From Dr Pui Ling Chan, Endocrinologist, CMDHB
What is Diabetes Mellitus?
Diabetes mellitus, or simply diabetes, is a group of metabolic diseases in which a person has too much sugar in the blood because the pancreas cannot make enough effective insulin.
The food we eat is digested and changed into sugar and taken up into our blood. Therefore, everyone has some sugar in their blood. This sugar provides energy for the body to live and grow.
Insulin helps move sugar from the blood into the body cells, like liver and muscle. When there is not enough insulin in the body, too much sugar stays in the blood.
If you are overweight, especially if you are carrying excess fat around your waist, insulin will not work so well – this is called “insulin resistance”.
Normal blood sugar level = 4 to 7 mmol/L
Diagnosis of diabetes
The diagnosis of diabetes can be made based on a person’s symptoms and blood sugar readings. A doctor can diagnose diabetes in one of the following situations:
- 糖尿病症狀（高血糖所導致的多飲、多食、多尿、體重下降、精神不振）加隨機血糖高於 11.1mmol/L
Presence of diabetes symptoms such as polyuria (passing frequent, large amount of urine), increased thirst, weight loss, lethargy or recurrent infections; with a random blood sugar of >11.1 mmol/L
- 空腹血糖高於 7.0 mmol/L
Fasting blood sugar >7.0 mmol/L
- 在口服糖耐量試驗中，口服75克葡萄糖2小時候，血糖在11.1 mmol/L以上
Plasma blood sugar of >11.1 mmol/L 2 hours after taking a 75g glucose load, in a glucose tolerance test
HbA1c (glycated haemoglobin) of >6.5% (48 mmol/mol)
Types of Diabetes Mellitus
- 1 型糖尿病 Type 1 Diabetes Mellitus
- 2 型糖尿病 Type 2 Diabetes Mellitus
- 妊娠期糖尿病 Gestational Diabetes Mellitus (GDM)
- 遺傳性胰島素抗拒 Genetic Diabetes
Others including medications such as steroids, endocrinopathies, pancreatic disorders
Type 1 Diabetes Mellitus
Type 1 diabetes is caused by an auto-immune reaction, where the body’s defense system attacks the insulin-producing cells in the pancreas. As a result, the body can no longer produce the insulin it needs.
The disease can affect people of any age, but it usually occurs in children or young adults. People with this form of diabetes need injections of insulin every day in order to control the levels of glucose in their blood. Without insulin, people with type 1 diabetes will die.
Type 1 diabetes symptoms such as:
- 口渴 abnormal thirst and dry mouth
- 多尿 frequent urination
- 精神不振 extreme tiredness/lack of energy
- 容易飢餓 constant hunger
- 體重下降 sudden weight loss
- 傷口愈合緩慢 slow-healing wounds
- 經常感染 recurrent infections
- 視力模糊 blurred vision
People with type 1 diabetes can lead normal, healthy lives through a combination of daily insulin therapy, close monitoring, a healthy diet, and regular physical exercise.
Type 2 Diabetes Mellitus
Type 2 diabetes is the most common type of diabetes. It usually occurs in adults, but is increasingly seen in children and adolescents. In type 2 diabetes, the body is able to produce insulin but it is either not sufficient or the body is not responding to its effects, leading to a build-up of glucose in the blood.
People with type 2 diabetes may remain unaware of their illness for a long time because symptoms may take years to appear or be recognized, during which time the body is being damaged by excess blood glucose. Many people are diagnosed only when complications of diabetes become evident.
There are several important risk factors. These include:
- 肥胖 obesity
- 飲食不當poor diet
- 體能活動不足 physical inactivity
- 年齡增長 increasing age
- 家族病史 family history of diabetes
- 種族 ethnicity
In contrast to people with type 1 diabetes, the majority of those with type 2 diabetes do not usually require daily doses of insulin to survive. However, they may be prescribed insulin together with oral medication, a healthy diet and increased physical activity to manage their conditions.
People with diabetes have an increased risk of developing a number of serious health problems.
Consistently high blood glucose levels can lead to serious diseases affecting the heart and blood vessels, eyes, kidneys, and nerves. In addition, people with diabetes also have a higher risk of developing infections.
In almost all high-income countries, diabetes is a leading cause of cardiovascular disease, blindness, kidney failure, and lower limb amputation. Maintaining blood glucose levels, blood pressure, and cholesterol close to normal can help delay or prevent diabetes complications. People with diabetes need regular monitoring for complications.
Treatments for diabetes
Diabetes is treated by “balancing” your food, exercise and insulin or tablets to keep your blood sugar level as close to normal as possible. A normal blood sugar helps one to keep well and helps prevent complications from diabetes.
Treatment of Diabetes include:
- 口服藥物 Medications/Tablets
- 雙胍類藥物 biguanides (metformin)，磺脲類藥物 sulphonylurea (glipizide, gliclazide, glibenclamide)，噻唑烷二酮類藥物 thiazolidinedione (pioglitazone)，α-糖苷酶抑制劑 (acarbose)
- 胰島素 Insulin
- 速效胰島素類似物 (rapid acting)、短效胰島素 (short acting)、中效胰島素 (intermediate acting)、長效胰島素 (long acting) 和預混胰島素 (pre-mixed)
Store your insulin in the refrigerator (2-8C) away from freezer or freezing coils. It should not exposed to excessive heat or direct sunlight and should never be frozen. You can keep the insulin you are using out of the fridge for up to a month.
When travelling keep your insulin vials/cartridges in their cartons in as cool a place as possible. Never keep insulin in the car glove-box.
When travelling away from home or overseas for short periods, try to take at least twice your calculated insulin requirements to allow for breakages etc – be prepared for the possibility of lost or stolen baggage by dividing your insulin supply in different luggage. Always take insulin on hand-carried luggage. Always keep a spare syringe or pen and insulin.
- 其他新一代藥物 例如腸泌素模擬物類的藥品 (incretin-mimetic group): 目前此類藥物在新西蘭並沒有支付
Other (newer treatment, incretin-mimetic group: not funded in new Zealand)
- 改變生活方式 Lifestyle modification
Stop smoking is important
- 飲食 – 低碳水化合物，低糖。選擇低升糖指數飲食 (glycaemic index = GI)。避免經常外食。
Diet – low carbohydrate, low/avoid simple sugar, control portion of carbohydrate. Choose food with low glycaemic index (GI). Avoid frequent eating out/fast food.
Tips for healthy eating: watch the amount, don’t overeat; eat 3 meals of similar size, always eat breakfast, eat less fat, limit alcohol (high in calories), choose food high in fibre (wholegrain bread, breakfast cereals), plenty of vegetables, raw fruit or tinned fruit with no added sugar, legumes such as kidney beans, soy beans and lentils, seeds and nuts
- 運動 – 一週只少100-150分鐘的有氧運動跟阻力訓練。例如慢跑，快走，游泳，騎腳踏車，割草，跳舞
Exercise – at least 100-150 minutes of aerobic +/- resistance exercises in a week. Examples: jogging, brisk walking, swimming, cycling, mowing the lawn, dancing
- 減重 – 保持 BMI 低於 25，如果是華人則目標為 23 以下
Weight loss – important to keep BMI < 25 , even better if it’s <23 kg/m2 (for Asian)
- 減重手術 Bariatric surgery
Other aspects of managing diabetes
- 控制血壓在 130/80mmHg 以下
Control high blood pressure to <130/80 mmHg
- 定期眼科檢查糖尿病是否有視網膜病變，尿液檢查是否有蛋白尿(proteinuria)及白蛋白尿(albuminuria) 跟腳底神經病變。
Very important to have regular retinal check, urine test to detect albumin in urine (“protein leak”), and testing the nerves in feet
- 低血糖 — 當血糖低於4.0 mmol/L，症狀包括頭暈，頭痛，視線模糊，口舌發麻，臉色發白，冒冷汗，手腳顫抖，心悸。當有這些症狀出現時，需要馬上測量血糖。糖分補充是最好的治療方法（例如：糖水，果汁，蜂蜜，果醬）。
Hypoglycaemia (“Hypo”) – low blood sugar, happens when blood sugar drops below 4.0 mmol/L. Symptoms of “Hypo” include light-headedness, headache, blurred vision, pins & needles of lips/tongue, pale, sweaty, trembling hands, thumping heart, hungry, weak and trembling knees. When this happens, it is important to test the sugar level. GLUCOSE IS BEST TREATMENT (glucose powder in water, jam, honey or sugar)
No need for routine screening for type 1 DM
Early screening for those with increased risk for type 2 DM, e.g. strong family history, BMI>25, physical inactivity, hypertension, hyperlipidaemia. Without risk factors can start screening on a yearly basis when age is >45 years.
Additional information (Diabetes Management) in PDF