Diabetes
Given a symptomatic or asymptomatic patient at high risk for diabetes (e.g., patients with gestational diabetes, obese, certain ethnic groups, and those with a strong family history), screen at appropriate intervals with the right tests to confirm the diagnosis.
Given a patient diagnosed with diabetes, either new-onset or established, treat and modify treatment according to disease status (e.g., use oral hypoglycemic agents, insulin, diet, and/or lifestyle changes).
Given a patient with established diabetes, advise about signs and treatment of hypoglycemia/hyperglycemia during an acute illness or stress (i.e., gastroenteritis, physiologic stress, decreased intake.
In a patient with poorly controlled diabetes, use effective educational techniques to advise about the importance of optimal glycemic control through compliance, lifestyle modification, and appropriate follow-up and treatment.
In patients with established diabetes:
Look for complications (e.g., proteinuria).
Refer them as necessary to deal with these complications
In the acutely ill diabetic patient, diagnose the underlying cause of the illness and investigate for diabetic ketoacidosis and hyperglycemia.
Given a patient with diabetic ketoacidosis, manage the problem appropriately and advise about preventing future episodes.
See DKA/HHS.
Screening
Assess risk annually if any risk factor (see FINDRISC/CANRISK calculator and risk factors below)
Screen with FPG and/or A1C q3 years if ≥40 years old or high risk (33% chance of DM2 within 10y)
Consider screening more frequently (q6-12 months) if very high risk (50% chance of DM2 in 10y)
A1C not recommended for diagnosis in children, pregnant women or suspected DM1
Risk Factors:
≥40 years old
First degree relative with DM2
High risk population (eg. Aboriginal, African, Asian, Hispanic, or South Asian descent)
Prediabetes (IGT, IFG, A1C 6-6.4%)
Gestational diabetes mellitus (GDM) or delivery of a macrosomic infant
Presence of end organ damage associated with DM
Microvascular – retinopathy, neuropathy, nephropathy
Macrovascular – coronary, cerebrovascular, peripheral vascular disease
Presence of vascular risk factors
HDL cholesterol level <1.0 mmol/L in males, <1.3 mmol/L in females
Triglycerides 1.7 mmol/L
Hypertension, Overweight, Abdominal obesity
Presence of associated diseases
PCOS, Acanthosis nigricans, OSA
Psychiatric disorders (bipolar, depression, schizophrenia), HIV
Use of drugs associated with DM
Glucocorticoids, atypical antipsychotics, HAART
Other secondary causes
Diagnosis
Diagnose Diabetes if two tests confirm (may do same test twice on different days)
FPG ≥7.0 mmol/L (8h fasting)
A1C ≥6.5% (falsely ↑ in anemia; ↓ in pregnancy and renal disease; ↕ in hemoglobinopathy)
2hPG in 75g OGTT ≥11.1 mmol/L or random PG ≥11.1 mmol/L
Consider 2hPG in 75g OGTT to identify IGT (2hPG 7.8-11) vs. diabetes (2hPG ≥11.1)
If FPG 6.1-6.9 or A1c 6-6.4%
If FPG 5.6-6 or A1c 5.5-5.9% and ≥1 risk factor
Diagnose Prediabetes if
A1c 6–6.4%
IFG (FPG 6.1-6.9)
IGT (2hPG 7.8-11)
Diagnose Metabolic Syndrome if ≥3
Elevated waist circumference
Elevated TG
Reduced HDL-C
Elevated BP
Elevated FPG
Treatment
See table below for antihyperglycemics
If A1c <1.5% above target, consider 3-6mo lifestyle
Otherwise start Biguanide - Metformin 500mg PO BID (Max 2550mg/day) and below (avoid DPP4i with GLP1 as no benefit from combination)
Sulfonylurea (avoid with short-acting insulin)
Gliclazide (Diamicron) 80mg PO BID (Max 320mg/day)
Least hypoglycemias out of sulfonylureas
DPP4i (rare risk of pancreatitis)
Sitagliptin (Januvia) 100mg PO daily / Janumet (Combo with metformin)
Linagliptin (Trajenta) 5mg PO daily / Jentadueto (Combo with metformin)
Saxagliptin (Onglyza) caution in heart failure / Komboglyze (Combo with metformin)
GLP1R agonists (weight loss, contraindicated in thyroid cancer, rare risk of pancreatitis)
Liraglutide (Victoza) 0.6mg SC daily x 1 week then 1.2mg SC daily (max 1.8mg SC daily)
Dulaglutide (Trulicity) 0.75mg SC weekly (max 1.5 mg SC weekly)
Semaglutide (Ozempic) 0.25mg SC weekly x 4 weeks then 0.5mg SC weekly (max 1mg SC weekly)
SGLT2i (risk of genital infections/UTI, hypotension, caution with loop diuretics)
Empagliflozin (Jardiance) 10mg PO daily x 1 week then 25mg PO daily / Synjardy (Combo with metformin)
Canagliflozin (Invokana)
Dapagliflozin (Forxiga)
If clinical CVD consider empagliflozin (or canagliflozin) and liraglutide
If comorbid NAFLD consider semaglutide, liraglutide, thiazolidinones
If symptomatic hyperglycemia or DKA/HHS
Consider starting insulin +/- metformin
Long-acting: Glargine (Lantus) or Detemir (Levemir)
Intermediate-acting: Humulin N, NPH
Short-acting: Novorapid, Humalog, Apidra
Target
Diabetes Canada recommends
6.5 in healthy
A1c ≤7.0 in most patients
7-8.5 in elderly, limited life expectancy, or recurrent severe hypoglycemia
ACP recommends target of 7-8 in most patients
Consider self-monitoring of blood glucose [SMBG] (glucometer, test strips, lancets) if on insulin, acutely ill, more frequent if hypoglycemia or target not met
Start once/day at different times for 6 months
Target preprandial 4-7 mmol/L, 2hr postprandial 5-10 mmol/L (or 5-8 if A1C not at target)
If glucose not at target despite titrating insulin upwards, think of
Missed dose, wrong dose (fear of hypoglycemia)
Injection Technique, Lipodystrophy
Insulin conservation (temperature exposure, expired)
Infection/inflammation
Complications of DM
Macrovascular: CVD, CVA, PAD
Microvascular: Retinopathy, nephropathy, neuropathy
Other:
Erectile dysfunction (macro/microvascular)
Foot complications (ulceration, Charcot arthropathy)
Infection
Follow-up Diabetes
A1c q3 months (until stable)
Each visit
BMI (18.5-24.9)/waist circumference
BP<130/80
Depression screening (PHQ-9)
Erectile dysfunction (Consider PDE-5 inhibitor if no contraindications)
Counselling
Nutrition (Mediterranean diet, low glycemic index)
Physical activity (aerobic >150mins/week, resistance 3 sessions/week)
Smoking cessation
Pre-conception counselling
Enquire about hypoglycemia
Driving safety
Investigations / Further Screening
CAD
Lipid profile q1y (until statin started)
Consider screening resting ECG repeat q3-5y:
Age >40 years
Duration of diabetes >15 years and age >30 years
End organ damage (microvascular, macrovascular)
Cardiac risk factors
Consider exercise ECG stress testing as the initial test:
Typical or atypical cardiac symptoms (e.g. unexplained dyspnea, chest discomfort)
Signs or symptoms of associated diseases
Peripheral arterial disease
Carotid bruits
Transient ischemic attack
Stroke
Resting abnormalities on ECG (e.g. Q waves)
Nephropathy q1y (if evidence of nephropathy - follow q6months)
eGFR (creat) and Urine ACR (albumin:creatinine ratio)
At least 2 of 3 random urine ACR abnormal to diagnose nephropathy (2-20 microalbuminuria, >20 overt nephropathy)
Retinopathy optometry q1-2y
If established retinopathy, refer to ophthalmology and consider fenofibrate/statins to slow progression
Neuropathy q1y
Monofilament - Score 0, 0.5, 1 point x4 per foot arrhythmically
Score 3/8=likely neuropathy, 3.5-5/8 = high risk in next four years, >5.5/8 = low risk neuropathy in next four years
Vibration perception tests (tuning fork, one point if perceived, one point for when stopped)
Treatment for pain: Consider Nortriptyline as first-line (Bansal 2020)
Foot Care q1y
Skin changes, structural abnormalities (e.g. range of motion of ankles and toe joints, callus pattern, bony deformities), skin temperature, evaluation for neuropathy and PAD, ulcerations and evidence of infection
Foot care education (including counselling to avoid foot trauma), professionally fitted footwear and early referrals to a healthcare professional trained in foot care management if foot complications occur
Treat ulcerations with glycemic control, infection, offloading of high-pressure areas, lower-extremity vascular status and local wound care.
Hypoglycemia
Defined by symptoms of hypoglycemia, a low plasma glucose level (<4.0 mmol/L for patients on antihyperglycemic agents), and symptoms responding to the administration of carbohydrate
Symptoms of hypoglycemia
Neurogenic (autonomic)
Trembling
Palpitations
Sweating
Anxiety
Hunger
Nausea
Paresthesias
Neuroglycopenic
Difficulty concentrating
Confusion
Weakness
Drowsiness
Vision changes
Difficulty speaking
Headache
Dizziness
Treatment (if glucose if <4.0 mmol/L)
15g carbohydrate (glucose or sucrose tablets/solution), recheck glucose 15 minutes and if <4.0 mmol/L can repeat
If severe (unconscious), Glucagon 1mg SC/IM or D50W 20-50mL IV over 1-3 minutes (Glucose 10–25g)

