Type 2 Diabetes mellitus, in adults

E11.9

DESCRIPTION

Type 2 diabetes mellitus is a chronic debilitating metabolic disease characterised by hyperglycaemia with serious acute and chronic complications. It is an important component of the metabolic syndrome (See Obesity in diabetes).
Most type 2 diabetes mellitus adults are overweight with a high waist to hip ratio.
In adults, the condition might be diagnosed when presenting with complications, e.g.:

  • ischaemic heart disease
  • deteriorating eyesight
  • peripheral artery disease
  • foot ulcers
  • stroke
  • erectile dysfunction

CLINICAL PRESENTATION

Symptoms of hyperglycaemia are:

  • thirst, especially noticed at night
  • polyuria
  • tiredness
  • periodic changes in vision due to fluctuations in blood glucose concentration
  • susceptibility to infections, especially of the urinary tract, respiratory tract and skin

Note: It is important to distinguish type 2 diabetes mellitus from type 1diabetes mellitus.
Suspect type 1 diabetes mellitus among younger patients with excessive weight loss and/or ketoacidosis.

DIAGNOSIS

  • Symptoms of diabetes plus a random blood glucose ≥ 11.1 mmol/L.
    • Random is defined as any time of day without regard to time since last meal.
  • Fasting blood glucose ≥ 7.0 mmol/L.
    • Fasting is defined as no caloric intake for ≥ 8 hours.

OR

  • 2-hour plasma glucose in a 75 g oral glucose tolerance test ≥ 11.1 mmol/l.

Note: If screening and not symptomatic: 2 positive tests done on separate days are required for diagnosis.

LoEIII[3]

MONITORING

At every visit:

  • Finger-prick blood glucose.
  • Weight.
  • Blood pressure.

Baseline:

  • Serum creatinine concentration (and calculate eGFR).
  • Serum potassium concentration, if on ACE-inhibitor or eGFR< 30 mL/min.
  • Urine protein by dipstix.
  • BMI for cardiovascular risk assessment if appropriate (See Prevention of ischaemic heart disease and atherosclerosis).
  • Blood lipids (fasting total cholesterol, triglycerides, HDL and LDL cholesterol).
  • Foot examination.
  • Eye examination to look for retinopathy.
  • Abdominal circumference.

Annually:

  • Serum creatinine concentration (and calculate eGFR).
  • Serum potassium concentration, if on ACE-inhibitor or eGFR<30 mL/min.
  • Urine protein by dipstix.
    • If dipstix negative, send urine to laboratory for albumin: creatinine ratio, unless already on an ACE-inhibitor. (See Diabetic nephropathy.)
  • HbA1c, in patients who meet treatment goals (3–6 monthly in patients whose therapy has changed, until stable).
  • Eye examination to look for retinopathy.
  • Foot examination.

TARGETS FOR CONTROL

Glycaemic targets for control:

Patient type Target HbA1c Target FBG* Target PPG*
  • Young, low risk

  • Newly diagnosed

  • No CVS disease
    		•  < 6.5% 4.0–7.0 mmol/L 4.4–7.8 mmol/L
  • Majority of patients
    		•  < 7.0% 4.0–7.0 mmol/L 5.0–10.0 mmol/L
  • Elderly

  • High risk

  • Hypoglycaemic unawareness

  • Poor short-term prognosis
    		•  < 7.5% 4.0–7.0 mmol/L < 12.0 mmol/L

    ∗ FBG: fasting blood glucose; PPG: post-prandial plasma glucose.

    • In the elderly, the increased risk of hypoglycaemia must be weighed against the potential benefit of reducing microvascular and macrovascular complications.
    • Prevent acute complications, e.g. hyperglycaemic and hypoglycaemic coma.

    Non-glycaemic targets:

    • Body mass index ≤ 25 kg/m².
    • BP ≤ 140/90 mmHg and ≥ 120/70 mmHg.

    Management of type 2 diabetes mellitus includes:

    GENERAL MEASURES

    • Lifestyle modification, including self-care practices.
    • Refer to a dietician if available for annual follow-up.
    • Refer to a support group if available.
    • Education about diabetes and its complications.
    • Increased regular physical activity, aim for 30 minutes 5 times a week.
    • Appropriate weight loss if weight exceeds ideal weight.
    • Discourage smoking.
    • Moderate or no alcohol intake (≤2 standard drinks per day for males and ≤1 for females).
    • Education about foot care.
    • All patients should wear a notification bracelet.

    Diet

    Encourage:

    • regular, evenly-spaced meals, with small portions
    • nutritionally balanced meals, with a variety of healthy foods.
    • meals that consist of one meat dish option with an option of vegetarian for those who are vegetarian, one starch option, two vegetable options, one fruit option and water.

    LoEIII [4]

    Carbohydrates

    • Strict control of carbohydrate intake:
      • encourage small portions of healthy carbohydrates, such as vegetables, fruits, whole grains (e.g. whole wheat bread, oats, brown rice, pearled wheat, maize meal porridge, sorghum porridge, samp, wheat rice), legumes (lentils, beans), and dairy products.
      • discourage intake of less healthy, highly processed/refined carbohydrate foods, especially those with added fats, sugars, or salt (e.g. takeaways, deep-fried foods, pies, doughnuts, cakes, biscuits, white bread, sugary drinks).

    Fruit and vegetables

    • Aim for 5 servings of fruit or vegetables per day (e.g. vegetables: spinach, morogo, cabbage, tomato, imifino (amadumbe, amaranth, cowpea, pumpkin and sweet potato leaves); fruit: apple, orange, naartjie, banana, mango, pear, peach).
    • Limit fruit to 2 servings per day, preferably in small portions throughout the day rather than all at one meal.
    • Limit intake of starchy vegetables like potatoes, sweet potatoes, mielies, butternut, and pumpkin.
    • Limit intake of concentrated fruit sources such as dried or tinned fruit, or juices.

    Legumes

    • Soy beans, dry beans, chickpeas, lentils, and split peas are an economical source of protein and fibre.
    • They do contain starch, so contribute to total carbohydrate intake (see portion sizes below).

    Dairy

    • Advise fat-free or lower fat options.

    Meat, fish, and eggs

    • Encourage less fatty cuts of meat if possible.
    • Encourage low fat cooking methods such as baking, grilling, or steaming. Trim excess fat from meat and remove skin from chicken before cooking.
    • Encourage patients to eat oily fish e.g. sardines and pilchards 2-3 times a week.
    • Limit eggs to 1 per day.
    • Avoid processed meats such as polony and viennas.

    Fats

    • Replace unhealthy animal fats (fatty beef, pork, lamb and chicken) and tropical oils (e.g. coconut and palm kernel oil) with healthier fats (e.g. avocado pear, fatty fish such as pilchards and plant oils such as canola, olive, sunflower, or peanut butter).
    • Do not reheat oil, and use softer margarines where possible.
    • Limit intake of takeaway foods, and rather prepare food at home most of the time.

    Sugar

    • Avoid sugar and sugary foods and drinks, such as: table sugar, honey, sugary drinks (fizzy drinks, fruit juices, energy drinks, sport drinks, sweetened flavoured milk/drinking yoghurt, flavoured water), sweets, desserts and baked goods.
    • If eaten on special occasions, advise in very small portions.

    Salt

    • Do not exceed a half teaspoon of salt per day. This is includes hidden salt in processed foods (e.g. stock cubes, gravy and soup powders, deli meats like polony and viennas, take-away foods, chips/crisps).
    • Avoid adding salt to food.
    • Use less salt when preparing food. Use herbs and spices to enhance the flavour of foods instead of salt.

    Portion control guide
    A portion is the amount of food that a person eats at one time, for a meal or snack.
    Advise the following portion sizes:

    • Make protein (e.g. fish, chicken, or meat) food portions the size of the palm of your hand (about 90 g or 1/2 cup).
    • Make fruit, vegetables and starchy food (such as rice, pasta and potatoes) portions no greater than the size of your clenched fist (1 cup).
    • Make healthy fat portions the size of the tip of your thumb (1 teaspoon).
    • Make hard cheese or peanut butter portions the length of your thumb (1 tablespoon).

    MEDICINE TREATMENT

    Oral blood glucose lowering agents

    Stepwise approach:

    • Add metformin to the combination of dietary modifications and physical activity/exercise.
    • Combination therapy with metformin plus a sulphonylurea is indicated if therapy with metformin alone (together with dietary modifications and physical activity/exercise) has not achieved the HbA1c target.
    • For persisting HbA1c above acceptable levels and despite adequate adherence to oral hypoglycaemic agents: add insulin and withdraw sulphonylurea.
    • Ensure patient is adherent at each step.
    • Oral agents should not be used in type 1 diabetes mellitus, renal impairment or clinical liver failure.

    STEP 1

    Lifestyle modification plus metformin

    Entry to Step1 Treatment and duration Target
    • Typical symptoms - thirst, tiredness, polyuria.

      • AND
    • Random blood glucose >11.1mmol/L.

      • OR
    • Fasting blood glucose ≥ 7 mmol/L.
    • Lifestyle modification for life.

      •  
    • Appropriate diet.

      •  
    • Weight loss until at ideal weight.

      •  
    • Initiate drug therapy with:
      Metformin.

      •  
    • Assess monthly.
    • 2-hour post-prandial finger-prick blood glucose: 8–10 mmol/L.
      OR
      fasting finger-prick blood glucose: 6–8 mmol/L.

      • AND/OR
    • HbA1c:7–8%.
    • Metformin, oral, 500 mg daily with meals.
      • Titrate dose slowly depending on HbA1c and/or fasting blood glucose concentrations to a maximum dose of 850 mg 8 hourly.
      • Contraindicated in:
        • uncontrolled congestive cardiac failure
        • severe liver disease
        • patients with significant respiratory compromise
        • renal impairment i.e. eGFR <30 mL/minute,

    In patients with renal impairment, adjust dose according to table:

    eGFR Metformin Dose
    eGFR >60 mL/min Normal daily
    dose (see above).
    eGFR 45–60 mL/min Standard dose, measure eGFR
    3–6 monthly.
    eGFR 30–45 mL/min Maximum dose 1 g per day;
  • measure eGFR 3–6 monthly
    		•
    eGFR <30 mL/min Stop metformin.

    LOEIII[5]

    STEP 2

    Add sulphonylurea:

    Entry to Step 2 Treatment and duration Target
    • Failed step 1: HbA1c > 8 % or fasting finger-prick blood glucose >8 mmol/L despite adherence to treatment plan in step 1 and maximal dose of metformin
      for 2–3 months.

      • OR

    • 2-hour post-prandial finger-prick blood glucose >10 mmol/L despite adherence to treatment plan in step 1 and maximal dose of metformin for 2–3 months.
    • Lifestyle modification.

      • AND
    • Combination oral hypoglycaemic agents, i.e.:
      Metformin, oral.

      • AND
    • Sulphonylurea.
    • 2-hour post-prandial finger prick blood glucose <8–10 mmol/L.

      • OR
    • fasting finger prick blood glucose: 6–8 mmol/L.

      • AND/OR
    • HbA1c:7–8%.
    • Sulphonylurea derivatives
    • Glimepiride, oral, daily with breakfast.
      • Titrate the dose by 1 mg at weekly intervals up to 6 mg daily (according to blood glucose levels).
      • Usual dose: 4 mg daily.
      • Maximum dose: 8 mg daily.
      • Preferred in the elderly.

    LoEIII[6]

    OR

    • Glibenclamide, oral, 2.5 mg daily 30 minutes with breakfast.
      • Titrate dose slowly depending on HbA1c and/or fasting blood glucose levels to a maximum of 15 mg daily.
      • When ≥ 7.5 mg per day is needed, divide the total daily dose into 2, with the larger dose in the morning.
      • Avoid in the elderly and patients with renal impairment.

    All sulphonylureas should be avoided in patients with renal impairment i.e. eGFR < 60 mL/minute.

    Sulphonylureas are contraindicated in:

    • severe hepatic impairment
    • pregnancy

    Missing meals while taking sulphonylureas may lead to hypoglycaemia.

    STEP 3

    Insulin therapy:

    See Type 1 diabetes mellitus, in adults.

    • Insulin is indicated when oral combination therapy fails.
    • Continue lifestyle modification.
    • Insulin therapy must be initiated and titrated by a doctor, until stabilised.
    • Stop sulphonylurea once insulin therapy is initiated but continue metformin.

    LoEIII [7]

    Education for patients on insulin therapy:

    • Types of insulin.
    • Injection technique and sites of injection.
    • Insulin storage.
    • Self-monitoring of blood glucose and how to self-adjust insulin doses.
    • Diet:
      • Meal frequency, this varies according to the type and frequency of insulin, e.g. patients may need a snack at night about 3–4 hours after the evening meal.
      • Consistent carbohydrate intake for patients receiving fixed mealtime doses of insulin.
    • Recognition and treatment of acute complications, e.g. hypoglycaemia and hyperglycaemia.
    Insulin type Starting dose Increment
    Add on therapy:
    ·  Insulin, Intermediate to long acting, SC     		10 units in the evening before bedtime, but not after 22h00. If 10 units not effective: increase gradually to 20 units (2–4 units increase each week).
    Substitution therapy:
    · Insulin, biphasic, SC     		Twice daily.
     
    Total daily dose:
    Start with 0.3 units/kg/day* divided as follows:

  • 2/3 of total daily dose, 30 minutes before breakfast.

  • 1/3 of total daily dose, 30 minutes before supper.


    • LoE III[8]     		4 units weekly.
     
    First increment is added to dose before breakfast.
     
    Second increment is added to dose before supper.

    LoE III[8]

    *Example of a dose calculation:

    • For a 70 kg adult: 0.3 units x 70 kg = 21 units per day; divided as 14 units 30 minutes before breakfast and 7 units 30 minutes before breakfast. 

    REFERRAL

    Urgent (same day)

    • Acidotic breathing.
    • Dehydration and hypotension.
    • Nausea, vomiting and abdominal pain.
    • Ketonuria (more than 1+).
    • Hyperglycaemia >25 mmol/L .
    • Gangrene.
    • Sudden deterioration of vision.
    • Serious infections.

    Note: Consider IV infusion with sodium chloride 0.9%, before transferring very ill patients.

    Non-urgent

    • Pregnancy.
    • Failure of step 3 to control diabetes.
    • eGFR< 30 mL/minute.
    • Ischaemic heart disease.
    • Cerebrovascular disease.
    • Refractory hypertension.
    • Progressive loss of vision.