Diabetes Mellitus

Definition

(Show Disclaimer) Note: I copy the "definition" of something straight from the book. I find it's best to have an all-encompassing definition in order to better orient myself when I am studying.

(Show Definition) Diabetes is a group of diseases characterized by high levels of blood glucose with a defect in insulin secretion or action caused by a chronic disorder of carbohydrate, fat, and protein metabolism. There are four categories of diabetes: type 1, type 2, gestational, and other specific types including genetic-defined forms and those related to other diseases or medication use.

Type 1 diabetes: destruction of β-islet cells in the pancreas.
Type 2 diabetes: impairment in insulin production AND/OR insulin resistance.
Gestational diabetes: disappears after pregnancy. May increase risk of developing T2DM later in life.
Other causes: Genetic, diseases of the pancreas (e.g. cystic fibrosis), HIV meds.
People w/ diabetes are more likely to have increased LDL, therefore increased risk of ASCVD. 2x - 4x higher risk of CVD in adults with diabetes. Stroke risk is 2x - 4x higher d/t 60 – 65% of clients with diabetes that have coincident HTN

Incidence/Prevalence

Likely not important for the NAC OSCE Exam:

(If you're a keener click here)

Approx. ⅒ Canadians have diabetes/
Approx. ⅕ Canadians have prediabetes.
At-risk populations include:
- South Asian, Asian, African, Hispanic, and Indigenous descent.
- Overweight, elderly, or have low income.
Indigenous peoples 3.5% more likely to have diabetes.

Pathogenesis

Not as important, but may be useful for patient teaching:

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Type 1 diabetes is autoimmune destruction of insulin secretion β-islet cells of the pancreas.
- Environmental factors which cause predisposition to developing T1DM include viral illness: mumps, coxsackievirus, cytomegalovirus, and hepatitis.
- Other factors include diets high in dairy, emotional-physical stress, and/or environmental toxins.
Major risk factors for Type 2 diabetes are genetics and obesity.
Screen pregnant women if they are high risk for undiagnosed type 2 diabetes early @ <20 weeks w/ hemoglobin A1c. If no pre-existing diabetes, screen during 2nd and 28th weeks of gestation.

Predisposing Factors

BMI ≥ 27 kg/m².
Physical inactivity.
First-degree relative with type 1 or type 2 diabetes.
Hemoglobin A1c ≥ 5.7%, impaired glucose tolerance (IGT) or impaired fasting glucose (IFG), on previous testing.
Indigenous, Hispanic, Asian, and African American.
HTN w/ SBP > 140 mmHg and DBP > 90 mmHg.

HDL of ≤ 1.0 mmol/L or less and/or TGL level of ≥ 1,7 mmol/L.
Hx of giving birth to babies > 9 lbs, or gestational diabetes.
Acanthosis nigricans or severe obesity.
Polycystic ovarian syndrome (PCOS).
Hx of CVD.

Screening Protocols for Diabetes:

Canadian Recommendations

Diabetes Canada recommendations:
- Fasting plasma glucose (FPG) and/or A1c every 3 years in individuals ≥40 years of age, or in individuals at high risk on a risk calculator.
- Screen earlier (every 6 to 12 months) for those with additional risk factors or very high risk.
Canadian Task Force on Preventive Health Care:
- For adults at low to moderate risk of diabetes (determined with a validated risk calculator), we recommend not routinely screening for type 2 diabetes.
- For adults at high risk of diabetes (determined with a validated risk calculator), we recommend routinely screening every 3 – 5 years with A1c.
- For adults at very high risk of diabetes (determined with a validated risk calculator), we recommend routine screening annually with A1c.

American Recommendations

U.S. Preventive Services Task Force (USPSTF) recommendations:
- Screen people aged 40 to 70 years who are overweight or obese.
- Consider screening earlier in patients with higher risk (i.e. one of the following):
  - Family hx of diabetes.
  - Black, American Indians or Alaska natives, Asian American, Hispanics or Latinos, or Native Hawaiians or Pacific Islanders.
  - Personal hx of gestational diabetes or PCOS

Note: Unclear of the frequency of screening outlined in USPSTF

Common Findings:

Classic triad: polyuria, polydipsia, polyphagia.
Weight loss.
Lack of energy.
Recurrent infections (urinary tract, vaginal, skin breakdown that is slow to heal).
Asymptomatic.

Other Signs and Symptoms:

Weakness.
Fatigue.
Nausea and vomiting.
Abdominal pain.
Anorexia.
Sexual dysfunction, including impotence or dyspareunia.
Pruritus.
Visual disturbances.
Signs and symptoms related to nephropathy, neuropathy, and/or retinopathy.

History

HPI:
ROS:
ALL/MEDS/HIITS: (What are HIITS? - Click to expand)
PMH/FAMHx/OBGYN: Review family history of diabetes, and other endocrine disorders.
SOCHx: Determine client’s nutritional status, 24-hour recall, weight history, and eating patterns. SocHx also includes smoking/EtOH, exercise.

Physical Exam

Will add soon.

Diagnostic Tests

A1C ≥ 6.5%.

FPG ≥126 mg/dL (7.0 mmol/L). *Fasting is defined as no caloric intake for at least 8 hours.

2-hour plasma glucose ≥200 mg/dL (11.1 mmol/L) during an OGTT (75 g).

In a patient with classic symptoms of hyperglycemia or hyperglycemic crisis, a random plasma glucose ≥200 mg/dL (11.1 mmol/L).

Differential Diagnosis

Benign pancreatic insufficiency.
Pheochromocytoma.
Cushing’s syndrome.
History of corticosteroid use.
Stress hyperglycemia.
Acromegaly.
Hemochromatosis.
Somogyi phenomenon: Early-morning hyperglycaemia due to very early morning (2:00 – 3:00 a. m.) hypoglycaemia.

Plan

General

Teaching should include pathophysiology of diabetes, procedures for blood glucose checks, and recognition and treatment of hypoglycemia.
Tobacco cessation should be offered in counselling.
Exercise, 150 minutes exercise/week, 10 minutes or more each session of aerobic exercise, recommended 2 sessions of resistance.
Nutrition, client will be referred to dietitian and individual plan will be made.
After initial diagnosis of type 2 diabetes, behaviour intervention first (physical activity, weight management, nutritional therapy) then metformin + drugs.
Initial follow up is at 3 months, and goal is target HbA1c. Escalation of care dependent based on achievement of A1c targets.

Follow-up

Retinopathy screen, type 1: 5 years after diagnosis if individual is ≥ 15 years.
Retinopathy screen, type 2: All patients at diagnosis.
If retinopathy is not present, every 1 – 2 years.
Other follow up includes diabetic neuropathy checks (monofilament testing, q1year), annual flu vaccine, adult vaccines (pneumococcal, shingles), regular kidney function tests.

Diabetes management goals:

Fasting plasma glucose (FPG) or preprandial glucose 4 to 7 mmol/L (72 mg/dL to 126 mg/dL).

A glucose level of 5.0 to 10.0 mmol/L two hours after meals (90 mg/dL to 180 mg/dL).

A1c < 7.0 % for most adults. May be lower for those with comorbidity. If low risk of hypoglycemia, < 6.5% to prevent CKD.

Diabetes Canada recommends SBP/DBP <130/80 mmHg.

Lipid targets (not shown). If not at target TGL, start fibrate to avoid pancreatitis. If no treatment is initiated, repeat lipid profile q.3yrs.

Consultation/Referral

Refer if DKA, pediatric clients with hyperglycemia/new onset diabetes, frequent hypoglycemia, hyperosmolar hyperglycemia, pregnancy, complications (retinopathy. nephropathy, or neuropathy).

Individual Considerations

For Pregnant, Pediatric, Indigenous, likely unimportant for the NAC exam.