Hunger
• Lack of coordination
• Sleepiness

Hypoglycemic Cues

• HE IS TIRED:
• Headache
• Irritable/Sweating
• Tachycardia
• Irritability
• Restlessness
• Excessive hunger
• Dizziness

Hypoglycemia Protocol

• Follow the “15/15 rule.”
• Check blood sugar.
• Treat depending on severity of symptoms.
• Wait 15 minutes.
• Recheck blood sugar.
• If <70 mg/dL, repeat process (treatment).

Mild Hypoglycemia

• Treatment options for bringing blood sugar back to normal:
• 1/2 cup OJ or fruit juice
• 1/2 cup soda/pop
• 1 cup fat-free milk
• 5 lifesavers candy
• Glucose gel or tablet

Severe Hypoglycemia

• Treatment options:
• 1 mg IM or SQ Glucagon- onset: 10 mins, however may cause vomiting
• 25 g IVP over 1 min of Dextrose, has rapid onset, however may cause phlebitis

Hyperglycemia: DKA & HHS

• This is classified by high Blood glucose level, usually above 180-200 mg/dL
• Includes these medical emergencies:
• Diabetic Ketoacidosis (DKA): greater than 300 mg/dL
• Hyperosmolar Hyperglycemic State (HHS): greater than 600 mg/dL

Reactive Hyperglycemia

• High blood sugar causes in people without diabetes:
• Pancreatic diseases
• PCOS
• Cushing's Syndrome
• Surgery and stress
• Trauma
• Infection
• Medication side effects

Hyperglycemia Etiology

• Additional Etiologies:
• Infection
• Infarction
• Infraction
• Infant
• Ischemic
• Illegal
• Iatrogenic
• Idiopathic

Hyperglycemia Symptoms

• Symptoms to look out for:
• Dry Mouth
• Increased Thirst
• Weakness
• Headache
• Blurred Vision
• Frequent Urination

Hyperglycemic Signs

• WATER:
• Weakness
• Abdominal pain
• Tired
• Extra thirsty
• Really hot

Hyperglycemia Protocol

• Nursing interventions include:
• Maintain Airway/Oxygen
• Decrease Blood Glucose:Regular Insulin
• Initiate Dehydration Control

Hyperglycemia - Take Action Items

• Different types of insulin have differing:
• Onset
• Peak
• Duration
• Type of Insulin
• Rapid Acting: Lispro (Humalog), Glulisine (Apidra), and Aspart (NovoRapid)
• Intermediate Acting: NPH(Humulin-N, Novolin-NPH)
• Slow or Long Acting: Glargine (Lantus), Detemir (Levemir)