Type 2 diabetes in primary care (WHO PEN and HEARTS-D)
Type 2 diabetes is common, often silent for years, and is frequently found only when complications have already started. Most of the work of keeping people with diabetes well can be done in primary care with a glucose meter, three or four essential medicines and a simple protocol. This course follows the WHO PEN and HEARTS-D approach step by step.
- Decide who to test for diabetes and confirm the diagnosis with WHO cut-offs.
- Recognise and give first-line care for hypoglycaemia, ketoacidosis and the hyperosmolar state, and advise on sick days.
- Start and step up glucose-lowering treatment with the WHO PEN protocol and set an individual goal.
- Examine the feet, stratify foot risk and act on active foot problems; protect the heart, kidneys and eyes.
- Organise follow-up and support self-care so that people stay on treatment.
- Start and adjust bedtime human insulin safely, and advise on storing insulin where refrigeration is unreliable.
- Recognise hyperglycaemia in pregnancy using WHO criteria and refer appropriately.
Finding and diagnosing type 2 diabetes
- List who should be tested for diabetes.
- Apply the WHO diagnostic cut-offs and know when to repeat a test.
In type 2 diabetes the blood glucose rises slowly, so symptoms are often mild or absent. Many people live with high glucose for years before diagnosis, and some already have damage to the eyes, kidneys, nerves or heart when they are first found. Testing the right people is the first step.
Who to test
- Adults with symptoms: thirst, passing a lot of urine, blurred vision, tiredness, unexplained weight loss.
- Adults aged 40 and over with a body mass index (BMI) of 25 or more, even without symptoms (HEARTS-D).
- Anyone found to have a complication that suggests diabetes, such as a foot ulcer that will not heal.
The diagnostic cut-offs
| Test | Diabetes if | Notes |
|---|---|---|
| Fasting plasma glucose (8 to 14 hours without food) | 7.0 mmol/L (126 mg/dL) or more | Cheapest test. Venous and capillary fasting values are the same |
| Random plasma glucose | 11.1 mmol/L (200 mg/dL) or more | Counts only if the person has symptoms |
| HbA1c | 6.5% (48 mmol/mol) or more | No fasting needed; can mislead with anaemia, haemoglobin disorders or kidney failure |
Type 1 or type 2?
Type 1 diabetes usually starts in children and young adults and is more likely to present with marked symptoms, weight loss and ketones. It needs insulin from the start and is usually managed outside primary care. The type cannot always be decided at diagnosis: base the first decisions on how unwell the person is and on the glucose values, and refer if type 1 is suspected.
Look for other problems at diagnosis
- Blood pressure, weight, BMI and waist.
- Feet: ulcers, pulses and sensation.
- Urine protein and, where available, creatinine.
- Cough: diabetes raises the risk of tuberculosis, so ask about cough and screen as your national programme advises.
Second case: a thirsty young woman
Ms J, 26, has been thirsty and passing a lot of urine for a month and has lost 6 kg. Her random capillary glucose is 21 mmol/L. Urine ketones are 2+. She is alert, drinking, not vomiting and breathing normally.
No. She has symptoms and a random glucose of 11.1 mmol/L or more, which is diagnostic.
2. Type 1 or type 2, and what next?
Young age, weight loss and ketones suggest type 1 diabetes. Glucose 18 mmol/L or more with ketones 2+ needs referral the same day: she may need insulin urgently and can become very ill quickly. Check for danger signs of ketoacidosis (lesson 2) while arranging transfer.
Mr K comes for a work medical. He feels well. His BMI is 29. A fasting capillary glucose taken this morning is 7.6 mmol/L. There is no HbA1c at your clinic.
Does Mr K have diabetes?
Not yet confirmed. He has no symptoms, so one raised fasting value needs repeating on another day, preferably with the same test. If the repeat fasting glucose is 7.0 mmol/L or more, the diagnosis is confirmed.
Was it right to test him?
Yes. He is 40 or over with a BMI of 25 or more, which is the HEARTS-D group to test even without symptoms.
- Test adults with symptoms, and adults aged 40 and over with a BMI of 25 or more.
- Diabetes: fasting plasma glucose 7.0 mmol/L or more, random 11.1 or more with symptoms, or HbA1c 6.5% or more.
- No symptoms: confirm with a second test on another day.
- Glucose 18 mmol/L or more, or symptoms: check urine ketones.
Diabetes emergencies, hypoglycaemia and sick days
- Recognise and treat hypoglycaemia.
- Recognise suspected ketoacidosis or hyperosmolar state, start fluids and refer.
- Prevent hypoglycaemia and give clear advice for days when a person with diabetes is ill.
Two kinds of emergency kill people with diabetes in places far from a hospital: a glucose that is too low, and a glucose that is very high with dehydration. Both need action within minutes.
Hypoglycaemia
Hypoglycaemia is a glucose of 3.9 mmol/L or less. It happens mostly in people taking a sulfonylurea (such as gliclazide) or insulin, especially if they miss a meal, are more active than usual, drink alcohol or have kidney disease. Signs include shaking, sweating, hunger, palpitations, confusion, odd behaviour, fits and drowsiness.
| Situation | What to give |
|---|---|
| Awake and able to swallow | 15 to 20 g of glucose by mouth, or a sugary drink, 1 to 2 teaspoons of sugar or honey, sweets, or a cup of milk. Recheck after 15 minutes and repeat if still low. Then give a meal or snack. |
| Unconscious, cannot swallow, or glucose 2.8 mmol/L or less | 20 to 50 mL of 50% glucose IV over 1 to 3 minutes. If there is no IV access, glucose or sugar solution in the cheek (buccal) while you arrange transfer. |
After a low, find the cause. If it happened on gliclazide, reduce or stop the dose. Hypoglycaemia that does not resolve needs same-day referral.
Ketoacidosis (DKA) and the hyperosmolar state (HHS)
Suspect a hyperglycaemic emergency in anyone with diabetes, or high glucose, who is unwell with vomiting, abdominal pain, deep fast breathing, dehydration, drowsiness or coma, or whose urine ketones are 2+ or more. In DKA the glucose is usually 13.9 mmol/L or more with ketones; in HHS it is usually 33.3 mmol/L or more with few or no ketones.
Insulin, potassium and close monitoring belong in hospital. Your job is to recognise the emergency early, start fluids, look for a trigger such as infection, and transfer safely.
Preventing hypoglycaemia
- Ask about lows at every visit, including at night (nightmares, sweating, morning headache).
- The main triggers are skipped or small meals, more physical activity than usual, and alcohol. Adjust the medicine when these are expected (HEARTS-D).
- Gliclazide causes fewer lows than glibenclamide. Do not use glibenclamide in people aged 60 or over, people who live alone or are at risk of falls, people who cannot sense a low, or people who drive or work with machinery.
- Long-standing diabetes can damage the nerves that give warning symptoms (autonomic neuropathy), so some people do not feel a low coming. They need a higher glucose goal and a carer who knows what to do.
- Everyone on gliclazide or insulin should carry sugar or sweets and know the signs: shaking, sweating, hunger, confusion.
Sick days
Infection, vomiting, diarrhoea and not eating all upset glucose control. Fever and infection tend to push glucose up; not eating while taking gliclazide or insulin can push it down. Plan for sick days before they happen.
| Advice for the person | Why |
|---|---|
| Keep drinking water or other unsweetened fluids; if not eating, take small amounts of carbohydrate-containing food or drink | Prevents dehydration and lows |
| Check glucose more often if you have a meter, or come to the clinic | Glucose can rise or fall quickly |
| If taking gliclazide and not eating: ask the clinic the same day; the dose may need reducing or stopping for a few days | Gliclazide keeps working without food |
| If taking insulin: do not decide alone to stop or change it; come the same day if vomiting or unable to eat | Insulin needs adjusting, not usually stopping |
| Come at once with vomiting that does not settle, abdominal pain, deep fast breathing, drowsiness, or glucose of 18 mmol/L or more that is not coming down | Signs of ketoacidosis or the hyperosmolar state |
When you are ill, keep drinking, keep taking small amounts of food, and come to the clinic the same day if you are vomiting, cannot eat, or feel very weak or sleepy.
Second case: fever and a cough
Mr S, 58, takes metformin 1000 mg twice daily and gliclazide 80 mg twice daily. He has had fever and a productive cough for 4 days and is eating very little. He is alert, breathing 22 per minute, not vomiting. Capillary glucose is 16 mmol/L.
The infection can push glucose up towards a hyperglycaemic emergency, while poor eating on gliclazide risks hypoglycaemia. He also needs assessment of the infection itself (pneumonia; TB if the cough continues).
2. What do you do?
Treat the infection per protocol, check urine ketones if glucose reaches 18 mmol/L, advise fluids and small carbohydrate meals, review the gliclazide dose while he is eating poorly, and see him again within 1 to 2 days. Refer the same day if he becomes drowsy, starts vomiting, breathes deeply, or glucose is 18 mmol/L or more and not improving.
Mrs L, 63, has type 2 diabetes treated with metformin and gliclazide. She has had diarrhoea and has eaten little for two days but kept taking her tablets. Her son found her sweaty and confused. Her capillary glucose is 2.4 mmol/L and she cannot swallow safely.
What do you do first?
Treat severe hypoglycaemia: 20 to 50 mL of 50% glucose IV over 1 to 3 minutes (she cannot swallow and glucose is 2.8 mmol/L or less). Check the airway, place her in the recovery position if needed, and recheck glucose.
She wakes up and eats. What next?
Gliclazide is the likely cause, made worse by not eating. Stop or reduce gliclazide while she is eating poorly, explain the warning signs of a low and how to treat one, and review soon. Because gliclazide lasts many hours, watch her for a recurrence and refer if the low does not resolve.
- Hypoglycaemia is glucose 3.9 mmol/L or less; treat with 15 to 20 g glucose by mouth if awake.
- Unconscious or 2.8 mmol/L or less: 20 to 50 mL of 50% glucose IV.
- Ill with high glucose, vomiting, deep breathing or drowsiness: suspect DKA or HHS.
- Refer, and give 0.9% saline 1 litre over 2 hours, then 1 litre every 4 hours on the way.
- Prevent lows: ask about them, watch meals, activity and alcohol, prefer gliclazide, no glibenclamide in older or at-risk people.
- Sick days: fluids, small carbohydrate meals, more glucose checks, same-day review if vomiting or not eating; never leave insulin decisions to chance.
The WHO PEN glucose protocol
- Start and step up metformin, gliclazide and insulin following the WHO PEN steps.
- Set an individual glucose goal and know the main cautions for each medicine.
WHO PEN, repeated in the HEARTS-D module, gives a simple stepwise protocol. Its strength is that every member of the team does the same thing, so treatment is predictable and medicines can be ordered in the right amounts.
| Step | If the goal is not reached | Review |
|---|---|---|
| 1 | Advice on diet and physical activity | 1 month |
| 2 | Start metformin 500 mg once daily | 3 months |
| 3 | Metformin 1000 mg once daily | 3 months |
| 4 | Metformin 1000 mg twice daily | 3 months |
| 5 | Add gliclazide 80 mg once daily; teach about hypoglycaemia | 3 months |
| 6 | Gliclazide 80 mg twice daily | 3 months |
| 7 | Refer, or add human insulin: NPH 10 units at bedtime, increasing by 1 to 2 units every 3 days until fasting glucose is 4 to 7 mmol/L | 3 days, then 3 months |
Symptomatic hyperglycaemia without an emergency
If the person has symptoms and fasting glucose is 15 mmol/L or more, or any glucose above 18 mmol/L, test the urine for ketones. With ketones of 2+ or more, refer. With ketones below 2+, start metformin 1000 mg twice daily and gliclazide 80 mg twice daily together, review in 3 to 5 days, and refer if not improving.
Cautions
- Metformin causes no weight gain and no hypoglycaemia. Do not use it with an eGFR below 30, severe liver disease, acute heart or breathing failure, alcohol misuse, or a past lactic acidosis.
- Gliclazide is the preferred sulfonylurea, and the first choice if metformin cannot be used. Avoid glibenclamide in people aged 60 and over and wherever hypoglycaemia would be dangerous.
- Human insulin (not analogues) is the WHO choice in primary care. Teach injection, storage and how to recognise and treat a low before starting.
- Other classes (SGLT2 inhibitors, DPP-4 inhibitors, pioglitazone) are not for routine use; use them only if national guidance and cost allow.
Goals
- Most people: HbA1c about 7.0% (53 mmol/mol).
- Without HbA1c: fasting plasma glucose 7.0 mmol/L or less, and 9.0 mmol/L or less 2 hours after a meal.
- A higher goal (for example HbA1c under 8%) is reasonable with frequent hypoglycaemia, advanced complications or short life expectancy.
Mrs M has had type 2 diabetes for two years. She takes metformin 1000 mg twice daily and says she never misses a dose. Her fasting glucose today is 9.8 mmol/L, and was 10.2 three months ago. She has no symptoms. Her eGFR last month was 65.
What is the next step?
Step 5: add gliclazide 80 mg once daily, teach her the signs of hypoglycaemia and how to treat them, and review in 3 months.
What would make you choose a higher glucose goal for her?
Frequent hypoglycaemia, advanced complications or a short life expectancy. Otherwise aim for HbA1c about 7.0%, or fasting glucose 7.0 mmol/L or less.
- Lifestyle for 1 month, then metformin 500 mg, 1000 mg, 1000 mg twice daily; then add gliclazide 80 mg, then 80 mg twice daily; then insulin or refer.
- Review every 3 months while adjusting.
- Symptomatic with ketones below 2+: metformin and gliclazide together, review in 3 to 5 days.
- Goal HbA1c about 7.0%; relax it when lows or frailty make tight control unsafe.
Protecting the heart, kidneys, eyes and feet: the diabetic foot in depth
- Manage blood pressure and cardiovascular risk in diabetes.
- Screen for kidney, eye and foot complications and act on the results.
- Examine the foot step by step, treat pre-ulcerative lesions and refer active foot problems at the right speed.
Most people with type 2 diabetes die of heart attack and stroke, not of high glucose. Blood pressure, statins and stopping tobacco save more lives than glucose control alone.
Blood pressure and statins
- Measure blood pressure at every visit.
- Treat blood pressure of 130/80 or more; aim below 130/80. HEARTS-D recommends an ACE inhibitor and a thiazide (see the hypertension course and protocol).
- Give a statin to everyone with type 2 diabetes aged 40 and over, as long as this does not reduce the supply of glucose and blood pressure medicines. Dose per national formulary.
- Low-dose aspirin (75 to 100 mg) only after a heart attack or ischaemic stroke, not for prevention.
Kidneys and eyes
- Once a year: urine protein (or albumin to creatinine ratio) and creatinine with eGFR where available.
- Refer if eGFR is 30 to 59 or there is moderate or severe protein in the urine; same day if eGFR is below 30 or there is no urine.
- Eyes: retinal examination at diagnosis, then every 2 years. Refer any recent loss of vision urgently.
Feet
Diabetes greatly increases the risk of losing a leg. Most foot ulcers come from two problems together: neuropathy, which makes the foot numb and often deformed so that pressure builds up under it, and peripheral artery disease, which is present in up to half of people with a diabetic foot ulcer and slows healing. Pressure causes thick callus, bleeding under the callus and then an ulcer, usually from ill-fitting shoes or walking barefoot. Walking on a numb ulcer stops it healing. A small number of ulcers are purely ischaemic; these are usually painful.
Examining the foot
- Remove shoes, socks, dressings and bandages, on both feet.
- Look: ulcers (current or healed), callus, blisters, cracks, fungal infection between the toes, nail problems, deformity (claw or hammer toes, bony prominences), previous amputation, redness, swelling, gangrene.
- Feel the pulses: dorsalis pedis (top of the foot, just outside the big-toe tendon) and posterior tibial (between the inner ankle bone and the heel tendon).
- Feel for warmth. A hot, red, swollen foot with intact skin may be acute Charcot arthropathy.
- Test protective sensation (below).
Testing protective sensation
| Test | How | Loss of protective sensation if |
|---|---|---|
| 10 g monofilament | Show it on the hand first. With the person's eyes closed, press at three sites on each foot until it bends, for about 2 seconds; do not slide it. Test beside, not on, callus or ulcers. Mix in a mock touch | The person does not feel it at the sites tested |
| 128 Hz tuning fork | Show it on the wrist first. Place on the back of the tip of the big toe; repeat twice with one mock application | Two of three answers are wrong |
| Light touch (no equipment) | Eyes closed; lightly touch the tips of the first, third and fifth toes of both feet with your index finger for 1 to 2 seconds; do not push or tap | Not felt at 2 or more of the 6 sites |
Nerve damage and poor blood supply make feet numb and slow to heal, so a small injury from a tight shoe or walking barefoot can become an ulcer, an infection and an amputation. Look at the feet at every visit, and do a full check once a year: pulses (dorsalis pedis and posterior tibial), sensation with a 10 g monofilament, calluses, deformity and past ulcers.
No monofilament? Use the light touch test: with the person's eyes closed, lightly touch the tips of the first, third and fifth toes of both feet for 1 to 2 seconds. Loss of protective sensation is likely if they do not feel the touch at 2 or more sites.
| Foot risk | Features | Action |
|---|---|---|
| Low | No risk factor except callus | Check every year |
| Moderate | Deformity, or neuropathy, or reduced blood supply | Check every 3 to 6 months |
| High | Previous ulcer or amputation, or two risk factors together | Check every 1 to 3 months |
| Active problem | Ulcer, spreading infection, critical ischaemia, gangrene, an unexplained red swollen foot | Refer urgently |
Acting on what you find
- Pre-ulcerative lesions should be treated by a trained health worker: remove callus, protect or drain blisters, treat ingrown or thickened nails, treat fungal infection.
- Refer (not urgent): gross deformity, absent foot pulses or suspected limb ischaemia, and any ulcer when there is no trained worker or the dressings and equipment needed at your clinic.
- Refer urgently: infected ulcer, spreading infection, critical limb ischaemia (pain at rest, cold pale foot), gangrene, suspected acute Charcot foot, or an unexplained red swollen foot.
- Stopping smoking, glucose control and BP control all help the foot.
Teach foot care at every visit
- Look at both feet every day, including the soles (a mirror helps).
- Wash daily in lukewarm water, never hot; dry gently, especially between the toes. Moisturise dry skin, but not between the toes.
- Cut nails straight across and not too short. Never cut corns or calluses yourself.
- Shake out and feel inside shoes before putting them on. Shoes should be about 1 to 2 cm longer than the foot, neither tight nor loose. Wear socks.
- Never walk barefoot, even at home.
The full one-page guide is the protocol The diabetic foot.
Second case: a black toe
Mrs T, 60, has had diabetes for 12 years and smokes 20 cigarettes a day. She comes because her second toe on the left has turned black over two weeks. The tip has a small deep ulcer. The left dorsalis pedis pulse is absent and the posterior tibial pulse is weak. There is no spreading redness and she has no fever.
Gangrene of the toe with poor blood supply: an active foot problem that needs urgent referral to a service that can assess the circulation and the wound, even though there is no spreading infection.
2. What else do you do today?
Keep the foot clean and dry and rest it (walking on a damaged foot stops healing), give clear stop-smoking advice and support, check glucose and BP, and examine the other foot.
Mr N has had diabetes for 10 years. At his annual check you cannot feel a dorsalis pedis pulse on the left. With his eyes closed he does not feel the light touch on 3 of 6 toes. There is thick callus under the left big toe but no ulcer. His BP is 146/88. He takes metformin only.
What is his foot risk, and how often should his feet be checked?
High risk: neuropathy with callus, and reduced blood supply. Check every 1 to 3 months. A trained professional should remove the callus, and he needs foot care advice.
What else should you do today?
Treat his blood pressure (130/80 or more in diabetes), start a statin as he is over 40, check urine protein and creatinine if due, and check when his eyes were last examined.
- In diabetes treat BP of 130/80 or more and aim below 130/80.
- Statin for everyone with type 2 diabetes aged 40 and over; aspirin only after heart attack or stroke.
- Every year: urine protein and creatinine; eyes every 2 years.
- Look at the feet every visit; full yearly check: pulses, protective sensation (monofilament, tuning fork or light touch), callus, deformity, past ulcers.
- Urgent referral: infected ulcer, spreading infection, critical ischaemia, gangrene, suspected Charcot, unexplained red swollen foot.
Follow-up, self-care and team-based care
- Plan follow-up visits and what to check at each one.
- Give clear self-care advice, including foot care and what to do when ill.
What to do at each visit
- Every visit (every 3 months while adjusting treatment): glucose (HbA1c if available), BP, weight, feet, tablets taken, any hypoglycaemia.
- Every year: urine protein, creatinine, full foot risk check.
- Every 2 years: eyes.
- Frequent lows on gliclazide: reduce or stop it.
Lifestyle
- At least 150 minutes of moderate activity a week, spread over at least 3 days.
- Healthy meals for the whole family; less sugar and fewer sugary drinks; lose weight if overweight.
- No tobacco; avoid harmful alcohol.
Foot care at home
- Look at your feet every day for cuts, blisters, redness or swelling.
- Wash in lukewarm, never hot, water and dry well between the toes.
- Cut nails straight across; never cut corns or calluses yourself.
- Feel inside shoes before putting them on. Never walk barefoot, even at home.
- Come to the clinic at once for any wound.
Diabetes cannot be cured, but it can be controlled. Take your tablets every day, look at your feet every day, and come back at once if you feel very unwell, are vomiting, or have a wound on your foot.
Sharing the work
Protocol-based care lets nurses and clinical officers start and adjust treatment safely, with doctors seeing people who are not reaching their goal or who have complications. Community health workers can find people who have missed visits, support foot care and healthy habits, and bring people with danger signs to the clinic. A simple register of everyone with diabetes shows who is due, who has missed a visit and how many are at goal.
Your health centre has 140 people with diabetes on its register. Last quarter 45 missed their visit, and the pharmacy ran out of gliclazide twice. There is one doctor who visits every two weeks.
How could you reduce missed visits?
Use the register to list who missed a visit each week and ask community health workers to follow them up; give enough medicine to last to the next visit; book visits on a fixed diabetes day; explain at every visit why treatment continues when people feel well.
How does a standard protocol help with the stock problem?
When everyone prescribes the same medicines at the same steps, the clinic can count how many people are on each step and order the right amounts of metformin and gliclazide.
- Every 3 months while adjusting treatment; every visit check glucose, BP, feet and adherence.
- Yearly urine protein, creatinine and foot risk; eyes every 2 years.
- 150 minutes of activity a week, healthy family meals, no tobacco.
- A register and community health workers keep people in care.
Insulin in low-resource settings
- Start and adjust bedtime human NPH insulin with the HEARTS-D protocol.
- Teach injection, hypoglycaemia care and self-monitoring before insulin starts.
- Advise on storing insulin safely when refrigeration is unreliable or absent.
Type 2 diabetes is progressive: insulin output falls over the years and many people eventually need insulin. People with type 1 diabetes need insulin from the start to stay alive. Insulin is on the WHO Model List of Essential Medicines, yet only about half of the people with type 2 diabetes who need it can get it.
Who needs insulin
- Type 2 diabetes not at goal on metformin and gliclazide (step 7 of the protocol, lesson 3): refer, or add human insulin if your clinic is set up for it.
- Suspected type 1 diabetes, or a hyperglycaemic emergency: refer; insulin is started under specialist care.
- Hyperglycaemia in pregnancy that diet does not control: managed by the antenatal or specialist team (lesson 7).
WHO recommends human insulin (NPH and regular) rather than insulin analogues for routine use, because analogues cost much more and offer at best marginal benefit, especially in type 2 diabetes. Insulin may be unsuitable when it costs more than tablets for the family, or when a person lives alone and depends on others to inject.
Starting bedtime NPH insulin (HEARTS-D)
| Step | What to do |
|---|---|
| Start | 10 units of NPH at bedtime. Continue metformin and gliclazide. Teach about hypoglycaemia and about symptoms of high glucose |
| Every 3 days | If fasting glucose is above 7 mmol/L, increase by 1 to 2 units. Continue until fasting glucose is 4 to 7 mmol/L |
| Fasting glucose below 4, or lows at night | Reduce insulin by 1 to 2 units. Do not increase insulin if there are night-time lows |
| Daytime lows with fasting glucose 4 to 7 | Reduce the morning gliclazide by 40 mg; stop the morning dose if daytime lows continue |
| Fasting glucose above 7 and lows at night | Refer |
| When stable | Review with HbA1c in 3 months; refer if HbA1c is above 7.5% |
Teach before the first dose
- How to draw up and inject the dose: show it, then watch the person (or a family member) do it before they go home.
- Using a glucose meter, if one is provided: WHO PEN includes self-monitoring of glucose for people on insulin. Write results in a notebook to bring to each visit.
- Hypoglycaemia: the signs, and to treat it at once with 15 to 20 g of sugar, then a meal (lesson 2). Family members should know this too.
- Sick days: do not stop insulin on your own; come the same day if vomiting or unable to eat.
Storing insulin when there is no reliable fridge
Manufacturers advise keeping unopened insulin at 2 to 8 °C in a fridge, and an opened vial at room temperature for about four to six weeks. WHO's 2024 technical brief on the thermostability of human insulin reviewed the evidence for places where refrigeration is poor or absent:
- Laboratory and manufacturer data showed no clinically relevant loss of potency in unopened human insulin vials and cartridges kept for up to six months at 25 °C or up to two months at 37 °C.
- Fluctuating temperatures (warm days, cooler nights) seem to harm insulin less than constant heat.
- WHO-prequalified human insulins are labelled for storage at up to 30 °C for four weeks before opening.
- Insulin must be protected from freezing, direct sunlight and prolonged high heat.
- Where reliable refrigeration is available, follow the manufacturer's storage advice.
| At the clinic | At home without a fridge |
|---|---|
| Keep stock in the cold chain; WHO encourages sharing the vaccine cold chain for temperature-sensitive medicines such as insulin | Keep the vial in the coolest, shaded place in the home, away from the stove, the roof and windows, and never in direct sun |
| Give a supply that will be used within the storage time on the label | Never put insulin in a freezer compartment or on ice |
| Record dispensing dates on the vial | Some programmes use simple evaporative coolers such as a damp clay pot; WHO notes only one small pilot study of this, so follow your programme's advice |
Second case: insulin in a hot village
Mr V, 55, lives in a village with no electricity where daytime temperatures reach 35 °C. Fasting glucose stays at 12 to 14 mmol/L on full doses of metformin and gliclazide. He fears that insulin will 'go bad' without a fridge.
Yes. Unopened human insulin keeps its potency for up to two months at 37 °C, and an opened vial is used within about four to six weeks. Give him a supply he will use within that time, kept in the coolest shaded place at home, never frozen or in the sun.
2. How do you start?
NPH 10 units at bedtime, continue his tablets, teach injection and hypoglycaemia care to him and a family member, and review every 3 days (in person, by a community health worker or by phone) to increase by 1 to 2 units until fasting glucose is 4 to 7 mmol/L.
Mrs W has type 2 diabetes and takes metformin 1000 mg twice daily and gliclazide 80 mg twice daily. Her fasting glucose is 11 mmol/L on three visits and HbA1c is 9.1%. She has a glucose meter and her daughter lives with her. Your clinic is equipped to start insulin.
How do you start insulin?
NPH 10 units at bedtime, continuing metformin and gliclazide, after teaching injection, glucose checks and hypoglycaemia care to her and her daughter. Review in 3 days.
After two weeks her fasting glucose is 6.2 mmol/L, but she has had two lows before lunch. What now?
Fasting glucose is on target (4 to 7), so do not change the insulin. Daytime lows with a fasting glucose of 4 to 7 mean reducing the morning gliclazide by 40 mg; stop the morning dose if the lows continue.
When should she be referred?
If she has lows at night with a fasting glucose above 7 mmol/L, or if her HbA1c is still above 7.5% after 3 months on a stable dose.
- Human insulin, not analogues, for routine use. Start NPH 10 units at bedtime with the tablets; increase by 1 to 2 units every 3 days to fasting glucose 4 to 7 mmol/L.
- Night lows: reduce insulin. Day lows with good fasting glucose: reduce morning gliclazide.
- Teach injection, glucose checks and hypoglycaemia care before the first dose.
- No fridge: unopened human insulin keeps its potency up to 6 months at 25 °C or 2 months at 37 °C. Keep it cool and shaded; never freeze it.
Diabetes in pregnancy
- Classify hyperglycaemia first detected in pregnancy with the WHO criteria.
- Prepare a woman with known diabetes for pregnancy, and refer pregnant women with hyperglycaemia.
High glucose in pregnancy, whether known before pregnancy or found during it, raises the risk of a very large baby, pre-eclampsia and shoulder dystocia. Treatment lowers these risks. Pregnancy is also a chance to find women who will develop type 2 diabetes later.
Two categories (WHO 2013)
| Category | Any one of these | What it means |
|---|---|---|
| Diabetes in pregnancy | Fasting plasma glucose 7.0 mmol/L or more; 2-hour value 11.1 mmol/L or more after a 75 g glucose drink; or random glucose 11.1 mmol/L or more with symptoms | Type 1 or type 2 diabetes found in pregnancy. It does not go away after birth |
| Gestational diabetes | Fasting plasma glucose 5.1 to 6.9 mmol/L; 1-hour value 10.0 mmol/L or more; or 2-hour value 8.5 to 11.0 mmol/L after a 75 g glucose drink | Milder hyperglycaemia that usually resolves after birth |
Who to test, and when
- WHO has no recommendation on whether or how to screen all pregnant women: follow your national antenatal policy.
- The usual window for diagnosing gestational diabetes is 24 to 28 weeks.
- Risk factors some programmes use to decide who gets a glucose test: BMI above 30, gestational diabetes before, a previous very large baby, a family history of diabetes, and an ethnic group with a high rate of diabetes.
- Glucose in the urine (2+ once, or 1+ twice or more) may point to undiagnosed hyperglycaemia; consider a glucose test.
What to do
- Both categories need referral and closer monitoring in antenatal care. Women with diabetes in pregnancy, especially if found early, usually need more intensive management.
- Treatment is stepwise: diet counselling and physical activity first, then glucose-lowering medicines or insulin if needed, chosen by the antenatal or specialist team.
- Measure BP at every contact: high glucose increases the risk of pre-eclampsia (see the hypertension course, lesson 6).
- After birth: gestational diabetes is a strong risk factor for type 2 diabetes later. Record it, and offer glucose testing after the pregnancy and at later health checks.
A woman with known diabetes who could become pregnant
- Ask about pregnancy plans and contraception at every review.
- Statins, ACE inhibitors and ARBs are not used in pregnancy. If she plans a pregnancy or stops contraception, review these medicines first (see the hypertension course, lesson 6).
- Aim for good glucose control before conception, and refer as soon as she is pregnant.
- Women with diabetes are at high risk of pre-eclampsia: in pregnancy they should be offered low-dose aspirin from before 20 weeks.
Second case: 26 weeks, a borderline result
Mrs Y, 33, is 26 weeks pregnant with her third baby. Her last baby weighed 4.6 kg. A fasting plasma glucose at the district laboratory is 5.6 mmol/L. She feels well.
Gestational diabetes: fasting plasma glucose 5.1 to 6.9 mmol/L in pregnancy. A value that is normal outside pregnancy is not normal here.
2. What do you do?
Refer to antenatal care for closer monitoring and treatment, starting with diet and activity counselling; check BP and urine; explain that she should have a glucose test after the birth and later, because her risk of type 2 diabetes is raised.
Ms Z has type 2 diabetes and hypertension. She takes metformin, a statin and lisinopril. Her HbA1c is 8.4%. She tells you she would like to become pregnant this year.
Which of her medicines need review before pregnancy?
The statin and lisinopril (an ACE inhibitor) are not used in pregnancy. Plan, with your protocol and specialist advice, a BP treatment without an ACE inhibitor, ARB or thiazide, and stop the statin when she stops contraception.
What else would you advise?
Improve glucose control before conceiving (her HbA1c is above goal), keep using contraception until her treatment is ready, and come as soon as she is pregnant so that she is referred for antenatal and specialist care, with low-dose aspirin from before 20 weeks.
If she had a fasting glucose of 7.4 mmol/L at her first antenatal contact, what category would that be?
Diabetes in pregnancy (fasting 7.0 mmol/L or more). In her case it is her known type 2 diabetes; she needs specialist antenatal care.
- Gestational diabetes: fasting 5.1 to 6.9, 1-hour 10.0 or more, or 2-hour 8.5 to 11.0 mmol/L after 75 g glucose.
- Diabetes in pregnancy: fasting 7.0 or more, 2-hour 11.1 or more, or random 11.1 or more with symptoms.
- Both need referral and closer monitoring; treatment starts with diet and activity.
- Before pregnancy: review statins and ACE inhibitors or ARBs, improve control, refer early; test again after birth.
Quiz and CPD certificate
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Sources
- World Health Organization. Diagnosis and management of type 2 diabetes (HEARTS-D). 2020 (WHO/UCN/NCD/20.1).
- World Health Organization. WHO package of essential noncommunicable (PEN) disease interventions for primary health care. 2020.
- World Health Organization. Guidelines on second- and third-line medicines and type of insulin for the control of blood glucose levels in non-pregnant adults with diabetes mellitus. 2018.
- World Health Organization and International Committee of the Red Cross. Basic emergency care: approach to the acutely ill and injured. 2018.
- World Health Organization. Thermostability of human insulin (technical brief). 2024 (ISBN 9789240089044).
- World Health Organization. Diagnostic criteria and classification of hyperglycaemia first detected in pregnancy. 2013 (WHO/NMH/MND/13.2).
- World Health Organization. WHO recommendations on antenatal care for a positive pregnancy experience. 2016 (ISBN 9789241549912).
- World Health Organization. WHO recommendations for prevention and treatment of pre-eclampsia and eclampsia. 2011 (ISBN 9789241548335).
- World Health Organization. WHO PEN training manual: management of type 2 diabetes. 2013.